3 or 4 bolt turbo mount

one thing you forgot also is classes.. you cant race a stock "type" class with a 4bolt

Nice write up now can you go into the difference between on center and tangental housings and the A/R sizes I just scored a pair of old TO4s cheap 54mm comp p trim exhaust but they have on center .96 housings on them old style bolt on downpipe flange I know I'm going to have to change them for .68s or .81s

I want to take off a TE63 and install a PT6265s . I have not revived the 6265s as of yet . What if any changes will I have to make?

hello!!!

hi

Back to back testing on a 70 series turbo from 3 bolt to 4 bolt produced 30-40 rhwp improvement, depending on boost levels.

If you were building scratch headers for a Turbo6 in a custom application (like I'm probably going to do eventually) which would you recommend using as the flange? I'm guessing 4 bolt is going to win due to wider selection but I could very well be wrong.

Thanks,

Already have an external gate and custom downpipe. I'll be building this stuff myself.

Lot of great info.

Curious if the guy above whith the turbo figured out what his is for ? It look's like my exact set up on my 83 T Type ? I also can not seem to find any info or pic's of how the vacumm lines run or go to on my 83 Buick T Type carb I just got this car and there some vacumm lines not hooked up & I can't seem to locate any link's to lead me in the right direction ? Maybe any 1 who has this year or has knowledge in all year turbo buick's ? I'm also looking for where I can find a replacement actuator mine is suppose to be a dual port ? & the 1 I have is a single port not factory can this work and wich 1 of the 2 port line's get's used and what happens to the other 1 sorry this is all new to me ?

Wow! Now a question I have not seen asked here is what about the difference in flow from a .63 housing to the .83 or is .85 on the 3 bolt
Sorry if this is off topic I was just wondering as Im looking at a new BB Turbo not wanting to step up to the 4 bolt flange. Maybe it will help others as well. If I need a new post just let me know.
Thanks