What suspension improvements should i make?

[jimsill]

Hey folks, i am about to overhaul the suspension on my '89 325i sedan and need some advice. Im leaning toward bilstein sports and an eibach pro-kit. My mechanic knows all the little things that should be done too, like shock mounts, etc.. But i must decide what performance componants to install. It is a daily driver and probably will never see a track, i just want to lower its stance and close the fender gaps while retaining somewhat reasonable ride comfort. Here are some components ive been considering:

Shocks: Blistein sports

Springs: Eibach Pro-kit
H+R
Bavarian Autosport

Other: H+R Coilover?

My spending allowance is about $600-700 TOPS!!! Help me decide. Thanks, Jim

[ettsn]

Although I haven't used those setups on an E30 (I had Konis on mine), I have used those setups on other cars (so take this advice with a pinch of salt). I'd probably go with the Eibach Prokits and Bilsteins, as the H&Rs, while fantastic, tend to be a bit firmer (thus farther from "reasonable comfort"). The coilovers are the best performing setup on there, but can you get those for your budget? I know on an E36 they're $1000+.

I had red Konis on mine with E30 M3 springs (I had a 318). Superb. I also know of a friend that did H&Rs with Tokiko Illumina 2s that, while firm was very, very good (87 325is).

-Paul

[Dub-Dub]

H&R and Bilsteins and love them. Never driven the others, so I can't compare, but I am happy with my choice, and never would I consider them too hard... not harsh by any means.

[ettsn]

Didn't mean to imply that H&Rs were "harsh" or "too hard", rather simply firmer than Eibachs. Sorry if that was not very clear.

-Paul

[Jared at Pelican Parts]

Take a look at these....
http://www.pelicanparts.com/bmw/techarticles/E30-Front_Suspen/E30-Front_Suspen.htm

http://www.pelicanparts.com/bmw/techarticles/E30-Rear_Suspen/E30-Rear_Suspen.htm

[jimsill]

Great tips guys, thanks!!!!

[ettsn]

Great writeup, Jared!

-Paul

[Rich911E]

I think your budget is a bit slim, but here are my suggestions:

Don't forget tires. The best suspension in the world won't be worth anything with 195/65/14 all season tires. I would try to get some used Koseis (check with the track guys, they all run them) and good tires. I have 205/50/15 Falken Azenis Sports (about $300 a set) which I like a lot. TireRack has Kuhmo Ecsta 711s (decent) for $43 each in 205/50/15.

As far as springs and shocks, I would go with a kit. Springs and shocks are going to be $600 if you go with H&R Sports and Bilstein Sports. I have H&R race springs which would be way too much if you are never going to the track. Even if you are going to the track H&R sport springs will do very well. A friend has them on his '88 325 and I did notice they were softer, but they were still quite a bit stiffer than stock (although stock is kind of marshmallowy to me). They are considerably more comfortable than the race springs. Bilstein Sports are great and reportedly last longer than the Konis (no hard data on this). My understanding is that the H&R cup kits are the same spring rate as stock.

If you aren't going to the track, I would suggest the a less expensive spring alternative and the standard bilstein shocks. You need the bilstein sports to control the action of the very stiff springs, but if you go with a standard spring rate (or just a bit more), you don't need a super shock to control it. Plus, your ride will be like factory. You will gain the look you want and a lower center of gravity with the lowered ride height. The lower profile tires on wider rims will give you a much crisper turn in and more grip.

You didn't mention any sway bars, but I would post an ad to see if you can find a different sway bar. My understanding is that the E30 M3 bars are effectively larger because of a different mounting location, so the M3 experience doesn't translate directly to the 325 series. Bigger sway bars, slight lowering, wheels and tires would be a nice combination without hurting the ride.

Some other little changes to help the handling which aren't expensive. M3 offset control arm bushings will help the turn in along with the "repair" offset upper bushings to get more negative camber. These are about $60 each set.

Check with Ireland Engineering for good advice. You might also ask if if they have some used springs and sway bars you could get at a discount.

Don't forget to budget for a GOOD four wheel alignment (about $75-$100).

My $0.02

Rich

[ettsn]

Rich makes some very good points, but one thing to note is that Bilstein Sports and Bilstein HDs are the same valving. The Sports simply have a shorter free length for use with shorter springs.

-Paul

[carolinus]

I have a Bilstein BTS setup that I like VERY much. It is essentially Bilstein Sports and H&R's custom rated for the Bilstein Sports.
Also, while I was in there, I replaced the control arm bushings with urethane two piece jobs. It really helped my cornering steer.