Which gear to run auto trans in on dyno?

[nicpaige]

Going for a baseline dyno on the tired stock engine tonight and was wondering what gear the pull should be done in?

[Cheromaniac]

Third gear would be preferable but if your tires aren't rated for 100+mph speeds, you might have to use 2nd.

[nicpaige]

Tires are rated for 100mph.

[jeepxj3]

3rd is best but when you floor it WOT it will down shift into 2nd. PITA. If you had manual shifting then you could have the trans in 3rd and stay there. Because of this, you might have to use 2nd gear. 3rd you might hit the speed limiter before you hit your max rpm.
Dynoing an auto is a pain. Can't wait to see your numbers.

[nicpaige]

BIG NUMBERS... after 247,000 miles this power plant put out 135 HP and 177 TQ to the 31.50 tires on a DynoJet dyno. Stock everything. Now time for this engine to take a well deserved rest.

[SilverXJ]

I did my 4.0l in third as well.

With a 60mm throttle body, 0630 head, header, cat back, HAI, 30s and stock gears mine did 149RWHP/183rwtq on a DynoJet with a slightly rich fuel trim.

[nicpaige]

This has been a great motor. It will go on the shelf as is for a backup. Burns no oil, runs great just a little noisy on cold startup.

[Cheromaniac]

BIG NUMBERS... after 247,000 miles this power plant put out 135 HP and 177 TQ to the 31.50 tires on a DynoJet dyno.

Sounds just about right for a stock 4.0 automatic in 3rd gear.