Beefing up the V6 trans

[ant02sev6]

I'm new to this pontiac scene :) but after a little searching I have found that this transmission is kinda weak, so I would like to know what my options are to beefing it up. Is it better to get a recalibrated VB and a stronger torque converter? Or does the GTP tranny bolt up? And the GTP has an LSD if I belive, correct me if I'm wrong. Thanks in advance.

[TA^Guy]

GTP transmission does not bolt right up and as far as I know they also do not have limited slip, however you can install a limited slip differental in them.

[MantaGreen97]

In 1998 GM started using the 4T40-E and 4T45-E transmissions in V6 Grand Ams. Prior to this, Grand Ams (1994-98) were using the 4T60-E transmission which was the one used in W-Bodies like the GP (4T65-E in the GTP, no LSD as mentioned by TA Guy above).

As pointed out, above, the 60 series transmissions will not fit a 99+ GA which were designed around the 40-series.

However there should definitely be companies out there that offer heavy duty rebuilt 40-series transmissions as well as ones with LSDs installed, that would be appropriate for your GA. Alternately you could find a local shop to [re]build you one as required...

[ant02sev6]

Ok thanks, for some reason I thought it had an lsd... Glad you cleared that up for me. I thought it did because the GTP has one of the fastest 60 foot times around for front wheel drive cars. Does the GT and SE transmission differ in anyway? gear ratio, strength ect.? thanks

[quadkid]

i dont want to hijack, and i dont want to start a new thread, but are there any companies out there that make a manual valve body for the GT's tranny? If I cant have a manual V6, a manumatic would be sweet.

[Pte Socks]

I know you can picked up a HD 4t-45e from a website, I just cnat remember which one. I also know an LSD on that same website runs about 550$

[ant02sev6]

550 for an LSD thats amazing, this car is not too expensive to mod at all

[ant02sev6]

550 for an LSD thats amazing, this car is not too expensive to mod at all

[Azrael]

I think it was http://www.domesticperformance.com but last I heard their website is down untill spring/summer...if it ever returns at all.

http://www.engineered.net makes the LSD in question and you can order straight from them but there's a long wait for the product.

[matts]

Originally posted by quadkid
i dont want to hijack, and i dont want to start a new thread, but are there any companies out there that make a manual valve body for the GT's tranny? If I cant have a manual V6, a manumatic would be sweet.


you ever drove a fully manual valve body? they're fun for a while, but they get old. if you haven't ever drove one just imagine having to shift every gear manually ALL the time. you dont shift it out you'll burn up the clutches in the tranny.

not trying to be a dick, just tryin to warn ya before you get something you might not like

[ant02sev6]

The PCM upgrades say they increase the line pressure, does anyone know if this means the tranny will be shifting at full line pressure at WOT? or is it just slightly higher pressure. If so with that and a torque converter you should be pretty set. Messing with the valve body will make it shift hard all the time, probably would get old.

[slowbird]

Does the GT and SE transmission differ in anyway? gear ratio, strength ect.? thanks

GT trannies have a bettter FDR than the SE.

As to the tranny swap question....I really want to do a Manual swap.

The only real hard issue is getting Custom Axles made. Otherwise...a Custome Tranny Mount, tuning, and the Manual Tranny from 2nd Gen V6 J-body would work great and hold all the power you can throw at it.