Bilstein B12 Kit

[dcaron9999]

Originally Posted by Indo Rider

This helps a lot, thanks! I have been trying to compare photos of different setups and it wasn't obvious to me whether the tire would be totally below the perch. Really was excited to get the b12 kit installed because it seems like it should allow an improvement over stock without the risk of me making things worse thru improper settings on adjustable coils. Then I got nervous because I questioned if it would be compatible with my tire goals. Time to go ahead and install!

I ordered the same dampers (B8) with Swift Spec-R Springs for my 135i. Goal was to have better handling at lapping events and maintain maximum clearance for wider wheels and tires. The only small concern I have is that the Bilsteins damper diameter will be slightly larger than stock BMW dampers. My current 18x8.5 ET52 RIMS, 10 mm spacers, and 255/35R18 Dunlop ZII tires are a few Mm away from the front strut right now, as you can see in this picture. The B8 may force me to use narrower tires or bigger spacer, perhaps with a slight fender pull or roll.

[Indo Rider]

Interesting! I've been dreaming of fitting 255/35/18 Z2s in the front and 285/30/18 Z2s in the rear. Have the apex arc8 in 1series offsets (45front, 62 rear) on back order. I'm not opposed to some fender rolling, but I wonder if I should go for the 38 offset wheel in front instead of the 45? No or thinner spacers would be preferred.

[dcaron9999]

Originally Posted by Indo Rider

Interesting! I've been dreaming of fitting 255/35/18 Z2s in the front and 285/30/18 Z2s in the rear. Have the apex arc8 in 1series offsets (45front, 62 rear) on back order. I'm not opposed to some fender rolling, but I wonder if I should go for the 38 offset wheel in front instead of the 45? No or thinner spacers would be preferred.

My effective offset in the front is ET42, but I also have a lot of camber up there... (M3 control arms, GC camber plates (resulting camber is -3.2*). My 255/35R18 ZII's result in minor rubbing to the fender under hard compression, on the passenger side only, which I do not feal or hear. Been tracking my dual duty 135i for two seasons like this with no issues. With less offset (<42mm), the rub on the fender would be worse. With more offset (>42mm), I would rub on my struts ...

I really hope I dont have to go back to thinner wheels in the front, as I need all the grip possible up there to keep understeer at a minimum. It's a delicate balance because in slow speed corners, or low grip conditions, the front tire contact patch is not fully exploited. With all this camber, the outside edge of the front tires are off the ground when there is no load (going in a straight line with light braking, or low speed cornering). During high speed turns and hard braking, there is plenty of front grip though, and full contact patch is applied to the ground.

Plan B is moving to 17x8 ET46 BMW wheels, and mounting DOT r-comp, semi-slicks, such as the Yoko AO-48 in 245/40R17 format. Reason is I barely have enough traction with my 255/35R18 Dunlop ZII's, Quaife LSD, and power Im putting down now. Wheels are spinning in 3rd gear, and sometimes even in 4th gear when tires or pavement is cold. I realize this would get worse with cold R-comps used on the street as dual duty though. So have not completely made up my mind and may stick with Extreme Performance tires such as RE-71R or ZII-SS for the 2015 lapping season...

[Xyloft]

Before:


After 2000 miles:


from some angles i can barely tell the difference in the ride height.

this angle does make it look a lot lower.


that is my winter setup. I just put my Summer tires back on (stock 128 sport package rims) but have yet to drive them or take any pictures. I'll post some up if anyone is interested. Also, I still need to get it aligned, but wanted to wait until the summer wheels were on and the suspension had time to settle out.

[optigrab]

Is it possible to get the B12 dampers without the springs?

I want to run them with the 2011 linears

[swagon]

Originally Posted by optigrab

Is it possible to get the B12 dampers without the springs?

I want to run them with the 2011 linears

Just get the Bilstein B8 dampers, they're in the B12 kit.

[aloksatoor]

Are they revalved for the B12 kit or the same as the B8. There was still doubt I believe.

[Rainier42]

Originally Posted by swagon

Just get the Bilstein B8 dampers, they're in the B12 kit.

B12 kit has B8 dampers and are designed for lowered springs. If using stock or Sport package springs, the B6 dampers are the ones you want. B8 and B6 dampers have the exact same valving.

[andrey_gta]

Originally Posted by aloksatoor

Are they revalved for the B12 kit or the same as the B8. There was still doubt I believe.

Marketing literature says they are valved to match the eibach springs in the kit. Weather it is true, one has to spend money to test.

[aloksatoor]

Originally Posted by andrey_gta

Marketing literature says they are valved to match the eibach springs in the kit. Weather it is true, one has to spend money to test.

hmm yeah. I have the b12 prokit but unless I open it up to look at the pistons theres probably no way

[sr2223]

I think i have bmw performance springs (yellow color )and want to try out this kit will this lower the car substantially? I only wany very minimal drop mainly looking at improving the handling and reducing body roll.

[Iron Man]

Originally Posted by sr2223

I think i have bmw performance springs (yellow color )and want to try out this kit will this lower the car substantially? I only wany very minimal drop mainly looking at improving the handling and reducing body roll.

BMWPS only drop around 10-15mm from the stock sport suspension. You don't really need this kit, if you have springs already. Just buy some new Bilstein shocks/struts.

Edit: Sorry, misunderstood your question. Going to this kit from the BMW springs, you'll probably drop another 20mm or so. I would be interested in your springs if you want to get rid of them.

[MarkkyyMan]

After 2 weeks of having this suspension on it makes you realize just how awful the OE shocks and struts are..

[Hops128i]

does anyone know how much wider the b6/b12 strut tubes are compared to stock?

[MarkkyyMan]

Originally Posted by Hops128i

does anyone know how much wider the b6/b12 strut tubes are compared to stock?

I don't know about the strut tube but the piston is wayyy bigger!

[dcaron9999]

Originally Posted by Hops128i

does anyone know how much wider the b6/b12 strut tubes are compared to stock?

Got my B8 dampers and Swift Spec-R springs installed last week.

Happy to report that the strut tube diameter is about the same as stock, and Im still able to run 255/35R18 in the front with about 4mm of strut tube clearance still available.

Only minor irritation is the rake I ended up with, using my combo: Swift Spec-R springs/Bilstein B8/GC camber plates/ Dinan Rear Shock Mounts. Car rides so much better and flatter in the curves, braking, and acceleration, both on the track and on the street.

Front wheels are slammed and 20mm lower than rears though. Im researching options, and our resident "fe1rx" member (mechanical engineer guru) has offered two corrective measures so far.

[aloksatoor]

Originally Posted by dcaron9999

Got my B8 dampers and Swift Spec-R springs installed last week.

Happy to report that the strut tube diameter is about the same as stock, and Im still able to run 255/35R18 in the front with about 4mm of strust tune clearance still availabe.

Only minor irritation is the rake I ended up with, using my combo: Swift Spec-R springs/Bilstein B8/GC camber plates/ Dinan Rear Shock Mounts. Car rides so much better and flatter in the curves, braking, and acceleration, both on the track and on the street.

Front wheels are slammed and 20mm lower than rears though. Im researching options, and our resident "fe1rx" member (mechanical engineer guru) has offered two corrective measures so far.

Might not be cost effective, but you can try the 335 based front springs, they are slightly higher rate so in theory should give a more even drop?

http://www.hpashop.com/Swift-Spec-R-...pec-R-335i.htm

[houtan]

Originally Posted by dcaron9999

Got my B8 dampers and Swift Spec-R springs installed last week.

Happy to report that the strut tube diameter is about the same as stock, and Im still able to run 255/35R18 in the front with about 4mm of strust tune clearance still availabe.

Interested in hearing your setup up front to fit the 255s. What wheel specs, amount of camber, and any fender mods?

[dcaron9999]

Originally Posted by houtan

Interested in hearing your setup up front to fit the 255s. What wheel specs, amount of camber, and any fender mods?

Stock style 261 rear wheels (18x8.5 ET52) + 10mm spacers + camber plates set for -3.2* of camber + M3 control arms + shaving of "fender- to-bumper" plastic tab + minor "fender lip" rolling done at home with a wooden hammer handle.

The last two "adjustments", I only made after I got the B8's and Swift Spec-R springs installed, which slammed the front 20 mm lower than the rear. Track and street tested with zero rubbing...

[houtan]

Originally Posted by dcaron9999

Stock style 261 rear wheels (18x8.5 ET52) + 10mm spacers + camber plates set for -3.2* of camber + M3 control arms + shaving of "fender- to-bumper" plastic tab + minor "fender lip" rolling done at home with a wooden hammer handle.

The last two "adjustments", I only made after I got the B8's and Swift Spec-R srpings installed, which slammed the front 20 mm lower than the rear. Track and street tested with no zero rubbing...

Thanks. Im running apex arc 8 et 45 up front, so pretty similar to your et42 setup. I have a minor front fender roll by my tires hitting the fender prior to camber plates being installed. I don think the dinan camber plates will get me to 3.2 degrees of camber though, I might be able to get 2.5 ish. Still, I might give the 255s a try when my 235s wear out.

[dcaron9999]

Originally Posted by aloksatoor

Might not be cost effective, but you can try the 335 based front springs, they are slightly higher rate so in theory should give a more even drop?

http://www.hpashop.com/Swift-Spec-R-...pec-R-335i.htm

According to this Swift Spec-R table, the 335i springs drop the rear even less, and the front 135i and 335i height are identical. The front 335i Spec-r spring rates are 223/615lbs versus 201/503lbs for the 135i.

http://www.swiftsprings.net/products...ct/spec-r.html

[aloksatoor]

Originally Posted by dcaron9999

According to this Swift Spec-R table, the 335i springs drop the rear even less, and the front 135i and 335i height are identical. The front 335i Spec-r spring rates are 223/615lbs versus 201/503lbs for the 135i.

http://www.swiftsprings.net/products...ct/spec-r.html

I meant, since the 135 weighs less than the e9x, the drop will be less with e9x fronts (length being equal). I originally meant only to cherry pick the front springs from the 335i swift kit and stick with the 135 rear springs to make it 223/503. My reasoning is, swift probably made an avg spring rate for both the lighter 128 and front heavier 135 and calc the drops based on that maybe?