sehnsucht_musik

Hey guys I have been designine a mid engine supercar for over a year now and have my heart set on the 20B engine to power it. There are a few problems that arise with this set up though. I had read about a year ago someone asked a few questions about an Attack kit car and didnt really get too much information about it. The two problems would be cooling and a transmission. I understand its going to be a hot engine, but I will have many vents on it, and if it is still a problem would putting a bigger radiator on or a second or third radiator help this problem out? Also the transmission is a problem. They were talking about a Porsche 911 transmission, I was looking for something a little cheaper, but that would hold up to around 600 RWHP. Any help would be appreciated.

zenjoe

get a used porsche tranny, I don't know if it will hold 600hp for that long though. How much do you want to spend on a trans? Mendeola makes some really nice ones, but they start at $6k. by the way, the attack kit car was designed around a transverse engine mounting (sideways like a FWD car) so you are going to have to fabricate the back half of the chassis to put a 20b in it.

RotaryExperimental

look into sandrail applications for the trans. I didnt search to hard but after about 2 minutes on google i came up with this i didnt look over the page just wanted to point you in the right direction.

http://www.dansperformanceparts.com/...buggytran5.htm

SoloRacer

I'm putting a 20b in a Porsche 914 and bought my adapters and clutch from Kennedy Engineering They are pretty much "THE" guys to talk to about mid engine conversions. They have been doing it for years and a lot of the other companies that offer kits are just reselling the original Kennedy stuff. The parts are of high quality and Hobart Kennedy has been very patient and helpful. I purchased the adapter plate, six puck copper unsprung clutch and stage 2 pressure plate from them for a total cost of around $1200 US. I'm using a stock Porsche 915 transmission am told this clutch set up will hold 500 ft-lbs torque. I'm told that torque is what kills transmissions. Kennedy Engineering sent me information on different transmissions that are available for mid engine use. I've been told that the 915 is good for about 400-500 ft lbs torque. More than that and you have to go to the 930 or G50 transmission. The downside to the 930 is it's only a 4 speed. The G50 is a 5 speed but I read that it is for rear engine use only. It has been successfully installed in a in a Delorean with a 20b.

To get the 915 to work you have to flip the ring and pinion for mid engine use and it's recommended that you convert it to a side shifter from the original tail shifter design.

WEVO makes some wicked transmission upgrades for the 915 but they are not cheap.

P.S. All torque numbers are at the flywheel - not the ground.

As for cooling I'm using a Renegade Hybrids set up that is normally used for V8 conversions. It was $1000 US for the set up and I was tempted to get one made cheaper but was told that the Renegade system works very well and chances are a home made system will only cause grief and possible overheated engines - which in the rotary usually means a rebuild.

Here is a pic of my car:

SoloRacer

A flywheel was also included in the Kennedy kit. You will also need the flywheel counter balance weight from an automatic transmission rotary car. Fortunately, all 20b cosmo cars were automatics. If you don't get the transmission with your engine be sure to request the counter weight.

SoloRacer

I noticed that I did not directly answer your transmission question. To my knowledge, and according to the chart that Kennedy Engineering provides, there are no mid engine transmissions (transaxles) that are both cheaper and stronger than the Porsche transmissions. They list only 4 transmissions that are stronger than the 930 and two of them are automatics. The two manuals are a Medeola MD 4S-2D which they list for $7000US and the Fortin which they list at $13600 US. Both are 4 speeds.

I saw a 1200 hp twin turbo V8 Ultima kit car for sale on e-bay a little while ago. I'm not sure what transmission it was using but I doubt it was cheaper than the Porsche seeing as how the guy claimed to have $300,000 tied up in it. I have also seen a Audi powered 914 that used an Audi transmission but I also doubt that it was cheaper than the Porsche and don't know how strong it was.

sehnsucht_musik

Hey thanks for the info guys Im gonna look all of this up. Thanks for the help.