Good tranny for this engine

[super40]

Well I want to get an engine factory 347 engine with the victor jr option package. The problem is that it makes 440 or higher hp. The only good transaxle I think is good for this motor is a ZF 5DS25-2 transmission but that needs engine mods. The engine without victor jr package may work on an audi or porsche but thats over the limit. Can you please help me on deciding which transmission to use?

[BT SNAKE]

Super40,
There are choices and they will mostly depend on your wallet size.
The Audi boxes are great because they are really cheap. Usually $150 to $300 range. As long as you keep the horsepower around 400 and the torque near 360 you should be fine with this choice. Higher horsepower will require the ZF box. It doesn't shift as smoothly but it will take much more HP and torque. This option is costly at near $9,000.
The G50 box from a Porsche 911 is another choice. It to is pricey as a rebuilt unit will cost around $2,500 at the cheapest.
Which ever way yo go the RF can be fitted with any of these.

Hersh

[super40]

The ZF needs modifications on the RF which might make it so you may not see the injection system from the exterior of the car.

[BT SNAKE]

Nop,
They are just about the same as any of the other replica GT40.
Besides, if needed, put on taller stacks..

Hersh

[super40]

Do you think it good to have the victor jr option for an engine factory 347. It's $550 and it adds 25 or more hp. But I might use the porsche g50 instead of the zf 5ds25-2 transmissions.

[BT SNAKE]

Super40,
More Horses and more torque..I say go to the strongest trans you can. The G50 box is a good choice up to a certain horsepower to wieght configuration. Just a guestimation but I'd say 500HP max for that box with 2300lb GT40.

Hersh

[super40]

I might just know a place that sells porsche transaxles.

[Cyklops]

GT-40 Transaxle:

Has anyone studied availability of the T-44 unit. Holman-Moody has them, but the price is high. G.

[super40]

Cyklops,

I heard that superformance was making some mkII toploaders but that could be a rumor. Somebody must be working on it.

[WBMusarra]

There are several good transaxels out there as Hersh made mention. I'm running (when finished) a porsche 930 posi unit. It is basicly the transaxel that porsche uses for racing and is probably one of if not the strongest unit porsche made. If price is no object go for the Boxster S unit. It is a mid engine configuration that needs only an adaptor to work. Check out Kennedy Eng. and Renegade Hybrids (Porsche) for adaptors. If you cruise Ebay under Porsche transmissions, they (all) pop up occasionaly. Audis as well. Just have to know which one you are looking for. There was a good thread on GT40s.com recently about the Audi boxes. The better units (stronger, gear ratios) are imported as they are as rare as hens teeth in the US if I remember correctly. The ratios can be changed and a Phantom Grip posi can be added to all.
Bill

[super40]

I might just go with the g50 with quaife lsd.

[rlearp]

You might be suprised. Take a look on this thread and scroll down. The Porsche units do well and I wouldn't discount the Audi unit either - a RF with one took top dog at Run and Gun, gear box is good still.

http://www.gt40s.com/ubbthreads/show...4590#Post25038

Just don't treat your GT40 like a dragster and you'll be fine.

R

[cscott67]

The g50 will probably be more than adequate for what you are going to use as a motor. It can be built to take some serious abuse. The 930 trans is stronger, but it is a 4 spd, and will be better off with a torque monster engine. I am using the 930 with a 600hp/600ftlb tq motor. And I am going to ABUSE it! What's the point of building a car you can't launch off the line because you are AFRAID it will break? Happy hunting, Scott

[super40]

the 347 engine factory motor is going to be adequate.

[super40]

I also heard that ERA is producing replica T-44 transaxles for less money than the Holman-Moody units.