BDC Street port vs. stock port dyno comparison
06-20-2011, 11:54 AM
#201
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Wow, Great info. Once my car is heat soaked there just does not seem to any way of shedding the heat other than just letting it idle a bit and shutting her down for a while. A second radiator is going in my car just to be safe.
Eric, can I ask what the highest intake air temps you see are?
Eric, can I ask what the highest intake air temps you see are?
06-20-2011, 12:10 PM
#202
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^ Unless you have an aftermarket AIT sensor or your MAF relocated post turbo (if applicable) you are going to get AIT numbers a bit higher than ambient and considering Eric is using the stock Intake system I imagine that would remain the same for him
06-20-2011, 12:59 PM
#203
Eric I appreciate all you comments and suggestions, seriously I do.
I understand what you run, why you run it and why it works.
But I do not have a race team, or a dedicated race car, so I have limitations. One of those is that I dont want to cut or modify stuff unless I have to. Swaping parts is cool, but cutting up the radiator support to get a big radiator in there is not for me right now. Thats why, if I can increase the effeciency of my intercooler, oil coolers and aluminum BHR radiator then thats what I will do. Obviously unplugging the front end would help with effeciency but the heat dissipation coatings do work, how much, I dont know. I for a fact that Swain coatings has been and still is used in racing applications. Not sure how much the heat dissipation coatings are used but their heat barrier coatings are used a lot. http://www.swaintech.com/store.asp?p...39&catid=19694
I prepared a big reply but not wanting to get off topic, anything specific to my car can be taken over to my build thread. Click the link in my signature.
I understand what you run, why you run it and why it works.
But I do not have a race team, or a dedicated race car, so I have limitations. One of those is that I dont want to cut or modify stuff unless I have to. Swaping parts is cool, but cutting up the radiator support to get a big radiator in there is not for me right now. Thats why, if I can increase the effeciency of my intercooler, oil coolers and aluminum BHR radiator then thats what I will do. Obviously unplugging the front end would help with effeciency but the heat dissipation coatings do work, how much, I dont know. I for a fact that Swain coatings has been and still is used in racing applications. Not sure how much the heat dissipation coatings are used but their heat barrier coatings are used a lot. http://www.swaintech.com/store.asp?p...39&catid=19694
I prepared a big reply but not wanting to get off topic, anything specific to my car can be taken over to my build thread. Click the link in my signature.
Last edited by Highway8; 06-20-2011 at 01:05 PM.
06-20-2011, 02:11 PM
#204
the lim has such a large footprint on the engine--you cant cool it. even a phenolic gasket cant be used becacause it is so thick it throws the apv's off. best you can do is to promote air flow around it. On track it doesnt heat the air up much anyway. maybe just a couple degrees. The air is moving too fast through it.
06-20-2011, 04:51 PM
#205
You can setup the warm-up enrichment any way you like.
This is a bad analogy. At least how you employed it.
The A/C unit in your house is designed to move a given volume of air and provide a nearly fixed temperature delta. Your cooling system in the car is quite similar.
It isn't that it got to hot to process - it is actually processing it quite adequately - it is just that the desired delta in an overheated house is nowhere near where you want to be comfortable.
The same goes for the RX-8 cooling system.
Once the cooling delta exceeds the heating delta, there is nothing you can do to get comfortable again.
In actual testing, having a vent with a negative pressure differential (like the stock shrouds) is better than having no shroud at all. Those slots are shaped the way they are for a purpose. Expanding them to a point will help, though.
The OE oil cooler plumbing is a way more important restriction.
In actual testing, no aftermarket fan flows more air (in loaded-side restriction only testing) than the OE fans. The OE fan combination out blows the high-dollar aftermarket stuff but several hundred CFM.
That "blocking" plastic actually generates a low pressure area behind the fan. Look up Bernoulli.
Not quite. Convection moves the water around quite a bit. Having the water pump spinning is better, of course, but somewhat negated by the heat being added by a motor that, at idle, is only running at 30% Ve at best. An electric pump would probably yield the best result.
True, but decel and part-throttle transition tuning is extremely valuable in maintaining normalized combustion temps.
I think the guys that are beating their heads against the detonation threshold when tuning a turbo motor might want to think about what a motor goes through in transition - especially on the street.
See above. You actually reduced flow through the fan by doing that.
Actually, we don't. But that is a topic for a different thread.
Or, just do what the rest of the civilized tuning world does and turn the fans on full at 192° instead of 217° like Mazda does. Same result.
I had a switch before the advent of flash tuning for the RX-8. The programming option works better.
Well, actually, I don't think anyone would argue that with you.
Under the car is where the low pressure is and the amount of airflow through the intercooler will never be enough to upset the body aero.
The A/C unit in your house is designed to move a given volume of air and provide a nearly fixed temperature delta. Your cooling system in the car is quite similar.
It isn't that it got to hot to process - it is actually processing it quite adequately - it is just that the desired delta in an overheated house is nowhere near where you want to be comfortable.
The same goes for the RX-8 cooling system.
Once the cooling delta exceeds the heating delta, there is nothing you can do to get comfortable again.
The OE oil cooler plumbing is a way more important restriction.
That "blocking" plastic actually generates a low pressure area behind the fan. Look up Bernoulli.
I think the guys that are beating their heads against the detonation threshold when tuning a turbo motor might want to think about what a motor goes through in transition - especially on the street.
I think I would like an emergency overide fan switch in the cabin. For example, you get stuck in traffic and you see you will be moving very slowly for some time, its really hot outside and you see the temps climbing. Rather than having to play catch up later, like Eric said, I would like to be able to ingauge the fans to prevent that heat soak from occuring in the first place.
I may work on this--add to list?
I may work on this--add to list?
I had a switch before the advent of flash tuning for the RX-8. The programming option works better.
Under the car is where the low pressure is and the amount of airflow through the intercooler will never be enough to upset the body aero.
06-20-2011, 09:18 PM
#208
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06-21-2011, 05:23 AM
#211
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Well, actually, I don't think anyone would argue that with you.
Under the car is where the low pressure is and the amount of airflow through the intercooler will never be enough to upset the body aero.
Under the car is where the low pressure is and the amount of airflow through the intercooler will never be enough to upset the body aero.
06-21-2011, 08:17 AM
#212
Jeff, would not the Bernoulli only apply if the air is flowing past the supports?
Thats the trouble with the fan supports--the air is not flowing past them enough to take advantage of that principle.
Do you or anyone else have another option to place the condensor elsewhere? Doing without it is not an option for me. Its too dang hot.
Agreed that automatic temperature based switch is the best for fan activation, however all of us are not Cobb friendly or even have one
Thats the trouble with the fan supports--the air is not flowing past them enough to take advantage of that principle.
Do you or anyone else have another option to place the condensor elsewhere? Doing without it is not an option for me. Its too dang hot.
Agreed that automatic temperature based switch is the best for fan activation, however all of us are not Cobb friendly or even have one
06-21-2011, 09:17 AM
#213
I posed the question on my build thread but it gets less traffic as this one, so I will ask it here and maybe get some replys.
In regards to ducting the intercooler air under the car, is it better for the radiator cooling to duct the air under the car or to allow the slow moving and slightly warmer air to to radiator?
I am inclined to try it the easy way first and then the other if cooling isnt up to par. Unless of course someone has some solid evidence or facts to persuade me one way or another.
In regards to ducting the intercooler air under the car, is it better for the radiator cooling to duct the air under the car or to allow the slow moving and slightly warmer air to to radiator?
I am inclined to try it the easy way first and then the other if cooling isnt up to par. Unless of course someone has some solid evidence or facts to persuade me one way or another.
Last edited by Highway8; 06-21-2011 at 09:21 AM.
06-21-2011, 10:24 AM
#215
Jeff, would not the Bernoulli only apply if the air is flowing past the supports?
Thats the trouble with the fan supports--the air is not flowing past them enough to take advantage of that principle.
Do you or anyone else have another option to place the condensor elsewhere? Doing without it is not an option for me. Its too dang hot.
Agreed that automatic temperature based switch is the best for fan activation, however all of us are not Cobb friendly or even have one
Thats the trouble with the fan supports--the air is not flowing past them enough to take advantage of that principle.
Do you or anyone else have another option to place the condensor elsewhere? Doing without it is not an option for me. Its too dang hot.
Agreed that automatic temperature based switch is the best for fan activation, however all of us are not Cobb friendly or even have one
In theory if your condenser fins are straight and it is clean it should not impede airflow to much certainly not enough to warrant its relocation. You should be cleaning your coils yearly and straightening the fins when they get banged up.
If you look at most 8's the lower section of the condenser will have extremely bent fins and the whole unit will be caked with dust. just because it looks clean doesn't mean that it is.
06-21-2011, 10:33 AM
#216
Very true, the condensor needs maintanence like everything else and without it, it can get worse..
i would like to ask if you have ever had this package out of the car and tested it? Airflow through the two versus air flow through radiator only?
you may be surprised.
i speak of airflow without the fans on.
i would like to ask if you have ever had this package out of the car and tested it? Airflow through the two versus air flow through radiator only?
you may be surprised.
i speak of airflow without the fans on.
06-21-2011, 10:48 AM
#217
I might remove my A/C system (compressor and condensor, leave the lines). I have a buddy who can evac the system for me so if I want to put it back in latter he will recharge it for free.
I leave in Northern California, between San franscisco and Sacramento. The weather is usually mild except during a few months of the summer. Even then we only hit 90+ 50% oftime during those 2 months and only for 4-5 hours a day.
I trailer my car to the track, I dont switch to a street brakes/tire setup during the 6-9 month spring/summer/fall track season and during the winter I really dont need A/C except for the defroster. But I dont drive in the rain so its not even an issue.
Less weight and better air flow. I would probably only see small gains with both, but it might be worth it to me.
Who knows if I will, but its a thought.
I leave in Northern California, between San franscisco and Sacramento. The weather is usually mild except during a few months of the summer. Even then we only hit 90+ 50% oftime during those 2 months and only for 4-5 hours a day.
I trailer my car to the track, I dont switch to a street brakes/tire setup during the 6-9 month spring/summer/fall track season and during the winter I really dont need A/C except for the defroster. But I dont drive in the rain so its not even an issue.
Less weight and better air flow. I would probably only see small gains with both, but it might be worth it to me.
Who knows if I will, but its a thought.
06-21-2011, 11:51 AM
#218
Very true, the condensor needs maintanence like everything else and without it, it can get worse..
i would like to ask if you have ever had this package out of the car and tested it? Airflow through the two versus air flow through radiator only?
you may be surprised.
i speak of airflow without the fans on.
i would like to ask if you have ever had this package out of the car and tested it? Airflow through the two versus air flow through radiator only?
you may be surprised.
i speak of airflow without the fans on.
I'm sure you would see some benefits in racing conditions not having a big condenser in the way of air flow.
Weight shouldn't be to much of a factor you are looking at 30 to 40 pounds at the most with refrigerant, condenser and compressor. If you removed the evap coil and blower you might save another 30 or 40 lbs not sure on the weight of those.
If you remove the rear seats and carpeting you'd most likely save more weight.
What does any of this have to do with street porting?
06-22-2011, 09:29 AM
#224
