Eibach/Koni vs. Bilstein PSS10 for a street setup

[ethan]

Great post Obioban - thanks. I'll have to investigate travel more thoroughly on my MCS 1WNRs - I just naively set ride height to 13.5F 13R with spring rates chosen using Shaik's calculator and then corner balanced from there, but I should see what the implications of that ride height mean for shock travel.

My daily M3 has some beat twintube Bilstein B4s and Eibach springs - sounds like Konis might be the right move. Would I have sufficient travel with stock strut hats and the Eibach springs paired with Koni SAs or should I be looking at a street plate and/or stock springs?

[Obioban]

Is this typically achieved by cutting the bump stops or using aftermarket street camber plates or both?

Also, I see the B6s are described as monotube shocks due to the design of their internals (despite their packaging for the E46 M3 platform as inserts inside strut housings), but Konis use "twin tube technology". In practice, are these roughly comparable dampers for dual duty work?

Were it me, I'd far prefer going the camber plate route to the bump stop modification route. The bump stops are part of the suspension-- modifying means your changing how the car behaves. At a minimum, which trimming a bump stop you should install a packer to ensure that full compression (of the bump stop) ends up at the same point.

Twin tubes and monotones both have their benefits. On the e46 chassis, monotubes are a bit limited because they're too large to actually fit (the functional part of the shock) within the clam shell up front. This is why all the monotube options for the car don't have a ton of front travel. This can work fine for stiffer track setups, but softer, street friendly setups benefit from more travel. The twin tube can fit down inside the clamshell. The net result of this is that something like TCK D/As I used to run (twin tube) have ~double the front travel of the Ohlins (monotube) I currently run.

... which is why for my softer, street M3 I run a twin tube (Koni Yellow) and a soft springs (Dinan) with a bunch of travel, and for my more hardcore/track M3 coupe I run a monotube (Ohlin) with a stiffer spring... and front ride height determined 100% by optimizing the available travel.

[Obioban]

Aren't the TCK rear shocks just Mustang shocks (Koni p/n 8241-1200Sport)?

https://www.tcklineracing.com/webdoc.../Details30.cfm
https://www.amazon.com/Koni-8241-124.../dp/B003620QQM

It's possible they're the same shock body, but all of TCK's Koni's are valved to TCK specifications-- so not the same part AFAIK.

Has anyone used the Dinan Springs and newer Koni SA shocks? Those seem that they would play well together.

That's the setup I have on my M3 wagon. Excellent DD setup IMO.

[r4dr]

Agreed— which is why I’m running TCK Koni SAs on the rear (on the M3 wagon), with generic Koni yellows up front. Softer and top adjustable (instead of compress to adjust).

Aren't the TCK rear shocks just Mustang shocks (Koni p/n 8241-1200Sport)?

https://www.tcklineracing.com/webdocs/Items/Details30.cfm

https://www.amazon.com/Koni-8241-1240Sport-Sport-Mustang/dp/B003620QQM

[Icecream]

Hmmmm, so I should be thinking about returning my New in box Konis for B6's?

Paired with Dinan springs . . . I got those sitting on the self too

I have the B6 with eibach springs, I like them just fine and enjoy it a lot on back roads, extremely composed when pushing it. I did not modify the bump stops and I really don't have an issue with it. If the dinans are lower than the eibachs, then yeah, you will need to modify them. I have said this before, just get the PSS10 and be done with it. If you are at the point of modifying the B6 with cut bump stops, GC plates or whatever the ****, it's not worth it. And the cost isn't much more for the PSS10 so it is a no brainer.
I also asked Bilstein about getting a different spring than the eibachs for the B6 shocks, they strongly advised against it for what it's worth. Do it right, do it once. I'm already itching to replaced my suspension again, not because these are bad, I just get bored and like adjustability.
I have never tried the koni shocks but in general I found the bilsteins to be a better shock for a few reasons while looking around. Mainly build quality of the Koni's was questionable and the twin tube design didn't appeal to me (whatever that's worth) and it sounded like their adjustability was, gimmicky (useless except to compensate for them wearing out which is....not why I want adjustable suspension). The bilsteins are extremely well built and highly regarded for a reason and at the price point, they are hard to beat.

[Tbonem3]

Is this typically achieved by cutting the bump stops or using aftermarket street camber plates or both?

I did both

[Apex Hitter]

Has anyone used the Dinan Springs and newer Koni SA shocks? Those seem that they would play well together.

[ethan]

If you go this route, you’ll need to significantly increase bump travel. The B6s have borderline too little bump travel with the stock springs, and once you start lowering it... you’re just parked on the bump stop.

Is this typically achieved by cutting the bump stops or using aftermarket street camber plates or both?

Also, I see the B6s are described as monotube shocks due to the design of their internals (despite their packaging for the E46 M3 platform as inserts inside strut housings), but Konis use "twin tube technology". In practice, are these roughly comparable dampers for dual duty work?

[r4dr]

Or maybe raising it meant your shocks actually had travel...

[old///MFanatic]

I will add everyone’s feel is going to be different. Especially on adjustable suspensions.
Heck my car is not dumped by any means (nor is it stock zcp height), but raising it about 3/4”-1” after having it dialed in over several years. I noticed I needed to dial it up a tad firmer. The new travel made it softer. In this case it rode better lower than when raised.
Point being adjustability brings a lot of different suspension feels that not every owner experiences. Or knows about, so results vary.

[old///MFanatic]

I’ve had Koni Sport Adjustable with stock springs and then later with H&R sport springs. Ride was pretty darn good. Only two gripes I have to say about the Koni SpA was the rears don’t adjust with a dial on the fly. Unless you send out to TC Kline to rebuild. The other was the dial has no numbering. It’s just a dial from Soft ➡️ Firm and it’s not linear. (I think it’s like 2.5 full turns to max). Not hard to figure out over time but worth mentioning in a review.

I’m currently on Bilstein PSS9s. Which are basically same as PSS10s but 9-way instead of 10-way adjustment. Obviously coil-overs adjustability of ride height a big plus. Front and rear dial that adjusts both compression AND rebound another plus over Koni SpA (Koni only rebound adjustable). Bilstein matches kit with H&R progressive rate springs.

I think the Koni’s were a tad more forgiving Street ride wise. I liked the H&R but recall Eibach a bit softer.
If you need to adjust/make your exact ride height, say no more, Bilstein PSS10s.

[cmstrilchuk]

If you go this route, you’ll need to significantly increase bump travel. The B6s have borderline too little bump travel with the stock springs, and once you start lowering it... you’re just parked on the bump stop.

A work around, you can trim 30mm off the internal bump rubber, helps alot!

[Obioban]

Hmmmm, so I should be thinking about returning my New in box Konis for B6's?

Paired with Dinan springs . . . I got those sitting on the self too

If you go this route, you’ll need to significantly increase bump travel. The B6s have borderline too little bump travel with the stock springs, and once you start lowering it... you’re just parked on the bump stop.

[mw14]

I went with ground control (KONI yellows) on my last setup. Ok ride quality, and both rear shocks blew within a year

[cbean]

Hmmmm, so I should be thinking about returning my New in box Konis for B6's?

Paired with Dinan springs . . . I got those sitting on the self too