1/4 mile time?

Flying Fridge

New member
Aug 20, 2017
20
0
0
Sterling, Illinois
Is there a formula to figure out the 1/4 mile time from a torque number on a chassis dyno and the weight of the vehicle? I'm going to chassis dyno my vehicle but they don't have the correct hookup to do horsepower, just torque.
 

ZeroGravity58

Well-known member
Mar 23, 2008
1,382
46
48
38
Maryland
Is there a formula to figure out the 1/4 mile time from a torque number on a chassis dyno and the weight of the vehicle? I'm going to chassis dyno my vehicle but they don't have the correct hookup to do horsepower, just torque.

Yea...take it and run it down the track. Then convert your 1/4 time to horsepower. Works alot better.
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,681
236
63
Boise, ID, USA
If you are on a "tough" chassis dyno, it will match pretty close with your 1/4 MPH. The ET is all setup & track prep, I never get ET as low as the calculator says, but MPH comes in really close.

The other thing to remember is the HP calculator wants the average HP down the track, not just peak HP. Remember your engine is not at peak HP for the whole run.

For example, my truck put down 660 HP on the Northwest Dyno Circuit chassis dyno, but my track MPH calculates out as ~605 HP. With my peak being 660 HP, I can believe that the engine averages 605 HP as the RPM goes up and down with the gears.