I have noticed a trend. It seems when people dyno in 3rd gear the numbers closely resemble GM's numbers. When people dyno in 4th gear the numbers seem a lot lower than what GM quotes. Here is an example.

Chevy claims 245hp with GM stage 2

My 3rd gear dyno yeilded 242whp.
A 4th gear dyno yeilds about 225whp.

I know a 4th gear dyno is "more accurate" but how much more accurate is it when 3rd gear pulls closely resemble Chevy's numbers?

 

You only dynoed 225whp in 4th with Stage 2 and your mods????

I was closer to your 3rd gear pull in 4th with Satge 2 being my only mod.

 

my third gear and 4th gear pulls had no differances, except 2 extra tq.

 

I'll know saturday when I go dyno again

 

just intake on mustang dyno(4th gear), i think i have highest numbers on here with just intake mod

 

No when I went and dyno'd my car I only hade GM stage 2 and the Injen CAI.
242whp. 3rd gear pull.

I have seen other guys with just GM stage 2 and a CAI putting down 225ish. 4th gear pull.

 

Is that 3rd or 4th gear?

Here is my 3rd gear pull.

 

4th gear

 

Why did you guys stop at 5,750 rpms? Nice numbers BTW.

 

did 3 runs that was best one, and we stopped at that RPM because you can see my power was going down after that, dont know why?? but was not gaining any more power past that, (HAD C.E.L. ON FOR RUNNING LEAN W/ INTAKE) maybe thats why not making power past 5,750????

 

Yeah it could have been. Cool. So there is still the question, 3rd or 4th gear pulls?

 

4th gear no doubt

 

I just don't understand dynos. They give such different numbers for the same mods.
yeah I know every car is different but not that different. It's all the same parts.
Yeah I know elevation plays a part too.

 

i understand, beats me man, it is confusing why numbers are soo different, but all i know is i am happy with my number but we will see when stage 2 is on, what numbers i get then, it is sitting in my room now!!!

 

Sounds good. Congrats on stage 2, you will love it. I'm going to dyno again too now that I have some other mods. This is too adicting....

 

Just so you guys know GM quotes that HP at the crank, not at the wheels. To that effect, if you're running 3rd gear pulls and hitting 240whp, you're really at or around 276 hp at the crank which gm rates theirs at 245 hp to the crank. Now a 4th gear pull of 225 whp is approx 258 hp to the crank which still shows you beating GM's figures, but not by as much.

We already know GM underrated our engines, I'd expect to see that same philosophy with the stage kits.

 

Very true. These motors are so underated I don't even know if GM means 245whp or 245 at the crank. If they mean at the crank then 4th gear pulls are the way to go.

 

i dont reccomend this company anymore!

I hade 250 whp with intake exhuast

i put a header on i then had 198 WTF? now i have stage 2, high flow cat, 2.8 pulley

ill prob make 200 hp lol ripped me off never again

 

It isn't that the cars are so different it is that the dynos are set-up that different. Like any equipment it needs to be calibrated every period of time and I am not sure many dynos are....

Put 2 cars with similar setups on the same dyno one after another and you may see small differences.

Also the 3rd vs 4th should not be that different unless the dyno is f'ed up.....Many people have shown this, sheik above and i know there are a few others on here who have shown both to within 5 hp.