First Suspension Upgrade

[stevebuccheri]

I just bought a 2008 135I with sport suspension. The car has only 20k miles on it. I would like to upgrade the suspension but I dont want to spend a lot of money. I will do the upgrades in phases. I won't be tracting this car but I do like great handling. My former car include 06 Evo MR, 08 STI. I would love some input.

THANK YOU!
Steve

[first135]

Originally Posted by stevebuccheri

I just bought a 2008 135I with sport suspension. The car has only 20k miles on it. I would like to upgrade the suspension but I dont want to spend a lot of money. I will do the upgrades in phases. I won't be tracting this car but I do like great handling. My former car include 06 Evo MR, 08 STI. I would love some input.

THANK YOU!
Steve

I'm in the same boat as you. I didn't want to spend too much so I just ordered eibach springs, spacers and m3 front sway bar. I'll upgrade to non rft's later. Just depends on your budget..

[KennyPowers]

Ive had a lot of suspension setups, and most of them did not meet my expectations or needs in one way or another.

The single worst mistake to make with a suspension system (if you like stock ride comfort and bounce levels) is to install springs without new shocks, or springs with shocks designed for stock HEIGHT springs.

Most people on these forums always talk about matching shock rates with spring rates, which is one consideration.

The problem is, these shocks are designed for OEM height springs. Therefore, when used with aftermarket lowered springs, they are already compressed much more than stock / they are designed for because the springs are shorter. This comprimises the handling and is not ideal whatsoever.

The best option for a comfortable setup that looks and rides great is a system like the eibach pro system kit which includes springs and matched dampers from eibach. These are designed specifically to match rates and height.

The kit costs about 675 bucks, and rides IDENTICAL to stock in terms of ride comfort, but has slightly less bounce in it and also corners a bit flatter. Match this with a good front sway like an M3 sway bar, and you will have a very good setup for a good price.

This kit isnt competition worthy, but will make your car look great, ride great, and handle a little better.

This is the kit my friend had on his 135i, and what I will be putting on my new 135i.

[ken1137]

It really depends on how much you want to spend. I've spent close to $4K on suspension parts and it was well worth it. I would recommend coilovers to start, then or at the same time, sway bars as already suggested. That said, a great mod is the M3 rear subframe bushings so if you are adding the rear sway bar you may as well add the bushings. GL...I wasnt going to spend much either but after each mod I found myself searching for other mods to improve the suspension.

[kevin @ eas]

If you are looking for an inexpensive suspension mod for the street, ST coilovers work well and are priced reasonable.

Here is a setup we installed at our shop

[Dackelone]

I think one of the best mods is installing the M3 rear subframe bushings. It not only firms up the rear end but also seems to make the front suspension work better. This will get rid of that rubber band effect when you turn the car hard into a corner. No more jiggle or wander from the rear end under power or cornering G's.

Have you thought about BMW's Performance Suspension Kit? For the 135i it comes with shocks, springs, and a front sway bar(I think?) plus all the mounting hardware. I think its priced around $1,100 for the kit.

Lots of guys install the M3 front sway bar. But I think that can only increase understeer at the limit. The reason why everyone seems to like this mod is bc they get no where near the limit on the street - and the stiffer bar really cuts down on front end sway and makes the steering feel more direct.

One of the Best mods for the suspension is getting rid of the RFT and going with a top tier tire like Michelin PS3's or PSS's. That was one of my best mods to date along with the M3 rear axle bushings.


Dackel

[Eddie135]

Originally Posted by Dackelone

I think one of the best mods is installing the M3 rear subframe bushings. It not only firms up the rear end but also seems to make the front suspension work better. This will get rid of that rubber band effect when you turn the car hard into a corner. No more jiggle or wander from the rear end under power or cornering G's.

Have you thought about BMW's Performance Suspension Kit? For the 135i it comes with shocks, springs, and a front sway bar(I think?) plus all the mounting hardware. I think its priced around $1,100 for the kit.

Lots of guys install the M3 front sway bar. But I think that can only increase understeer at the limit. The reason why everyone seems to like this mod is bc they get no where near the limit on the street - and the stiffer bar really cuts down on front end sway and makes the steering feel more direct.

One of the Best mods for the suspension is getting rid of the RFT and going with a top tier tire like Michelin PS3's or PSS's. That was one of my best mods to date along with the M3 rear axle bushings.


Dackel

Hi Dack

I am plaaning to get the BMW Performance Suspension Kit plus replacing the four subframe bushing with the M3 ones.

Is this a good setup for daily driving?

[Dackelone]

Originally Posted by Eddie135

Hi Dack

I am plaaning to get the BMW Performance Suspension Kit plus replacing the four subframe bushing with the M3 ones.

Is this a good setup for daily driving?

Yes, I think that would be an awesome bang for your buck(s).

[GaryS]

Originally Posted by stevebuccheri

I would like to upgrade the suspension but I dont want to spend a lot of money. I will do the upgrades in phases. I won't be tracting this car but I do like great handling.

You didn't say how much is a lot of money. The least expensive mods are,

1. more aggressive alignment with alignment pins pulled
2. E92 M3 front swaybar (I disagree with Dackelone's analysis above [edit: just the part about understeer at the limit])
3. HD front control arm bushing upgrade (HPA Shop)

You should do all of those for sure. But I think the biggest problem with the stock suspension is the shocks. You should upgrade them the first chance you get.

If you want shorter or firmer springs at the same time, there are lots of choices. I'll add that the stock springs are already pretty stiff for street.

The next biggest improvement is M3 rear subframe bushings.

All that should keep you busy for a while.

[BiscottiGelato]

Here's what I'm doing personally. Currently only executing stage one.

1. More aggresive alignment with Ground Control Camber Plates
2. Front control arm and Rear subframe bushing upgrade
3. Shocks or Coilover

I doubt i'll ever get to 3, as my next upgrade would be on the brakes department before I'll revisit suspension. I do track the car, otherwise I would've left everything stock and save some time and $.

[CGMike]

Great thread! This is answering so many of my questions too.

[stevebuccheri]

Thank you guys for all the input........Great help!

[cwg]

I have the performance suspension - great set up for a daily driver - super happy with it. would buy it again in a heart beat

[vwrefugee]

On my 2011 I have:

M3 subframe bushings
M3 front control arms
M3 front and rear sways
Alignment pins pulled for max camber (M3 arms give a bit more too)
1/8th toe out in front
Replaced runflats with Star Specs

= night and day difference over stock for all-around handling. With these mods the stock springs & shocks are actually pretty good for a sporty road setup - as hard as that is to believe (not sure if my opinion would be the same for the progressive springs on the 2008-10 models).

Subframe bushings are not cheap (because of labour to install) but I wouldn't advise anyone to upgrade the shocks/springs before doing the bushings. The soft stockers will always compromise even the best suspension setup.

[MteK]

Based on my experience modding a 335 and a 135 I have found this:

Street Driving and not in any order

- Matched shocks / springs or coil overs - biggest bang for the buck. Now some serious time and research went into your stock suspension. Don't go with some half-assed makeshift combo like HR springs and PS shocks. There is so much more to suspension then that. Get a professionally matched set up or a good set of coil overs.

- Camber Plates, really improve handling and will let you fit bigger rubber up front. Worth every penny.

- Proper size sway bar links. Do this before you buy aftermarket sway bars

- Aftermarket sway bar bushings. A good alternative to new sway bars (I'm not a fan of huge sway bars)

- M3 Tensioner/Wishbone. Increase camber but most importantly really improve steering feel. No more steering slop.

- Rear Subframe bushings. On the street not a big deal. On the track or Auto-X sloppy bushings are the cause of more spin outs then people realize. Top notch Coil Overs are wasted without them.

- Sway bars - too hyped. There is a distinct difference between real mechanical grip and less sway. Only AFTER you have dialed in the rest of your suspension should you experiment with this.

- Rear M3 bits. Less deflection, but not worth it unless you are really going high end everywhere else.

- LSD. By far my favorite mod.

[GIdriver]

Originally Posted by KennyPowers

Ive had a lot of suspension setups, and most of them did not meet my expectations or needs in one way or another.

The single worst mistake to make with a suspension system (if you like stock ride comfort and bounce levels) is to install springs without new shocks, or springs with shocks designed for stock HEIGHT springs.

Most people on these forums always talk about matching shock rates with spring rates, which is one consideration.

The problem is, these shocks are designed for OEM height springs. Therefore, when used with aftermarket lowered springs, they are already compressed much more than stock / they are designed for because the springs are shorter. This comprimises the handling and is not ideal whatsoever.

The best option for a comfortable setup that looks and rides great is a system like the eibach pro system kit which includes springs and matched dampers from eibach. These are designed specifically to match rates and height.

The kit costs about 675 bucks, and rides IDENTICAL to stock in terms of ride comfort, but has slightly less bounce in it and also corners a bit flatter. Match this with a good front sway like an M3 sway bar, and you will have a very good setup for a good price.

This kit isnt competition worthy, but will make your car look great, ride great, and handle a little better.

This is the kit my friend had on his 135i, and what I will be putting on my new 135i.

Do you know if this kit can be used in a 135i convertible? I'm so used to my M3's handling that I'm afraid of driving the convertible hard. Literally it is scary. It floats and pushes like there's no tomorrow. The difference in handling between the two is night and day. I've always thought of some suspension upgrades for my 135i vert but not seriously until I came across this thread. I know it will still be a convertible but if something can be done I would seriously consider it.

[1ToBeOn2Wheels]

After 62k miles on the stock 135i suspension (except front M3 sway), I just this weekend added the ///M front/rear control arms, bushings, rear sway, and some adjustable Koni Sport shocks. What an amazing transformation! Without the bounce/slop, the ride is greatly improved. It's just about perfect for me.

[1Pirate]

Originally Posted by 1ToBeOn2Wheels

After 62k miles on the stock 135i suspension (except front M3 sway), I just this weekend added the ///M front/rear control arms, bushings, rear sway, and some adjustable Koni Sport shocks. What an amazing transformation! Without the bounce/slop, the ride is greatly improved. It's just about perfect for me.

Your set up is very similar to mine and I like it as well. The only differences I see is that I have 2011 M sport springs rather than the 2009 springs that came on my car and I still have the stock rear sway bar. The 2011 M sport springs are linear (at least the rears are) compared to the progressive springs that came on the 2008-10 1s. The springs and the Koni Sports virtually eliminate any bounce, especially in the rear.

[2012one35i]

I was planning on keeping my run-flats, but just could not live with the punishment when hitting any kind of road imperfection. I have since switched to Michelin Pilot Sport A/S Plus tires and that was an improvement, but still the car sometimes feels like a bowl of jello. It is just so soft. If I drive over a speed bump, it feels like it's gonna bottom out in the rear. I really don't want to screw up the "BMW ride" I paid for, but the car feels a little scary on undulating roads. I call it "porpoising" for want of a better word. It rocks back and forth like a rocking chair. What do I need to do to fix this, without reinventing the entire suspension?

[cvc 22349a]

^M3 subframe bushings and better dampers

[2012one35i]

Bushings first, or dampers, or needs to be done at the same time?

[KennyPowers]

Originally Posted by GIdriver

Do you know if this kit can be used in a 135i convertible? I'm so used to my M3's handling that I'm afraid of driving the convertible hard. Literally it is scary. It floats and pushes like there's no tomorrow. The difference in handling between the two is night and day. I've always thought of some suspension upgrades for my 135i vert but not seriously until I came across this thread. I know it will still be a convertible but if something can be done I would seriously consider it.

i see no reason why it wouldnt work

if you add new front sway and some stiffer sway bushings, it could be the answer you are looking for