My question to Red03SVT was; what was the Temperature and humidity. Your response was; that's what we have correction factors for.

Looking at that statement one would think that the SAE #'s are an accurate way of comparing our supercharged engines, sorry if I misunderstood you.

SAE #'s are only accurate on normally aspirated internal combustion engines. To my knowledge there is no correction factor for forced induction engines.

So when you say you see typically 340-350, and B-Man's #'s are within 2% of that, how can you say they are low? Being that the SAE correction factor could be the reason for the discrepancy. His uncorrected peak # is 341 RWHP. (341 X .98CF=334)


Please correct me if I am wrong.

 

Uncorrected is 341 correct. But the 0.98 CF is the correction from STD to SAE and believe it or not STD is ALSO a correction factor itself...just a different temp and pressure....

 

But still not a corection factor for a supercharged engine.

 

Here's my stock dyno run from a month ago - a 2002 with 2700 miles on it. Only non-stock item is a K&N drop-in - no airbox mods. Temp was 61 in the garage, very low humidity (middle of winter in Chicago).

I wouldn't hope that our difference is the K&N. Now I wish I had made a pull with the paper filter. I was pretty happy with my 353 rwhp 425 rwtq.

 

All I am trying to say is there is no correction factor that is accurate enough on supercharged engines to make fair comparisons. I feel the #'s are a great way to compare your progress, but for me to try and compare my #'s to someone where the air is cooler and dryer, it just will not work.

-Mike

 

I read on-line that on a "proper" dyno chart, the torque and HP plots should cross at roughly 5250 RPM.

Could someone explain why the graph ILLINI-SVT posted doesn't cross like mine does ?

Thanks in advance for any info you can provide...

 

Mine crosses...

 

B-Man

The HP and Torque each have their own legend on his graph. (HP on left side, TQ on right side).I think you are assuming that they are sharing a legend. If you look at the Right side the Tq legend starts at 350 and the power # starts at 250. They still meet at the right place.

Mike

 

Yeah, mine looks like it crosses just before 4200.

Hmmm. I hadn't heard that before. Does anyone have an answer to that? If those jobbers screwed up my dyno runs, I'm gonna be pissed.

I did 2 pulls that day, and on my other chart (351/421) they cross around 4350.

 

Ahh, now I remember why I didn't pursue that trigonometry degree.

Actually, yes, it looks like they are actually the same number around 5250 now.

Thanks Sharpshooter!

 

Good eye !! Thanks !!!