Michael_Rudy

Well i have been having trouble desiding what transmission i am going to use in my project, and we are almost ready to start cutting and getting ready to mount the 23a and whatever transmission i choose to use. First of all the tranny has to be able to hold a minimum of 900 rwhp. If i could afford it i would by a jerico or lenco but they all run $3000+, so i have been leaning towards a C4 with a transbrake, 5,500 stall converter, full manual valve body, with 6 gear planitarys. That will run me just over $1000, then i could just keep the foot to the floor through the 3 gears. Only thing about that is first gear is 2.42, so it won't get out of the hole quite so well, that is why i am trying to find out and see if you guys have any other ideas, thanks, mike

gambone

iTrader: (3)

To me it sounds like your the person I would go to for info. and it sounds good

hillbillyhector

ask the aussies.

they know a thing or two about big HP drag rx3s.

http://ausrotary.dntinternet.com/forums/index.php

Rotortuner

A t2 trans would be your most affordable choice to start with. then later go to a jerico or something. as long as your not running huge slicks, the t2 boxes hold. there are a few 2700 lbs. FC's with 500 + hp running 10's on stock boxes. i think it would hold up for the light rx3 for at least a little while. Who made the shaft for the 23a?

CJG

rotorhead_1

T2 trans hold up pretty well, try finding one from 89 or 90 then move on to G-force

Michael_Rudy

i designed the shaft and we are getting the machine shop to fab it up right now, it won't sound as neat as others as it is running 180 degrees apart instead of 90, i would like to see if it makes a broader torque band. We are only going to run about 18 psi which should net us around 800-900 whp on pump gas. Can you dog ring a TII trans?

Michael_Rudy

Also what type of clutch would be able to hold that kind of power?
The prices of the fancy clutches make me lean more towards the automatic

Doc Holiday

iTrader: (2)

Guru makes a dog ring kit for the T2 trans. The case is still the same however. I would think an auto would be more streetable, but depending on the power band of the engine, the stall could be so huge that the car is slipping the convertor just driving down the road. Who knows. A manual wont want to shift at high rpm, so dog gears are the answer to that, but then its hard to drive on the street. Ive pondered this dilemma for a while now. I'm going to watch the RX3 thread with the guy with the clutchless trans, to get his thoughts, and I have a buddy that has a old school colt with an 8000 rpm 2.0 engine and TH350 trans. It has a 5500 rpm convertor, and should be running the start of next year. If that car is streetable, I'll probably choose the automatic.
I would think that, since you will have such large displacement, you should be able to run an auto with no problem.

grease

If you can find one, look into a MOPAR 727 tranny..toughest auto transmission ever made..any Dodge/Plymouth/Chrysler care with a big block engine from the 60s and 70's had them. Add a 5000 rpm stall speed torque converter and manual shift valve body and you're good to go. If you really want to go wild, eleminate the torque converter and build a "clutchflite" transmission...regular dry clutch with the 727 transmission...use the clutch for launch and at stop/start, shift without it..just push the button...I had this setup in a 63 Dodge factory super stock car years ago and it was awesome, not to mention almost indestructable.

rotaryengineering

If your interested I have alot of knowledge about the C4 and the Turbo II with Dog Ring configurations. I did research on this a couple of years ago for my own turbo charged RX7 but, ran out of funds. I have a full race complete C4 setup running in my car and I am putting it up for sale this weekend. The whole setup cost me about $5,000.00 dollars because everything is custom. I am asking $3,500.00 for everything 13B Engine Adapter, Starter, Tranny Mount, Aluminun Flywheel, 6500 RPM 7" Converter, Oil Cooler, SFI Certified Bell Housing, C4 w/Transbrake/Reverse pattern shifter and the drive shaft. This is a complete bolt on unit ready to run just install and add oil.

Thanks
Albert

Michael_Rudy

727 trannys are extrememly heavy and a buddy i have just broke one with a nitrous'd 440, i think i might go with the C4 that i can get a deal on, it has a 9 inch converter which has been loosened up a bit, i think a 7" would be much to small for a car making that much torque.
Also with the automatic the engine will launch onder more boost

Michael_Rudy

I found a deal on a a 4 speed jerico i like but now i am wondering, if i launch at 9,500 rpm with the jerico, will the boost be as high as leaving at 5,500 off of the transbrake on the auto?