can someone please explain to me why aftermarket suspension...

[mtla4]

Best combination for ultimate handling = Coilovers+corner weighting+dialing(camber etc)
Depending on a lot of variables suspension has to be adjusted to race. BTW a lot of people want to fill the wheel gap. I used to leave my shocks at the stiffest before for the streets but I find them too harsh even tho I'm hardcore. So I adjust I'm blessed to have a shop.To each his own.
Anywhow depends on style of driving.(There is always room for improvement in the suspension dept)

[professor]

people contributing in this thread seem to have strong opinions so perhaps i'll ask for your opinions on the "bmw performance" suspension kit.

if bmw itself is putting a new one out i'd like to know whether (a) they are doing so simply because they would like to cater for those "misguided" people who think that stock isn't good enough OR (b) they genuinely believe that an upgrade is needed for spirited drivers and they would like a piece of the (after)market for themselves.

also what do you guys think of the really cool coilovers systems our there like the bilstein ride control, the kw v3 and kw clubsport? which do you all think is the best one out there for a 70/30 split of car-duty between street and track driving?

[roadburn]

Suspension performance consists of several main elements: tire construction, tire pressures, suspension components and suspension settings.

At the factory, BMW engineers controlled all of these variables.

At home, fiddling around and switching these elements on a hunch, it's surprisingly easy to screw things up.

With coil-overs, "infinitely adjustable" means that, in addition to the one set-up that's fastest, there are an infinite number of ways to dial things wrong.

What's often missing in the aftermarket is a truly knowledgeable and tested group of settings to accompany your shiny, new parts.

I'm new to the world of BMWs, but in the land of Miata where I used to live, such wisdom was available. Whether for autocross or for Spec Miata racing, you could find a group of good, track-tested settings that would at least get you close to optimum. In addition to defining specific components (dictated by the rules in Spec Miata), you could find specific recommended settings for tire pressures, ride height, camber, caster, toe, etc.

Reading the original post, that's what I take as its point: Without a defined and tested group of components and settings, it's hard to achieve as sophisticated a result as the factory engineers did.

That's why they call it "trial and error."

That said, here's some stuff to look at....

KW coilovers: http://www.kw-suspension.com/en/30_P...vers/index.php

TEIN coilovers: http://www.tein.com/price/bmw.html

Koni coil-overs: http://www.koni-na.com/1150.cfm

ST coilovers: http://www.stracing.com/coilovers.html

H&R coilovers: http://www.hrsprings.com/products/coilovers/

B&G coilovers: http://b-gsuspension.com/coilovers.php

Eibach coilovers: http://eibach.com/cgi-bin/htmlos.exe...36741200024423

[Mad Dragon]

I wouldn't put suspension parts designed for an E9x on an E8x.

[BMWeber]

Originally Posted by Mad Dragon

I wouldn't put suspension parts designed for an E9x on an E8x.

why not? same suspension. I'm most likely getting a bilstein PSS10 kit for my car and I'm personally planing on the E92 kit because the only difference is slightly higher spring rates.

[UberDTM]

Originally Posted by roadburn

Suspension performance consists of several main elements: tire construction, tire pressures, suspension components and suspension settings.

At the factory, BMW engineers controlled all of these variables.

At home, fiddling around and switching these elements on a hunch, it's surprisingly easy to screw things up.

With coil-overs, "infinitely adjustable" means that, in addition to the one set-up that's fastest, there are an infinite number of ways to dial things wrong.

What's often missing in the aftermarket is a truly knowledgeable and tested group of settings to accompany your shiny, new parts.

I'm new to the world of BMWs, but in the land of Miata where I used to live, such wisdom was available. Whether for autocross or for Spec Miata racing, you could find a group of good, track-tested settings that would at least get you close to optimum. In addition to defining specific components (dictated by the rules in Spec Miata), you could find specific recommended settings for tire pressures, ride height, camber, caster, toe, etc.

Reading the original post, that's what I take as its point: Without a defined and tested group of components and settings, it's hard to achieve as sophisticated a result as the factory engineers did.

That's why they call it "trial and error."

That said, here's some stuff to look at....

KW coilovers: http://www.kw-suspension.com/en/30_P...vers/index.php

TEIN coilovers: http://www.tein.com/price/bmw.html

Koni coil-overs: http://www.koni-na.com/1150.cfm

ST coilovers: http://www.stracing.com/coilovers.html

H&R coilovers: http://www.hrsprings.com/products/coilovers/

B&G coilovers: http://b-gsuspension.com/coilovers.php

Eibach coilovers: http://eibach.com/cgi-bin/htmlos.exe...36741200024423

dang thanks bro the first thing im doin to mine is lowering it

[Fair]

Originally Posted by TGrits10

Aftermarket suspension doesn't ride better; it handles better. When they say it rides better, they're referring to the tauter feel of a better buttoned-down suspension. Of course it's not going to like bumps as much...well ok sometimes the factory uses cheap crap shocks that compromise ride quality, but ignore this exception.

Now that we've cleared that up...

The stock setup is always going to be a compromise between ride (for DD duty) and handling (for spirited driving). The factory picks a spot somewhere between the two extremes. Enthusiasts often find that they'd like it further toward the handling extreme, and modify to suit their taste. Some of us know from experience that the stock setup is always way too soft for us, and see immediate suspension upgrades as an added cost when buying the car, much like an option package. "Such-and-such car can be had for $40k, but you have to factor in $2k for an LSD and another for $3k for suspension and brake tweaks, so it's really more like $45k for the final product." etc. etc.

Also, don't forget the all-important psychological factor. Even if it weren't true, we'd convince ourselves that our money hasn't been wasted.

+1 to this.

The OEM suspensions on BMWs, even the sportiest M models, is still very soft and ride height is set relatively high, for better clearance and compliance over bumps and such. The BMW strut front suspension also lacks optimal dynamic geometry, and it goes much faster a good bit of negative camber in the front, which is lost as cornering loads go up. So if going fast in a timed competition is important to a BMW owner, the suspension is the first thing to receive attention, or should be.

And contrary to popular belief, a properly designed, higher end racing shock can still offer a complaint ride with increased spring rates and a lowered ride height - within reason.

Still, at least 3/4 of all BMW owners that "put on a suspension" do it for the lowered look. What can I say? :wink: