Which transmission should I go with? [Archive] - GrandAmGT.com Forum


View Full Version : Which transmission should I go with?

06-29-2008, 10:36 AM
Im in the process of buying two transmissions right now, but havent completely followed through on either. Just looking for some serious opinions here. Before anyone suggests it (not saying names) I will not even consider building a 4t45, end of story.

My two goals for the transmission upgrade are long term reliability behind a powerful motor (300+WHP), and second to that would be improving 1/4 mile times as a result of gearing etc. This is with drag racing in mind only.

Option 1: Getrag F40 6 speed swap. This is the swap that tim did.
The cost of all of the parts is somewhere in the neighborhood of $1500-$2000 plus any other fabrication materials needed for mounts
Pros: Better gearing, has been swapped into a lot of v8 fieros and can hold power, lighter than stock trans, less drivetrain power loss, fun to drive
Cons: Some hard to find parts, custom fab. of mounts, and Ive only driven stick a couple of times.

Option 2: Intense Built 4t65HD with 3.69 gears, 7/8ths chain, 3000RPM stall, shift kit, upgraded clutches, hardened input shaft, and a new valve body. The transmission is $1900 (I can probably get him to knock $100 or so off)
Pros: Better gearing, proven to handle some big power numbers, aftermarket support from numerous vendors, I couldnt touch the same build on a 4t45 or 4t65 for the price
Cons: Custom mounts, need to adapt wiring, slightly heavier than a 4t45, not sure what axles will work.

06-29-2008, 05:15 PM
i vote for 6 speed. driving stick isnt too hard. i guess it depends on how much power you plan on having and if the 6 speed would need to be upgraded.

06-29-2008, 05:25 PM

06-29-2008, 05:28 PM
thanks for the input guys, the 6 speed seems to be the general concensus

06-29-2008, 05:30 PM
4t65HD built

Just 1 bit of advice from experience,

Do Not get the LSD from Intense!!!

06-30-2008, 07:19 PM
I bought the 4t65 guys. Going to pick it up tomorrow.

4t65HD built

Just 1 bit of advice from experience,

Do Not get the LSD from Intense!!!

Werd. Ive heard too many horror stories. ZZP uses the stock HD diff in their drag cars.......

06-30-2008, 07:32 PM
congrats on picking it up. hope the install works out for you.

06-30-2008, 07:59 PM
congrats on picking it up. hope the install works out for you.

Thanks. After consulting a few people, and doing some thinking, I think the automatic wasthe better choice. It should go in with minimal difficulty

06-30-2008, 08:09 PM
excellent choice man :)

im yet to see zzp's tt gp run :( they broke the drive shaft at MGM :(

06-30-2008, 08:10 PM
when you do this install writeup if you do one..make sure you take alotta pics and jot down alotta notes..im in a debate also with what trans i want to go with...i dont need to d.d the g.a anymore so i can start thinking about this kinda stuff...lol

03-29-2012, 05:20 AM
Yea the 6 speed in our car.would be pretty damn fun to drive but it would take a lot of custom work and time and money with that project. Good choice on the 4t65.

03-29-2012, 06:12 AM
Thread is 4 years old and OP no longer has his car.
But there are a few other 6-speed swaps around.

03-29-2012, 06:42 AM
like me ;)

Matt, i like how we both have Black GLS sedans haha. and you have a razzi kit, honestly.. everything done to your car is where i plan on going with mine. its weird ive already had all the stuff you have, planned out for mine (brakes, seats, body kit, etc.) basically i can look at your car and see my how my car would be in the future lol.

03-29-2012, 10:35 AM
What is up with the crazy thread revivals? Guess it could be from the sudden influx of newbies.

04-10-2012, 08:28 AM
I'd rather have them bump old threads than start new ones!