Bilstein Sport Shocks with Stock Springs

[rasmuw]

When I purchased my M Roadster 15 months ago, the previous owner had installed H&R lowering springs and Bilstein Sport shocks. The car rode too firmly for northeast United States roads so I replaced the springs with stock units that the owner had given to me. The ride has improved somewhat and I can more easily get the car on a lift. From searching past threads, it seems that the rear shocks will be compatible with the taller springs but the front struts don't have enough travel. Is that correct? I'm ready to buy a set of HD Bilstein or Koni if necessary.

[rf900rkw]

Bilstein sport shocks have the same ride characteristics as a length of Carolina white pine 2x4. Switching to Koni's will drasticly improve your ride quality.

[rasmuw]

Bilstein sport shocks have the same ride characteristics as a length of Carolina white pine 2x4. Switching to Koni's will drasticly improve your ride quality.

I know you are a fan of the Konis and I'm leaning in that direction. There is a good deal at one supplier for a set at $565. How will I know how to adjust them without having to take them off once I try an initial setting?

[rf900rkw]

Contrary to what the interwebz say, the adjustment on the Koni has nothing to do with ride; it's a tuning device for transient handling. For a street car with no track or autocross, half a turn from full soft is a good place to be.

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And it's not that I'm a Koni fan, I'm just against the too common practice of propping under-sprung or sloppy suspension with excessively stiff shocks (Bilstein) or tire sidewalls (Michelin).

[rasmuw]

The only remaining question is if I can use the Bilstein fronts I have to cut up to use the Koni inserts, or if I need to source OEM struts.

[rf900rkw]

Oh. crap, this is a M. Yeah. You must have stock strut housings for Koni, and they are getting hard to source. In addition, you'll need all the hardware and bump stops Bilstein has you throw away.

[rasmuw]

Do you have any suggestions where to begin my search? Breaker yards? Perhaps a Forum member who is about to install Bilsteins??

[doclip]

I had Koni (from Dinan) for over 10 years, and when I tried to replace them with new Koni's, the shop couldn't get them out of the housing. I ended up paying for new stock struts (at some discount but still expensive), and have the shop cut them for me.

[rasmuw]

I had Koni (from Dinan) for over 10 years, and when I tried to replace them with new Koni's, the shop couldn't get them out of the housing. I ended up paying for new stock struts (at some discount but still expensive), and have the shop cut them for me.

That would be an expensive way to go. The cheapest I've seen stock struts is $310. Add in the cost of the Koni inserts and the front struts come in at $1000 at least. I would think a more prudent choice for me would be TC Kline coilovers at $350 each, provided they are not the rock-hard ride I "enjoy" with Bilstein Sports.

I've found two passenger side struts on Ebay for around $100 each. If I were able to find a driver side for the same cost, front struts with Koni inserts would cost me under $550. If I could only find a Forum member with a pair of trashed OEM struts willing to sell for less!

[rf900rkw]

Also search for 95-99 E36 M3.

[rasmuw]

Also search for 95-99 E36 M3.

Thanks! I found two complete 1999 assemblies in Maryland on Ebay and made the purchase. One needs a dust cover. Is that the bump stop you referred to in an earlier post?

[rf900rkw]

The bumpstop is inside the dust boot. They are always destroyed.

[rasmuw]

The installation of the Koni struts and shocks went well. Fortunately, the used struts came with the proper conical washers that I needed under the upper spring plate, parts that were thrown out when the Bilsteins were installed. In the process, I added some Rogue rear shock mounts. After an alignment and with some good spring weather, I'll be able to try out the new ride!

The Bilsteins have 32K on them and are languishing in my garage in case anyone wants them...

[abqhudson]

Wayne - Please let us know how your new shocks/struts compare to the old. I am in the same situation - new to me M roadster with Bilstein Sports and stock springs - very harsh ride. I am now confused by all of the talk about inserts. I am advised by TC Kline customer service that my car uses the same Koni struts as an "e36" what ever that means (E36 sedan? E36 Coupe? M3 sedan? E 36 sedan with sport suspension? all the same , or what?). Guess I'll have to call Koni.

[rasmuw]

From my understanding, the Bilstein Sport struts are not supposed to be used with stock springs, but lowered springs only. I'd guess they are not quite long enough. The Sport shocks in the rear are compatible with either. Replacing the stock springs on my car helped the ride a little, but it was still too firm for my normal driving.

Koni doesn't make struts for the M Roadster/Coupe. They do make inserts which require the stock Sachs struts. Finding those is the challenge since so many owners replaced their worn out components with Bilstein and likely threw them away. I was able to find a pair of struts from a 1999 M3 (thanks Randy!) and converted them with the Koni inserts. I think your only choices for the proper struts are an M Roadster/Coupe or a 95-99 M3. Those cars are from the E36 family. Other cars in the E36 family will have a different suspension setup. The Koni rear shocks are a direct bolt in replacement.

TC Kline makes a nice coilover strut ($375 each) for the front of our M's. I chose to use the Koni inserts once I found the pair of old struts for $130, bought the inserts and rear shocks for $535, and a pair of Rogue Engineering rear shock mounts for $105. The struts are adjustable on the car, but the shocks need to be removed to adjust them. The Rogue mounts mean you don't have to get inside the car to remove them, but it's still some work to remove them from the bottom. Once set to my liking, I don't plan to change the rear adjustment.

It only took an hour or two to make the struts, and I am a painfully slow worker. There's a good YouTube about how to do it. Most people don't release the tension on the spring the way it's done in the video...they use a tool to compress the spring.
https://www.youtube.com/watch?v=qzNZCnUYtzo

[rf900rkw]

I quit watching when the moron started cutting the strut housing with an angle grinder on top of his used oil pan. Youtube videos are typically made by someone that made such a has of a simple job that they had to share their idiocy for others to follow. Pulling the door glass to change sliders is a classic example.


The Z3M uses the same front struts as the E36 M3. They are inserts from Koni. The bugger is the spring seat welded to the strut, it is unique to the M, and Koni never tooled up for it. TCK does their own thing that doesn't use M springs. Not comparable.

[rasmuw]

I quit watching were the moron started cutting the strut housing with an angle grinder on top of his used oil pan. Youtube videos are typically made by someone that made such a has of a simple job that they had to share their idiocy for others to follow. Pulling the door glass to change sliders is a classic example.


The Z3M uses the same front struts as the E36 M3. They are inserts from Koni. The bugger is the spring seat welded to the strut, it is unique to the M, and Koni never tooled up for it. TCK does their own thing that doesn't use M springs. Not comparable.

While the YouTube video does demonstrate some poor shop practice, I did find it helpful as well as entertaining. Knowing that the author could do it suggested that I could do it as well, while also improving on his technique. Your example of the window sliders is the reason I spend so much time reading this forum to learn better, and often quicker, methods.

[Chamberlin]

Two things:

I'm about to install some new bilstein (non sport) struts on a friend's 2000 M Roadster. I'd like to get a head start on the job and install the new upper mounts along with some '99 M3 coupe springs I have lying around, as opposed to doing all the spring transfer work when he is here. I searched all over the net last night but couldn't determine for sure how much higher the spring rate was on the M3 fronts than the M Roadster. Either way do you guys see any major problem in using the old M3 springs on the new bilsteins? My friend already has new bilstein rear shocks installed, so we're just matching up the front end. I hope it's not too harsh for him either way. If I remember correctly, the non sport bilsteins are the same dampening rate as the sports, but just sized for stock springs vs. lowering springs, correct?

Secondly, I do have the front pair of OEM M3 struts for sale and they're in great shape. I upgraded my M3 to Koni insert/Dinan struts and springs (purchased used complete). I wasn't really interested on shipping them, but at least with the springs removed, it would make the package a little easier to deal with. Let me know if anyone's interested.

[rasmuw]

Wayne - Please let us know how your new shocks/struts compare to the old. I am in the same situation - new to me M roadster with Bilstein Sports and stock springs - very harsh ride.

After a summer driving season with the Koni inserts and shocks with stock springs, I couldn't be happier with the performance and comfort of the setup. The ride is firm and controlled. My dentist isn't as happy--my fillings aren't being jarred out anymore.