AmericanSpeed

Damn, first I have to give you some props for pulling 1.5x short times, thats awesome. As far as rwhp, its hard to say, what temp & track alt were you at? I'm guessing 470 wheel. I'd guess that you'd be less with the 4r70 but you should make up for it with the short time. My entire point is that who cares what anyone dynos, shoot I could get a dyno graph that shows 1000 wheel, but what I'm trapping in the 1/4 will show how fast my car is. If your car is trapping more, then you know the pulley upgrade is doing you right.

What psi were you running on those slips?

mygt500

Your running 11.6 in the 1/4 mile.....now that is real good for 450 RWHP. I know the excellent 60 ft time helps but I think based off that time you may have a bit more HP then that.... I am running 11 psi Whipple H.O. Gen 1, 60 lb injectors and the GT500 dual pumps, and 17 deg timing (or was it 19) on the stock block, and have 465 RWHP. Pretty sure it was 17 degrees but not 100% on that......no dynos are the same and your A/F ratio is great so no worries....how does the butt dyno feel and your times are very nice IMHO.

You car is set up different then mine as I am running heavy 20's and know I can run low 12's or very high 11's in the 1/4 (most likely 12's)) and I have a totally stock tranny and suspension setup right now....

So basically I am baffled.....maybe pose this question in the street strip as those guys run their cars and dynos don't mean much when it comes to real world application and at the track.
Want me to move this thread there just shoot me a PM

moosestang

I only dynoed 404rwhp. Your altitude is going to affect the dyno numbers, just like it affects the track numbers.

Do you have the stock throttle body?

hotairgypsy

i am running a gt500 TB on the car. i know the 4r70 is stronger tranny and now i can beat on it a bit more. do you think that it lowered, kept the same, or helped my HP numbers?

HaneyMotorsport.Com

You are going to have more loss with the 4R7W, compared to the 5sp or 5R55 auto. A dyno is nothing but a tool, so you will see different #s from dyno to dyno.

I would say it does seem a little down on power though. Our car will trap 118 (cool engine), 114-115 hot lapping. It has a 3.4 pulley...about 8.5-9 psi.

Tell that track to include 330 and 660 marks.

Also, converter size, stall and flash will affect HP #s on a dyno.

Casey