gnx7

iTrader: (28)

I'm building a motor for boost with a target of around 1000rwhp. 364ci/GT88 turbo going in a '93 Mazda RX-7 (another one I have collecting dust). Target weight is around 2800lbs without driver. Putting either an IRS 8.8" out back or a solid axle 8.8" with 2.73 or 3.08 gears.

I just bought an Fbody T56 with some upgrades: steel 3/4 shift fork, bronze pads, billet keys, rebuilt synchros, carbon blockers, and the nice upgrade which is a Viper 30 spline output shaft. I'll be running a Textralia triple disc clutch.

Will this transmission hold 1000rwhp? I don't plan on launching it that hard so hopefully that will help.

The next upgrade from this is pretty much billet input/output shafts right? After that G-Force billet gears?

I would appreciate any and all input. I'm hoping the lightweight of the car will help parts last longer. I'm building it as a fast street car, play around at the dragstrip, and try it at the 1 mile top speed shootout events. This fall at the TX Mile we went 196mph with around 650-700hp flywheel in another RX-7 like this one. I'm thinking with another 500hp on top this car should be a handful.

85MikeTPI

iTrader: (9)

You'll have no problems with a viper-spec output shaft and a 2800# car.. You might stress it doing full-spooled clutch dump on slicks, but otherwise those T56s can handle 800lb-ft in 3600#+ vehicles..

good luck

haighter

iTrader: (55)

it is usually not the shaft that will break on the viper spec but the gears themselves. Upgrading the shift forks, billet keys, bronz pads and carbon synchros make NO DIFFERENCE for how much power the trans can take. The only thing they do is help when you are trying to shift the thing harder. The other thing that most people miss and why they brake there trans is that they run the wrong lengths on there drive shafts!

gnx7

iTrader: (28)

I've heard the gears themselves are the next weak link as well. I would imagine the input shaft is on that list since it takes a ton of abuse.

Any other input?

haighter

iTrader: (55)

What I have seen that will also kill a t-56 is when you have a hard take off and all the atf goes to the 5,6,R gears and away from the 4,3,2,1 gears. This will cause heat and metal on metal wear that I have seen the gears break or bearing get hot and come apart. To fix this you can pump the oil from the back of the case to the front so your input shaft and 3,2,1 gears get oil also. As for the Input shaft there are a few different ones you can get. check out these links.

Stock input shaft.
http://www.ddperformance.com/shop/po.../IMG_6226.jpg&

Not an fbody one but its thicker and would be an upgrade that some companys make for the m6 trans. The pic is to give you a idea about the size difference.
http://www.ddperformance.com/shop/po.../IMG_6280.jpg&

gnx7

iTrader: (28)

Link to the oiling mod he described:
https://ls1tech.com/forums/manual-tr...h-hp-cars.html