Torch Red GT

By lower i meant steeper gears. For example if a car had 3.55's and put down 305 rwhp and 320 rwtq and then swapped to 4.10 and went on the dyno again it would read less, but the car wouldnt really be slower. This is why people say dynos are nothing more then tuning tools and real world results at the track is what matters.

SpartaPerformance

I don't know what to tell you about your tune but judging by your E.T.'s something isn't right. I don't have cams or gears (3.31:1) I ran a 13.0@107. So something doesn't add up, I don't care if your 1,000 feet above see level and it was 100 degrees out you should run better then what you're running.

Gene K

His track is something like 5800' ASL and the DA on those passes was well over 8,000'.
I havnt done the math to know if he is running good or bad but 1,000' and a hundred degrees isnt even in the same hemisphere.

BlownNBagged

those numbers sounds about right to me...hmmm

Snakebite64

Well put. As far as dyno's I will never go to one as I am fine with what I have. A machine telling me I have 400 rwhp is not making the car any faster but going down the 1/4 with mods and the times will tell me everything I want to know.

Socal6r

i have detroit rockers and thats about what i dynoed at. was disappointed.


Nick

jahudso2

yeah running 14s in the 1/4 would net less than 300 rwhp. Move somewhere closer to sea level or get a turbo to make up for the thin air

pinche_maniaco

well i had mine done on a DynoJet and i got
RWHP: RWTQ:
28663 290.14
283.78 287.51
286.68 292.39
ive got C.A.I., T.B. under drive pullies, short headders, x-pipe with highflow cats,frpp stingers, and a 87 tune that came in the tuner.

Nuke

I'd bet you'd pick up another roughly 10-15 RWHP with a custom 91 or 93 octane tune over that canned 87 tune.

dkersten

So in order to be accurate then, you would have to also have the same tire diameter on every car. Sorry, not buying it.

The dyno is hooked to a plug wire (or coil wire) to determine engine RPM, and that is factored to the revolutions of the drum to correct for any final drive gear ratio. The torque is going to be a function of force over a "distance" (determined by the revolutions of the drum and the diameter of the drum) after the correction factor is figured. The taller the gears or greater the diameter of the tire, the less force, but also more distance, so the end result should be the same. If the engine RPM was not considered, and only the revolution of the drum was accounted for, then shorter gears (higher number) would mean MORE torque because you would be putting more torque to the ground over a shorter amount of time. However, without an engine reference factor, it would be impossible to give an actual torque number.. the dyno would have to be calibrated for one gear ratio and one tire diameter and everything else would just be wrong.

You use a 1:1 transmission gear when possible so you can get the longest pull possible without overdriving the speed of the drum. The longer the pull, the more accurate the results. Most overdrives will run the drum too fast.

And for what it's worth, track times are only relevant if conditions are the same, just like a dyno. You go run on a perfect track in 60 degree weather with a slight tail wind on a zero humidity day at sea level and you will always outperform the same vehicle at a higher elevation, higher humidity, higher ambient temp, or crappy track conditions. What really matters is if you like your car's performance or not.