Semi new tranny slipping in 3rd gear.

[Rell87]

I was supposed to take my car to the track today in Sacramento for test and tune but I got a call from the shop at the last min saying that the tranny is slipping in 3rd gear. It seemed fine 3 months ago when I had a 3 inch dp, 70gtq turbo, and stock headers(19in rims with street tires= no grip). I decided to finalize my S1 build because I wasn't satisfied with the power it was putting out so I got a 3.5" dp, tial V60 external wastegate, TA headers, and a dual BB 74 HPS turbo. I also took the 19's off and put 16 inch GNX style rims on with MT street slicks. This is very upsetting I'll appreicate any help as well as info on some good tranny builders, I'm located in San Francisco bay area... Thankx in advance:frown:

 

[KL Mallender]

Sorry to hear you lost a test and tune opertunity, but something we all need to keep in mind about these cars is that it is so easy to get a bit greedy(I've been there many a time) that we can't see past our desires, these cars(really, ALL cars, the transmission is usually the weakest link in the powertrain) get us into a tight spot in the reliability department where something was working just fine a minute ago now rears it's ugly side, it happens to all of us(make of car means nothing) but the Turbo Buick community knows this all too well, boost pressure increases torque output in such a way it is easy to glaze a band/clutch assembly where once it's "hit" it is never the same untill it's refreshened, sounds bad I know, but it's the truth.
What I can tell you is the experienced builders here have faced these issues time and time again and their knowledge is priceless for getting these units to stand up to ungodly outputs, get with them to sort out your needs and you will be years ahead of having to learn the step by step heartaches, if possible always get a better trans build before getting happy see'ing that boost guage head to the high water marks. You don't need everything under the sun to have a reliable trans, but you need to build it ahead of your "I should be ok" ideas, we sting ourselves every time otherwise.

Kevin.