Best way to dyno a auto?

[BLACKCAT]

Just wondering what is considered the most effective way to dyno a auto.

With mine (7M Cressida) they always just use 2nd gear starting in a rev range just outside where it would kick down to 1st, usually around 3500rpm.

Would it not be better to disconnect the auto kickdown cable so you are able to use wot from a much lower rpm say 2000?

 

[IJ.]

We don't have a "kickdown cable".....

It's a line pressure cable, kickdown is done via the ECT box and the TPS/Speed input.

Unplug the ECT then manually shift it to 3rd gear (2 on the shift)

this is the 1:1 gear and will give an accurate pull.

Some operators don't like this as it's done at a high wheelspeed.

 

[amichie]

I could bodgy up a switch for you that lets you manually select 2nd gear. Also you may want to manually lock up the torque converter. At our last dyno day it gave an extra 5rwkw with the torque converter locked.

I have another spare ECU at home that could be set up as above.

 

[IJ.]

Biggest hassle is the thing kicking down unexpected
(that's why the unplug the ECT suggestion)

 

[amichie]

Biggest hassle is the thing kicking down unexpected
(that's why the unplug the ECT suggestion)

The cressida engine ECU and the gearbox ECU are in the same box.

Do you mean unplug at the gearbox end or at the ecu end?

 

[IJ.]

Ahhhh sorry!
(was thinking Mk3)

You need some way to fault the ECT so it goes into Manual mode then.
(Unplugging the Trans end would work but then you lose lockup as well)