Anybody running a 502 with an automatic

[stepinwolf]

I have a friend who has just purchased a 502 Ram-jet, and needs to run an automatic with overdrive. The local dealership recommended one of their newest automatics with OD, but after checking the HP recommendations, I noticed it's far from adequate for the HP output.

They also mentioned that he would be needing an additional electronic module ( almost as expensive as the tranny ) to control the shift points. Sounds way to expensive for me. :nono

Would anybody care to comment, either through their own experience, or first hand knowledge on this type of installation. I am tempted to recommend he go with one of the " Streetfighters " from TCI, but not having installed one, I don't feel comfortable in suggesting something I have not used myself.

Thank's to those of you who take time to respond to this request.

Stepinwolf

 

[BarryK]

Bob
John McGraw I think is running an Auto trans in his '59 project. It's not a 502, I believe it's a LS2(?). sorry, don't remember excatly and can never keep those new motors straight in my mind anyway. Either way it's a decently powered system so hopefully he will chime in.

 

[IH2LOSE]

I am running a built 700R4 trans behind my GM performance 454 HO crate motor.The motor is rated at 425 HP with 500 fpt. The only electonics in the trans is a painless wiring converter lock up. Real simple wiring.

At first I was told the 700R could not stand up behind a big block. My builder did some home work and built me a stout trans . The service wrighter actually found a picture of a C1 hanging the wheels and put it on the builders bench and said thats what the trans has to stand up to

When I picked up the trans from them the builder siad I dare you to blow it up

 

[cbernhardt]

The local dealership recommended one of their newest automatics with OD, but after checking the HP recommendations, I noticed it's far from adequate for the HP output....

I chose the GM 4L80E overdrive automatic to go behind my 572 cu.in. engine. I believe that the 4L80E is the highest torque rated, readily available 4 speed auto that GM uses (excluding the Allison), and it is used primarily in the heavier duty trucks. It is essentially a Turbo 400 with an OD gear. I'm not sure exactly what the power/torque rating is, but I figure if it blows up, I can have it rebuilt to higher specs. Hopefully the tires will be the limiting factor and keep the rest of the drivetrain from breaking.
You do have to use a controller with the 4L80E if you are running it with a non-computer controlled motor. I have the TCI software for mine. I'm not far enough along with my project to have even cranked the engine so I cannot comment on the transmission operation.
Charles

 

[stepinwolf]

I chose the GM 4L80E overdrive automatic to go behind my 572 cu.in. engine. I believe that the 4L80E is the highest torque rated, readily available 4 speed auto that GM uses (excluding the Allison), and it is used primarily in the heavier duty trucks. It is essentially a Turbo 400 with an OD gear. I'm not sure exactly what the power/torque rating is, but I figure if it blows up, I can have it rebuilt to higher specs. Hopefully the tires will be the limiting factor and keep the rest of the drivetrain from breaking.
You do have to use a controller with the 4L80E if you are running it with a non-computer controlled motor. I have the TCI software for mine. I'm not far enough along with my project to have even cranked the engine so I cannot comment on the transmission operation.
Charles

Charles, The 4L80E was one of the tranny's recommended to me, along with an additional electronic controller. However in as much as the 502 Ram-Jet, is already computer controlled, I was wondering if it could not be programmed to also take care of the transmission. Seems as though most Forum members using the 502, are running them with a carburetor.

Stepinwolf

 

[cbernhardt]

I'm pretty sure that the injection system on the 502 Ram Jet will not support an automatic transmission. In addition the computer on the Ram Jet is not even user programmable. Your only recourse would be to adapt a "normal" GM injection system to the Ram Jet. I know someone who has done this with the 350 Ram Jet and I believe there is someone on the Chevytalk forum who did it with the 502. Lots of work though.
Arizona Speed and Marine is the only company I know of that can reprogram the Ram Jet computers. You might give them a call and ask if they offer any automatic transmission support.
Forgot to mention - the 4L80E is no lightweight, weighs in at about 225#.
Charles

 

[Wilkinshc]

Have you considered a 200r4? There are several tranny builders who build them for the buick Grand National community and they hold up in 700hp plus cars. The fact that they put out as much or more torque then the 502 and the trannys are in heavier cars (GN 3800lbs) then a vette I would expect it to hold up in a vette with a 502 ram jet with no problems. No electronics to worry about unless you use a lockup torque convertor which I would, there are contollers which are priced fairly cheap to lock and unlock it. Price for a built tranny will set up back about 2800-3000 but at that price they hold up in 3800lb cars running 7-8 sec 1/4's. It also wieght alot less then a 4L80E. I plan on running one in my twin turbo vette with goal of 800-850 hp. I soon will be setting up the tranny mount for the 200r4 so I can let you know what it takes to putting it in.

Chuck