legacycentral bbs

Got a project in the planning stages.



We've decided, for reliability and cost, we're going 4EAT. Power will start in the 270 range, at the crank. Might be more later.

There's a guy over on USMB who figured out how to solder a programmable EEPROM chip to a first-gen legacy TCU. He then re-worked the code to allow paddle shifters. I have one of these TCUs.....

We have a '91 SS parts car with a 4EAT in it.



So, a few questions....I'm under the impression that the SS trans is somewhat unique and durable.

Could a person install 4.111 or 4.444 R&P in it?

I see Modena makes a front LSD for the WRX 4EAT. Would that work in our application? Any other options?

Torque converter. Want a slightly higher stall. Options?

Paddle shifters in a rally car?!? Sounds awesome. Isn't Derek in the cities kinda the 4eat god?

Hey Chux,


The SS transmission is built to a higher spec than the N/A units, but at 270 CHP, you would be on borrowed time.

At the least, I would recommend the reprogramming kit from Tans-Go. As for the higher stall converter, things are availible. The original unit can be modified by places that rebuild torque converters. I'm not sure where Derek sources his. Otherwise, you can switch to WRX input shaft and use the WRX converter.

As far as the shorter gears for it are concerned, you wouldn't want to. First is so short that it would be useless with a shorter final drive.

The Modena unit does work in the SS auto. It's a bit spendy, but nice.

Thanks Dan! Should have known you'd be the one to know. Yea, that diff is pretty pricey, but there's a Modena torsion front diff in the 5MT in Izzy's rally car. That trans has some seriously hard miles on it (broken shift fork, R&P teeth sharpened, both front bearing locating pins broken), and the diff is still in pretty good shape....except the broken stub, which may have happened doing donuts in his back yard.


We'll see how our next fix 'n flip project goes before we decide on the budget, but hopefully that diff will be in it.



Do either of you guys know of a good shop in MN that would rebuild/modify the converter?

Sounds very interesting. I wonder what this "parts car" you speak of is? make sure you only take the 4EAT stuff off it LOL. Let me know if you guys need any help.

93forestpearl wrote:Hey Chux,

The Modena unit does work in the SS auto. It's a bit spendy, but nice.

Does that mean the Modena unit would fit any phase1 4eat transmission? No change of drive shafts? Just bolt it in?