e30 suspension

[bryson]

ok, i've searched already-- nothing came up :)
which suspension pieces from an e30 (85-91 3 series) will be swappable to a 'ti if any? i've got a 91 318is and it's on racing dynamics springs and bilstein sports and i've got some adjustable sway bars and i don't want them to go to waste if/when i buy a ti. they're based on the same suspension, so i figured that they might be interchangeable.
and does anybody know of a cheap 318ti with a blown motor, skipped timing chain, etc, near San Diego that won't go for much? i've got another motor to build one good one up from.
thanks guys
-bryson -- future 318ti 6 owner

[J!m]

The E30 rear springs will swap in. Not sure about anything else.

M Coupe`/Roadster rear sub-frame assembly bolts in (as a unit) for the best of everything...

The front struts MAY be useable, but again, I'm not sure. The spindles/brakes etc. are all different- 4 bolt vs. 5 bolt wheel pattern. Brakes may work. I'm really not sure about those either...

[bryson]

thanks Jim,
i know that the brakes won't work, but i was just thinking that if the spring perch diameter was the same on my car as on yours, my fronts may be able to work as well. i'm gonna go out on a limb here and say that the front sway bars will not work, which i'm 99% sure of.
what are some companies that make ti springs? (i'm assuming that they're different than normal e36 fronts). the racing dynamics springs were a little too soft for me, i'm looking for something close to a j-stock race spring.
i've also heard of/seen ti's that lift rear wheels during hard cornering.. is it common, or does it only happen with really stiff sway bars in the back?
one more question: do the hatchbacks tend to understeer or oversteer while stock and on a lowered suspension (without aftermarket sway bars)?
thanks again,
-bryson

[J!m]

I would venture a guess that the diameter of the springs are the same. The area of concern is the length, as well as rate. I believe the E30 is lighter in the front than the E36. (assuming both are 1.8 models) If the length is the same, I would try E30 M3 front springs (which you should be able to find used) and see how those work out with the stock 1.8/1.9. If you like those, there are TONS of E30 front springs available out there. The E30 rear springs will fit, as I have seen a converted ti with E30 rear springs in it (Bimmer Magazine a few years back).

All the respected companies make ti springs. I would go with H&R's, but that's personal preference. Since I have the six in my car now, I went with factory Euro M3 fronts, and M Roadster rears. The fronts are stiffer than I expected, but the car DOES NOT ROLL on a hard corner.

I have never seen a ti lift a rear wheel, but I'm sure it's possible with slicks and a FAST, hard corner. The suspension 'droops' more than it can be compressed, so it tends to stay on the track.

If you up-rate the rear sway bars, you must reinforce the mounts on the stock ti's rear trailing arms. They will rip out, espicially at the track. The M-Coupe` and M-roadster rear sway bars bolt right in (I have the M Coupe` rear sway bar in my car now) with the Coupe`/Roadster's bushings and clamps.

The stock sport ti (slightly lower) understeers horribly. There is no power to swing the rear around, either. Better allignment setting would certainly help, as would slicks, but in street trim, it wants to go straight (even without a LSD). This always bugged me about such a well-balanced car...

[bryson]

If you up-rate the rear sway bars, you must reinforce the mounts on the stock ti's rear trailing arms. They will rip out, espicially at the track. The M-Coupe` and M-roadster rear sway bars bolt right in (I have the M Coupe` rear sway bar in my car now) with the Coupe`/Roadster's bushings and clamps.

The stock sport ti (slightly lower) understeers horribly. There is no power to swing the rear around, either. Better allignment setting would certainly help, as would slicks, but in street trim, it wants to go straight (even without a LSD). This always bugged me about such a well-balanced car...

thanks again Jim,
we e30 guys have that same goddamn trailing arm problem :( i guess i could save my reenforced trailing arms for the ti...
i might just not use e30 springs at all and go with adjustable coil overs from ground control, that way I get to pick my spring rates and I don't get insane negative camber, thus making the car understeer way too much. but the car will not have a 4 banger in there. that's just not right :D i'm thinking of getting an m50tu and swapping in M3 cams, valve springs, tappets, and retainers and i should be pushing around 10-15 hp/15-20 ft/lbs shy of what the s50 has. for a LOT cheaper :)
god damnit I want a 'ti
and if you could guess, how much would a 95 ti with a ****ed up engine, in generally decent condition go for? i like projects :P
-bryson

[J!m]

I think it will be easirer to find a f-ed up body than a motor. The 1.9 is a nice motor, and quite tuff.

I would find a 2.8 from a Z3 roadster. These (and only these) have aluminum blocks, as opposed to the cast iron used for all the others (Including the M-roadsters). This will keep the weight distribution near ideal.

THEN instal your M3 cams, and/or a 3.0M head (I think that will fit OK) and get an OBD-I wiring harness/ECU from a '95 M3 as well.

I have the 3.2M motor in my car, and it is VERY nose heavy. BUT, all I have to do is apply gentile pressure with my right foot to steer the rear around. Not possible with the 1.9. I also have the complete M3 front suspension, so the caster plates are installed, offset bushings, Euro M3 springs, big (stock US M3) front sway bar, and it seems to work VERY well. I really must get to an auto-x course and see how hard I can push it, but the LSD I got with the M roadster rear sub-frame makes this car easier than ever to drive now. It scared me at first, but now we have an understanding... I kept the rear springs from the M roadster, and am using the SLIGHTLY stiffer (than the M roadster) M `Coupe rear sway bar.

This mis-mash of factory suspension parts seems quite happy under my bastardized car, and I recommend it to anyone. The ride is a bit harsher than the stock ti's sport suspension, but it rolls less to... (you could sub in the US M3 front springs for a softer ride, and a bit more roll.)

A problem we Compact6 owners all face is an exhaust system. I am currently using a cut and well dented M3 muffler. I was told that the Supersprint E46 330ci muffler mounts perfectly, and only the input pipes have to be shortened. This from someone who has done it (at BMP I think). I saw a REMUS exhaust for the 330ci on another Compact6 that turned out to be a NIGHTMARE to install.

[bryson]

interesting setup you've got there :D i'd like to solve all those problems by going to ground control and getting some adjustable linear-spring 'coil overs' (since the rears aren't really)

heh, my m42 skipped the timing chain before i bought the car, so they do go bad every so often. although it's extremely rare.

exhaust shouldn't be a problem, I can bend all my own piping, and weld them all together, which should save some effort and money.

i've thought about one of those alu blocks, and no matter how tempting they may be, it's a bit out of my price range. so i'm looking for a 95 ti, and a 94/95 2.5L, which would be the cheapest way to go (no converting anything). I'm even entertaining the idea of slapping in an m50 cammer (no VaNoS), i've heard that they're top end screamers if built well :D
if worst comes to worst, I could even use a spare m20 tranny (i'll be using the flywheel anyway (Much lighter)) although that would probably require a custom driveshaft :?

and the instrument cluster... is there a coding plug that you just swap out from the front of the cluster like in e30s? or do you have to swap clusters all together?

eventually, i'll be going with the 4 door dash/door panels.... but that's after the engine :D
after reading more and more, i'm really realizing how similar tis are to e30s-it's amazing.
thanks again Jim, you're my go-to-ti guy ;}
-bryson

EDIT: what's the ratio on your diff? i'm thinking of getting a 3.25:1 or a 3.73:1 depending on the power i decide to build the engine up to. large case limited slip, of course.
I had a 4.10:1 with my 6 once and the thing topped otu 5th in NO TIME, so I know that's going to be too short with an even more powerful motor.
it's either brute force acceleration, or 'gearing assisted'... i can't decide

[J!m]

Stock ti w/5-speed is 3.45:1. M-`Coupe/Roadster is 3.23:1. I am fairly sure anything lower than 3.45 will be rather stupid with the six, if it's on the road. If you are trying to drag race, go even lower, and cut the car to get some rubber under it.

I missed the aceleration at first when I switched the rear, but the 3.23 is a better match to the trans gears once the 6's torque is available. It broke loose ALL the time with the open 3.45, and now only if i want it to with the 3.23LSD. (this is with 245 tires- 275's are the replacement, IF they will fit under the car...)

Honestly, something in between would be perfect for people like us, but the increase in fuel economy is nice too. It's not like the 4, but it is better than the 3.45 rear was. I think I was getting 27-28MPG with the 3.45, and it's slightly better now, maybe 29-30.