Off the wall E36 compact question

This is in regard to nothing, as I have no plans or actual interest in doing this, but something popped into my head at lunch time today. I love the E36 compact, to me it’s the best looking E36 model of all, but then I love hatchbacks. We all know that the compact had the E30/Z3 style semi trailing arm rear suspension and anemic 4 pot up front. The power part is easy to resolve, but what about the rear suspension? Obviously the mounts are different, but how different is the actual floor pan? Is it feasible (anything is possible with metal melting equipment, but I’m talking feasible here) to put in the regular IRS from the E36/E46 cars in an E36 compact, or is it a totally different floor pan? Also although we didn’t get them this side of the pond, what was the rear suspension on the E46 compacts sold in Europe?

Just musings.

Anything can be done with enough fabrication. However, I don't think the end result would be worth it. The e36's multilink design is completely different from the ti, z3, and e30 suspension and short of totally re-fabbing the back half of the car you won't be using e36 suspension on any trailing arm BMW.

Nothing wrong really with the design, its just a little different. Z3M stuff is a direct swap in for beefier control arms/diff/axles/brakes. The only thing it'll do differently than the coupe/sedan is oversteer if you liftoff mid corner.

Will e30 M3 rear suspension drop in? Not that those are easy to find or cheap...

In reply to Cone_Junkie:

No, only the differential from e30's will bolt up.....even the ti rear suspension is an updated and upgraded version of the e30 stuff.

nokincy wrote: Anything can be done with enough fabrication. However, I don't think the end result would be worth it.

YEah, that's why I said feasible not possible. Anything is possible with metal melting toys and a good ruler, feasible is different. It sounds like the answer is 'No' to feasible.

As to why, no matter how much work you do to a semi trailing arm set up you can't get over the camber control issues in jounce/roll which can lead to snap oversteer. Like an arse engined porker, you can polish the pig, but you can't make it silk, just a very very nice pig (said by an oil cooled Porker fan)

I understand that the coil spring in this setup, E30 and E36, will "bind". The spring rates used in auto crossing, north of 800 lb. rears in the stock spring perches, will have the cars on as little as two wheels going around corners. Converting to true coil overs does help but... You have to reinforce the shock mount and tie it into the cage.

In reply to Adrian_Thompson:

Hit me up once I have the ti going back to autoxes, I'll make it to one that you can codrive at. They seriously aren't bad.

I kind of wanted one of these cars with a S52. I like them quite a bit, probably my favorite E36.

When I had my Ti.. I never once wanted for the more advanced IRS from the sedan or Coupe'. It is a decent system and as long as you do not life mid-corner, is a very strong workhorse of a rear suspension.

Somebody mentioned using the E30M3 rear suspension.. I do not think there is must difference between the Ti's rear suspension and the Original M3s.

the standard answer is z3m rear bits and e36 m3 bits up front. Never quite understood the disdain for these cars. Same rear that everyone raves about on an e30, better front end than e30 and pretty close in weight to an e30. Tis with m42s can take boost well or if you want to add some weight, the chassis is designed to take m/s50-54s.

I agree with you OldTin. While the hatchback body style is not everyone's cup of tea, the disdain most Bimmer lovers have for this car cannot be believed.. It is absolutely everything people loved in the E30.. but with a stiffer body, more usable interior, and a better front suspension.

The same people that hate the Ti.. will rave about the E30 to no end

I have (like many here) an affinity for hatchbacks and the 318ti is no exception. If I won the lottery one would be in my garage, this is a tag for future reference.

I don't like the 318 because the rear end of the car has a different proportion to the rest of the car.

In reply to Mr_Clutch42:

I believe you only perceive it that way because you've seen so many E36 sedans.

I agree that it does look funky, but in a good way kind of funky.

I like how the compacts look. The market seems to value them more than 325i and 328i. There was a 323ti sold in Europe with the aluminum block 2.5L engine. Semi-trailing arms are 1960's tech:

jr02518 wrote: I understand that the coil spring in this setup, E30 and E36, will "bind". The spring rates used in auto crossing, north of 800 lb. rears in the stock spring perches, will have the cars on as little as two wheels going around corners. Converting to true coil overs does help but... You have to reinforce the shock mount and tie it into the cage.

Front coilover springs tend to bind on E36 cars not any spring at the rear stock location. The front struts are very height restrained. Lowering the front and using "camber" plates in front to add static negative camber lowers the front roll center a bunch. Also people run taller than stock tires to get slightly wider tires.

If you are going to swap in a different rear suspension on a compact, there are much better options than an E36 Z-axle.

Adrian_Thompson wrote: Also although we didn’t get them this side of the pond, what was the rear suspension on the E46 compacts sold in Europe?

The E46 compact used the same rear suspension as the other E46 cars and the E85/E86 Z4s.

Matthew Huizing wrote: If you are going to swap in a different rear suspension on a compact, there are much better options than an E36 Z-axle.

Such as? I could always use ideas.

If you want to stick with BMW pieces the E9x\E8x rear suspension has better geometry and everything attaches to the subframe unlike the Z-axles. The Mercedes W201 190E rear suspension might be a cheaper, easier to find alternative--probably a better width for the compact.

the biggest issue with swapping suspensions on the E36/5 is the fuel tank. It straddles the driveshaft and sits above the rear suspension. It was literally designed around the suspension design.. unlike the sedan and coupe' where it sat behind the wheels, it is under the backseat on the compact

In reply to mad_machine:

And that is why I haven't had the desire to put a fuel cell in.....its already in a great spot for the time being.

Other than a need for safety, as the stock tank is plastic, I cannot see a reason to replace the stock tank in the Compact. I doubt anybody could get it lower or in a more central location without doing a -lot- of fabrication

The Interior.

Yes, that's why most BMW people dislike them. The e36 interior likes to fall apart, and many parts are NLA.

Other than that, they are fine cars

The only thing that falls apart on the interior is the door panels. They used bad glue to hold the door posts to the panel; some JB Weld and a few hours of your time and you'll have rock solid door panels. Other than that, the headliner may start sagging, but many other cars have that same problem.

My interior is holding up like a champ besides my driver's door panel. I put it back together but there are some screw holes from the previous owners.