let us take a vote

[BlackGT97]

so i already started gathering parts for a topswap. now i have a 97 and that is the issue.

should i keep the car and replace the trans
or
sell it and get a different gt....and no im not getting a gtp lol


also. if i put the supercharger on with the 4t60e trans and keep the hp down to like 250hp (crank) and drive nice...will it hold up at all?

[Bio248]

the problem is that the 4t60e doesnt know what to do when there isnt VACUUM applied to the transmission (boost is the opposite of vacuum). therefore it doesnt know when to shift, because it isnt seeing vacuum.

you seriously need to swap in the 4t65e, or let off the gas when you want to shift.

[BlackGT97]

the problem is that the 4t60e doesnt know what to do when there isnt VACUUM applied to the transmission (boost is the opposite of vacuum). therefore it doesnt know when to shift, because it isnt seeing vacuum.

you seriously need to swap in the 4t65e, or let off the gas when you want to shift.

you know what bio..now that i know this, i feel like a real dumb***.lol

[BlackGT97]

just curious though. some of the series 1 3800s were supercharged and used the 4t60e hd trans. How did this work out?

[KeithGTP03]

Im pretty sure all GTP's had the 4t65. The 4t60's were designated for the L36

[BlackGT97]

the 92-96 bonneville used the 4t60e transmission and it was supercharged. after 97 they used the 4t56e trans according to good ol' wiki

[Scottydoggs]

cant you just toss a HD diff into your trans, tune for the new gears and call it a day?

i think i read that somewhere, not sure if im right tho.

[BlackGT97]

again, going back to bios post. i am simply confused.

[Bio248]

it will work, yes. however, it takes some tuning to get it to work right. lots of guys have issues and it is just easier to swap the 4t65e in.

[Scottydoggs]

swing and a miss! i tried.

[ctracer]

just swap the damn tranny lol its your safest bet