• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Transmission upgrade

king04305

king04305

New member
Thanx in advance for whoever replies with help


I have 2005 grand prix with 24 inch rims,on it...,yes im fully aware their bad for the car. However they arent coming off, also I drive the car pretty aggressive... My first transmission lasted 122 thousand miles. So I ll say probably about 15 thousand with the wheels on. In the near future the car will have a rocker, plog, downpipe setup hopefully running e85... Looking to find out what tranmssion upgrads I,can do to extend the life of my currwnt transmission
 


Just throw a cooler on it to start. The reason bigger wheels are harder on it, is because you're basically changing the ratio. So it's harder for 1st gear to get the car moving. It being harder, makes the torque converter work harder(creating more heat) You need to be able to disperse more heat, so a cooler is a good idea. Especially if you're a maniac.
 
I'm dealing with a few too many other cars currently, can't remember if all GP's were 3.29 if they aren't charged or not. If you aren't supercharged, you may be able to change the differential (and programming) to lower your gear ratio and help it out. That with a cooler and shift kit in the accumulator I'd think that's about all you can do on the current to help it.
 


There's plenty of upgrades you could do if you were having one built.

I'd start off with saying TEP would likely be your best builder. They take the time to talk to you and understand your ideas/goals then match trans upgrades etc to your build. I'm not aware of many others that do that.

In that case, I'd automatically say.. look at your tire size and how much % it's different than stock and consider making up some of that with a gear ratio change. Afterall the manufacturer uses many different variables in building our cars and the biggest single things they do in the trans to mediate less power, larger tire size, etc are torque converter stall and gear ratio.
 
BillBoost37 said:
There's plenty of upgrades you could do if you were having one built.

I'd start off with saying TEP would likely be your best builder. They take the time to talk to you and understand your ideas/goals then match trans upgrades etc to your build. I'm not aware of many others that do that.

In that case, I'd automatically say.. look at your tire size and how much % it's different than stock and consider making up some of that with a gear ratio change. Afterall the manufacturer uses many different variables in building our cars and the biggest single things they do in the trans to mediate less power, larger tire size, etc are torque converter stall and gear ratio.
Click to expand...


Is this something that could be addressed in a custom dyno tune?
 
Wouldn't need a dyno tune to get that stuff straightened out just a tune after the gear ratio change.
 


So to change gear ratios.... Can u do tgat on current trans or,must I,have a built trans? Any other company than TEP?
 
You could do it yourself with the right tools. First is to check what ratio you have currently. Then consider what is available. I know that diffs are available in ratios like 2.86, 3.05 and 3.29. If all GP's are 3.29, then you are out of luck. If your car is a 2.86 or 3.05, you can pull the passenger axle, pop the diff and sungear out, replace them with a higher ratio and put the axle back in. Reprogram for the change in ratio along with your tire size and be done. This requires a programmer and some basic tools.
 
My 05 GT n/a has 3.05 so I assume since he is SC then it would be the 3.29

Easy way to find out is call dealer service desk and tell them what you are looking for and give them your VIN. They will be able to tell you what ratio you have currently
 
Where's it show he's sc?

Being SC, the diff would already be a 3.29 and a trans rebuild would need to be done to change the overall ratio. SC has 1:1.121 drive/driven gear ratio plus the 3.29 that makes it a 2.93 overall. Not charged transmissions have a 1:1 ratio in the drive/driven.
 


BillBoost37 said:
Where's it show he's sc?

Being SC, the diff would already be a 3.29 and a trans rebuild would need to be done to change the overall ratio. SC has 1:1.121 drive/driven gear ratio plus the 3.29 that makes it a 2.93 overall. Not charged transmissions have a 1:1 ratio in the drive/driven.
Click to expand...

Yes i am supercharged. a rebuild isnt such a bad thing seeing as i plan on keeping the car. I am going to try and save the the current one as much as possible with the transmission cooler and a shift kit. However im guessing whatever builder i use needs to understand to change the ratio for the wheels, also going to upgrade input shaft for the additional power i plan to have... Correct? Setup I will be running is plog/downpipe/rockers hopefully running e85 as well?
 
dsmuts said:
Only the comp g sc cars had 3.29
Click to expand...

You mean only the Comp G's were SC'd with drive/driven gear ratio of 1:1? All the SC aka HD transmissions had a 3.29 diff.

King.. what you could do to rebuild while your still driving is have a non hd trans rebuilt with all the upgrades etc, then toss your HD diff and diff cover into it. Presto, insta 3.29 overall ratio because the non hd has the 1:1 ratio
 
You must log in or register to reply here.
Back
Top