My New Suspension Set Up - Koni Sport Adjustable Dampers/2011 M Sport Springs

[1Pirate]

Originally Posted by HP Autowerks

I apologize.

Guys, any question that is not directly related to the Koni setup, please PM me instead.

Harold

No problem Harold, I was just kidding.

[1Pirate]

Update. I've been playing around with the front damper settings. I have finally settled in to one full turn from soft in front. That setting seems to work really well with the 2011 M Sport springs. The rear shocks are set at 2/3 of a turn from full soft.

[1Pirate]

Just had a 4 wheel alignment done this morning. Now the car really feels good.

[Focusedintntions]

Any chance you can post the part numbers of the koni's you got?

[1Pirate]

I purchased my Koni's from Harold at HP Autowerks. Apparently only HP and Dinan have the externally adjustable rears shocks. I happen to still have the boxes the dampers came in out in the garage. I need to put them in the attic since the OEM shocks are in them now.

The part numbers for the Konis are as follows:

Left front: 8741 1484LSPOR
Right front: 8741 1484RSPOR
Both rears: 8241 1275SPTC

If you compare the part numbers. for instance with the Koni Sports Tirerack sells the front part numbers are the same, but the rear is a different part number. The rear shocks Tirerack sells are not externally adjustable.

[Focusedintntions]

Thanks for the info

[1Pirate]

Over the holiday weekend I decided to tinker with my front damper settings. For a while now I've had the front dampers set at one turn from full soft. Recently I've noticed that the car still had too much movement in front. So I tried one and one-eighth and then one and one-quarter turns. I've settled in on one and one-quarter turn from full soft. The car rides slightly stiffer in front, but the overall feel is better. The rears are still set at 2/3 of a turn from full soft.

What settings are others with Koni Sports using?

[cvc 22349a]

^ Different car and stiffer springs, but 1.5 turns from soft in front and 3/4 turn from soft in rear. Your settings sound right. My tech said they don't work right at 50%, so I'd avoid that.

[1Pirate]

Update: Since my last post in this thread I've added M3 rear guide rods, upper links and sub frame bushings. I finally feel like I've got the car dialed in like I want it in terms of handling. I highly recommend the M3 suspension upgrades.

[pwn]

I've got a question for you...not sure if you'll know what I'm talking about.

I just got a 2011 135, and I notice it gets very unsettled in the rear over bumps when going through corners, like the rear end just wants to jump off the ground. Its really unsettling and makes me very hesitant to push the car. Feels like it skips.

Did you ever experience that, and did these various mods help at all? I'm not sure what the cause of the instability is exactly (got an alignment too).

I've been planning on doing the control arms, guide rods, sways, rear bushings and maybe ohlins.

Thanks,
Morgan

[cvc 22349a]

Originally Posted by pwn

I've got a question for you...not sure if you'll know what I'm talking about.

I just got a 2011 135, and I notice it gets very unsettled in the rear over bumps when going through corners, like the rear end just wants to jump off the ground. Its really unsettling and makes me very hesitant to push the car. Feels like it skips.

Did you ever experience that, and did these various mods help at all? I'm not sure what the cause of the instability is exactly (got an alignment too).

I've been planning on doing the control arms, guide rods, sways, rear bushings and maybe ohlins.

Thanks,
Morgan

Your rear subframe bushings are too soft and allow for excessive vertical movement and the shocks are underdamped. Car was designed that way to make ride quality acceptable to the masses riding on rft's.

[pwn]

Originally Posted by cvc 22349a

Your rear subframe bushings are too soft and allow for excessive vertical movement and the shocks are underdamped. Car was designed that way to make ride quality acceptable to the masses riding on rft's.

Yea, I switched away from the run flats a couple weeks ago when I threw on VMRs, thanks.

[1Pirate]

Originally Posted by pwn

I've got a question for you...not sure if you'll know what I'm talking about.

I just got a 2011 135, and I notice it gets very unsettled in the rear over bumps when going through corners, like the rear end just wants to jump off the ground. Its really unsettling and makes me very hesitant to push the car. Feels like it skips.

Did you ever experience that, and did these various mods help at all? I'm not sure what the cause of the instability is exactly (got an alignment too).

I've been planning on doing the control arms, guide rods, sways, rear bushings and maybe ohlins.

Thanks,
Morgan

Originally Posted by pwn

Yea, I switched away from the run flats a couple weeks ago when I threw on VMRs, thanks.

As the previous poster stated the stock suspension is set up for the car to use runflat tires and for a comfortable ride. Therefore the suspension has a lot of movement built into it. Switching to non runflat tires just magnifies the softness of the bushings and the underdamping of the dampers. While we are talking about the dampers, my personal opinion is that the stock dampers are are the weakest link in the suspension.

At least your car is a 2011 model which has the linear rear springs. 2008-2010 model year cars have progressive rear springs which translates to even more movement in the rear of the car.

Ultimately it depends on what you goals are and what you are willing to spend to improve the suspension. The car can be made into a very good handling car with the right suspension mods. I did mine in stages with each mod improving the handling of the car. I couldn't afford to do everything I wanted to do at one time.

If I were ranking suspension mods here is how I would rank them.

1. Dampers/Coilovers (and possibly springs). A good set of aftermarket dampers will greatly improve the feel and unsettledness of the car. I have Koni Sports which are ajdustable. If you are going to lower the car (mine is not lowered) I'd also add aftermarket springs (or coilovers) at the same time. Many people like the BMW Performance springs which only lower the car about a half inch.

2. Front Sway Bar. An M3 or aftermarket FSB will significantly reduce body roll. I went with an E93 M3 FSB.

3. M3 (or TRW) front control arms and tension rods. These along with the M3 FSB significantly improve steering feel and turn in. It seems odd, but improving the front suspension actually seems to help settle down the rear of the car.

4. M3 rear guide rods (optional M3 rear upper links). This mod alone made a significant difference in the way the rear of the car felt. I only added the rear guide rods at first. The upper links were added to my car when I added the M3 rear sub frame bushings.

5. M3 subframe bushings. The only reason I rank these so low is because of the cost/work involved in installing them. The bushings and installation will cost $1,000 or more if a shop or dealer installs them. There is a lot involved in the process including dropping the sub frame and disconnecting the rear brake lines. For the same price of the M3 rear sub frame bushings you could add the M3 FSB, M3 front control arms and tension rods and M3 rear guide rods.

At this point my car is very settled and it handles very well, with really not much sacrifice, if any, in overall ride quality.

[Katkarot]

Great info 1Priate!
Your setup is very similar to what I plan to do. I, too, don't want to lower the car much if at all. I already settled on Koni Sports and got M3 sway bar getting delivered anytime now.

[1Pirate]

Katkarot, Thanks. I started with the Konis and the M3 FSB too. I also installed 2011 M Sport springs, since my car is a 2009, when I installed the Konis.

[///S55]

Originally Posted by 1Pirate

Katkarot, Thanks. I started with the Konis and the M3 FSB too. I also installed 2011 M Sport springs, since my car is a 2009, when I installed the Konis.

Hey 1pirate
I am looking to add the same Koni yellows to my 2009 135i
From reading some sections of the thread, I figure that it's a pretty good choice to go with the Koni with STOCK m-sport springs ?

If so, does it just effect the drive, does the car seem lower at all ?

[Focusedintntions]

Height of the car is determined by the springs.... if youre going to upgrade your 09, it'd be highly recommended to get the 11+ rear springs as well. They're linear springs vs progressive and will give you a more predictable rear end as well better planted w/o sacrificing any real drive ability.

[1Pirate]

Originally Posted by ///N54

Hey 1pirate
I am looking to add the same Koni yellows to my 2009 135i
From reading some sections of the thread, I figure that it's a pretty good choice to go with the Koni with STOCK m-sport springs ?

If so, does it just effect the drive, does the car seem lower at all ?

Sorry I've been out of town for a few days and haven't checked the forum. As Focusedintntions commented ride height is controled by the springs, so if you have stock M Sport springs the height won't change.

Other than providing much better damping than the stock dampers, the best thing about the Konis is their adjustability. You can dial them in just like you want them.

Another thing. Since your car is a 2009 you might want to look for a set of 2011 or later model rear springs which are linear rather than the progressive springs that came on the 2009s.

[tjswarbrick]

Can I just flag this (3 year old) thread for future reference?
My Koni Sports and Swift springs just arrived, and I'll be installing them in a few weeks.