3.08 to 3.42

[David8399]

i changed my rear end the other day to one with a posi and discs out of a 97 z28 and i am wondering if anyone knows why and how much diffrent the torque convertors are in a car with 3.08 and a car with 3.42. what i do know is that the torque convertors on a z28 are diffrent from those in the 3800 cars, also the convertors are diffrent because they have diffrent part no's. i thought the internals of the transmission were diffrent but after going through part no's the diffrence is in the convertor and i am wondering what it is. should i be looking for a 3.42 convertor is it a better performance option over the convertor in the 3.08 cars? maybe just something to help people out later as a cheaper performance mod.

[cam98aro]

Re: 3.08 to 3.42

the different part number converters is due to the different size flexplates they used between the lt1 and 3800

they are probably around the same stall (stock) which would be in the neighborhood of 800-1500rpm (just a guess)

[vanbibber]

Re: 3.08 to 3.42

stock stalls are all 1800

[David8399]

Re: 3.08 to 3.42

the different part number converters is due to the different size flexplates they used between the lt1 and 3800

they are probably around the same stall (stock) which would be in the neighborhood of 800-1500rpm (just a guess)

i know the lt1 and 3800 have diffrent flexplates and convertors and transmissions. the torque convertor for a car with an l36 and with 3.08 is a diffrent number from a car with an l36 and 3.42. gotta be something in the stall i would guess.

[Shodown]

Re: 3.08 to 3.42

If you change gears like that you dont have to do anything with the torque converter. Your stock TC is fine with new gears.

[ssms5411]

Re: 3.08 to 3.42

I went from 3.42's to 3.73's and the converter is fine, it moved my shift rpm up from each gear which is what I wanted. I'm always above 3000 rpms when it shifts at WOT. Also every converter is not the same in stall, I can brake stall mine at 2200 rpms this is with me not really mashing the brakes. Once I get my Earl's brake hoses on. I'll really see what I can stall it to. HPtuners plays a great part too. You will have to have your computer flashed for the new gears because it will mess up the transmission shift points if it is not programed right for the gears. It will try to shift early. I think thats what mine was doing before I reprogramed it.

[David8399]

Re: 3.08 to 3.42

i went from 3.08 to 3.73 then back to 3.42 with posi and haven't had any trouble. just wondering what the difference is between the two converters. why would gm use a different converter on a car with 3.42 then on a car with 3.08. guess i am gonna have to call generous motors and ask.

[ssms5411]

Re: 3.08 to 3.42

When switching gears did you have your PCM flashed for the gears, like hptuners? If not the car will have problems shifting.

[kristen]

Re: 3.08 to 3.42

yes your speed - o will be off

[ssms5411]

Re: 3.08 to 3.42

More than his speed will be off, he has a auto so all the shift points and TC functions are all going to be off. I wouldn't run the car with out the proper tune , it is going to cause more stress on the tranny.