Re: Koni vs Bilstein Sport, Eibach vs H&R (archive)

The complete automotive resource for buyers, sellers, and owners like you.

Now, you will want to get good damping with these springs. Bilsteins are good quality, easily available, have lifetime warranty (but only to the original purchaser). They are a good value.

Koni's are more expensive, better quality, finer tolerances, and they are adjustable. Personally, I'd go for the Koni's just for the adjustability.

So now, the most "performance" tuned ride, you'd want Koni's with RD Springs. H&R are less stiff, and are better over bumps and other road irregularities. (BTW, Dinan Springs are only about 210 lb-in, they use specially valved Bilsteins or Koni's to get the handling they desire). I've driving a car with H&R's and Bilstein Sports and I can attest to it that it's less harsh than RD/Bilstein combo or RD/Koni combo. The RD/Bilstein combo has more tendency to porpoise than a well adjusted RD/Koni. But that also had to do a little with the tires/wheels combo that the two cars had was different, allowing the one with Bilsteins to have more sidewall and bounce. H&R are more supple with Bilstein and doesn't have the porpoising with RD's - even though RD's are stiffer and offer better control.

The BEST combo would be H&R with Koni. Eibach aren't as good because they have poorer quality. Bilstein is generally a good value, but you will be much more happy with spending the extra cash on the Koni's. You'll LOVE the adjustability.

Another recommendation. Drive cars with those suspension set-ups. Doing that FIRST, you can better guage exactly what you're looking for.

Also, with the stiffer suspension, I recommend getting a front strut brace to stiffen the body. It makes a huge difference.

BAS springs are too soft. And *may* allow the car to bottom out more easily. They are 1.25" lower, and whenever you shorten a spring, you need to make them much stiffer to compensate for bottoming them out. They are around the relative stiffness of the Dinan's (200lb-in), but the Dinan's only drop 5/8th to 3/4 of an inch, not 1.25 inches.

Objective: My car is an 88 635, running 16x8 wheels with 225/50 16s in the summer and 15x7 wheels in the winter. I wanted to lower it while finding a good compromise and not making the ride too firm. It's a daily driver and would not be used for track events...

Potential Setup: I'm looking at going with either the Bilstein Sports or Konis, along with either the Eibach or H&R lowering springs.

My impression: So far, it sounds like a lot of folks are using the Bilstein Sports and are happy, but there is a big mystery about the Konis. I haven't tracked down numbers (part#/prices) on these, but sounds like a possible alternative, especially since they can be adjusted while on the car. As far as springs, again it's the Eibachs that most tend to favor, but I did read something about them having an "annoying" resonance, and that the H&R were comperable, but without the resonance...

Does this sound like I'm going down the right path, or is it all going to end up too stiff for what I'm expecting? I like to drive "enthusiastically" (as the bmw manual calls it), but don't want to have some unenjoyable ride if anyone comes along... Should I be looking in more of the direction of the Bav Autosport springs, for instance? If so, would I still want to go with the Bilstein Sports, or is that bringing me back to the same firmness as with the eibachs?

Any clues on where I can get the Bilstein/Eibach stuff cheaper through a non-BMW source? I found some Konis a while back for another car and found them much cheaper once I got out of the enthusiast mail order catalog world :)

Questions, comments, or problems, please visit the Roadfly help desk.