Need Data: Oil Temp & Coolant Temp
05-08-2010, 11:54 PM
#27
Registered
You will take advantage of FREE gains that are already in your current system when you duct 100% of the air that enters the oil cooler openings and the front radiator openings THROUGH those respective rad/coolers. This can be done as simple as using duct tape, zip ties and cardboard to as complex as custom cut sheet metal parts.
This is one of those things that is so easy for newbees it is difficult to grasp. Here it is again------a cooler or radiator ONLY WORKS WHEN AIR FLOWS THROUGH IT. So.......make sure the air entering the frontal areas of the bumper exits through the coolers and radiator.
Why wouldn't it do this normally? Because air will take the path of least resistance. Grab a flashlight or trouble light and stick your head in front of and into the air openings. LOOK where the air escapes. Block it. Notice the holes in and around the black plastic bellypan. Tape them up. Look at the upper front portion of the radiator. See where the air escapes here? Block it off. The old racer's trick is to use inexpensive window foam you can buy at Ace hardware for $6 or so. Buy extra. This is really easy DIY stuff. If this is beyond your comprehension then any swapping out parts is probably too risky for you. If you need to have a pretty engine then you are a waxer and deserve to have your engine overheat and blowup. I say this because some people are too hard headed to understand that in order to get gains or improvements you have to CHANGE things. There are some people on this forum you don't, can't or won't do this. There is no magic bullet. You have to change your system to get improvements. The good thing is your not far off more conservative and safer temps. If you can play in the 210-220 range you should have zero issues. I would be concerned if you are playing above 230F for 20 minutes or more at a time.
The remedy water pump will help but only at high rpm and you'll need a water temp gauge to validate it works (which it does). High loads and high rpm is where it shines/the stock water pump cavitates.
The other easy thing you can do is remove the black plastic front wheel well fenders. This helps air flow through the oil coolers. Cooler oil helps the engine cool and makes the job of the water radiator easier. The oil and water temps go hand in hand.
The next steps you can do that are a little more outside the DIY is to remove as much of that stock crap behind the radiator to improve airflow THROUGH the radiator. This is an area of debate for rookies and forum wannabes but it works. Period. It's also easy to do. Bag the stock cosmetic plastic on top of the motor and the stock lower air intake tray that sits in front of the rad. This is easy if you are running a MSpeed or AEM intake as you don't need this tray.
If you do all of these (which are easy) you will reduce your op temps and your engine will be less at risk.
We've done a few more things to our cars and run 190F oil and water for 50 minute sprint races operating at 6,000 - 8,500 WOT.
Try some, any or all of these tricks and you shouldn't have any issues. The SpeedSource cars that ran Motec enigne mngt in 2004+ ran 215'ish both water and oil using the stock oil coolers for sometimes several hours in a row and didn't have issues.
Happy rotoring
This is one of those things that is so easy for newbees it is difficult to grasp. Here it is again------a cooler or radiator ONLY WORKS WHEN AIR FLOWS THROUGH IT. So.......make sure the air entering the frontal areas of the bumper exits through the coolers and radiator.
Why wouldn't it do this normally? Because air will take the path of least resistance. Grab a flashlight or trouble light and stick your head in front of and into the air openings. LOOK where the air escapes. Block it. Notice the holes in and around the black plastic bellypan. Tape them up. Look at the upper front portion of the radiator. See where the air escapes here? Block it off. The old racer's trick is to use inexpensive window foam you can buy at Ace hardware for $6 or so. Buy extra. This is really easy DIY stuff. If this is beyond your comprehension then any swapping out parts is probably too risky for you. If you need to have a pretty engine then you are a waxer and deserve to have your engine overheat and blowup. I say this because some people are too hard headed to understand that in order to get gains or improvements you have to CHANGE things. There are some people on this forum you don't, can't or won't do this. There is no magic bullet. You have to change your system to get improvements. The good thing is your not far off more conservative and safer temps. If you can play in the 210-220 range you should have zero issues. I would be concerned if you are playing above 230F for 20 minutes or more at a time.
The remedy water pump will help but only at high rpm and you'll need a water temp gauge to validate it works (which it does). High loads and high rpm is where it shines/the stock water pump cavitates.
The other easy thing you can do is remove the black plastic front wheel well fenders. This helps air flow through the oil coolers. Cooler oil helps the engine cool and makes the job of the water radiator easier. The oil and water temps go hand in hand.
The next steps you can do that are a little more outside the DIY is to remove as much of that stock crap behind the radiator to improve airflow THROUGH the radiator. This is an area of debate for rookies and forum wannabes but it works. Period. It's also easy to do. Bag the stock cosmetic plastic on top of the motor and the stock lower air intake tray that sits in front of the rad. This is easy if you are running a MSpeed or AEM intake as you don't need this tray.
If you do all of these (which are easy) you will reduce your op temps and your engine will be less at risk.
We've done a few more things to our cars and run 190F oil and water for 50 minute sprint races operating at 6,000 - 8,500 WOT.
Try some, any or all of these tricks and you shouldn't have any issues. The SpeedSource cars that ran Motec enigne mngt in 2004+ ran 215'ish both water and oil using the stock oil coolers for sometimes several hours in a row and didn't have issues.
Happy rotoring
Last edited by EricMeyer; 05-09-2010 at 12:00 AM.
05-09-2010, 12:21 AM
#28
Super Moderator
The above is fine if you are track racing or you are in summer...
But for Southern Hemisphere guys (now going into winter) I do not recommend removing Water and Wheel Arch black splash guards, and remember stock Oil coolers have Thermostat restrictors so if it is Cold (18c or 65F or below) your oil will not get hot enough as air flow is too high...just ask 9K.
BTW: With my Mods (just gone through Summer) my Coolant Temps never passed 208F or 98C at lights during 38C or 100F...when moving always around the 86-88 c range. Not sure if the extra fan speed the series II's have also makes a difference.
But for Southern Hemisphere guys (now going into winter) I do not recommend removing Water and Wheel Arch black splash guards, and remember stock Oil coolers have Thermostat restrictors so if it is Cold (18c or 65F or below) your oil will not get hot enough as air flow is too high...just ask 9K.
BTW: With my Mods (just gone through Summer) my Coolant Temps never passed 208F or 98C at lights during 38C or 100F...when moving always around the 86-88 c range. Not sure if the extra fan speed the series II's have also makes a difference.
Last edited by ASH8; 05-09-2010 at 12:29 AM.
05-09-2010, 10:07 AM
#31
Registered
Correction:
Apologies but I was unaware that the pictures of the centrally located oil cooler were of your car. If you've already gone this route then you've presumably spent your hard earn dollars on this oil cooler and want to make your current system work.
Were the stock oil coolers not doing the trick for you? Please offer details if available.
Your additonal air flow frontal area reduction makes your radiator efficiency that much more important. Essentially you have traded the open R & L stock oil cooler openings and trading this cooling space for reduced water radiator cooling (which I'm uncertain why you've gone this route). This gets you reduce water cooling. Please don't take this as a critique on your personal decisions about how to operate your car. I applaud you for trying something and your willingness to talk about it. More people should do as you do instead of defending their decisions based on zero data and a defensive attitude.
It is my wish to share information to others who may be reading this subject to introduce non-OEM soltuions to typical problems that arise from daily and weekend warrior operation. Guys---these cars we love are STREET cars. Every car has some sort of weakness that can be improved. Brakes, exhaust, intake, cooling, shifting, A/F. Corvette, import, turbo, domestic or foreign. They all have an achilless heal that can become exposed when you push your car.
Want a better radiator? $750 for a custom dual pass model from C&R radiator. Yes sportsfans it's possible to have custom radiators made--it happens all the time. ALL the time. A tour through C&R (and probably other rad companies) will reveal IndyCar, SportsCar, Baja, LateModel, etc., etc. Ever see a radiator dyno operate? One of the limitations of current radiator designs is the stock location of the entry and exit hoses of their cooling system. Typically aftermarket solutions will use these same in and out locations and can and do use the same radiator hoses. These in/out water locations only allow for a single pass of the water through the radiator. Want to learn something radiator people? Look at your stock or Ron Davis or PWR or other rad and see where the water enters. It enters from the top. Now see how it flows. It flows straight down vertically. I recall this is about 17" or so from memory. Don't hold me to this number oh owners of the mighty Stanley tape measures. The water is captured at the bottom of the tank then exits back into the system and circulates through the motor. This means the water is exposed to about 17" of surface area for the airflow to cool it/reduce it's temp.
Compare and contrast this to a DUAL PASS design. Water enters from the side, travels horizontally (and farther) to the other side and then returns back to the originating side. I recall ours travels 22" each way I believe. That 44" toal or 250% of a stock design. Naturally this will allow for better water cooling.
I offer this not as a solution to your particular issue (how many people can afford a $700+ rad) but as the logic that goes into cooling any car (not just an RX8 and not just a race car thank you very much the person who is likely to chime in and argue something stupid).
Your end result should all go back to what you want to do.
A larger and more powerful SINGLE radiator fan located in a good airflow location will reduce your water temps big time ONLY WHEN IT OPERATES. This is overkill for normal street use but if you want the insurance (which is overkill if your below 220F if you ask me --- and you should). Keep in mind that these bigger fans typically pull more amps and require some electrical wiring thought when implementing. Thier initial draw can be pretty hefty put they can blow like a twister. SPAL is just one manuf. There are several V-8 engine solutions available at Summit or Jegs at very reasonable pricing. Having your fan turn on at a lower water temp will help prevent your water from getting high in the first place which makes it easier to cool should you push your car hard in a hot environment.
Some of you don't know me as we are in the midst of our racing season so I'll share a few things that hopefully will earn me (or earn me back) some credibility.
Two years ago we were blowing at least one engine per car per Koni race. At LEAST. I've had every smart engine builder and tuner in the US build or contribute knowledge to help us get to our current solution. I have over $30K of engine management and consulting PER car. The Grand-Am spec Bosch ECU is $12K + without wiring harness and sensors. A Motec ADL2 display runs $6K plus. Have you ever spent $2K on a wiring harness? Guess what---it's the going rate for a professionally built race car. Am I some rich guy that spends money right and left and get robbed? Come to my shop and I'll educate you on what the cost of a top notch race car includes. There is a reason why high end race cars cost what they do. We've been on the dyno validating power before and after each motor for the past 20+ motors. Probably more. Part of our process is to dyno before and after a race. This can include pulls inbetween races as well as compression tests when we keep the same motor in the car. Originally making about 209-210 with a stock ECU we've made as high as 223 on a dynojet in 4th g at 8,000 - 8,100. Note: there is no power North of 8,500 rpm. You do not need to go there ever. The additional rotor wobble will contribute to rotor tip wear on the irons, grooving and reduce compression/power. I know this for a fact fellow rotary owners. We make about 217-219 depending how fresh the motor is consistantly on a dynojet and currently about 212-215 and 144-148 torque with a more conservative tune. We have been using dual EGT (exhaust gas temp) sensors for a few years know and have even logged Lambda (A/F) in both rotor banks. Fuel pressure, fuel temp, oil, water, crankcase pressure, air temp, manifold temp are several of the engine parameters we've been logging for the past 3 years. I think we've had 12 different exhaust designs hunting for hp running anything from 1.5 to 2" primary runner diameter to $800 collectors to 3, 3.5 and 4.0" exhausts.
So why am I so confident about water and oil temps? Because we initially felt our 210-220 water temps were part of our engine failure issue. Because these temps were easy to control (because high water and oil temps are not unique to the RX-8), we addressed these via several radiators and oil coolers. Yes we've owned some Ron Davis purchased through Mazdaspeed and yes we've found better. These rads are fine when used properly with the stock fans and oil coolers. You need only to maximize thier current operation. They will run about 220F water and 210-215 oil and will run the heck out of the fan when you pull them off the track but they work. We wanted more to insure excessive heat wasn't contributing to the demise of our engine compression (which we later found out and solved).
Note: Our oil temps currently run lower than water because we run much larger aftermarket oil coolers with larger lines -10 lines. This allows for larger oil capacity which allows the system to cool better (which is why you see giant dash 16 lines on dry sump systems with large capacity tanks) in bigger Sportscars. Look at the oil system in a ALMS, Grand-Am Rolex or WC car. GT3 cup porsches have big *** lines under the bonnet.
Hopefully I've earned some credibility because I've been there, done that, bought the T-shirt factory.
So regardless of if an RX-8 is used on the street or track or both rest assured there is some experienced help out there for you.
It all goes back to what you want to do.
Feel free to contact me if you want to take this conversation off-line to avoid some of the BS contributors that think they know what their talking about.
Happy rotoring,
Eric
meyermotorsports@mac.com
Apologies but I was unaware that the pictures of the centrally located oil cooler were of your car. If you've already gone this route then you've presumably spent your hard earn dollars on this oil cooler and want to make your current system work.
Were the stock oil coolers not doing the trick for you? Please offer details if available.
Your additonal air flow frontal area reduction makes your radiator efficiency that much more important. Essentially you have traded the open R & L stock oil cooler openings and trading this cooling space for reduced water radiator cooling (which I'm uncertain why you've gone this route). This gets you reduce water cooling. Please don't take this as a critique on your personal decisions about how to operate your car. I applaud you for trying something and your willingness to talk about it. More people should do as you do instead of defending their decisions based on zero data and a defensive attitude.
It is my wish to share information to others who may be reading this subject to introduce non-OEM soltuions to typical problems that arise from daily and weekend warrior operation. Guys---these cars we love are STREET cars. Every car has some sort of weakness that can be improved. Brakes, exhaust, intake, cooling, shifting, A/F. Corvette, import, turbo, domestic or foreign. They all have an achilless heal that can become exposed when you push your car.
Want a better radiator? $750 for a custom dual pass model from C&R radiator. Yes sportsfans it's possible to have custom radiators made--it happens all the time. ALL the time. A tour through C&R (and probably other rad companies) will reveal IndyCar, SportsCar, Baja, LateModel, etc., etc. Ever see a radiator dyno operate? One of the limitations of current radiator designs is the stock location of the entry and exit hoses of their cooling system. Typically aftermarket solutions will use these same in and out locations and can and do use the same radiator hoses. These in/out water locations only allow for a single pass of the water through the radiator. Want to learn something radiator people? Look at your stock or Ron Davis or PWR or other rad and see where the water enters. It enters from the top. Now see how it flows. It flows straight down vertically. I recall this is about 17" or so from memory. Don't hold me to this number oh owners of the mighty Stanley tape measures. The water is captured at the bottom of the tank then exits back into the system and circulates through the motor. This means the water is exposed to about 17" of surface area for the airflow to cool it/reduce it's temp.
Compare and contrast this to a DUAL PASS design. Water enters from the side, travels horizontally (and farther) to the other side and then returns back to the originating side. I recall ours travels 22" each way I believe. That 44" toal or 250% of a stock design. Naturally this will allow for better water cooling.
I offer this not as a solution to your particular issue (how many people can afford a $700+ rad) but as the logic that goes into cooling any car (not just an RX8 and not just a race car thank you very much the person who is likely to chime in and argue something stupid).
Your end result should all go back to what you want to do.
A larger and more powerful SINGLE radiator fan located in a good airflow location will reduce your water temps big time ONLY WHEN IT OPERATES. This is overkill for normal street use but if you want the insurance (which is overkill if your below 220F if you ask me --- and you should). Keep in mind that these bigger fans typically pull more amps and require some electrical wiring thought when implementing. Thier initial draw can be pretty hefty put they can blow like a twister. SPAL is just one manuf. There are several V-8 engine solutions available at Summit or Jegs at very reasonable pricing. Having your fan turn on at a lower water temp will help prevent your water from getting high in the first place which makes it easier to cool should you push your car hard in a hot environment.
Some of you don't know me as we are in the midst of our racing season so I'll share a few things that hopefully will earn me (or earn me back) some credibility.
Two years ago we were blowing at least one engine per car per Koni race. At LEAST. I've had every smart engine builder and tuner in the US build or contribute knowledge to help us get to our current solution. I have over $30K of engine management and consulting PER car. The Grand-Am spec Bosch ECU is $12K + without wiring harness and sensors. A Motec ADL2 display runs $6K plus. Have you ever spent $2K on a wiring harness? Guess what---it's the going rate for a professionally built race car. Am I some rich guy that spends money right and left and get robbed? Come to my shop and I'll educate you on what the cost of a top notch race car includes. There is a reason why high end race cars cost what they do. We've been on the dyno validating power before and after each motor for the past 20+ motors. Probably more. Part of our process is to dyno before and after a race. This can include pulls inbetween races as well as compression tests when we keep the same motor in the car. Originally making about 209-210 with a stock ECU we've made as high as 223 on a dynojet in 4th g at 8,000 - 8,100. Note: there is no power North of 8,500 rpm. You do not need to go there ever. The additional rotor wobble will contribute to rotor tip wear on the irons, grooving and reduce compression/power. I know this for a fact fellow rotary owners. We make about 217-219 depending how fresh the motor is consistantly on a dynojet and currently about 212-215 and 144-148 torque with a more conservative tune. We have been using dual EGT (exhaust gas temp) sensors for a few years know and have even logged Lambda (A/F) in both rotor banks. Fuel pressure, fuel temp, oil, water, crankcase pressure, air temp, manifold temp are several of the engine parameters we've been logging for the past 3 years. I think we've had 12 different exhaust designs hunting for hp running anything from 1.5 to 2" primary runner diameter to $800 collectors to 3, 3.5 and 4.0" exhausts.
So why am I so confident about water and oil temps? Because we initially felt our 210-220 water temps were part of our engine failure issue. Because these temps were easy to control (because high water and oil temps are not unique to the RX-8), we addressed these via several radiators and oil coolers. Yes we've owned some Ron Davis purchased through Mazdaspeed and yes we've found better. These rads are fine when used properly with the stock fans and oil coolers. You need only to maximize thier current operation. They will run about 220F water and 210-215 oil and will run the heck out of the fan when you pull them off the track but they work. We wanted more to insure excessive heat wasn't contributing to the demise of our engine compression (which we later found out and solved).
Note: Our oil temps currently run lower than water because we run much larger aftermarket oil coolers with larger lines -10 lines. This allows for larger oil capacity which allows the system to cool better (which is why you see giant dash 16 lines on dry sump systems with large capacity tanks) in bigger Sportscars. Look at the oil system in a ALMS, Grand-Am Rolex or WC car. GT3 cup porsches have big *** lines under the bonnet.
Hopefully I've earned some credibility because I've been there, done that, bought the T-shirt factory.
So regardless of if an RX-8 is used on the street or track or both rest assured there is some experienced help out there for you.
It all goes back to what you want to do.
Feel free to contact me if you want to take this conversation off-line to avoid some of the BS contributors that think they know what their talking about.
Happy rotoring,
Eric
meyermotorsports@mac.com
05-09-2010, 10:21 AM
#32
Registered
Correction:
Apologies but I was unaware that the pictures of the centrally located oil cooler were of your car. If you've already gone this route then you've presumably spent your hard earn dollars on this oil cooler and want to make your current system work.
Were the stock oil coolers not doing the trick for you? Please offer details if available.
Your additonal air flow frontal area reduction makes your radiator efficiency that much more important. Essentially you have traded the open R & L stock oil cooler openings and trading this cooling space for reduced water radiator cooling (which I'm uncertain why you've gone this route). This gets you reduce water cooling. Please don't take this as a critique on your personal decisions about how to operate your car. I applaud you for trying something and your willingness to talk about it. More people should do as you do instead of defending their decisions based on zero data and a defensive attitude.
It is my wish to share information to others who may be reading this subject to introduce non-OEM soltuions to typical problems that arise from daily and weekend warrior operation. Guys---these cars we love are STREET cars. Every car has some sort of weakness that can be improved. Brakes, exhaust, intake, cooling, shifting, A/F. Corvette, import, turbo, domestic or foreign. They all have an achilles heel that can become exposed when you push your car.
Want a better radiator? $750 for a custom dual pass model from C&R radiator. Yes sportsfans it's possible to have custom radiators made--it happens all the time. ALL the time. A tour through C&R (and probably other rad companies) will reveal IndyCar, SportsCar, Baja, LateModel, etc., etc. Ever see a radiator dyno operate? One of the limitations of current radiator designs is the stock location of the entry and exit hoses of their cooling system. Typically aftermarket solutions will use these same in and out locations and can and do use the same radiator hoses. These in/out water locations only allow for a single pass of the water through the radiator. Want to learn something radiator people? Look at your stock or Ron Davis or PWR or other rad and see where the water enters. It enters from the top. Now see how it flows. It flows straight down vertically. I recall this is about 17" or so from memory. Don't hold me to this number oh owners of the mighty Stanley tape measures. The water is captured at the bottom of the tank then exits back into the system and circulates through the motor. This means the water is exposed to about 17" of surface area for the airflow to cool it/reduce it's temp.
Compare and contrast this to a DUAL PASS design. Water enters from the side, travels horizontally (and farther) to the other side and then returns back to the originating side. I recall ours travels 22" each way I believe. That 44" toal or 250% of a stock design. Naturally this will allow for better water cooling.
I offer this not as a solution to your particular issue (how many people can afford a $700+ rad) but as the logic that goes into cooling any car (not just an RX8 and not just a race car thank you very much the person who is likely to chime in and argue something stupid).
Your end result should all go back to what you want to do.
A larger and more powerful SINGLE radiator fan located in a good airflow location will reduce your water temps big time ONLY WHEN IT OPERATES. This is overkill for normal street use but if you want the insurance (which is overkill if your below 220F if you ask me --- and you should). Keep in mind that these bigger fans typically pull more amps and require some electrical wiring thought when implementing. Thier initial draw can be pretty hefty put they can blow like a twister. SPAL is just one manuf. There are several V-8 engine solutions available at Summit or Jegs at very reasonable pricing. Having your fan turn on at a lower water temp will help prevent your water from getting high in the first place which makes it easier to cool should you push your car hard in a hot environment.
Some of you don't know me as we are in the midst of our racing season so I'll share a few things that hopefully will earn me (or earn me back) some credibility.
Two years ago we were blowing at least one engine per car per Koni race. At LEAST. I've had every smart engine builder and tuner in the US build or contribute knowledge to help us get to our current solution. I have over $30K of engine management and consulting PER car. The Grand-Am spec Bosch ECU is $12K + without wiring harness and sensors. A Motec ADL2 display runs $6K plus. Have you ever spent $2K on a wiring harness? Guess what---it's the going rate for a professionally built race car. Am I some rich guy that spends money right and left and get robbed? Come to my shop and I'll educate you on what the cost of a top notch race car includes. There is a reason why high end race cars cost what they do. We've been on the dyno validating power before and after each motor for the past 20+ motors. Probably more. Part of our process is to dyno before and after a race. This can include pulls inbetween races as well as compression tests when we keep the same motor in the car. Originally making about 209-210 with a stock ECU we've made as high as 223 on a dynojet in 4th g at 8,000 - 8,100. Note: there is no power North of 8,500 rpm. You do not need to go there ever. The additional rotor wobble will contribute to rotor tip wear on the irons, grooving and reduce compression/power. I know this for a fact fellow rotary owners. We make about 217-219 depending how fresh the motor is consistantly on a dynojet and currently about 212-215 and 144-148 torque with a more conservative tune. We have been using dual EGT (exhaust gas temp) sensors for a few years know and have even logged Lambda (A/F) in both rotor banks. Fuel pressure, fuel temp, oil, water, crankcase pressure, air temp, manifold temp are several of the engine parameters we've been logging for the past 3 years. I think we've had 12 different exhaust designs hunting for hp running anything from 1.5 to 2" primary runner diameter to $800 collectors to 3, 3.5 and 4.0" exhausts.
So why am I so confident about water and oil temps? Because we initially felt our 210-220 water temps were part of our engine failure issue. Because these temps were easy to control (because high water and oil temps are not unique to the RX-8), we addressed these via several radiators and oil coolers. Yes we've owned some Ron Davis purchased through Mazdaspeed and yes we've found better. These rads are fine when used properly with the stock fans and oil coolers. You need only to maximize thier current operation. They will run about 220F water and 210-215 oil and will run the heck out of the fan when you pull them off the track but they work. We wanted more to insure excessive heat wasn't contributing to the demise of our engine compression (which we later found out and solved).
Note: Our oil temps currently run lower than water because we run much larger aftermarket oil coolers with larger lines -10 lines. This allows for larger oil capacity which allows the system to cool better (which is why you see giant dash 16 lines on dry sump systems with large capacity tanks) in bigger Sportscars. Look at the oil system in a ALMS, Grand-Am Rolex or WC car. GT3 cup porsches have big *** lines under the bonnet.
Hopefully I've earned some credibility because I've been there, done that, bought the T-shirt factory.
So regardless of if an RX-8 is used on the street or track or both rest assured there is some experience help out there for you.
It all goes back to what you want to do. I applaud you for wanting to improve the performance of your car where others will just sit there and talk about why it might not work because their uncle cooter's garage says it probably won't work. Try something and take lots of notes and you'll find out what works best for your particular application.
Feel free to contact me if you want to take this conversation off-line to avoid some of the BS contributors that think they know what their talking about.
Happy rotoring,
Eric
meyermotorsports@mac.com
Apologies but I was unaware that the pictures of the centrally located oil cooler were of your car. If you've already gone this route then you've presumably spent your hard earn dollars on this oil cooler and want to make your current system work.
Were the stock oil coolers not doing the trick for you? Please offer details if available.
Your additonal air flow frontal area reduction makes your radiator efficiency that much more important. Essentially you have traded the open R & L stock oil cooler openings and trading this cooling space for reduced water radiator cooling (which I'm uncertain why you've gone this route). This gets you reduce water cooling. Please don't take this as a critique on your personal decisions about how to operate your car. I applaud you for trying something and your willingness to talk about it. More people should do as you do instead of defending their decisions based on zero data and a defensive attitude.
It is my wish to share information to others who may be reading this subject to introduce non-OEM soltuions to typical problems that arise from daily and weekend warrior operation. Guys---these cars we love are STREET cars. Every car has some sort of weakness that can be improved. Brakes, exhaust, intake, cooling, shifting, A/F. Corvette, import, turbo, domestic or foreign. They all have an achilles heel that can become exposed when you push your car.
Want a better radiator? $750 for a custom dual pass model from C&R radiator. Yes sportsfans it's possible to have custom radiators made--it happens all the time. ALL the time. A tour through C&R (and probably other rad companies) will reveal IndyCar, SportsCar, Baja, LateModel, etc., etc. Ever see a radiator dyno operate? One of the limitations of current radiator designs is the stock location of the entry and exit hoses of their cooling system. Typically aftermarket solutions will use these same in and out locations and can and do use the same radiator hoses. These in/out water locations only allow for a single pass of the water through the radiator. Want to learn something radiator people? Look at your stock or Ron Davis or PWR or other rad and see where the water enters. It enters from the top. Now see how it flows. It flows straight down vertically. I recall this is about 17" or so from memory. Don't hold me to this number oh owners of the mighty Stanley tape measures. The water is captured at the bottom of the tank then exits back into the system and circulates through the motor. This means the water is exposed to about 17" of surface area for the airflow to cool it/reduce it's temp.
Compare and contrast this to a DUAL PASS design. Water enters from the side, travels horizontally (and farther) to the other side and then returns back to the originating side. I recall ours travels 22" each way I believe. That 44" toal or 250% of a stock design. Naturally this will allow for better water cooling.
I offer this not as a solution to your particular issue (how many people can afford a $700+ rad) but as the logic that goes into cooling any car (not just an RX8 and not just a race car thank you very much the person who is likely to chime in and argue something stupid).
Your end result should all go back to what you want to do.
A larger and more powerful SINGLE radiator fan located in a good airflow location will reduce your water temps big time ONLY WHEN IT OPERATES. This is overkill for normal street use but if you want the insurance (which is overkill if your below 220F if you ask me --- and you should). Keep in mind that these bigger fans typically pull more amps and require some electrical wiring thought when implementing. Thier initial draw can be pretty hefty put they can blow like a twister. SPAL is just one manuf. There are several V-8 engine solutions available at Summit or Jegs at very reasonable pricing. Having your fan turn on at a lower water temp will help prevent your water from getting high in the first place which makes it easier to cool should you push your car hard in a hot environment.
Some of you don't know me as we are in the midst of our racing season so I'll share a few things that hopefully will earn me (or earn me back) some credibility.
Two years ago we were blowing at least one engine per car per Koni race. At LEAST. I've had every smart engine builder and tuner in the US build or contribute knowledge to help us get to our current solution. I have over $30K of engine management and consulting PER car. The Grand-Am spec Bosch ECU is $12K + without wiring harness and sensors. A Motec ADL2 display runs $6K plus. Have you ever spent $2K on a wiring harness? Guess what---it's the going rate for a professionally built race car. Am I some rich guy that spends money right and left and get robbed? Come to my shop and I'll educate you on what the cost of a top notch race car includes. There is a reason why high end race cars cost what they do. We've been on the dyno validating power before and after each motor for the past 20+ motors. Probably more. Part of our process is to dyno before and after a race. This can include pulls inbetween races as well as compression tests when we keep the same motor in the car. Originally making about 209-210 with a stock ECU we've made as high as 223 on a dynojet in 4th g at 8,000 - 8,100. Note: there is no power North of 8,500 rpm. You do not need to go there ever. The additional rotor wobble will contribute to rotor tip wear on the irons, grooving and reduce compression/power. I know this for a fact fellow rotary owners. We make about 217-219 depending how fresh the motor is consistantly on a dynojet and currently about 212-215 and 144-148 torque with a more conservative tune. We have been using dual EGT (exhaust gas temp) sensors for a few years know and have even logged Lambda (A/F) in both rotor banks. Fuel pressure, fuel temp, oil, water, crankcase pressure, air temp, manifold temp are several of the engine parameters we've been logging for the past 3 years. I think we've had 12 different exhaust designs hunting for hp running anything from 1.5 to 2" primary runner diameter to $800 collectors to 3, 3.5 and 4.0" exhausts.
So why am I so confident about water and oil temps? Because we initially felt our 210-220 water temps were part of our engine failure issue. Because these temps were easy to control (because high water and oil temps are not unique to the RX-8), we addressed these via several radiators and oil coolers. Yes we've owned some Ron Davis purchased through Mazdaspeed and yes we've found better. These rads are fine when used properly with the stock fans and oil coolers. You need only to maximize thier current operation. They will run about 220F water and 210-215 oil and will run the heck out of the fan when you pull them off the track but they work. We wanted more to insure excessive heat wasn't contributing to the demise of our engine compression (which we later found out and solved).
Note: Our oil temps currently run lower than water because we run much larger aftermarket oil coolers with larger lines -10 lines. This allows for larger oil capacity which allows the system to cool better (which is why you see giant dash 16 lines on dry sump systems with large capacity tanks) in bigger Sportscars. Look at the oil system in a ALMS, Grand-Am Rolex or WC car. GT3 cup porsches have big *** lines under the bonnet.
Hopefully I've earned some credibility because I've been there, done that, bought the T-shirt factory.
So regardless of if an RX-8 is used on the street or track or both rest assured there is some experience help out there for you.
It all goes back to what you want to do. I applaud you for wanting to improve the performance of your car where others will just sit there and talk about why it might not work because their uncle cooter's garage says it probably won't work. Try something and take lots of notes and you'll find out what works best for your particular application.
Feel free to contact me if you want to take this conversation off-line to avoid some of the BS contributors that think they know what their talking about.
Happy rotoring,
Eric
meyermotorsports@mac.com
05-09-2010, 11:21 AM
#33
SARX Legend
Thread Starter
iTrader: (46)
Holy ****, thanks for the info Eric I will have to read all that in a bit 
I realize now I should have done better oil coolers in the stock location but for now I'm trying to make this work. I will seal everything up and get some Hymee data. My real reason for the oil cooler upgrade was high oil temps on hot days, and not having a true oil thermostat in cold weather worried me.
Going to this oil cooler setup netted me increased oil pressures (less restriction I suppose), more oil out during regular changes.
Oh and Brettus I cut that lip off already
I realize now I should have done better oil coolers in the stock location but for now I'm trying to make this work. I will seal everything up and get some Hymee data. My real reason for the oil cooler upgrade was high oil temps on hot days, and not having a true oil thermostat in cold weather worried me. Going to this oil cooler setup netted me increased oil pressures (less restriction I suppose), more oil out during regular changes.
Oh and Brettus I cut that lip off already
Last edited by 9krpmrx8; 05-09-2010 at 11:23 AM.
05-10-2010, 12:11 AM
#39
3-wheeler
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The discussion regarding cooling on the track is pretty good however I think the issue at hand was cooling issues as it relates to a canyon run.
Since Arizona has plenty of mountain driving this is something I've had considerable experience with. The two main problems with cooling the RX8 on canyon or mountain runs deal with RPM, load and speed.
The first issue is normally the good mountain runs involve tight turns which naturally are taken at low speed. The second issue is the cooling issues are a result of higher RPMS and high load at that same time. The low speed situation means you are getting less airflow to the radiator which reduces the cooling capability of the system. Normally you're operating at higher RPMS to keep power to the wheels but going uphill means creating higher loads.
So in the end you have a situation where the motor is generating tons of heat due to the high load/RPM operation and reduced cooling ability because of the slower speeds. There is one specific drive in Phoenix that if it's done in temperatures above 85 degrees I'll have to back off at some point but other drives I could do in temps above 90 degrees and have no issues.
Point being, this type of driving doesn't really translate well into track conditions unless you have a race track that is 100% uphill driving all the time.
There are ways to mitigate cooling issues with canyon runs but the effort and cost involved is extensive when you can simply lift off the throttle or pull over to let the car cool off.
Since Arizona has plenty of mountain driving this is something I've had considerable experience with. The two main problems with cooling the RX8 on canyon or mountain runs deal with RPM, load and speed.
The first issue is normally the good mountain runs involve tight turns which naturally are taken at low speed. The second issue is the cooling issues are a result of higher RPMS and high load at that same time. The low speed situation means you are getting less airflow to the radiator which reduces the cooling capability of the system. Normally you're operating at higher RPMS to keep power to the wheels but going uphill means creating higher loads.
So in the end you have a situation where the motor is generating tons of heat due to the high load/RPM operation and reduced cooling ability because of the slower speeds. There is one specific drive in Phoenix that if it's done in temperatures above 85 degrees I'll have to back off at some point but other drives I could do in temps above 90 degrees and have no issues.
Point being, this type of driving doesn't really translate well into track conditions unless you have a race track that is 100% uphill driving all the time.
There are ways to mitigate cooling issues with canyon runs but the effort and cost involved is extensive when you can simply lift off the throttle or pull over to let the car cool off.
05-10-2010, 12:35 AM
#40
SARX Legend
Thread Starter
iTrader: (46)
Yes Flash you are right as I said the canyon runs are harder on my caeh under tray r than the track or autox is. But since I do many more canyons runs than track runs then I would like to get things situated.
I did some poking around today and the gap between the bottom of the radiator and the undertray is significant and I did not tranfer the foam from the factory rad to the koyo. So I will have to seal that up. I also removed my factory intake and tray and I see what Eric is talking about I'm not sure how air flows through the rad with all the crap there.
I may have to get the AEM even though I hate the way it looks and the water issues.
I did some poking around today and the gap between the bottom of the radiator and the undertray is significant and I did not tranfer the foam from the factory rad to the koyo. So I will have to seal that up. I also removed my factory intake and tray and I see what Eric is talking about I'm not sure how air flows through the rad with all the crap there.
I may have to get the AEM even though I hate the way it looks and the water issues.
05-10-2010, 06:53 AM
#41
Registered
Flash makes a fantastic point. I had no idea your environment would see uphill loads. Wonderful post flash.
Now that I think about it I'm not so sure there is a doable solution to your situation. Our big *** 30 ton, 78 foot car hauler with 1,650 ft lbs of torque will easily trip the gargantuan engine fan in longer, gradual uphill climbs in midwestern summer weather. The fan diameter is bigger than the engine bay in an RX-8. It's huge. This leads me to believe that a huge radiator and serious fan with a lower temp thermostat trigger may be the ticket. A vented hood should facilitate hot air escaping but to validate this would require some effort.
Now that I think about it twice I think (not sure) you are asking the car to have super cooling potential and therefore you would need to invest in addtional cooling efforts in the entire system.
I'll suggest to you that we probably have the biggest radiator in any rotary out there. Same for oil coolers and fan. 12" square oil coolers with -10 lines with inline thermostat. Wheel arches removed. Heavy, heavy belly pan ducting. Mazdaspeed front nose with the black plastic trim upper trim piece removed (which causes lift at high speeds --- and probably a fair amount of drag) but it cools like a ****. We've had our oil galley's enlarged to reduce oil flow through the engine. That being said my gut says the fan would turn on in the uphill environment flash describes.
I wonder if a power adder would allow the engine to operate at lower rpms and therefore generate a noticable reduction in heat. Remember, these little motors have crap for power and I suspect you may be "flooring it" uphill. That being said I would strongly believe that huge temp increases are the norm.
Just trying to save you some $ so you don't pick at it to death only to find out that version 10.0 still doesn't do the trick.
If it were me I would tap smarter resources. Call a radiator company and ask for their .02. If it were me I would think about the cost benefit of fixing this problem in an N.A. motor. Perhaps you should buy a high torque Dodge Viper and do an engine swap?
Now that I think about it I'm not so sure there is a doable solution to your situation. Our big *** 30 ton, 78 foot car hauler with 1,650 ft lbs of torque will easily trip the gargantuan engine fan in longer, gradual uphill climbs in midwestern summer weather. The fan diameter is bigger than the engine bay in an RX-8. It's huge. This leads me to believe that a huge radiator and serious fan with a lower temp thermostat trigger may be the ticket. A vented hood should facilitate hot air escaping but to validate this would require some effort.
Now that I think about it twice I think (not sure) you are asking the car to have super cooling potential and therefore you would need to invest in addtional cooling efforts in the entire system.
I'll suggest to you that we probably have the biggest radiator in any rotary out there. Same for oil coolers and fan. 12" square oil coolers with -10 lines with inline thermostat. Wheel arches removed. Heavy, heavy belly pan ducting. Mazdaspeed front nose with the black plastic trim upper trim piece removed (which causes lift at high speeds --- and probably a fair amount of drag) but it cools like a ****. We've had our oil galley's enlarged to reduce oil flow through the engine. That being said my gut says the fan would turn on in the uphill environment flash describes.
I wonder if a power adder would allow the engine to operate at lower rpms and therefore generate a noticable reduction in heat. Remember, these little motors have crap for power and I suspect you may be "flooring it" uphill. That being said I would strongly believe that huge temp increases are the norm.
Just trying to save you some $ so you don't pick at it to death only to find out that version 10.0 still doesn't do the trick.
If it were me I would tap smarter resources. Call a radiator company and ask for their .02. If it were me I would think about the cost benefit of fixing this problem in an N.A. motor. Perhaps you should buy a high torque Dodge Viper and do an engine swap?
05-10-2010, 08:37 AM
#42
the less expensive route at this point imho would be
1- a secondary radiator.
2- Make sure it is an open fin type for good low speed airflow,
3- run it from the heater hose supply--non thermostated route--
4- drill a very small hole in the thermostat so that the entire system will have some flow even 5- when the bypass system is open,
6- get the fans to come on at 180F (if you havent already)
7- Mazdaspeed front end is a good idea.
8- vented hood not only for letting heat escape but also to allow a more negative pressure in the engine bay. This increases the air flow through the radiator.
Somthing also to keep in mind that you may already know----partial throttle high rpm's build heat faster than full throttle, do full throttle applications as much as possible, dont hold it in the high rpm range with just partial throttle, if you are not trying to gain speed shift to a lower gear.
rotor on dude.
OD
1- a secondary radiator.
2- Make sure it is an open fin type for good low speed airflow,
3- run it from the heater hose supply--non thermostated route--
4- drill a very small hole in the thermostat so that the entire system will have some flow even 5- when the bypass system is open,
6- get the fans to come on at 180F (if you havent already)
7- Mazdaspeed front end is a good idea.
8- vented hood not only for letting heat escape but also to allow a more negative pressure in the engine bay. This increases the air flow through the radiator.
Somthing also to keep in mind that you may already know----partial throttle high rpm's build heat faster than full throttle, do full throttle applications as much as possible, dont hold it in the high rpm range with just partial throttle, if you are not trying to gain speed shift to a lower gear.
rotor on dude.
OD
05-10-2010, 09:20 AM
#43
SARX Legend
Thread Starter
iTrader: (46)
I am going to seal everything up and see what that does. The hills are a problem but I also notice at speed my coolant does not cool down very quickly the way my oil does. I have to increase the flow across my radiator.
05-10-2010, 09:23 AM
#44
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Join Date: Oct 2006
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Very nice write up Eric! I've been logging some coolant temp data myself around NH. For about a month, maybe a month and a half I ran a 3rd party universal thermostat while I waited for mazda to get one in for me and for me to have the time to change it (been busy at work with travel). Anyway, this was a 180*F thermostat with a larger opening then the OEM one does. On the couple hot days we saw up here (temps in the 80's) I noticed my coolant temps would barely hit 190*F, mostly at the hottest part of the day it would stay around 185*F. Now as the temps came down into the 70's and 60's, I would see coolant temps drop to 178*F. These were temps that I was very well satisfied with, then the day that I went to change the thermostat it was in the 40's again (was actually like 38 when I woke up that morning and for record purposes I took it for a short drive and found that in that cold of weather it had a hard time getting over 165, staying around 160 and prompting me to end my journey early and swap the thermostat.
Now at the same time I asked a friend to log some temps here and there and I recorded those as well. He was saying that he was seeing temps getting up to 200 easily on 70 degree days, and as the temps dropped into the 60's he would see temps staying up around 195 and only as the temps drop toward 50 did he start seeing his temps coming down around 190 and just below.
-------
Now I know that for a cooling system to work it's more then just blowing air over the coolant just as it's more then trying to move as much coolant as you can. Cooling systems work by moving the coolant at the right speed so that as it moves across the heated surface area in the engine that it absorbs as much thermal energy as it safely can, to that end if you increase the flow too much you won't get as good of a transfer and if it's too slow you can push the coolant past it's thermal threshold and thus boil it. The same goes with the radiator, as the coolant makes a pass through the radiator it's contacting a certain surface area and so on and so forth.
So I've been curious with the larger opening in the temporary thermostat I used was able to raise the efficiency too much and if thats the case, could a thermostat be made for the 8 to increase cooling while not becoming an issue when temps drop.
Now at the same time I asked a friend to log some temps here and there and I recorded those as well. He was saying that he was seeing temps getting up to 200 easily on 70 degree days, and as the temps dropped into the 60's he would see temps staying up around 195 and only as the temps drop toward 50 did he start seeing his temps coming down around 190 and just below.
-------
Now I know that for a cooling system to work it's more then just blowing air over the coolant just as it's more then trying to move as much coolant as you can. Cooling systems work by moving the coolant at the right speed so that as it moves across the heated surface area in the engine that it absorbs as much thermal energy as it safely can, to that end if you increase the flow too much you won't get as good of a transfer and if it's too slow you can push the coolant past it's thermal threshold and thus boil it. The same goes with the radiator, as the coolant makes a pass through the radiator it's contacting a certain surface area and so on and so forth.
So I've been curious with the larger opening in the temporary thermostat I used was able to raise the efficiency too much and if thats the case, could a thermostat be made for the 8 to increase cooling while not becoming an issue when temps drop.
05-10-2010, 01:58 PM
#45
i'm curious as to what kind of thermostat you used? Are you certain that it would open/close the bypass system as it should? A while back i searched high and low for a replacement thermostat and couldnt fine any.
If it didnt close/open that bypass--then you may be in trouble dude. The temp recorded at the oem site would not be accuate and the rotor areas could have been much hotter than you thought. I hope that did not happen.
Sounds like a plan 9K---one thing at the time
OD
If it didnt close/open that bypass--then you may be in trouble dude. The temp recorded at the oem site would not be accuate and the rotor areas could have been much hotter than you thought. I hope that did not happen.
Sounds like a plan 9K---one thing at the time
OD
05-10-2010, 02:23 PM
#46
05-11-2010, 06:52 AM
#47
Registered
Very nice write up Eric! I've been logging some coolant temp data myself around NH. For about a month, maybe a month and a half I ran a 3rd party universal thermostat while I waited for mazda to get one in for me and for me to have the time to change it (been busy at work with travel). Anyway, this was a 180*F thermostat with a larger opening then the OEM one does. On the couple hot days we saw up here (temps in the 80's) I noticed my coolant temps would barely hit 190*F, mostly at the hottest part of the day it would stay around 185*F. Now as the temps came down into the 70's and 60's, I would see coolant temps drop to 178*F. These were temps that I was very well satisfied with, then the day that I went to change the thermostat it was in the 40's again (was actually like 38 when I woke up that morning and for record purposes I took it for a short drive and found that in that cold of weather it had a hard time getting over 165, staying around 160 and prompting me to end my journey early and swap the thermostat.
Now at the same time I asked a friend to log some temps here and there and I recorded those as well. He was saying that he was seeing temps getting up to 200 easily on 70 degree days, and as the temps dropped into the 60's he would see temps staying up around 195 and only as the temps drop toward 50 did he start seeing his temps coming down around 190 and just below.
-------
Now I know that for a cooling system to work it's more then just blowing air over the coolant just as it's more then trying to move as much coolant as you can. Cooling systems work by moving the coolant at the right speed so that as it moves across the heated surface area in the engine that it absorbs as much thermal energy as it safely can, to that end if you increase the flow too much you won't get as good of a transfer and if it's too slow you can push the coolant past it's thermal threshold and thus boil it. The same goes with the radiator, as the coolant makes a pass through the radiator it's contacting a certain surface area and so on and so forth.
So I've been curious with the larger opening in the temporary thermostat I used was able to raise the efficiency too much and if thats the case, could a thermostat be made for the 8 to increase cooling while not becoming an issue when temps drop.
Now at the same time I asked a friend to log some temps here and there and I recorded those as well. He was saying that he was seeing temps getting up to 200 easily on 70 degree days, and as the temps dropped into the 60's he would see temps staying up around 195 and only as the temps drop toward 50 did he start seeing his temps coming down around 190 and just below.
-------
Now I know that for a cooling system to work it's more then just blowing air over the coolant just as it's more then trying to move as much coolant as you can. Cooling systems work by moving the coolant at the right speed so that as it moves across the heated surface area in the engine that it absorbs as much thermal energy as it safely can, to that end if you increase the flow too much you won't get as good of a transfer and if it's too slow you can push the coolant past it's thermal threshold and thus boil it. The same goes with the radiator, as the coolant makes a pass through the radiator it's contacting a certain surface area and so on and so forth.
So I've been curious with the larger opening in the temporary thermostat I used was able to raise the efficiency too much and if thats the case, could a thermostat be made for the 8 to increase cooling while not becoming an issue when temps drop.
We had a similar situation to this in that some of our initial gigantic monster pizza box size oil coolers were doing the trick in 100F track temps but 135F in cold weather. We would tape the faces up only to pit, remove tape, make a run and see where the temps fell---a futile excercise is tape on/tape off. Grand-Am called us out and said it was an Aero gig and slapped our hands (stupid) and requested us to stop. This was at Daytona.
So we began experimenting with various thermostats with these larger oil coolers and both Northern and Southern temps. Winter at Homestead FL at 85F is a helluva lot different than winter at BeaveRun PA at 40F. So we had both ends of temp in our testing at the same time. I beleive it took us 3 oil thermostats to find the right one---not to hot while racing in hot weather and good enough to keep the oil warm enough in cold weather testing. FYI. I recall one being from Summit Racing (an alum block) and another from Pegasus (a twin barrel config). We ended up with the alum rectangular block----FYI. Might be some trial and error in your world.
FYI again----The famous rotary engine builder Daryl Drummond engine dyno tests his engines in the 170-180F range for power. I have found that oil at 210 makes a smidge more power, water below 190 on the chassis dyno. Intake air as cool as you can obviously---80's F.
05-12-2010, 02:45 AM
#49
Registered
http://www.summitracing.com/parts/EAR-501ERL/
-10 lines in the entire system. I think that low-speed issue that Flash and OD describe is the gremlin. I am illequipped to comment on that solution.
-10 lines in the entire system. I think that low-speed issue that Flash and OD describe is the gremlin. I am illequipped to comment on that solution.