Hold Switch On The Automatic Gearbox

[Nic_A31]

technically overdrive isn't a gear in itself. it's a modifier on the 3rd gear. But for the purposes of a dyno, it should be left off to be a 1:1 ratio.

Yes and no.

5th gear in manual transmissions is also a higher ratio than 1:1 as well

[Sarumatix]

there is a bunch of plugs in the front left side down a little disconnect the brown plug will lock it in 3rd for dyno run so it dont kick back to 2nd

hope this helps

Yup this is exactly what I was referring to.

[Lum]

Neither pulling that fuse, or disconnecting that plug (which would be a pain in the arse to do at the rolling road) would lock up the torque converter though, would they?

Any easy way to do that?

[Sarumatix]

No.

Can I ask why you would want to?

[Lum]

No.

Can I ask why you would want to?

To stop the torque converter interfering with the dyno run?

[Sarumatix]

Interfere isn't the right word.. it's an integral part of your automatic transmission. It makes a lot more sense to tune with it running.