TKO600 VS. T56 Viper Spec

Which Tranny


  • Total voters
    30
Such a tough choice. The 6 speed would be an awesome tranny because of the extra gear and could handle 500 ponies. It's probably a bit smoother than the TKO 600, but the 600 can handle more power if you plan on growing in the future. The T56 is also going to be more expensive and a bit more work to put in unless it's already set up for a T56.
 
At that power level, either tranny will work. However, the T-56 is a much stouter tranny with a lot more room to grow. I would go this direction if you plan to push over 600 rwhp in the future. I also have a personal preference for the .50:1 6th gear instead of the standard Cobra .63 (?) 6th. Why get a 6 speed if the 5 speed has a nearly identical overdrive. The .50:1 gear lets you get away with a numerically higher rear gear while still pulling down the rpm and increasing mileage on trips.

Chris
 
At that power level, either tranny will work. However, the T-56 is a much stouter tranny with a lot more room to grow. I would go this direction if you plan to push over 600 rwhp in the future. I also have a personal preference for the .50:1 6th gear instead of the standard Cobra .63 (?) 6th. Why get a 6 speed if the 5 speed has a nearly identical overdrive. The .50:1 gear lets you get away with a numerically higher rear gear while still pulling down the rpm and increasing mileage on trips.

Chris

this is a 90/10 track car and will never see any trip time maybe a some really really quick runs to the supermarket
 
Well, I didn't vote because either tranny will get the job done at that power level. However, even the modifications that aftermarket companies have applied to the TKO600 have not prevented their destruction behind high hp cars. MMR has gotten their MMR900 to go 8s, but I've seen several members on another board that focuses on turbo mustangs post about destroying 3rd gear with this tranny, and all of them let go north of 800 rwhp.

danimal and Wolverine on that board have both posted about their trannies. They both use a fully built T-56 from G-force (not that this is the only company who can build this transmission). Both guys made over 1000 rwhp with long-surviving T56s behind them.

Strip or street, both trannies are good ones. I would personally spend the extra coin on the built T56 if I were you and I planned to push over 600 rwhp. If that's the case, spend the money one time instead of several.

I imagine your next question will be about clutches, and in this case a Spec Stage 3+ will work fine at your power level, but if you're going up in the future, then you should think about a twin-disk from one of the well-known brands. These clutches have a higher torque capacity rating than their single disk counterparts, but actually have a lighter pedal than the high-performance single disk pedals.

fastfox86, the figure you posted is probably accurate for the stock T56s that come in vettes and cobras. However, the built ones can handle significantly more.

Good luck,

Chris
 
I havent heard a lot of people that are happy with the tko600

I'm rockin one right now and I've been very impressed with it so far. It's only got about 1,800 miles of use since I always have the car apart, but I've had no issues with it. I'm only putting down maybe 300+ at the crank so it just laughs at me when I shift, but it's pretty quiet and shifts smoothly. I put it in there after my atuo to manual conversion when the beefed up T-5 blew after about 600 miles. I hit third at about 5500 and it went sky high.
 
If you ever consider some thing like the Hot Rod Power tour the sixth gear would be a plus. Also most of what I have read on road course racing people run a .80 fifth gear, so again the sixth gear would be a plus.

My Alti has a six speed and when I bought the 86 GT on the test drive I tried at least two times for sixth out of habit. I will probably go six speed on both ponies in the end, just based on my future plans for the cars.

It all depends on what the car will be used for: A nice street car, drag car, autocross or all three.

I do want all three.
 
Viper spec T56 and your 'ol cobra t56 are different animals and shares not much in common internally other than the workings of it. Not that parts for the tko600, cobra t56 or viper spec is going to be hard to find from a tremec parts vender like DD. Either in your situation would be well suited. T56 would be nice and the .8 5th would be a good freeway pulling gear. Then again the viper spec with all the needed parts is going to cost a bundle more than the tko600. It really comes down to cool factor and budget. For a high HP build I tend to trust a built 5 speed more than a built 6 speed in holding the power more. Either choice won't be wrong.
Kevin
 
ViperHead.jpg

:)