I'm going with a fully built sleeved turbo d16 for around 400whp. Based on gear ratios, I'm trying to find out what transmission is best? I've heard I want the y8 tranny but I'm just looking for more info and opinions. Thanks

 

Y8 tranny with new internals....

 

I've been using the DX transmission. Has served me well. Of course, I have NO clue how exactly to tell them all apart, DX vs Si, etc.. They all have the same look and tags, just a slightly different gearing. It revs fairly quick, maybe it's the Si trans? I dunno.. It was attached to the original B7 engine when I got the car and has been through 3 turbo setups.. The B7 setup, and 2 on a Z6. I've beat the **** out of that transmission and it's serving me well.. **shrug**

 

There's a casting next the the passenger axle seal. A000 is base model, B000 is ex/si. IIRC!

 

400 WHP is kind of that "either way" area... the shorter geared EX/Si trans may be a bit more difficult to drive because of the closer gearing, but it will feel very strong and pull hard when you have traction... and the DX trans will be better spacing leaving you in boost longer in each gear, but you will lose a bit of acceleration in each gear as well. My opinion is use the DX trans as Txdragon suggests.

 

It really depends on how broad or narrow your power band is, the y8 trans is still about as long as a hydro ls Tranny so its not like it super short geared either way.

 

It all depends on what you want to use the car for. Quarter mile? Half mile? Top speed record? Daily driver? Use this calculator to play with gear ratios to help you decide: https://www.zealautowerks.com/transcalc.php

The Y8/S40 transmission is desirable due to the steel shift forks. The Z6/S20 transmission has cast aluminum forks.

 

Damn... Really? They'd have been only marginally worse if they were made of glass.