this guys 1000 hp build has some good info


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look thru the linked info


"I chose to use a Precision Industries 9.5" Vigilante with a 3200rpm stall speed, billet steel case/anti-balloon plate, and 3-disc lockup clutch capable of holding up to 1600hp under WOT. I'm skeptical about that, and will probably not lock it up under WOT/Boost for reliability reasons. All of this is programmable with the F.A.S.T./TCI transmission controller. Interestingly, it's painted with a special heat sensitive paint which is normally purple but turns dark if overheated. I suppose that's how P.I. handles warranty claim issues."


Due to the intended usage and power output of my twin turbo SBC 427, it became necessary to switch from the Tremec TKO 5-speed I had previously installed. I really like the Tremec TKO, and prefer to do my own shifting, but the reality is that street driven turbo cars usually perform better with automatic tranmissions since the automatics let the turbos build and maintain boost quicker and better than the manual transmissions do. I figure if I'm going to all the trouble and expense of building a custom twin turbo system, I may as well do it right and ensure the results will be worth it.

I decided to go with a built up 4L80E for a few reasons. First, I wanted an overdrive transmission for good drivability when I'm just cruising around or stuck in traffic. This meant my obvious choices were either the 700R4/4L60/4L60E, or the 4L80E. Although the 700R4 and it's derivatives are fine transmissions, I had already had experience with them in high-performance applications. There are numerous companies and shops that can build a 700R4 to handle the power and torque of most hot rods or street machines, but with my twin turbo SBC 427 making 1200-1300 horsepower and 1000+ lb. ft. of torque, I needed something stronger. So I decided to go with the 4L80E which has a reputation of being "bulletproof", expecially when built correctly.

I purchased a GM Service Replacement Transmission on eBay and then took it to Don Stanley at Transmission Specialties Inc. (TSI) in Addison, IL. Don is well known for building alot of the tranny's used by NMCA-NSCA, NMRA, and other "Outlaw" racers. Upon disassembly, Don was impressed with the construction of the transmission, commenting on it's straight cut gears/planetary's which increase strength significantly, but at the expense of increased gear noise. Since these tranmissions were originally installed in heavy-duty trucks, that is typically not a problem. I doubt it will be for me either... Anyway, the entire tranmission was blue-printed and modified with additional Hi-Energy clutches for the Forward(6), Intermdiate(5) and Direct(6) drives, Kevlar bands, Kolene steels, wider case bushings to provide additional support for the mainshaft, roller rear thrust bearing, and all the plastic shims were replaced with metal or Torrington bearings. Additional modications include the installation of a Transgo HD-2 reprogramming kit, a Transgo Hi-temp/Low-Shrink o-ring kit, plus some custom modifications to the lubrication system that Don wanted to make. The end result is a transmission that should reliably handle the power I am going to through at it.

I've been told by several experts that the weak link on this tranny is actually the OEM computer and software that is used. That I why I chose to use a programmable F.A.S.T./TCI T-Com transmission control unit. Not only will it allow me to control shift points, firmness and speed, convertor lockup and modulation, but it will also allow control over the line pressure to ensure maximum clutch engagement.

To handle the increased heat generated by the power going through the trnamission, I also added a Fluidyne oil cooler, which I mounted under the front air dam.

I also used a 9.5" Vigilante torque convertor from Precision Industries. The stall speed is rated at 3200rpm, and it is equipped with a 3-disc lockup clutch, which PI claims will handle up to 1600hp locked-up under WOT. I am cautiously skeptical about that and don't intend to lock it up on WOT/Boost for reliability reasons.

I had a custom driveshaft made, a "Nitrous Ready" shaft from Denny's Driveshafts, it is 27 3/8" long. I also received a new steel pinion yoke for the Corvette's Dana 44 rear differential, as well as a slip yoke for the 4L80E transmission, both feature solid Spicer 1350 ujoints. If you need a new driveshaft, I'd recommend Denny's, they have a nice website with downloadable order/specification forms, they were very helpful, and they told me exactly when it would be shipped. Plus they give you a free "girly" poster featuring their shafts...LOL!