SanJoRX7

Well, it's not like I'm seriously working on something like a tranny swap, but I got to thinking about it and if the MKIV Supra tranny (the Getrag) can handle the monstrous horsepower that those cars can put out, is there any chance at all that unit might be able to mate with a 3rd gen engine?

Given that it's a 6 speed, that would be sort of nice for the RX-7, and it appears to be bulletproof too, which would make for good longevity and lots of HP.

Just a thought...anyone?

Patrick

jimlab

Phsyically bigger (doubt it'd fit without modification to the exhaust and at least losing the main cat, if you haven't done so already) and heavier, and there's the problem of adapting it to a rotary engine with a bellhousing adapter plate, and shortening or lengthening the driveline, as required.

In addition, it would not have provisions for mounting the powerplant frame which supports the transmission in the FD, so you'd either have to modify a PPF and the transmission to integrate them, or provide a transmission support brace like the Supra has, and then eliminate the PPF and use a Camaro-style torque arm for the differential like the one my V8 conversion uses.

And finally, they're not bulletproof although they will take a lot of abuse. The Borg Warner/Tremec T56 6-speed in the Camaro and Viper is stronger, cheaper, and more readily available.

Most of the 600+ RWHP Supras have automatic transmissions, many rebuilt by Sound Performance or Level 10 because the stock ones don't live that long, even behind ~500 horsepower engines, and the highest rear wheel horsepower cars have either HKS sequential gear boxes, or converted GM transmissions (3-speed Turbo Hydromatic 400 or 2-speed Powerglide) like Vinny Ten.

RX7_Fast_Lane

You said most of the 600+ RWHP Supras have automatic transmissions? Seriously? Why is that?

DomFD3S

Because they cannot shift/change gears fast enough. The fastest 300ZXs are also automatics.

jimlab

Because most of them are drag cars, and at that point, the cars with built automatics and stall converters are quite a bit quicker (and easier to drive) than the 6-speed cars.

Jim Swantko

The Titan motorsport car is a 6-speed, SW is running a 6-speed, and there are many more 600+ RWHP 6-speeds out there.

I'm not arguing with Jim... a "built" auto is definetly quicker and easier at the drag strip. But I'll keep my Getrag... it's been dealing with my 500+ RWHP just fine.

The T-56 is a fine tranny too..

jimlab

I just said "most" Jim, not "all".

Of course there are several 600+ RWHP "street" Supras with 6-speeds, because it's a lot more drivable than an auto with a huge stall converter. They can also be very quick in the quarter mile, not to mention the highway, but you are making a compromise in quarter mile performance by having to operate the clutch during each shift.

For this reason, you usually won't see a street manual transmission in most (again, most) drag cars capable of low 9s or better, regardless of horsepower. At that point, a clutchless Lenco or Liberty, a sequential gear box like the HKS, or an automatic transmission is almost required because you can't "lift and shift" quickly enough, and the street gear boxes generally don't like the power or the abuse very much, and won't put up with it for very long.

That's the problem with generalizations, of course. There's almost always an exception to the "rule" you've just created.

Absolutely, but many Firebird/Camaro and C4 Corvette (ZF 6-speed) owners who are drag racers scrap it for a TH-700R4 if they're serious about winning.

Jim Swantko

Yep... it's all about what the result your shooting for. Autos rule for ultimate drag racing... no arguments there. I'm waiting for someone to stuff a hydro-static tranny in a drag car. Set the RPMs to max torque or HP... then just engage as quickly as the traction will allow.

But unless you're going all out... I'll take a 6-speed any day on a daily driven street-car. High stalls and tranny rebuilds would get quite tiresome to me.

jimlab

Agreed. Which is why I'm using a built T56 with a McLeod Street Twin twin disc clutch in my RX-7.

Jim Swantko

What do you mean by "built"... what have you done to the T-56?

jimlab

Carbon fiber synchros, cryo'd gears, and steel shift forks.

Jim Swantko

Wow! You really are going all the way with this car. Damn...

You certainly do not leave any stone unturned! How cool!

jimlab

Well, I did pass on the Quaife 6-speed sequential gearbox... I could kill three prepped T56s and nearly buy a fourth for the same cost.

yzf-r1

iTrader: (1)

Jim (Labreck),

will you ever be willing to divulge the total expenditure of your project, after all is said and done, not including anything that breaks after the first run down the strip?

jimlab

Sure, if I ever add it all up, but I'm not sure I want to know. It's bad enough that I have a pretty good idea of what the engine cost...

yzf-r1

iTrader: (1)

I also have a question for you, Mr. Swantko.....btw, I think I told you we have a Mark Swantko that works at our firm and lives near you....strange

anywho, now that it has been a year with the almighty Sup-Dog, can you provide some seasoned insights on the pros and cons of owning Toyota's finest? have you ever, even for a fleeting moment, regretted your purchase, or found yourself staring lustfully at M5 Beemers?

I still plan on getting a high mileage Sup for a daily driver

Jim Swantko

Mark,

That is weird that there is a Swantko in Charlotte other than my sister.

When I first got the car I wasn't as exciting (handling wise) as the RX-7. But once I put more tire under the car I honestly can't think of much to fault about it.

You will notice the weight... but the brakes are excellent. It's not as nimble... but it's very confidence inspiring... you can push until you get in over your head... AND then back off and drive out of it. There are a few little things to watch out for on these cars. The tranny (6-speed) has a small external seal that dries and cracks over time. When this happens (like my car) it will lose some tranny fluid onto the exhaust. I haven't had a chance to replace mine but I hear it's a bear unless you drop the tranny. Valve seals start to go around 80k miles which means you'll get a little smoke at start up (until warm) and at WOT. But it's not a major operation to get them replaced... it can be done with the head still on the motor.

The tranny is superb IMO... I had a T-56 in my old '95 Z-28 and the Getrag feels smoother... but I wasn't real kind to my old T-56 either.

Other than those few quibble (none of which are big deals) I really love this car.

As for your daily driver I think there is quite a deal for sale in Wilmington. It may need a new motor.. but a new short block is about $2k... I think he was asking $14k for it as is.

As for the M5... of course I lust over them... but they aren't worth the cost of admission in my opinion. Not to mention I don't think that I'd want to pay for the service of that puppy. If I were to shell out that kind of money I'd be looking at a Lexus SC430. It might not be as fast.. but it's gorgeous. I like Japanese maintenance over European any day!

If you have more questions feel free to e-mail me jimswantko@hotmail.com

Jim

neo_omega

I think you should go with the HKS 6 speed for FD. Or you can swap a GT-R tranny.

spooledUP7

Truely a five star thread.
Jimlab, as always a pleasure to read, and Jim Swantko (had to scroll up to spell), nice objective outline of your experience with the Supra. Much better than the typical "My Supra will kick your RX-7s *** any day" comments we read so much on these and other forums.
If there were a catagorized technical forum, this thread belongs in it under tranny opinions.

Jim Swantko

Spooled

I appreciate both cars...always have... the 7 is awesome (when running properly). The Supra is not quite as much fun.. but pretty darn close with suspension/tire upgrades (but is almost always running properly)... just decide which is more important to you and your car choice is simple. There's nothing more to it than that for me.

I still enjoy poking fun at the 7... but it's all in fun... it's a huge rivalry (Supra vs RX-7). I'm just thankful that we have 2 great cars to choose from (and many more now or on the way - Z06, Evo, WRX, etc).