Garrett turbo ID

[Wicked WE4]

I bought my WE4 and have had it for a month, the guy I bought it from was not the one who did the mods on it and was not sure if the turbo was stock or not. It has pullies, hotwire, walboro pump, voltage boost and that is about all that I could see that was obvious. This is my first Turbo Regal. The turbo says Garrett on the cover, and I was wondering if these cars came with Garrett turbos from factory and is there any way to identify what size the turbo is? Thanks in advance for the help.:smile:

 

[RUQWKNF]

First off, Welcome Aboard. Congrats on your new WE-4.
All '86-'87 Turbo Buicks rolled off the assembly line with a Garrett TBO-348 turbocharger. (The GNX's received a custom ceramic turbine wheel equipped Garrett turbo)

One quick way to tell, on the inlet side of the turbo, where the air inlet hose/pipe connects, does the turbo have a 2-bolt inlet bell?
And if so, is it a rough finish cast aluminum bell with a port built into it with a rubber hose plug or pipe connecting to the passengers side valve cover? Or is it a smooth finish Billet aluminum inlet bell?

Cast finish inlet bell with breather port is a factory style inlet bell. And chances are, it could be a stock turbo.
Here are two pictures of a stock turbo.

99% of all aftermarket turbos for Buicks, starting back in the early 90's had a billet aluminum 2-bolt inlet bell. I know the first upgrade turbo I ever saw for a Buick, was an old Stage 2 turbo from ATR back in '91. It had a billet aluminum inlet bell. If the turbo looks like these pictures below, chances are it's an upgraded turbo.

The TA series of upgrade turbos, utilized the factory TA series compressor cover that was machined to match the contour of the compressor wheel. (TA-49, 60, 51, 52, 53, 54, 61, 63, 66) Circa '91 - current.


If the compressor cover does not have a bolt on inlet bell, but rather a molded in style inlet, it would definitely be an after market turbo.
Pics would be great, but if not, you could take some measurements of the compressor wheel by taking off the compressor cover and we can better help ID the turbo.
Hope this helps a little and welcome to the world of Turbo Buicks.

Patrick

 

[Wicked WE4]

Thanks for the help. It appears to be a stock turbo. How much boost can the factory installed turbo make?

 

[RUQWKNF]

Some have taken the stock turbo, to the limit. The problem is, charge temps sky rocket once you get past 26psi. The TBO-348 stock turbo, has been known to push full weight Buicks into the high 11's with supporting mods. Not liking it, but it's done it. It has a good user range of 14 - 24psi. 24psi is starting to get to the limits. I've pushed a stocker to 27psi, but back in the day, without having a good intercooler, it made no more power.
Maybe if we would have had alky injection back then it would have been a different story.
With todays pump gas formulas out there, we're lucky to see 16-17psi on straight 93 pump. Timing in the 19-20* range under WOT is still common.
But with 100 octane unleaded, we can bump up the boost and timing. I always liked 18-21psi and 22* timing on 100 octane unleaded with a good intercooler.

Hope this helps.

Patrick