Dyno tune transmission issue

modular46

Member
I am trying to dyno tune my new setup and when I have it in 3rd gear at 2500 Rpm it down shifts into 2nd gear. Even trying it from 3000-3500 rpms the car down shifts.
I saw a youtube video with another guy having the same problem with his Grand National. Anyone else have this issue?
 

750H.P.V6

Brutal 6 Racing
If the car still has the 2004R trans the detent downshift you're describing is a function of various pressures in the valve body including TV pressure, governor pressure and MTV downshift pressure. None of these are adjustable as the valve body is strictly hydromechanical. There could be slight differences between vehicles based on transmission mods, shift kit installation etc. but unfortunately I don't know of a way around what you're seeing.

Neal
 

Turbo6inKY

Short Guy
If the car still has the 2004R trans the detent downshift you're describing is a function of various pressures in the valve body including TV pressure, governor pressure and MTV downshift pressure. None of these are adjustable as the valve body is strictly hydromechanical. There could be slight differences between vehicles based on transmission mods, shift kit installation etc. but unfortunately I don't know of a way around what you're seeing.

Neal

There is no way around it. Some will disconnect the TV cable thinking it's a kickdown, and quickly destroy the transmission.

The solution is to start the dyno run above where you'll get a kickdown to second. Pretty much starting at ~65mph and running it out to 110
 
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