midengine mopar

alfonso · Post by **alfonso** » Thu Jan 31, 2008 4:37 pm

anybody have experience with mid engine v8 transaxle matchup
would like to build a can am v8 style 2 seater with a mopar small block
but do not have budget for ultima
racefab has a mid engine chassis that can be used
couple questions
were would i buy a zf or getrag transaxle? which is better what model to choose
adapter plate for mopar
if not
who will manufacture one

another notion was to use the trans axle set up on amid engine truck
for desert running anybody doin this?

MadBill · Post by **MadBill** » Thu Jan 31, 2008 5:10 pm

Probably wouldn't be too difficult to adapt a C5/6 Corvette trans axle to mid-engine. The right wreck would also provide suspension and more, if desired...

Keith Morganstein · Post by **Keith Morganstein** » Thu Jan 31, 2008 8:19 pm

MadBill wrote:Probably wouldn't be too difficult to adapt a C5/6 Corvette trans axle to mid-engine. The right wreck would also provide suspension and more, if desired...

Thats sounds like a good idea. I see these on ebay. Anything from complete drive line to transaxle only.

http://cgi.ebay.com/ebaymotors/Corvette ... enameZWDVW

Warpspeed · Post by **Warpspeed** » Fri Feb 01, 2008 2:29 am

I would give some very serious thought about how you plan to get the gear linkages around the engine.

While a ZF transaxle will have this already sorted out, and even the rear engine Porsche boxes can be adapted, the Corvette, or Porsche 928 torque tube transaxles have the gear linkages coming straight out into where the bell housing.will be.

Unless you run a hollow camshaft (joke !) the linkages will need to go right around the engine. Nobody that I know of has been able to make this work well enough to be drivable, including myself.

alfonso · Post by **alfonso** » Fri Feb 01, 2008 9:04 am

i want a package like a pantera , gt40 transaxle
and use a mopar motor

Warpspeed · Post by **Warpspeed** » Fri Feb 01, 2008 4:15 pm

The Pantera used the German ZF transaxle which would be perfect if you can find one..
The genuine GT40s used a Hewland racing dog box without synchromesh which may not be so street friendly..

Most of the fake GT40 kit cars use a Porsche 911 box of some description. This requires reversing the crown wheel, to place it on the opposite side of the pinion, This changes the rotation so it is correct for mid engine configuration. This is a straight simple disassemble/reassemble job.The top gearbox breather needs to be moved, there is a hole already there in the right spot to do this too.

A normal Porsche box has the shifter coming straight out of the end of the box. Ideal for rear engine, useless for mid engine. But there is a side cover on the box that can be removed, and a standard Porsche gear linkage kit fitted, that works exactly like the ZF box. This allows a shift linkage to run forward beside the engine block. This was first used by Porsche in the mid engined 914/914-6, and I believe you can still buy the gear linkage parts to convert most if not all Porsche boxes to this gear linkage configuration.
http://books.google.com/books?id=CZoH7l ... pFKU-dQFZo

There are a vast variety of different Porsche transaxles around. Four, five, and six speed. These have widely different strengths and gear ratios for different applications, so some research and a bit of hunting around will be required. As far as I know, every single one of these boxes is easily convertible to either rotation, and has a very similar gear linkage setup with the same two bolt side cover plate.

Your best bet might be to get onto a good Porsche Forum and start asking some questions, unless you can score yourself a Pantera box.

Noob · Post by **Noob** » Sat Feb 02, 2008 9:52 pm

the problem with these conversions is everyone wants the same "year" gear box that's supposed to be cheap. It's not. Unless you want a mid engine'd car with out a limited slip diff then the price is around $5k with some basic R&R and the requirements to flip one. Plan your budget wisely.

Warpspeed · Post by **Warpspeed** » Sat Feb 02, 2008 10:10 pm

I guess it depends on the power level and how harshly it is to be driven..

There are a bewildering variety of used Porsche boxes around and the price varies accordingly.

Almost any of the rear engined boxes can be converted to mid engine configuration using the 914 gear linkage parts. Some of the early boxes, although not particularly strong, are relatively low cost and readily available.

Something like an early 911 turbo box is particularly robust, but only has four gears.

alfonso · Post by **alfonso** » Sun Feb 03, 2008 5:58 pm

thank you for the answers

Engineguy · Post by **Engineguy** » Mon Feb 04, 2008 8:22 pm

Some "V8-capable" road-going (helical gears and syncro) transaxle sources.

Kennedy Engineered Products

They don't sell transaxles, but they adaptor kits (about $500 for adaptor & flywheel) to adapt nearly anything (incl. Viper V10) to VW and Porsche transaxles... as well as HD clutches and custom starters where needed.

"We manufacture over 60 different kits to fit 100 different engines to rear engine Volkswagen or 911, 914, 915, 930 & G50 Porsche and all gear boxes styled after these transaxles."

http://www.kennedyeng.com

Renegade Hybrids

Kits to put SBC or LSx engines in Porsche 911, 914, 944, and 928... or Turbo Subie in 914. They also sell rebuilt and converted (mid-engine and/or inverted) Porsche transaxles to specialty car builders ( ~ $4,700 to $11,900)... and cable shifters ( ~ $800). Tons of info about pros and cons of the various transaxles on their site... they've been in this niche for 25 years.

"With 25 years worth of roots firmly planted in Porsche to Chevy conversions, Renegade knows how to connect the correct combination of horse power, gearing, clutch components and shifters, for almost any mid or rear engine Kit Car design. Super cars like the GTM from Factory Five, or the GTR from Ultima, and even GT-40s, Diablos, and the occasional home built replica, all seem to find the Porsche transaxle design, coupled with the Renegade custom accessories, a fantastic solution to the missing link between the motor and the rear axles.

Porsche's G-50 transaxle, the most popular kit car transmission, can now be shifted using a custom Side Shifter assembly. Add the new billet rear plate with custom mounting tabs, and you have a more compact, easy shifting, quick mounting, kit car tranny, with few adaptations to your chassy. Going REALLY big? ...Coolers, pumps, filters, spray bars, and even the fittings, can be purchased from Renegade (seen here with the side shifter and rear plate). A custom high quality cable shifter, that is adaptable to just about any application, is also available (seen here)."

http://www.renegadehybrids.com

Mendeola

Manufacturers of high-end off-road racing transaxles for years, Mendeola is now making a road-going (helical gears and syncro) mid-engine sports car transaxle ( ~ $11,500 for 550 ft-lbs or ~ $13,500 for 650 ft-lbs as I recall). Another company, Hargett Precision, makes high quality cable shifters for them ( ~ $500).

http://www.mendeolatransaxles.com

RBT Transmissions

Bought rights to ZF (Pantera, BMW M1) 5-speed transaxle (now RBT-5) and they make a new 6-speed (RBT-6). They also have parts and service for the ZF if you can find one.

http://www.rbttrans.com

X-trac

Long-time racing transmission manufacturer, they are now making a road-going (helical gears and syncro) 811 ft-lb mid-engine sports car transaxle (longitudnal engine, but with the gearbox portion transverse for much less rear length)... (~ $15,000)... cable shifters and paddle shift systems available.

http://www.xtrac.com

Quaife

Long-time racing transmission manufacturer, they make several road-going (helical gears and syncro) 450 & 650 ft-lb mid-engine sports car transaxles... ( ~ $15,000 w/cable shifter?).

http://www.quaife.co.uk

.

alfonso · Post by **alfonso** » Mon Feb 04, 2008 8:47 pm

thank you so much for the sources
half the adventure is the research

BillyShope · Post by **BillyShope** » Wed Feb 06, 2008 9:05 am

There's another, cheaper, solution. Consider the solution Pontiac found for their mid-engine Fiero. In effect, they simply pushed a FWD drivetrain back to the rear wheels.

Once you become open to this sort of solution, there are all kinds of possibilities. With your Mopar preferences, the possibilities are fewer, but still plentiful. How about the hemi engine and FWD arrangement from a recent Mopar, for instance?

Warpspeed · Post by **Warpspeed** » Wed Feb 06, 2008 4:56 pm

Hmmm.

What about the front wheel drive Oldsmobile Toronado ? A three speed auto, transaxle that would be absolutely unbreakable. Get rid of the chain drive and fit a bell housing and clutch. It could work if the diff rotation could be reversed. I have no idea if that is possible with that particular box.

http://www.ultimatecarpage.com/car/2315 ... onado.html

BillyShope · Post by **BillyShope** » Wed Feb 06, 2008 5:51 pm

Warpspeed wrote:Get rid of the chain drive and fit a bell housing and clutch. It could work if the diff rotation could be reversed.

You're making the job much more difficult. Just use the whole assembly "as is." Think of the rear of the Toronado "leap frogging" over the front. It's still going in the same direction, but what were the front wheels are now the rear.

Or, are you trying to find some way to get a Mopar engine in there instead of a GM engine? If that's the case, I think it's better to forget the Toronado and start with a FWD Mopar assembly.

Warpspeed · Post by **Warpspeed** » Wed Feb 06, 2008 7:02 pm

That is true. The only real problem with the Toranado layout is that the engine sits beside the transaxle, making for a very wide and asymmetrical layout.

Another way to reverse the rotation of any transaxle is to just turn the whole thing upside down. In any transaxle, the input shaft crosses the diff. Usually the input shaft passes over the top of the diff. But if you are planning a dry sump competition car, the engine can be lowered by inverting the transaxle. The input shaft then passes below the diff, and this will lower the centre of gravity, as well as perhaps allowing straighter driveshafts with large diameter rear wheels. The Porsche 917 race car was built like that.