E30 BMW Questions: Grassroots Motorsports forum: Grassroots Motorsports Magazine

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Jan. 9, 2010 7:12 p.m. Woody SuperDork

While I've always loved E30 BMW's, I've yet to own one and some of the details are a little sketchy for me, so I need some enlightenment.

Wheels: 4x100 14's, right?

Steering rack: Is it ahead of (front steer) or behind (rear steer) the center line of the front wheels?

Limited Slip: Did all the "is" 3 series cars have the limited slip? What about the "es" or later 325i? What should I look for in order to find one with a Limited Slip? I know that just lifting the rear wheels and watching how they spin isn't always reliable.

Brakes: Will 13" wheels clear the brakes?

Suspension: Shocks or struts?

Thanks
Jan. 9, 2010 7:43 p.m. DukeOfUndersteer Dork

From what i remember from my e30...

Wheels - 4x100 - yes 14's stock - yes

Steering Rack - Rear steer (if my memory serves me right)

Limited slip - not on mine, i had an open diff 4.10

Brakes - dont think the will clear... but dont hold me to it..

Suspension: the fronts are Macpherson struts, rears are IRS with the shocks seperate...
Jan. 9, 2010 8:29 p.m. bam2002 Reader

e30tech r3vlimited are sites on E30s.,
Jan. 9, 2010 8:59 p.m. Sonic Dork

I have an 88 325is in the garage now, owned it since 2002 and have put nearly 90k miles on it.

4x100 14's are stock, non "is" cars get 14x6s, "is" models get 14x6.5 BBS basketweaves which are very light. Center bore is 57.1mm, preferred offset is +22 to +35 depending on wheel size. 4x100 Miata/Honda wheels need spacers to get the right offset.

Steering is front steer (I just went to the garage to check). Steering ratio is a bit too slow for my preference, but that is solved with E36 or Z3 racks.

"is" and "es" models have limited slip from the factory. By this time, though, so many have had them swapped in or out, but originally, that is what they came with. Mine noticeably has it, happily.

Brakes: nope, 14's are tight, no room for 13s.

Suspension: Mac struts in the front, trailing arms with separate shocks/springs in the rear.

I'm about to put mine up for sale if you are in the market, black/black 325is, excellent original paint and interior, all the wear items have been replaced, and it's a ball to drive, but I just bought another Miata and don't have room for the Miata, MGA, and E30. As great as the E30 is, I've had it so long that it is time to move on.
Jan. 9, 2010 9:08 p.m. Woody SuperDork

Thanks for the info. I'm just looking for a parts car.

Did the ES get the BBS wheels as well?
Jan. 9, 2010 9:24 p.m. JohnW Reader

Woody wrote:

Thanks for the info. I'm just looking for a parts car.

Did the ES get the BBS wheels as well?

No, the ES got the same bottlecap-style wheels as the run-of-the-mill e30s.
Jan. 9, 2010 9:27 p.m. Giant Purple Snorklewacker SuperDork

Sonic wrote:

I'm about to put mine up for sale if you are in the market, black/black 325is, excellent original paint and interior, all the wear items have been replaced, and it's a ball to drive, but I just bought another Miata and don't have room for the Miata, MGA, and E30. As great as the E30 is, I've had it so long that it is time to move on.

Sonic, if Woody isn't interested, I may be. I am culling my own herd but I'll still need a good daily driver when all the rest of the machinery has moved out. Do you have details and a price yet?
Jan. 9, 2010 9:30 p.m. Woody SuperDork

JohnW wrote:

No, the ES got the same bottlecap-style wheels as the run-of-the-mill e30s.

Bottlecaps are relatively heavy, right?
Jan. 9, 2010 9:31 p.m. Giant Purple Snorklewacker SuperDork

Woody wrote:

JohnW wrote:

No, the ES got the same bottlecap-style wheels as the run-of-the-mill e30s.

Bottlecaps are relatively heavy, right?

The bottle caps are heavier than the BBS basketweaves but not really heavy at all. They are very narrow though so not really very good for performance rubber.
Jan. 9, 2010 10:02 p.m. z31maniac Dork

Limited slips will have an "S" on the tag of the diff before the ratio indicating an LSD.

3.73 is 6cly manual 4.10 is auto M3 is 4.10

4 cyls got a small instead of medium case, manuals got a 4.10, auto verts got a 4.27, e36 autos got a 4.45

i've got a couple of E30s right now
Jan. 10, 2010 9:40 a.m. mad_machine SuperDork

if you want to go crazy with the suspension, the front suspension out of the E36 will fit.. you will need the rear suspension from a Z3 or a 318ti to compliment it.

Get a wrecked (or parts from) 2.8 or M Z3 and swap the suspension over (including steering rack) and you will not only gain 5 bolt rims (5 x120) but you can easily fit 17s (width my dictate) and some MUCH larger brakes for not a lot of money
Jan. 10, 2010 10:36 a.m. Giant Purple Snorklewacker SuperDork

mad_machine is correct about the E36 front, however, when you use them you will get some odd geometry that puts a lot of unremovable castor into the front - its not a huge problem but it can compound the steering effort if you also widen the track, run huge wheels and put R rubber on it. Doubly especially if you add the weight of an S52 motor and remove the power steering.

Ground Control makes coilovers called a "Bastard Kick" for exactly this situation and they basically restore E30 geometry while using the E36 spindles.

If you go this route with or without the GC kick, go all the way to M3 spindles up front so you can use the larger brakes and get the benefit of the bigger wheel bearings. They are a bit heavier but will take the pounding of ponking the curbing as well as increased side loading from 17" wheels with 245/40 R comps. I have some brackets I had made that allow the use of Wilwood Superlites with OE rotors i can send your way at my cost (I had to make 10 sets to make the CNC worthwhile). They increase the clamp force, feel better and allow you to buy $100 race pads instead of $250 pads.
Jan. 10, 2010 5:33 p.m. z31maniac Dork

^How much you want for a set of those brackets?