Cross platform 2.8 MPFI to 3.1 MPFI swap ?'s

[scottryman]

I have a 91 cavalier with a good engine, bad transmission and bad body I picked up for $50. Some years ago, I also acquired a 1988 Beretta GT with a blown engine that I kept on the farm figuring I could one day either sell off for the body or swap an engine into. That day has come, but I want to make sure I'm using the right parts from each car to make everything work. Here are my concerns:

1) I'm going from a manual to an automatic, and a J body to an L body. Whose ECU do I use?

2) Will my suspension parts carry over? I know the STB fits (already test fitted), and I've been told I can use the J-body brakes, but what about the struts/shocks/springs? Can I use the Z24 sway bars?

3) Can I re-use my J-body exhaust if I need to? What about swapping mufflers?


In case you didn't notice, this is a very budget conscious build. I've already dumped money into new parts to get the engine going, and I'm hoping to not spend much more than another $100-200 to get it on the road and running safely.

[bszopi]

ECM shouldn't really matter, but you should probably swap the MEMCALs (the chip inside the ECM). That way all the wiring is correct, as well as the programming.

Not 100% sure on the suspension. Best idea would probably just look up new parts for the 2 cars and compare part numbers. If they are the same, then the stock parts will swap over.

J-body exhaust probably won't be bent right for the L-body, and possibly not long enough either. Muffler should be able to be swapped no problem though.

Oh, and welcome to the site!

[Superdave]

Yep, J body and L body exhaust routing is way different. most of the rest of that stuff should swap over just fine.

the 2 ECM's are the same but the chip inside is different. Use the memcal that matches the transmission. In your case it would be best to leave the entire 2.8 harness and ECM in the Beretta and just drop in the 3.1. The 2.8 chip will run it fine however you will need to swap over the EGR, throttle body and the plastic vacuum line setup to match those from the 2.8.

Welcome!

[scottryman]

Thanks guys. I want to keep the muffler for that nice growly sound the stock Z24 exhaust has. As for the TB, EGR and vacuum lines, those were all getting swapped in anyways. The 2.8 in the body now isn't even worth trying to repair from what I can tell. I just hope the wiring isn't too bad.

Silly question, but if I decide to add a WOT-Tech chip into my build, I should use the Beretta chip setup with the 3.1L engine?

[phonedawgz]

gmtuners.com is a great place to get your chip burned.

Ryan Gick is the guy to ask for.

[scottryman]

Unfortunately, I had to sell the car. I may try to find a 3rd gen cavalier and 3400 swap it in the spring though. I may be poor, but I'm not without ambition.