As it pertains to GS400-

First, I am not planning on making the kind of power that would require a built tranny for quite some time. However, after looking at the cost of a TC, VB upgrade, LSD etc.. I am wondering if I would be smarter to just buy a built tranny up front (like the SRT). Is there a built tranny option that incorporates these other typical transmission upgrades?

I have searched and read many threads on built transmissions, and these various upgrades. It just seems like after adding up the cost of these tranny upgrades it comes very close to buying a built unit.

I specifically am in need (want) of a LSD, and the torque converter just seems like a great concept even though I have no experience with one. The supra gearing will fit better for my style of driving.

What do you guys advise? I am paying someone else to put this stuff in either way, so with the labor cost, should I just spring for a built unit now, or will it drive like ****?

 

You're not really comparing similar functioning things. They all have their own purpose. The tranny will need to be built if you need to handle additional torque. The rear will house the LSD and is used for traction. The ring/pinion will change the drive ratios, either take off faster or a higher top end speed. The TC can allow a stall to help spool a turbo, etc. The VB will change shift points and/or shift firmness depending on what you want to do. You should set a goal and then decide. I wouldn't judge the two options you have listed because they are really different. Some one else can chime in.

 

thank you, and excuse my ignorance this car is quite different from anything I have owned before!

I guess what I was wondering, is whether a built tranny incorporates any of the other things.

To rephrase, if I add TC/LSD/gearing now, and need to upgrade to a built tranny to handle big power down the road, did I waste my $?

 

Actually, you need to factor 2 things.What built tranny will you use?Are you going to swap a th-400 in or a built srt tranny?Second, what route n/a or n/a t or s/c??Your gear ratio is dependent on many factors i.e. motor, tranny gears and tire height and lastly for what purpose the car is being built.YOu have to modify a car with the big picture already planned.

 

The LSD and gearing are in the rearend and are not inside the transmission.

 

alright good info, ultimately I plan to go forced induction. Not sure yet turbo vs S/C, but I want to plan as much with the 'big picture' in mind as I can, hence this post!

As far as upgrading the tranny, I think the SRT will suffice for my purposes, I don't plan on ever making this car more than 500whp. By the time I could afford to I will already own a porsche or two

 

The built tranny is not going to give you any of the other functions. The only thing you will get is the VB upgrade. When they build the tranny they will ussually do the VB at the same time. The only thing the tranny will give you is the abillity to handle the 500+ hp oh and firmer shifts.

If you want performance improvement now then do the torque converter, LSD with the taller gears.

Bear in mind that when you do go FI you may want to go back to the stock gearing with the LSD. You may also want to have the torque converter adjusted to a different stall speed when you go FI

Basically you have to ask yourself how long till you go FI to determine if you should do the upgrades now or later. If it is 6 months or so I would wait and do the mods that compliment the FI, if we are talking 2 years then do the mods now and then adjust them later on when you do the FI

 

yep it will be a while, and by then I may change my mind so I willgo with the the uprades I guess...

thanks for the advice guys!

 

Basiclly you want your stall speed to be 500 rpms below your peak torque rpm.Thats why, Think of the big picture, and save yourself time and money.Their are still too many variables to play with before you can really decide.Is this going to be a drag car or a road course car??