my 99 is almost done, when I finally get that project finished I'll have a ton of money to throw towards the 91z, I was thinking of doing something different with it. I know that the turbo 3.8 has been done before, but has anybody ever mated that motor with a 5 or 6 speed? I personally have never seen a grand national or TTA or anything with the 3.8 with a manual transmission, so Im not sure if it would even be possible. what do you guys think, should I research more on this, or just go the more tried and true route with this car and build up a healthy small block for it?

The Turbo trans ams had a setup similar to the gn. They just had to relocate a few parts to make it fit. Im not sure whether they were offered with a 5 speed but a suitable belhousing could be found to make it work.

a lot of people will tell you that it shouldnt be done... I say do what you like... but you might want to look into a turbo that'll spool faster....
I have heard that when gm did r&d on the tta, they worked on possibly having a 5 speed 3.8 turbo, but it didn't make anywhere near the power as having an auto behind it.....

GM is the only one I've ever heard of putting a manual behind a turbo buick V6 in a TTA but the idea was scrapped when the car's performance was off by over a second to 60mhp and in the 1/4 mile.

That being said I think it can be done and looked into it at one time before I wised up and built an auto. It will require fairly extensive fabrication skills, alot of time parts hunting, and possibly some custom made/one off parts.

There have also been many posts on this board about the why's and why nots of putting a manual behing a turbo buick so doing a search might help also.

HTH,
Steve

The way I see this is if you boost airflow through the engine through redesign, therefore increasing pressure on the turbo at a lower rpm, then recalibrate the turbo to compensate, you may be able to pull it off. Lot's of thought, research and dollars will get you there. The only way new things are discovered is by determined people figuring it out.

this topic has been beat to death on various buick forums & listsservs.

Basically, the great majority of people will cry out that you will lose boost between shifts. This is true.

The great majority of Turbo Buick people also have a very tunneled vision of car building. If it's not suited for the 1/4 mile, then they may not have kind words for it. It being a part or concept for a car.

The other thing is that as-built, the 3.8L turbo Buick is very good at making torque. Not ripping off high RPM. So you are better off with an automatic with it in all honesty. If you want something run to rev through the gears, build a turbo something else like a SBC.

Here is a pic of the 6-speed in an 89 TTA, this was one of the prototypes PAS built. Click on the 2nd thumb down.


http://www.gtasourcepage.com/89pmdplaythings

Ok, I understand now why the whole manual thing would not be a good idea. the car will not see the track, just something to cruise around in, maybe the occasional highway run or whatever. The reason I was considering trying to run a 5 speed is that the car has a brand new T5 in it, I guess I'll have to end up selling that stuff when the time comes, and run a 2004R or something like that. I'll keep you guys posted on what i ultimately decide to do with the car though, thanks for all of your help!!

There's nothing 'wrong' with using a manual trans behind a turbo engine.
If your intent was to build a 'take no prisoners' drag car, then an auto would be the logical choice.
If your goal is just cruising around or a highway run once in a while, a stick will be more fun - you just need to be aware that the T5 is not overly strong.
You could probably use an adapter plate to make the SBC pattern bellhousing mate to the BOP pattern of the 3.8. Locating an appropriate flywheel and a clutch would be one of the bigger concerns. There have been enough 3.8 Turbo installs done so that most of the other idiosyncrasies have been worked out.

Be prepared to spend quite a bit of money and fab up some parts.

Aside from GM a few people in the Turbo Buick community have done the swap and every single one said they'd never do it again due to the weak trans/clutch, time spent on the swap and most importantly the $$$.

I too looked into it, thought it'd be fun. But I'd rather go fast than thinking I'm cool because I can shift gears

A nicely built 200-4r with a trans-brake and a manual valve body will do the trick

Also, there is no question you WILL go slower, just something to think about.