Diy- How To Dyno The Rx8
12-02-2007, 06:50 PM
#26
It's a Cavalier
So, why would you do any of that for a dyno run.
Oh yeah, I remember.
To cheat.
Why would you dyno a car in an undrivable state?
More importantly, it is only applicable on a vehicle that still has its OEM PCM in the loop in its original tune.
If you have the Int-X or if you have the ability to re-flash the PCM and change the A/F targets, then it is an irrelevant (and stupid) trick.
Oh yeah, I remember.
To cheat.
Why would you dyno a car in an undrivable state?
More importantly, it is only applicable on a vehicle that still has its OEM PCM in the loop in its original tune.
If you have the Int-X or if you have the ability to re-flash the PCM and change the A/F targets, then it is an irrelevant (and stupid) trick.
I had my 8 during the dyno / horsepower conspiracy or "HP denial" days as MM puts it. It was painful. I like this "just dyno it and what it says is what it is" philosophy.
12-02-2007, 07:14 PM
#27
I think that the dyno is so entrenched in the minds of the typical clueless performance consumer that they will buy anything that is papered with results that can be sold as significant.
It is a measuring tool. If you use it to measure ****, the only thing you will know for sure is how much **** you have.
It is a measuring tool. If you use it to measure ****, the only thing you will know for sure is how much **** you have.
12-02-2007, 07:48 PM
#28
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Yes, they say you can pull the room fuse, but you put it back in before you dyno.. Also, they say 1% loss of power, so your looking at 1-2 whp difference.. Hardly anything to worry about or needed duing a dyno run. Especially if you dont pull it on a base run & any other time, then the number increase will still be the same. So what is the point?
Last edited by WoodsOfGreenRx8; 12-02-2007 at 07:50 PM. Reason: The Point
12-02-2007, 09:43 PM
#30
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a) I said it was useless to do if your running an external engine management system
b) if you don't do it, you sure as hell better not try comparing your own dyno runs on different days to see the effects of mods since your no longer comparing apples to apples... in NA mods a few hp here and there is actually significant when looking at mods that only gain a few hp. God all help us if we want any kind of consistency in our dynos.
...didn't someone on this forum have a sig that was something like
3hp from a REVi intake $300
7hp from resetting the ecu priceless
b) if you don't do it, you sure as hell better not try comparing your own dyno runs on different days to see the effects of mods since your no longer comparing apples to apples... in NA mods a few hp here and there is actually significant when looking at mods that only gain a few hp. God all help us if we want any kind of consistency in our dynos.
...didn't someone on this forum have a sig that was something like
3hp from a REVi intake $300
7hp from resetting the ecu priceless
12-02-2007, 09:51 PM
#31
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that philosophy leads to such things as intercoolers being iced down with CO2 fire extinguishers, dynos done on freezing days and not corrected for temperature, dry ice on intakes, exhausts uncorked, oil and water pressures adjusted to meet someone's agenda, tire pressures adjusted to meet wanted outcomes, dyno information being wrongly inputted, fans being used or not used...
...if your not going to do a legit dyno that is repeatable, then your wasting your money
...if your not going to do a legit dyno that is repeatable, then your wasting your money
12-03-2007, 11:15 AM
#32
Registered
^ that's a great point. How many people cheat? Most! The one's that don't, make excuses when their numbers are lower than they wanted. People run high octane race fuels or alcohol at dynos when they don't on the street and then use the excuse "it was for safety". That's crap.
I don't see how pulling a fuse is a bad thing or cheating. An n/a engine can only make so much power. If it's consistent, that's all that counts. That's the important thing. It isn't the total number.
Dynoing a car IS done when the car is in an undrivable state. The front wheels don't move, there is no wind resistance, and it's strapped down. It doesn't get any more undrivable or unrealistic than that. I just don't see why there's such an argument and why anyone is so hellbent that their method must be the only correct one. Just pull the fuse and dyno it. It's easy to do. If you don't want to do this, push and hold the button in. Big deal. Pick one. It's your car.
I really want to see 2 different dyno sessions with each method now. I want to see one dynoed with the button pressed and held. Dyno 3 times back to back to back. Then go back in a week and repeat. Compare numbers. Do the same thing with the pull the fuse method. Use the same car. Compare results between both for consistency. The total power number isn't important. Consistency is. That's what I want to see. If one method consistently produces a higher power number on an n/a car it would actually be the more accurate one to use anyways.
Someone try this and post the results.
I don't see how pulling a fuse is a bad thing or cheating. An n/a engine can only make so much power. If it's consistent, that's all that counts. That's the important thing. It isn't the total number.
Dynoing a car IS done when the car is in an undrivable state. The front wheels don't move, there is no wind resistance, and it's strapped down. It doesn't get any more undrivable or unrealistic than that. I just don't see why there's such an argument and why anyone is so hellbent that their method must be the only correct one. Just pull the fuse and dyno it. It's easy to do. If you don't want to do this, push and hold the button in. Big deal. Pick one. It's your car.
I really want to see 2 different dyno sessions with each method now. I want to see one dynoed with the button pressed and held. Dyno 3 times back to back to back. Then go back in a week and repeat. Compare numbers. Do the same thing with the pull the fuse method. Use the same car. Compare results between both for consistency. The total power number isn't important. Consistency is. That's what I want to see. If one method consistently produces a higher power number on an n/a car it would actually be the more accurate one to use anyways.
Someone try this and post the results.
12-03-2007, 12:24 PM
#33
That's all fine and good, but my original point was that there is some misunderstanding of how the DSC/TCS actually works and what happens when you push that button.
The whole "cheating" thing was an aside.
Really, all one needs to do it datalog the timing, injection and throttle position to see if the PCM is interfering.
I datalog these things at all times (driving, dynoing, parking, whatever) and I can tell you conclusively what the PCM does and does not like.
The whole "cheating" thing was an aside.
Really, all one needs to do it datalog the timing, injection and throttle position to see if the PCM is interfering.
I datalog these things at all times (driving, dynoing, parking, whatever) and I can tell you conclusively what the PCM does and does not like.
12-03-2007, 01:06 PM
#37
Lol. Yep. True.
I logged that area, but I never really paid much attention to it since the likelihood of popping the motor there is pretty slim. Usually I'm still in "stomp on it mode" at that point and between the PCM's adjustments and the acceleration map, there is a lot of transition going by in that second that the RPMs are below 3500.
BTW - you can force the PCM into open-loop whenever you want with the EMU as it stands right now.
I'm not sure of the benefit particularly, but wherever you have an "ON" cell in the NCVS map, the PCM will be in open-loop, regardless of load.
I have a bunch of fun datalogs that might be useful. I've been driving the car in a fashion that might be considered "uncharacteristic" of me lately. Lots of crazy transition in and out of full and partial boost at all kinds of weird load points (like part throttle to 7200 RPM and then stomping on it or "pumping" the throttle all the way through the RPM band up to the rev limit - stuff that makes the driver look like a retard, which, according to his SO, he is).
I also have several where I bog the car down to 2k in 6th and tromp on it all the way until I feared for my life and the validity of my driving permit.
12-08-2007, 12:32 PM
#39
The Professor
Thread Starter
^ that's a great point. How many people cheat? Most! The one's that don't, make excuses when their numbers are lower than they wanted. People run high octane race fuels or alcohol at dynos when they don't on the street and then use the excuse "it was for safety". That's crap.
I don't see how pulling a fuse is a bad thing or cheating. An n/a engine can only make so much power. If it's consistent, that's all that counts. That's the important thing. It isn't the total number.
Dynoing a car IS done when the car is in an undrivable state. The front wheels don't move, there is no wind resistance, and it's strapped down. It doesn't get any more undrivable or unrealistic than that. I just don't see why there's such an argument and why anyone is so hellbent that their method must be the only correct one. Just pull the fuse and dyno it. It's easy to do. If you don't want to do this, push and hold the button in. Big deal. Pick one. It's your car.
I really want to see 2 different dyno sessions with each method now. I want to see one dynoed with the button pressed and held. Dyno 3 times back to back to back. Then go back in a week and repeat. Compare numbers. Do the same thing with the pull the fuse method. Use the same car. Compare results between both for consistency. The total power number isn't important. Consistency is. That's what I want to see. If one method consistently produces a higher power number on an n/a car it would actually be the more accurate one to use anyways.
Someone try this and post the results.
I don't see how pulling a fuse is a bad thing or cheating. An n/a engine can only make so much power. If it's consistent, that's all that counts. That's the important thing. It isn't the total number.
Dynoing a car IS done when the car is in an undrivable state. The front wheels don't move, there is no wind resistance, and it's strapped down. It doesn't get any more undrivable or unrealistic than that. I just don't see why there's such an argument and why anyone is so hellbent that their method must be the only correct one. Just pull the fuse and dyno it. It's easy to do. If you don't want to do this, push and hold the button in. Big deal. Pick one. It's your car.
I really want to see 2 different dyno sessions with each method now. I want to see one dynoed with the button pressed and held. Dyno 3 times back to back to back. Then go back in a week and repeat. Compare numbers. Do the same thing with the pull the fuse method. Use the same car. Compare results between both for consistency. The total power number isn't important. Consistency is. That's what I want to see. If one method consistently produces a higher power number on an n/a car it would actually be the more accurate one to use anyways.
Someone try this and post the results.
I have seen some dynos where even without the button + 8 seconds press power remains unaffected. This leads me to believe that there is still variability in the sensitivity of the wheel speed sensors and ECU control in different cars. Just like some folks running a catless midpipe show no CEL even though so many others do.
Until I see a oscilloscope reading of the ABS/DSC relay to be sure that it is drawing no power during a dyno (meaning its inactive) I am going to assume that its still doing something at some level even if you give it the system fault (button +8 seconds). Lets start getting some consistency in our dynos by doing a simple unplug.
12-08-2007, 01:33 PM
#40
You don't need to monitor the DSC/TCS. Why don't you guys get this?
If you log the throttle position, you will see that the PCM does NOT interfere. This is the only engine input the PCM has in relation to the DCS/TCS.
The ignition timing and injector pules width are also similarly unaffected.
If you suspect that the PCM is messing with your dyno sessions, why don't you just log it? sCANalyzer, CANScan or whatever. It doesn't matter.
Anything that can show the throttle position will show you what is going on.
I log through my e-Manage, so I get the raw data and that TPS doesn't move an iota on the dyno.
As subtle as the PCM might seem in certain situations, it is not so in regards to the DSC/TCS.
Its that simple.
If you log the throttle position, you will see that the PCM does NOT interfere. This is the only engine input the PCM has in relation to the DCS/TCS.
The ignition timing and injector pules width are also similarly unaffected.
If you suspect that the PCM is messing with your dyno sessions, why don't you just log it? sCANalyzer, CANScan or whatever. It doesn't matter.
Anything that can show the throttle position will show you what is going on.
I log through my e-Manage, so I get the raw data and that TPS doesn't move an iota on the dyno.
As subtle as the PCM might seem in certain situations, it is not so in regards to the DSC/TCS.
Its that simple.
12-10-2007, 03:42 PM
#44
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Doing back to back runs on a RX8 without cooling down is a recipe for destruction. Put a big fan in front of the car and let it run for as few minutes between runs.
Trust me.
Vince
Trust me.
Vince
12-10-2007, 03:50 PM
#45
You don't need to monitor the DSC/TCS. Why don't you guys get this?
If you log the throttle position, you will see that the PCM does NOT interfere. This is the only engine input the PCM has in relation to the DCS/TCS.
The ignition timing and injector pules width are also similarly unaffected.
If you suspect that the PCM is messing with your dyno sessions, why don't you just log it? sCANalyzer, CANScan or whatever. It doesn't matter.
Anything that can show the throttle position will show you what is going on.
I log through my e-Manage, so I get the raw data and that TPS doesn't move an iota on the dyno.
As subtle as the PCM might seem in certain situations, it is not so in regards to the DSC/TCS.
Its that simple.
If you log the throttle position, you will see that the PCM does NOT interfere. This is the only engine input the PCM has in relation to the DCS/TCS.
The ignition timing and injector pules width are also similarly unaffected.
If you suspect that the PCM is messing with your dyno sessions, why don't you just log it? sCANalyzer, CANScan or whatever. It doesn't matter.
Anything that can show the throttle position will show you what is going on.
I log through my e-Manage, so I get the raw data and that TPS doesn't move an iota on the dyno.
As subtle as the PCM might seem in certain situations, it is not so in regards to the DSC/TCS.
Its that simple.
When I had the EMU installed it would retard timing and enrich the mixture until the car lost power if the fuse was removed because it couldn't control the TPS anymore so it had to find another way to keep the driver from "killing" himself. If I left the fuse in and pushed the button for 10sec it would just close the throttle.
I have yet to try the car with the Int-X and the fuse removed, I have faith that this will eliminate the issues or I will have to find another way around the system(i.e.temporary mechanical throttle body).
Any other thoughts, anyone?
Chris
Last edited by ChrisRX8PR; 12-10-2007 at 03:53 PM.
12-10-2007, 03:51 PM
#46
Yeah, its a giant heater when it is moving.
Its a furnace standing still.
What year is your car?
I have dynoed OEM and with both versions of the e-Manage and have seen no such interference.
Is your MAF in the normal location with the Int-X?
I know from looking at your EMU tuning (the "1000ccMOD_OctaneBoost.EM2" file) that the PCM was going to freak on the dyno because of what you were doing with the AFM map.
Its a furnace standing still.
I have dynoed OEM and with both versions of the e-Manage and have seen no such interference.
Is your MAF in the normal location with the Int-X?
I know from looking at your EMU tuning (the "1000ccMOD_OctaneBoost.EM2" file) that the PCM was going to freak on the dyno because of what you were doing with the AFM map.
Last edited by MazdaManiac; 12-10-2007 at 03:55 PM.
12-16-2007, 10:38 PM
#48
All of you, shut up !!!!!
Im gonna go dyno my car after this week, suppose to do it last week but **** *** Clutch Bracket broke in the *Right* time, took them 3 days to fix it, got my car back on friday, too late.
and this coming week I have finals and **** work bugging me like crazy.
Gonna do it the xmas week I guess. I will try the *DSC button* method first. 1 hour unlimited pulls for 120 bux (aye...), weather is gonna be cold.
After that I will do another pull after the new year using the *Pull fuse* method. Alright ?
Im gonna go dyno my car after this week, suppose to do it last week but **** *** Clutch Bracket broke in the *Right* time, took them 3 days to fix it, got my car back on friday, too late.
and this coming week I have finals and **** work bugging me like crazy.
Gonna do it the xmas week I guess. I will try the *DSC button* method first. 1 hour unlimited pulls for 120 bux (aye...), weather is gonna be cold.
After that I will do another pull after the new year using the *Pull fuse* method. Alright ?
