Koni adjustable or Bilstein sports?

[E30 Wagen]

What's better for a daily driven e30, Koni adjustable or Bilstein sports? I want track-day capability but the priority is quality and comfort. I will be running a new set of Vogtland springs, M3 solid rubber control arm bushings, and street compound urethane rear subframe bushings (but still considering rubber, too).

Thanks.

[acolella76]

I prefer Bilstein. A Bilstein sport will outperform its Koni counterpart. I just wish they didn't use that stupid inverted strut :|

[jlevie]

I disagree, for the stated priority I think Koni SA shocks will be the better choice. The Bilsteins will be more harsh. About 1 to 1-1/2 turns from full soft should be a good match for those spring rates.

[Jean]

It depends on application, both can work fine but for DD comfort Koni is the way to go.

[bubbajan21]

+1 for konis, they are way more comfortable on the street. I'm on H&R Sports and I ran bilstein sports for a few years. I recently swapped the rears to koni SA (fronts will be swapped out soon) and driving the car with the bilsteins up front and konis in the back it's a very noticeable difference in comfort. There's just something about the konis when they hit a bump that is just less harsh than the bilsteins. It's certainly still very firm, just a little less harsh (I'm running 1.5 turns from full soft btw). I'd definitely recommend the Konis over the bilsteins for a dd or primarily street-driven car.

[Northern]

Konis are still 20% off on tirerack until the end of the month.

Now you have no reason to think about billy sports.

[BlackbirdM3]

Bilsteins have a higher compression damping rate, but are softer on the rebound, whereas Konis have a very soft compression damping rate, but can be tuned to have huge rebound damping. I run Koni sports set full hard (since its only rebound being damped) The car is very well planted all the time.

Will

[E30 Wagen]

Alright, I'm going with Koni.

[jlevie]

Bilsteins have a higher compression damping rate, but are softer on the rebound, whereas Konis have a very soft compression damping rate, but can be tuned to have huge rebound damping. I run Koni sports set full hard (since its only rebound being damped) The car is very well planted all the time.

If rebound damping is set too high for the springs in use, the tires won't be able to follow a rough or undulating surface. The ideal setting is just enough rebound damping to prevent spring oscillation.

[BlackbirdM3]

The car has no issues whatsoever. Always planted and predictable. They are just H&R race springs, but even so they are right on the edge of being too much spring for the dampers. The car is awesome. I wish it had a little more compression damping, but rebound wise, its spot on.

Will

[JeffRR]

Neither one is ideal out of the box for a lowered car since they were both tuned at production ride heights, the biggest problem is that once you pair either one with a lowered spring they start crashing the jounce bumpers. At least with the Koni’s you get the rebound adjustment which does help it work with a range of spring rates.

I have Bilstein sports with h&r’s, pretty constant bottoming, both front and rear on the crappy MI roads. I’m guessing that the “harshness” that most people feel with the Bilstein’s is not too much comp damping its actually too little when paired with a lowering spring.

My buddy is on the koni SA’s paired with a GC coil over kit. They also would bottom pretty heavily, I helped him run through a number of valve codes just to get the bottoming under control.

[Varinn]

My only concern with going Koni SA's or DA's is it seems all the local shops around me see significantly more failed Koni's than bilsteins. I've seen street cars and track cars alike that have outright destroyed the Koni shocks where the bilsteins seemingly held up find. That being said, H&R sports and bilsteins is a touch on the firm side and the car really slams into bumps hard. It does however, handle great.

Still undecided for my next set that's coming up soon.

[JeffRR]

I worked with Koni DA's on a T2 car. We had trouble with a leak coming out of the rebound adjuster on the rod stem, same issue on 2 different sets. We sent them to Koni and they fixed the leak.

The other problem with that specific set-up was that we maxed out the compression stack which was a problem since we were sitting low ~ 2" lower than stock, on a 3400lb car. So we were back to heavy bottoming, espically in the rear. That car needed more ride height to get some travel back, but in T2 on that car we were stuck with a spec spring.

What issues are the shops seeing on the Koni's? leaks around the rod guide? broken valves?

I'm not a ton of help with this, just offering my experience.