gear shift and the dyno
 

How would you use the dyno sheets to help determine what to shift 1st to 2nd and then 2nd to 3rd in a small block stocker? We use the dyno sheets as a guide for the converter stall, is there a formula or guide for torque & HP in relation to shift points? Then it will be time to test that theory. How does everyone determine before testing what to shift at their cars at?

Re: gear shift and the dyno
 

this is a very good question, i use peak tq to figure stall speed and peak hp for shifts
and then look at the playback to see where motor falls back to after each shift and
adjust accordingly. P.S. Joe you have p.m.

Re: gear shift and the dyno
 

Ron, I have PMed you back.

Re: gear shift and the dyno
 

Dyno with shift simulator.. This is cool!

http://www.youtube.com/watch?v=7py-d7arEnM

Re: gear shift and the dyno
 

Joe,

The way I do it is to determine the RPM drop going from 1-2. Then look at your Torque curve to find the peak and also see how flat the curve is around the peak. I take the net rpm difference and overlay that around the torque peak to try to take as much advantage of the flattest part of the torque curve when the engine is recovering from the shift. For the 2-3 I would run the car out closer to the HP peak using the same RPM Drop philosophy.

Re: gear shift and the dyno
 

Superflow says about 10% above peak, on glide that work pretty good,but 3 spd. or stick is a little much for low gear, what I always have found is usually shift low as soon as can without bogging then second close to peak to about 10% above peak hp rpm.
Like everything else depends on lots of factors,closer ratios are together less you'll need
to stretch out that gear,most cases the sooner you can get in high gear the quicker it will be.
Mike Taylor 3601

Re: gear shift and the dyno
 

Joe, here is my theory. First maximize the HP put to the track in high gear by gearing the car to go through the eyes at approx. 10% above the dyno peak HP rpm. Next choose a convertor that flashes 150-250 rpm above the dyno peak torque rpm. The 1-2 shift is done at the track by testing. Shifting early (below the peak HP rpm) takes you back into torque multiplication in the convertor while in the high torque rpm's. You are trading HP for more torque at the wheels early in the run. This usually helps ET. The 2-3 shift should be such that the engine falls to approx. 10% below dyno peak HP rpm. The result is that high gear (the one you spend the most time in) goes from -10% to +10% of dyno peak HP rpm.
Testing is the hard part. You need good shift points and good data (air shifter and data logger) as well as good traction and a good valve train.
Good luck, Vic

Re: gear shift and the dyno
 

Vic you have a pm.

Re: gear shift and the dyno
 

Who makes this for engine dyno ?

Re: gear shift and the dyno
 

That looks to be a Depac dyno systems controller.
https://www.depac.com/loadcontrol.htm