Jump to content

Auto Transmission swap


schaffman
 Share

Recommended Posts

I have considered 200r4, th350, and the 700r4. The problems I have been looking at, is the price of the adapter plate, the 200r4 is not meant for a lot of torque, th350 = no OD, and the 700r4 sucks up the most horsepower. Pluses, much more parts availability, easy to obtain stronger/ built models including modified torque converters, along with more favorable drive/gear ratios. Edited by movin on
Link to comment
Share on other sites

I've built my own race auto trans before. If you have a spare I could look into beefing it up for you. Also a higher stall converter would make a world of difference without having to resort to a higher rear gear.
Link to comment
Share on other sites

What would you do to beef up the L4n71B? HD plates, steels and bands and probably a better torque converter I would think. I am trying to get Mike to chime in so that I can hopefully get some of his rebanded kevlar, however no response as yet. Also, what would you be charging? Their may be members here that would take you up on that..
Link to comment
Share on other sites

I haven't looked inside one yet so I can't say for sure what could be done. When I did my ford trans I doubled the plates in the clutches, put in a better band, replaced 3 pinion gears with 4 pinion units, modded the governor so WOT shifts happened at a higher RPM, rebuilt then added a custom shift kit to the valve body and added a higher stall converter. It shifted very fast and slammed into the next gear. The tires would chirp with every gear change at anything past 1/2 throttle.

 

Slamming into gear sounds bad but it's actually good for the trans. Soft shifts are achieved by overlapping 2 gears as it shifts. The clutches are slipping during the overlap. So by setting up the valve body to slam into the next gear you drasticly reduce clutch slippage and prolong their life. The tradeoff is the jolt when the trans shifts gears.

 

 

 

If anyone local has a spare auto I can dig into I can see what could be done.

Link to comment
Share on other sites

If you are considering a GM trans, I'd look real hard at the 200R4. While fairly weak from the factory, they can be built to take whatever you throw at them and they are tiny compared to the 700R4. The Grand National guys are running them and doing some pretty impressive wheel stands with them. While I haven't mocked one up in a Quest, they will fit an RX7 tunnel without mods but a 700R4 won't. The Ford C4 is another small trans that can be built to take some serious punishment, but no overdrive.
Link to comment
Share on other sites

  • 1 month later...

I have done some research on the L4N... There seems to be a lot of different opinions on what can be done to beef up that trans. Almost all agree that performance mods can be done at a speciality speed shop but the $$ spent to do that seems high. I like the C4 as it is cheap, reliable and very easy to maintain and repair. Has anyone done this before as I have not researched it, If someone has then send me in that direction.... ALso, are the stock torque converters in an 88 conquest all the same? I was asked for the "stamped" ID number on the torque converter as it was needed for a custom build... Does anyone know?

 

I can probably get an L4N to you if you want to tear into it.... Will PM you (ucw)

Link to comment
Share on other sites

According to the forum threads a healthy L4N should be able to handle around 250-300 hp... For a "light duty" trans that is not too bad if correct..
Link to comment
Share on other sites

 Share

×
×
  • Create New...