I have a 1992 325is and have replaced the engine with a 1995 M3 engine, ECU and Turner Chip...Big improvement!!! I left the original trany and rear diff. What would I gain by installing a 95 M3 Trany and LSD rear diff. Any other suggestions???
Subframe renforcements. for sure. When you do swap out all that driveline stuff, you better weld in renforcement plates while the whole subframe is down, seriously. With the extra power the M3 engine provides, it'll put extra stress on it and will rip it out very quick, especially since you have an early body car. If you didn't already know, it's a weak element in the design of the car, and when it fails... Damn it's expensive. Swap out all the bushings too, you'd be amazed at how much the subframe rotates under load. (It rotates the same direction the wheels spin under load, I'd say about 1-2 full degrees on my weak-ass 323is with a slushbox & only 100k miles. Go ahead, strap a camera under your car and see for yourself!)
If you like getting the back end loose or drive in snow or track your car, you are gonna want that yummy LSD, and your going to want those renforcement plates more.
M3 tranny is stronger than the regular ones, other than that I can't tell you much more about it, sorry.
The infamous X brace, get that. People report a tremendous improvement in handling and overall stiffness. They say way better than front and back shock tower braces. It's fairly cheep, hundred to $200 usd. Plus, it helps guard your oil pan from getting SCREWED from bottoming out, though your tranny sumps will still be exposed.
I dont know what ratios your tranny and diff have but if you do the tranny swap and lsd swap you would be gettign a final drive ratio of 3.15 or 3.23. Depending on what yours is now it could mean mroe acceleration or more top end. Anyone know his final drive?
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