Last time out, my big-horse LC2 build had progressed to the point where I could ship it from Florida to Ron's Custom Auto in Jersey for final assembly and installation into my awaiting 1987 Turbo-T.
Though the engine sat expectantly in a corner of the shop, I decided to take a break from the motor build as my brand-new Precision Industries torque converter had arrived.
With my TR being a street/strip ride, I wanted to be able to up the stall speed for the bigger turbo and retain the converter lockup function on the street for better mileage and lower revs--that's a no-brainer that many converters, including the 10.5-inch lock-up unit currently in my 200-4R, are capable of.
But I also wanted this high-powered Buick to be able to abuse the hell out of the converter without it flinching, as well as lock it up at WOT for the best performance possible--and for that, I would need a multi-disc Vigilante.
The secret to this WOT lockup madness is the multiple clutch discs used in this converter. Guys with near-stock Turbo Buicks tapped into this trick for years with the factory 12-inch converter--and picked up some decent ET as well. Trouble is, the stock-type lock-up clutch in most converters isn't built to take this kind of abuse, and at the kind of power level I'm shooting for, it would be stupid to even try it--except with Precision's three- or five-disc offerings. I chose a five-disc, 9.5-inch unit for maximum reliability.
Correctly sizing the turbo and torque converter can be tricky, especially if the Buick will be used in a street/strip capacity. Based on the size and type of the turbo I chose, as well as my goals at the drag strip, I requested a Vigilante with approximately a 3,300- to 3,500-rpm stall speed. The multi-disc option will enable me to lock up the clutch at WOT for additional gains, and I purposely made the stall a couple hundred rpm higher just in case I wanted to try a bigger turbo down the road.
However, choosing the multi-disc meant installing a pump kit into the trans. The 200-4R is notorious for cross-leaks in the valve body, and a pump kit ensures better clutch apply. This is not extremely complicated, but I thought it was best to leave it to a pro--enter Dynotech's Eric Schertz. Since he built my 900-horse-capable Hi-Pro transmission, he was the right man for the job. Follow along to see how it's done.
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