Joe Weinstein

Hi all.
Has anyone measured their intercooler temperatures during
a dyno run? I just got a pyrometer, and find that one minute
of spirited driving gets them up to 140 degrees.
Has anyone seen the power benefits on a dyno from icing the
intercoolers?

thanks,
Joe

cohare

That's funny I was thinking about this yesterday. More so running a NO2 kit to cool them off. I know a lot of ricers do this on their turbo's supposedly with good results.

special tool

Well - you are really "cheating" if you do that.
Most guys who want real results will hit the ic with room temperature water from a spray bottle after the first pull to regain some of the cooling which would be present at speed on the road/track.

Joe Weinstein

so the question remains, how much difference does it
make? If it's not against the rules, it's not cheating.

1999Porsche911

The rule of thumb is about a 5% loss for every 30F increase in intake temperature.

Joe Weinstein

Thanks!! Yow! That sounds like a *serious* difference.
Joe

Kevin

Water with alcohol sprayed on your IC, as the special tool has mentioned.

Jean

IMO, you should only see a difference if your intercooler is heat soaking, if it is within its thermal efficiency, the difference will be little if any...in other terms, if you run a 0.8 Bar run on the dyno I doubt anything will happen.

On the road, you would need to constantly keep spraying, manually, or via a programmable system (boost dependent etc..)

The way to read the temps is by checking out how much your intake temps are higher than ambient levels, so 140F is only relevant if you compare it to outside temperature during that run. There was an interesting thread lately by MOD500 on the 993TT board testing a Secan.

Joe Weinstein

I got info from Todd Knighton. He says:

You get about .5hp/degF you lower the temps. So, in an ideal world,
you have nearly 30hp to gain if you could get the temps back to ambient (81deg).

MidnighTT

Here's a Durametric log showing RPM and intake air temp from a recent 3 gear highway run:

RPM Temp (C)
2,786 35.3
3,188 35.3
3,705 35.3
4,390 36
4,841 36.8
5,466 37.5
5,908 38.3
6,447 41.3
6,842 42.8
6,580 44.3
4,817 45
5,099 45
5,399 46.5
5,678 48
5,946 49.5
6,207 51
6,470 53.3
6,668 54.8
7,148 55.5
5,524 55.5
5,541 55.5
5,681 56.3
5,849 57
6,008 58.5
6,146 59.3
6,254 60
6,371 60.8
6,498 61.5
6,623 63
6,755 63
6,033 63
5,422 63
5,603 61.5
5,645 61.5
5,744 62.3
5,822 62.3
5,893 63
5,982 63
6,080 63
6,325 63.8

If the associated time stamps are to be believed, the intake air temp climbed from 35C (95F) to 64C (147F) in 16 seconds. Ambient air temp was in the low 70s. While I swore off nitrous more than a decade ago because of the hassle factor, a WOT I/C cooling system using misted alcohol or a compressed gas might last long enough between refills to be interesting.

Of course, once you go that far, it's just another small step to injecting nitrous or alcohol into the engine rather than spraying it on the intercoolers.

Jeff

VZ935

The black lines on top of my intercooler take water from my cool suite tank. The Motec activates the spray at .8 bar of boost. Never tested it on the dyno but the Motec does track the temp..I don't know the exact temps but it does make a difference... we also utilize Moroso fuel coolers with dry ice... sometime put dry ice on top of the intercooler.. good for some initial HP gains for a lap.. anything to get an edge

JasonAndreas

If you are trying to get consistent measurements than I would think anything that helps stabilize intake temperatures would be useful. How useful are chassis dynamometer results when there is a 50°F temperature delta between runs? The SAE correction formulas don't take into account what the ECU does to ignition timing or fueling in response to rising air temperatures.