Beretta.net

Ryan...can't do the "e" in our cars without ALOT of modification...the "e" is the designation for the electronically controlled transmissions. There are non-"e" versions of the 4t60 out there however. I wish i could answer your question, but it has been some time since i poured over the info that i found regarding the differences in the gear and final drive ratios compared to the 3t40's that we currently have.

True, I had forgotten that little snag. Yeah, they would require the computer change, harness work, yikes.

In fact...if you can find a turbo grand prix, THAT is the non-e version you want...or the "F7" version out of a Cadillac Alante'.

ronaconda wrote:In fact...if you can find a turbo grand prix, THAT is the non-e version you want...or the "F7" version out of a Cadillac Alante'.

chad91gtz has a TGP auto tans for sale right now actually!

I made this chart a long time ago to compare my gearing and Eric's. You can achieve a higher ratio in first than you can in a 3t40, so you will have better starts off the line.

There is a 4t60 in the Hot Indy Pace cars too... I couldn't remember if it was an E or a mechanical one. I'd have to re-check my illegal engine bay pics to see if I snapped a shot of a plug on the front.

Info from a guy who did one on a Fiero...

http://spacecoastfieros.com/tech/440-4T60/

97-90 Buick Park Ave's, LeSabre, Reatta, Riviera, Oldsmobile 88, Pontiac Bonneville, stuff like that had the 4t60. As noted on the Fiero website 87-90 is what your looking for.

TH440 is the technical code your looking for too, 3 speed is a TH125C

You know something, I just realized I must know nothing about the gearing. That file made absolutely no sense to me! lol

There are three different choices for gearing from the motor to the main drive of the trans, so thats the Input gearing... It can be
1:1
1.12:1
0.89:1

Then you have the ratios of the individual gears themselves... and then you have 3 options for a differential... 2.84, 3.06, 3.33. In 95 they changed those numbers to 2.86, 3.05, 3.29 because they changed how the gears were cut. They changed that again in 96, but kept the same ratio, so you can only use a 95 diff in a 95 and 96+ is specific to 96+

SO that gives you 9 different final drive ratios you can run... I just multiplied all of those options by each gear in the two types of transmissions to see the full gear spread.