BMW 135i Suspension

[Gangplank]

Just throwing a link out there for strutmonkey pre assembled kits. I haven't used them before (b/c I went w/ Ohlins which I highly recommend if you want the best) but if you looking for a Billy or Koni kit preassembled their prices save shop labor and/or make it DIY for those so inclined.

http://www.strutmonkey.com/store/c5/128i%2C_135i.html

[asbrr]

Originally Posted by Luftmeister

I run stock wheels and tire sizes. No rub problems?

Nope, none whatsoever.

[dandandan]

I'm happy I found this thread.

I'm def going to go with Koni Special Active in all four corners. At the same time new bump stops, and rubber dampening components.

I'll be doing 1M/M3 control upper/lower arms and possibly rear 1M/M3 arms as well.

2012 135i DCT

My question is how do I know if I should also replace my springs? Cars at 115,000k and there are no signs of rust or damage on the stock M-Sport springs. Ideally I want to just re-use mine.

Any thoughts on general lifespan?

Toronto roads are total garbage btw.

Thanks everyone!

[PcarDefector]

Originally Posted by dandandan

I'm happy I found this thread.

I'm def going to go with Koni Special Active in all four corners. At the same time new bump stops, and rubber dampening components.

I'll be doing 1M/M3 control upper/lower arms and possibly rear 1M/M3 arms as well.

2012 135i DCT

My question is how do I know if I should also replace my springs? Cars at 115,000k and there are no signs of rust or damage on the stock M-Sport springs. Ideally I want to just re-use mine.

Any thoughts on general lifespan?

Toronto roads are total garbage btw.

Thanks everyone!

You should be fine at 115k unless the coil springs are rusty, broken or sagging. Google for information on this.

Toronto roads aren't that bad. Try the roads in San Fran or some Mid-west cities or even Montreal.

You may want to consider upgrading your RSFB or adding inserts. That squatting motion during cornering from the rear suspension is a top complaint amongst e82 owners.

Here's a link to the inserts (which are lower cost than the RSFB. https://www.whiteline.com.au/product..._number=KDT918

I also have an extra set if you're interested.

[gorilla]

I'll bump this thread instead of creating a new one.
I'm trying to decide between Bilstein B4($312 CAD) and Koni Special active ($732 CAD) for my daily driver. Leaning towards B4s because of the price. Planning to use it with my factory M-sport springs, just want something more comfortable than my 70K miles suspension.

I see it often recommended to replace all the rubber and hardware while doing this job. I see these 2 kits froms Turner/ECS:
https://www.turnermotorsport.com/p-5...tallation-kit/ ($206.77)
https://www.ecstuning.com/b-assemble...1306775098kt1/ ($278.37)
The ECS kit includes the following but the turner doesn't:
Front Lower Spring Pad - Genuine BMW - 2 31336764372
Front Upper Spring Pad - Genuine BMW - 2 31336767500
Upper Rear Spring Pad - Genuine BMW - 2 33536764419
Lower Rear Spring Pad - Genuine BMW - 2 33536764420

Do I need to replace these spring pads? Do these kits include everything recommended to be replaced while doing the shocks and struts? Do I even need all the hardware in these kits? should I just purchase the rubber items/mounts separately (Rockauto)?

Another concern I have is an increase in ride height after doing this refresh. I like my ride height where it is now, about a finger gap between wheel well and tire, I see some posts about a significant ride height increase after swapping, any thoughts/experiences? ulrichd

Or if anyone has other recommendations for me to look into for under $1K

I'll tag these Canadians who I got a lot of valuable information from while researching: PcarDefector dandandan asbrr hunginator fast1eddy

[Petro135]

My buddy runs koni str.t w m sport springs and loves them. I think under $500. Im looking at bilstein b12 or b14 from fcpeuro so warrantied for life. Both under $1k.

[asbrr]

The Konis may ride slightly better than the B4s - I'm not entirely sure they are OK to run with M-Sport suspension (since that is like 20mm or whatever lower than non-sport) just double check that.

The B4s will be very similar to original.

The spring pads etc are just a few dollars, I thought they used to come in the installation kit. I woudl just get them as the old rubber ones in your car are probably quite tired. The main things you need from the kit are the shock mounts upper and lower rear, and the strut mounts at the front. All the other bits are just hardware etc and if you price out the shock and strut mounts separately it might end up coming to the same so might as well grab the kit.

Most of the ride height increase will be due to the refreshed strut mount at the front. They get beat up over time and compress. I don't think we're talking a ton but it depends on what kind of life the car has lived. I would say 5mm to 10mm max. The rear shouldn't really change much if any.

The other factor is when the suspension is installed, you have ot make sure you only torque down the key control arms once under load and after moving the car a bit so it settles. Otherwise torquing while unloaded, you will torque the bushings and that will give you uneven/unpredictable height not to mention a premature failure on that bushing.

Good luck.

[blue135]

I have Koni Special Actives. Been on about 6 mos. Ride Height seems unchanged from previous (stock M-sport). Ride is better than 75k shocks as is handling. I am well satisfied with them.
Considered B-6 but seems many people view them as a bit rough on certain roads.

[gorilla]

Originally Posted by blue135

I have Koni Special Actives. Been on about 6 mos. Ride Height seems unchanged from previous (stock M-sport). Ride is better than 75k shocks as is handling. I am well satisfied with them.
Considered B-6 but seems many people view them as a bit rough on certain roads.

With m-sport springs? Did you install them yourself? Refresh all the hardware and rubber?

[blue135]

I did not install myself. Had it done at local shop. Takes me too long to get up and down now. Was much easier when I changed to Konis on 535 in 80’s. Updated all relevant pieces/mounts with Kits from ECS.
And just to show there is no bias, I spent 4 hours with Bilstein to find shocks for my truck (limited production, factory lowered suspension).

[dandandan]

I haven't done this yet (117k km) but I need to very soon. I'm leaning towards the Koni Special Actives.

For street daily driving I have heard they are reliable and well built.

I would love to hear peoples first hand opinions if you've made the swap to these.

Thanks folks, looking forward to hearing more!

[gorilla]

I'm leaning towards B4s, mostly because of the price, but the lifetime warranty, although people reportedly have trouble with it, sounds good as well.

[fast1eddy]

Originally Posted by gorilla

I'll bump this thread instead of creating a new one.
I'm trying to decide between Bilstein B4($312 CAD) and Koni Special active ($732 CAD) for my daily driver. Leaning towards B4s because of the price. Planning to use it with my factory M-sport springs, just want something more comfortable than my 70K miles suspension.

I see it often recommended to replace all the rubber and hardware while doing this job. I see these 2 kits froms Turner/ECS:
https://www.turnermotorsport.com/p-5...tallation-kit/ ($206.77)
https://www.ecstuning.com/b-assemble...1306775098kt1/ ($278.37)
The ECS kit includes the following but the turner doesn't:
Front Lower Spring Pad - Genuine BMW - 2 31336764372
Front Upper Spring Pad - Genuine BMW - 2 31336767500
Upper Rear Spring Pad - Genuine BMW - 2 33536764419
Lower Rear Spring Pad - Genuine BMW - 2 33536764420

Do I need to replace these spring pads? Do these kits include everything recommended to be replaced while doing the shocks and struts? Do I even need all the hardware in these kits? should I just purchase the rubber items/mounts separately (Rockauto)?

Another concern I have is an increase in ride height after doing this refresh. I like my ride height where it is now, about a finger gap between wheel well and tire, I see some posts about a significant ride height increase after swapping, any thoughts/experiences? ulrichd

Or if anyone has other recommendations for me to look into for under $1K

I'll tag these Canadians who I got a lot of valuable information from while researching: PcarDefector dandandan asbrr hunginator fast1eddy

I've got Mperformance suspension on my car. A rear shock broke when I replaced my lower shock mounts so I took the opportunity to try out Koni Special Active. So far I really like them but I've had limited time behind the wheel. The difference is not night and day but noticeable none the less. The Mperformance suspension was a great compromise between ride and handling. The Konis improved the ride without compromising the handling at all. The roads here In Edmonton are really bad especially this time of year. When I hit rough roads I cringe expecting crashing suspension but it just handles it in stride. It's no Cadillac but really good for a sports coupe.
As far as Bilstein vs Koni. I had Bilstein on my E36 M3 and they were way too stiff. The high speed handling was great however. I'm not sure how they would be on the E82 chassis.
I'd do the install kit without the spring pads. They don't really wear. I'd definitely do the strut and shock mounts at the same time. I ended up needing to do them both after the fact. I also have Dinan rear shock mounts but to be honest I didn't notice any difference at all with them.

[fast1eddy]

I only have the Konis on the rear so far. I might switch the front struts this summer but the Mperformance ones are still in great shape.

[PcarDefector]

Originally Posted by gorilla

I'll bump this thread instead of creating a new one.
I'm trying to decide between Bilstein B4($312 CAD) and Koni Special active ($732 CAD) for my daily driver. Leaning towards B4s because of the price. Planning to use it with my factory M-sport springs, just want something more comfortable than my 70K miles suspension.

I see it often recommended to replace all the rubber and hardware while doing this job. I see these 2 kits froms Turner/ECS:
https://www.turnermotorsport.com/p-5...tallation-kit/ ($206.77)
https://www.ecstuning.com/b-assemble...1306775098kt1/ ($278.37)
The ECS kit includes the following but the turner doesn't:
Front Lower Spring Pad - Genuine BMW - 2 31336764372
Front Upper Spring Pad - Genuine BMW - 2 31336767500
Upper Rear Spring Pad - Genuine BMW - 2 33536764419
Lower Rear Spring Pad - Genuine BMW - 2 33536764420

Do I need to replace these spring pads? Do these kits include everything recommended to be replaced while doing the shocks and struts? Do I even need all the hardware in these kits? should I just purchase the rubber items/mounts separately (Rockauto)?

Another concern I have is an increase in ride height after doing this refresh. I like my ride height where it is now, about a finger gap between wheel well and tire, I see some posts about a significant ride height increase after swapping, any thoughts/experiences? ulrichd

Or if anyone has other recommendations for me to look into for under $1K

I'll tag these Canadians who I got a lot of valuable information from while researching: PcarDefector dandandan asbrr hunginator fast1eddy

Fwiw, I'd go for the monotube bilsteins like the B6 or B8. They are a little firmer than the stock Msport. And they weren't much more than the B4 when you consider the cost of installation.

Pads are a good idea. You should condor the Monroe pads as they are firmer.

If you want to try what a mild performance setup feels like, I have the B8 with BMW performance springs (- 15mm & 160/420#). Car feels nicely firm, minimal 1/2"lowering and no more jiggly stock ride.

I may replace the B8 setup next month with coilovers if you are interested. They have about 10,000 KM of use and I can do $1000 with a set of new Whiteline RSFB inserts.