edit-that should have said ET and not RT above...

What would the following MPH's equal for ET's, all things being equal (I realize this is an estimate)?

100mph, 105mph, 110mph, 115mph, etc, etc...is there a rule of thumb I could use? I hear a lot of people talking about running a mph, and others saying, "you're mph says you should be running xx.x time". Just wondering...

Originally posted by SS_Sean:
edit-that should have said ET and not RT above...

What would the following MPH's equal for ET's, all things being equal (I realize this is an estimate)?

100mph, 105mph, 110mph, 115mph, etc, etc...is there a rule of thumb I could use? I hear a lot of people talking about running a mph, and others saying, "you're mph says you should be running xx.x time". Just wondering... I think if you are talking about a certain car and weight you can guesstamte what a car's potential et can be. But you can't really put a label on mph and ets because of different car weights and their hp/torque ranges. You might say that cars in the 100mph range can be capable of mid 13s in a 3800lb car.....BUT....you put that same motor, or horsepower figure, in a car that weighs, lets say 2600lbs, the et will obviously be different....maybe high to mid 12s (just an example...nothing specific)......but if you want something that you can "classify" what a car can potentially do....then cars that are in the 100mph bracket can be around high 13s, 110mph bracket can be in the low 13s/high 12s, 115mph bracket mid to low 12s, 120mph 11s, 125-130mph high 10s.......again, nothing I've previously stated is exact! Everthing depends on factors....car, weight, driver, weather, etc. From cars that I've seen run I think you can ROUGHLY guesstamate a car's potential by "loosly" refering to the figures I've stated. I hope I've helped out some. smile.gif

I've got some formula's that work good, and yes, you can. The main variables with a given HP (or trap speed) is traction and proper gearing.

The best thing to do is take a look at the records for all the NHRA stock eliminator classes. That just about tells you the best ET for a given MPH, granted they optimize gearing and traction.

Some rough rules for street/strip cars with reasonable gears and traction:

100 MPH - 13.0-13.5
110 MPH - 12.0-12.5
120 MPH 11.0-11.4

I've gone 11's with 111 MPH in my street/strip car.

With real street tires, forget all of that.

That's close enough. Thanks. I know it's an exercise in futility but there is a method to my madness...

Personally I think there are to many factors to take into consideration to really estimate it much. Basically the MPH is related to the amount of horsepower a motor puts out. Unless you really screw up a run (miss a shift or what not) your MPH remains pretty consistant once you have your car dialed in. There are a lot of variables that affect your ET, to name a few: gearing, transmission, weight of the vehicle, traction, 60' times, altitude and driving style.

Just for the heck of it I ran on small radial street tires the other night. The best I could go was a 12.69 at 111 with a 2.07 best 60'. With my ET streets I'd have gone 12.0's at 111 in the air. That was running 10 degrees of timing with my EFI up to 4500 RPM with a 4000 flash converter. Was a real chore not to really annihilate the tires even with no timing.

MPH is power related and I like to think of ET as being more about efficiency. If your car makes 450hp on an engine dyno but only runs 14.0s when it "could" run 12.0s, working on the drivetrain and suspension should help alot. If it runs 12.2s tweaking the suspension may help a little, but adding more power is probably your best bet in making it go faster.