[taylor99ss]

Im researching suspension upgrades and have found very valuable information on this board, thank you to all who have contributed.

Why do I, and so many others, assume the BMW performance parts will "outperform" the aftermarket vendors? Is it because of the BMW label? Do we assume they put millions of dollars into their R&D that they have found the ideal configuration under "normal" driving variables?

on to the suspension....

Again, from reading and researching, its seems a quality and popular option to improve suspension is the KW coilover kit. Has any analysis been done in comparing this kit to the BMW Performance Suspension Kit? Obviously, i'm torn between the two.

Thank you!

[brocklanders]

this is only my opinion and is not fact based, but i believe that it is because the aftermarket caters to many different makes and models. therefore i dont see how they wouldnt mix and match between them. where as a bmw suspension is designed for a particular model with the same components. for instance from my reading and what little understanding i took from it, i had just purchased aftermarket parts to overhaul my suspension. i would be willing to bet that lap times are going to suffer from the "upgrades" that i made. due to the fact that our cars dont have lsd's and the stiffer rear end will loose traction around turns. i chose the items for my own reason i want to feel like im driving a better car, numbers are not important. i think for real performance the zsp setup, as in spring rate, size of sway bars, and the suspension bushings are probably the best for this car.

[acerboo]

i drove a bmw performance 335i kitted demo the other day, the suspension was faultless on the road. no rubbing, no pulling, no clonking, no problems with the steering, thats why you buy oem bmw

[David1]

Originally Posted by acerboo

i drove a bmw performance 335i kitted demo the other day, the suspension was faultless on the road. no rubbing, no pulling, no clonking, no problems with the steering, thats why you buy oem bmw

Even better when you put the M3 control arms on with it.

[brocklanders]

if you are like most, myself included, who will never use their suspension to its ability, i would get the kw's. you can lower it as much as you desire, and change it later if you change your mind.

[e90pilot]

The advantage of the BMW performance is not really the performance in terms of grip and balance, it's the fact that will work without issue. Some aftermarket solutions wi have some clunks or rattles on some cars and not others. Some were tuned with different wheels and tires. The BMW performance was tuned with factory wheels with similar weights and runflats with the same width as a stock ZSP.

[lawwailok]

i was debating between a very common setup: H&R sport with koni yellow and bmw perf.
ended up i went with bmw perf because it is engineered for the specific car. i had Tein, Tanabe and some other brands suspensions on my previous cars and the first thing i notice that how well the bmw perf suspension can achieve the stock ZSP feel ride during normal daily driving. not anything bumpier than ZSP (maybe just slightly bit) but it improves the handling.

[brocklanders]

Originally Posted by lawwailok

i was debating between a very common setup: H&R sport with koni yellow and bmw perf.
ended up i went with bmw perf because it is engineered for the specific car. i had Tein, Tanabe and some other brands suspensions on my previous cars and the first thing i notice that how well the bmw perf suspension can achieve the stock ZSP feel ride during normal daily driving. not anything bumpier than ZSP (maybe just slightly bit) but it improves the handling.

which performance suspension did you get if you dont mind me asking

[lawwailok]

Originally Posted by brocklanders

which performance suspension did you get if you dont mind me asking

i ordered them separately, i got the Perf struts kit and a set of Perf yellow spring kit from tischer, but i did not get the front sway bar tho.

[David1]

Originally Posted by lawwailok

i ordered them separately, i got the Perf struts kit and a set of Perf yellow spring kit from tischer, but i did not get the front sway bar tho.

You need the bar. It makes a huge difference.

[acerboo]

Originally Posted by David1

You need the bar. It makes a huge difference.

is the bar that much different from standard? its the same diameter

[lawwailok]

Originally Posted by acerboo

is the bar that much different from standard? its the same diameter

+1, according to tischer, the fsb comes with Perf suspension is 26.5mm, and stock ZCP fsb, also the stock E9x M3 (exclude E93) fsb is 26.5mm.

[philsteroni]

One thing I like about BMW performance is that nobody can really criticize your choice of mods, because it`s oem .

[brocklanders]

the fact that bmw has different spring rates for sedan or coupe, and manual or automatic and every spring has a strut to match that alone tells me that there is more engineering in bmw parts, o.e. or performance. i doubt the struts and shocks are any different between the h&r touring and sport cup kit, sure they work but there's got to be a compromise somewhere.

[brocklanders]

Originally Posted by lawwailok

i ordered them separately, i got the Perf struts kit and a set of Perf yellow spring kit from tischer, but i did not get the front sway bar tho.

i thought the new performance suspension came with a rear sway bar and the front was retained. the performance rear is 14mm instead of the sport pack 13mm. also ive read that the sport pack front sway is 26.5mm at the thickest point, maybe the m3 sway is 26.5mm all the way across.

[lawwailok]

the previous suspension kit came with the rear sway, but the new generation suspension kit comes with front sway now. when i ordered mine, even tho it is separate orders, they still need to verify my vin so they can match up with the right springs.

[David1]

Originally Posted by acerboo

is the bar that much different from standard? its the same diameter

Same diameter but stiffer with different angles. When I had the old and new side by side I was like "that can't be right".

[michaelthepsycho]

Is it possible to install just BMW Performance springs on a non-ZSP 335i?

[brocklanders]

of course it is possible, i dont think anyone could tell you the outcome with any certainty unless they have that setup. i doubt many do, and i doubt many would recommend it.

[acerboo]

its best not to mess around just fit the complete suspension from bmw and you know it will do what it says on the box with no issues. i recently drove a bmw 335i demo car with the suspension fitted and i thought it was perfect for the road, it hardens up the faster you go and it actually rode better than my car with the m sports suspension so im having mine changed on monday. it will be cheaper in the long run as well.

[Murph335]

the stance of the HR Sports is excellent, stock ZSP shocks get bouncy on dips. Shorter shock is the way to go.

Bought BMW performance shocks to install in hopes of improving the ride. Appears no one has done this combo.

If successful it will be the best look, handling, and most affordable setup!!

[ackrepps]

For you guys that have installed the factory performance suspension does it drop the car lower than ZSP and by how much? I want just a little lower and stiffer. Have had H&R sports with FSD and Eibachs with FSD recommended. Yes I know coilovers are best option but I don't live in a mod friendly area and can't see wasting a day to drop the car off and pick it up. Any input is welcomed.