Performance gains with cooler input air temps??
07-31-2001, 12:25 PM
#1
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Location: ROSEVILLE, MN
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I'm trying to cost justify different options to decrease my input air temps to the intake.
Now in this scenario let’s assume that the engine is generating a peak of 300RWHP at 10psi with intake temps at 180 F degrees. Now what would the power increase be if those air temps were reduced to 80 F degrees? I have heard a rule of thumb of 1% for every 10 F degrees reduction in air temp intake in other words 330RWHP peak. Is this about right???
Ken
"94 White
www.nopistons.com
Now in this scenario let’s assume that the engine is generating a peak of 300RWHP at 10psi with intake temps at 180 F degrees. Now what would the power increase be if those air temps were reduced to 80 F degrees? I have heard a rule of thumb of 1% for every 10 F degrees reduction in air temp intake in other words 330RWHP peak. Is this about right???
Ken
"94 White
www.nopistons.com
08-01-2001, 03:05 PM
#3
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I found this on the Aquamist web site.
"30. How much density increase if I were able to cool the charge air? Amazingly large increases, Chart shows the density increase as charge air is being cooled. This will apply to compressor exit temperature right up to 300 C(632F).
If you manage to drop the temperature by 75C(150F), you will get a density gain of 33.6%. A 300bhp engine will have a theoretical power increase of 100 BHP !!!."
If this is true then it would be higher than 1% power increase for 10F degrees cooler air intake. Maybe more like 1% for every 5F degress. I sure hope that is true.
I calculated what the air intake temp would be reduced by dumping water/methanol into the air intake after the IC cooled it down. If my calculations are correct and if the temperature coming out of the IC is 280F degrees at 15psi and 7500rpms and the solution injected is 350cc/min it will drop the 280F degrees by 116F degress. Hopefully that 116F degress reduction is worth 25% increase in power. ####, I'd settle for 15% increase. So assuming 300RWHP with 280Fegrees intake air temp and it is reduced to 164F degress than power should increase to 345RWHP if it is a 15% gain.
Does this make any sense???
I did get a real world example from my Aquamist guy. He had a person with a supercharged GranAm. He was turning a best of 14.1 in the 1/4 mile. He added water injection and after tuning was turning a consistant 13.7. I did a drag simulation of that car to see what BHP increase it would take to reduce the 1/4 mile time .4 seconds and it needed about 50bhp increase or about 16%, so maybe my calculations are close to being accurate. We'll see if I'm right in about three weeks from now.
Anyways, we all know cool air intake makes more hp, whether it is 1% per 10F degrees or 1% per 5F degrees. This should help cost-justify bigger ICs when your engine is running high boost and high rpms. The closer you can get it to ambient the better.
When my car gets to the dyno I think I'll have Dave dump in methanol/water into my 4 gallon fuel cell at 0F degress out of a freezer. Obviously the IC doesn't do much good on the dyno.
If you like this kind of stuff there is all kinds of neat technical stuff at: http://www.aquamist.co.uk/rescr/rescr.html
Ken
“94 PEP, White, Red Leather
www.nopistons.com
"30. How much density increase if I were able to cool the charge air? Amazingly large increases, Chart shows the density increase as charge air is being cooled. This will apply to compressor exit temperature right up to 300 C(632F).
If you manage to drop the temperature by 75C(150F), you will get a density gain of 33.6%. A 300bhp engine will have a theoretical power increase of 100 BHP !!!."
If this is true then it would be higher than 1% power increase for 10F degrees cooler air intake. Maybe more like 1% for every 5F degress. I sure hope that is true.
I calculated what the air intake temp would be reduced by dumping water/methanol into the air intake after the IC cooled it down. If my calculations are correct and if the temperature coming out of the IC is 280F degrees at 15psi and 7500rpms and the solution injected is 350cc/min it will drop the 280F degrees by 116F degress. Hopefully that 116F degress reduction is worth 25% increase in power. ####, I'd settle for 15% increase. So assuming 300RWHP with 280Fegrees intake air temp and it is reduced to 164F degress than power should increase to 345RWHP if it is a 15% gain.
Does this make any sense???
I did get a real world example from my Aquamist guy. He had a person with a supercharged GranAm. He was turning a best of 14.1 in the 1/4 mile. He added water injection and after tuning was turning a consistant 13.7. I did a drag simulation of that car to see what BHP increase it would take to reduce the 1/4 mile time .4 seconds and it needed about 50bhp increase or about 16%, so maybe my calculations are close to being accurate. We'll see if I'm right in about three weeks from now.
Anyways, we all know cool air intake makes more hp, whether it is 1% per 10F degrees or 1% per 5F degrees. This should help cost-justify bigger ICs when your engine is running high boost and high rpms. The closer you can get it to ambient the better.
When my car gets to the dyno I think I'll have Dave dump in methanol/water into my 4 gallon fuel cell at 0F degress out of a freezer. Obviously the IC doesn't do much good on the dyno.
If you like this kind of stuff there is all kinds of neat technical stuff at: http://www.aquamist.co.uk/rescr/rescr.html
Ken
“94 PEP, White, Red Leather
www.nopistons.com
08-02-2001, 04:51 AM
#5
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Join Date: Jul 2001
Location: ROSEVILLE, MN
Posts: 423
Ya, can't hurt. I don't know if Dave uses one. I'm mainly interested in getting it tuned right for the water/methanol injection. This is new for him.
Ken
'94 PEP White
www.nopistons.com
Ken
'94 PEP White
www.nopistons.com
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