Just curious. Has anyone ever dynoed on a hot day, then again on a cold day with the same setup? Any idea how much outside temp affects hp when running a supercharger or turbo??

 

TONS!! Not even worth doing on a hot day, in my opinion.

 

Covered this in detail in this months GMHTP.
Now that it is cooling of a bit I need to get back on the dyno so I can get a worthwhile baseline.

 

You could see as much as a 50HP difference.

 

yeah i wonder what the difference would be on a truck that makes 350hp to the wheels on a day with 100* temps as opposed to a day with 75* temps?

 

The non-intercooled whipple isn't helping either.

 

As far as heat or cold hurting on a dyno, It wont affect a thing as long as you are sae corrected or have some type of correction factor that factors in temperature. Now if you were dynoing non corrected, then you would see a change in hp/tq in different temperatures and weather conditions.

 

i dont think the corection is acurate for forced induction but it is better than nothing. i dont have any real reason for saying this other than my seat of the pants observations but i would say heat and cold have more of an effect on a boosted set up than NA. 100deg day you will make much less power and on a 40deg day you will be making much more power.

last week when i was tuning on my truck it was 95deg. i dont have any gtechs but i do have my scan tool. my 0-130mph was in the 10.4sec range. a little later i raced that bike and it was 60 deg and it was way faster. scan tool showed 9.3 0-130 times. it felt like an easy 100more hp just from the temps.

 

I realize this, but just how accurate is the correction? I would be very interested in seeing 2 dyno charts in differnt temps, same dyno ,same vehicle. Just to know how accurate the corrected number is.

 

I understand correction factors, but I'd put money down that corrected numbers for a 50* day would be higher than a 110* day especially on a boosted vehicle. There is so much more involved than just the intake air temps.