Anyone curious how air temp affects engine output? Honestly, the results made me want to find more ways to keep the air temp cooler.

The dyno chart below indicates the results from my most recent tests. The two runs were exactly 3 months apart and around the same time during the day on the same dyno. The results shown below are uncorrected = the numbers you see were the power produced that day to the ground.

Results: the engine produced more power under cooler condition than adding the UR pulleys under warmer condition. However, the same UR pulleys setup under the same cooler condition should yield higher output (I hope ).

Run 16 - Red
Date: 2/20/06
Time: 12:50pm
Air temp: 43 degrees F


Run 17 - Blue
Date: 5/20/06
Time: 11:54am
Air temp: 64 degrees F

Temp difference since run 16: 21 degrees F
Component added since run 16: UR pulleys

 

Wow... that is really incredible that cooler air w/ NO pulleys > warm air w/ pulleys. Good investigative reporting.

 

Great info Johnny

That really tells a lot. Looks like I'm be using my CAI soon

 

I'm also trying to implement the 06 TSX front grille cover which has vents to draw outside air to the engine bay. Okay, I'm jealous of the 06 power. . I don't think it's a direct fit but wonder if it can be done...

2004/2005 cover


2006 cover

 

yeah my SV (mc) loves cool days...it really pulls. its the 03 FI motor.

I wonder how much added performance 06s get from icebox? since the new engine specs seems to be optimized. if it's on 5 HP it's not worth it. 10HP would be.

 

Good info. The chart is informative because the dyno was switched from SAE to uncorrected (for air temp and air pressure).

Have you installed our Heatshield gasket?

 

Yes, I did. It provided 3 solid hp.

 

do you have your mod list?

 

- Hondata reflash
- Hondata gasket
- Big bore throttle body with port matched intake manifold and ceramic coating
- K&N CAI
- UR underdrive pulleys
- DC header
- Metal' cat converter (200 cell)
- Tanabe Medalion Touring exhaust
- Coolant bypass
- Oil catch can

 

Good info.

 

Very interesting. You're the best person to do this, too, as having one of the most modified NA engines means the difference in warm/cool air performance will be most pronounced; i.e. the more horsepower your engine makes the better testing resolution becomes.

Also, it's no wonder that you noticed such an increase in power: a 21F temperature difference is the rough pressure equivalent of going from sea level to 7700 feet of elevation!

 

Are the vents on the 06 denoted by #3? I guess I never noticed those before.

 

Holy crap.... good example!

*loves living in cooler climates where I get coolers temps in summer and fall than you suckers in the southern states, LOL*

 

so i guess this means i should get my lazy ass to convert my short ram to CAI...

 

I'm so jealous of those dyno's.

 

Oh, I forgot to mention the Hondata gasket test was done with synthetic oil (first oil change). That might have helped to achieve the 3 hp gain.

The old school of cooling effects:
- coolant = responsible for 70% of cooling effect.
- air = 20% of cooling effect.
- oil (dino) = 10% of cooling effect.

IMO, I believe today's synthetic oil probably contribute a little more cooling effect by further reduces frictions of engine components.

 

Johnny, if you're putting 203-207 hp to the ground, that's got to put you in the ~225-230 range at the crank, eh?

 

So JT...what did the dyno run look like stock? how far have your mods taken you?

Thanks...

 

I think it's about 239 - 244 chp range using 15% loss calculation.

239 - 15% = 203.15
244 - 15% = 207.40

 

thats crazy JTSO, you're in like previous series Audi S4 territory

 

Here is a comparison between the very beginning stage of modding and now. Note: We will continue to use uncorrected numbers to keep things consistent for this particular topic. We would normally use SAE numbers.

Run 3 was done in 3/27/2004. The biggest gain obviously from the Hondata reflash. I believe run 3 was tested with CAI and possibly header as well. I don't have a bone stock baseline.

 

Wow, that's awesome...I just got my '04...a little worried about voiding my extended warranty but can't wait to get started working on the mods...this gives me hope!

On cold air... I can totally feel the difference in my butt...driving this car at night in the cold versus in the day heat.

I'm in Colorado where you lose 15% of your power due to lower air pressure...so I am basically driving a 170hp car unmodified.

 

Do you record IAT during testing or just ambient? I've found that they generally correlate with one another, but not in a strictly linear fashion. I'm just thinking that the reading from the thermistor right before the TB might be a more accurate representation of engine conditions.

The obvious solution to that is a supercharger. How do you think WWII-era piston-driven aircraft made 1200bhp at 32,000 feet?

 

I usually record IAT temp during testing and comparing to ambient. The IAT reading when a car is moving during a cold day is usually the same as ambient. The IAT reading under warmer condition (car moving) is usually 4 - 7 degrees F warmer than ambient. However, if the engine is heat soaked, the IAT reading can be very high and it takes awhile for moving air to lower it back down to ambient range. The temp readings from above are ambient.

 

I remember something like 'for every 10deg drop in air temp, you get ~1hp'...seems to fit your case. Just not sure how that rule changes based on QTY of air/engine displacement...

 

Johnny, I think you're ripe for a 2006 head swap.

 

Crazy mods JT....you give us TSX all hope (except me, cuz i have a AT )

So....if I move even more North like in the North Pole or Yukon, then my TSX will be SOOOOOOOOOOOO FAST!! and drifting in the snow y0!

 

In that case Im getting one of these installed..

300.00 at sears 2000 btu that should keep the air at 30 degrees

 

LOL.

Even better, save yourself the $300 and route the cabin A/C lines to the CAI tube to cool the tube and thus the incoming air.

 

How do they function?
like add horsepower, improve your car or something else?

 

^^
The idea is to add horse power with a better breathing engine and cooler intake temp.

 

Just pull the fuse for the AC compressor. Doesn't matter much though, the ECU disengages the clutch at WOT anyway.

 

I should have put my post in red text.

 

An easy test to perform alto but may take up to 6months for each, drive your car in winter and drive your car in summer. One'll pull hard and the other not so hard!