How accurate do you think they really are? Curiosity got the best of me today...since I haven't had a chance to dyno the Sierra since the latest round of mods, I wanted to get a general idea of what it could be putting down.

Wow.....going by mph, at 4430lbs:

13.91 @ 101 = 356hp (almost exactly what I dyno'd b/f it went to Speedfab)
13.19 @ 107 = 424hp (motor ET and MPH after the mods)
11.57 @ 118 = 568hp (N2O ET and MPH after the mods)

Could I really be pusing over 550rwhp?! I guess that's about what it takes to get that much truck moving that fast, but it never even dawned on me until I was messing around with the calculators today.

What I really don't understand is the 70hp boost on the motor #'s. There was no tuning done, and the only thing that changed was the exhaust (single stock pipe to dual 3" mandrel bends). I had the 20's on for the before dyno pull...maybe they soaked up more HP than I thought?

 

I think they are pretty acurate. It is just a symple physics calculation. There are many variables there not calculated though like tire slip, head wind, time lost during shift & how hard you launch(mainly with a straight shift of course). Yeah, they are acutate, more acurate than some rear wheel dyno's.

 

Yeah, there are so many variables... I figured you'd be more close to 480rwhp with the hundred jet. Are you goin' to have it dyno'd any time soon?

 

Hopefully soon. I just have to find some time to get reverse fixed and then it's off to get tuned!

 

You going to dyno in reverse or something?
That's no stinking excuse! get it to the dyno!

 

No, but I need reverse to get it on and off of the dyno at HP Performance here in town. Trust me, it will be MUCH easier w/ reverse.

 

not close in my case.

 

Yeah, I just can't see a cammed LS1 w/ bolt ons and a 100 shot putting 550+ to the tires. That would be 625+ at the crank. Something just doesn't add up to me. I guess I just need to put all the estimates and calculators away and go for the dyno itself, huh?!

 

13.19 @ 107 = 424hp

I went 12.58 @109 with 431rwhp(dynoed) and my weight was probably around 4500? The mph isn't far off from what yours was. I had the spare tire, towing hitch, toneu cover a small tool box in the cab, and 275/55 20's on the front. Whatever weight you think that is and I weigh 240.

 

yup, it said i was 550ish too, i was actually 416/478