Question for the Dyno GURU's

D

DieselAddiction

New member
Hello,
Have a question for those that dyno a lot. What gears do you use for all the makes when you do a dyno run.
Dodge, chevy, ford, ( 5spd, 6spd, auto,)
Can someone tell me what gear to use to make a dyno run in all these vehicles.

:thankyou2:
Thanks
 
My 96 is always done in 5th, (5-speed), and the 04 is done in D. It doesn't get rolled into until the TC is locked. 6 speeds are usually done in 6th.
 
Depends on the type of dyno.

Load dyno, whatever is 1:1

Inertia dyno, overdrive or the highest gear.
 
I wanted to help the dyno operator with this info, because he does not deal with diesel trucks. I just wanted to get as close to correct numbers for everyone as possible.
Thanks
 
Chevy/GMC, Duramax, Allison, 4th gear for all years. T/H on, OD locked out and use a Tech II or EFILive to select (lock in) 4th gear. Other wise it will shift. It can be done without the TechII/EFILive, but it takes some practice to keep it from down shifting.
 
Most all automotive transmissions have a 1:1 ratio, and normally this has the least gear loss. This is 4th on the Dmax Allisons, and 5th on the ZF-6's. Should be 3rd on 4-sp transmissions. Think it's 4th on the Ford 5-sp.

However. Tireslip and spin goes down as MPH goes up. And on inertial dyno's they can't simulate real world engine load, hence can't get the charger to wake up.

I've dyno'd Casper in both 4th and 5th, and there isn't alot of difference on a loadcell like a Superflow. My last pulls were 4th on a Mustang.

We dyno'd Wendy on Monday and did a pull in 5th for a sanity check, and both gears dyno'd the same within 2 rwhp. We did the pulls in the 4th anyhow since we were going to use the numbers publically (533rwhp and flat) later on in a comparison test. Some people think there is a nitrous jet located in the O/D ratios that skews the numbers. I've seen many of these transmissions apart, but cannot find it yet. It must be pretty small, or I need glasses.
 
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