DavidPHumes

iTrader: (1)

I've got a 1990 Mazda RX-7 that had an LS1 with a T56 in it. I was at 400RWHP and it was fun, but naturally I want more.

So, out came the LS1/T56 and here is the substitute for the LS1:



The motor is going to the machine shop for some forged rods/pistons/the works. I'm shooting for 700RWHP.

I know the T56 can handle that power, but for how long/reliably remains to be seen. Plus I'd need a big expensive clutch to hold the power.
I'm going to be running a Ford Explorer 8.8" IRS with 2.73 gears. This is because the car will be driven on the highway sometimes.

So the question is... what's good for my application... TH350 vs the 400? And in either case, where's a good place to buy a built on online? I'm thinking a 3600 stall for the converter. Seem like an OK choice?

I'm new to autos...

PBA

Go with the TH400 as it is cheaper and easier to build to hold up to the stated horsepower. Stay with a 2,800 - 3,200 rpm stall. Too much stall and you will lose mph in the quarter mile. Go with the P.I. Industries Vigilante as they have one just for a turbo setup.

TA1364

iTrader: (11)

th400 and th350 will suck on the highway. Keep the converter stall low if you must drive highway. I would use a better company for a converter that P.I.

tim99ws6

iTrader: (31)

I prefer the TH400 over the TH350. Major upgrade is going to be the center support and the Sprag setup in the car. Really depends how hardcore you want to get with the trans. For a sponsor, i'd go to FTI and get their converter. We are running their converter in 3 of our cars and all of them we are very pleased with.

Gilbert@Ace Racing

Think of it this way... the 350 is a medium duty transmission from the factory. The 400 was designed as a heavy duty unit. If you took a 350 to 700 h/p it would be a high maintenance / repair proposition. And a 400 can be taken to much, much more capacity than that.


I am a Dealer for ATI and Transmission Specialties. There are actually several different components that I would incorporate into this unit. If you would like to discuss some build options I would be happy to take the time to discuss your needs and help you to decide what a good build would be for your project. I am capable of building you a very nice, custom TH400 that can take any amount of power you can put to it.
.

g

tim99ws6

iTrader: (31)

Sweet Jesus Gilbert, I didnt know you were a sponsor on this board, haha. In that case, I'd DEFINITELY recommend Gilbert's TH400! Matter of fact, one of our local cars (Gilbert-->Brian's 3rd gen with the LT1 on spray and a TH400) just bought Gilbert's drum upgrade setup to fix the sprag problem common on the TH400. Put it simply, all internal parts from our camp will come from Gilbert unless anything changes. I still like my FTI converter though

DavidPHumes

iTrader: (1)

I know a TH400 is necessary and I also don't believe it will be terrible on the highway with 2.73s (~2,500PM).

It looks like ATIs Street/Strip trans is a good price but they don't specify the power levels they're built for.

tim99ws6

iTrader: (31)

Don't sell yourself too much on "power level" in a trans. Weight and how the power is being applied plays a MUCH larger factor in "will it hold" than the website capabilities.