e36 front sway and/or rear sway

Chris Brown · **Posted:** Fri Jan 25, 2008 12:01 pm

so in an effort to keep up with rodney's modding, i need a front sway...i think...the thing is, everywhere i look, i see them sold as front/rear packages but from what i understand, i really only need the front.

any opinions? front only or get both?

also, is the x-brace worth it?

i'm also shopping for stiffer and taller springs (than my h&r sports) so if you know if any, i'm all ears.

MarcusMcRae · **Posted:** Fri Jan 25, 2008 12:25 pm

Chris Brown wrote:

so in an effort to keep up with rodney's modding, i need a front sway...i think...the thing is, everywhere i look, i see them sold as front/rear packages but from what i understand, i really only need the front.

any opinions? front only or get both?

also, is the x-brace worth it?

i'm also shopping for stiffer and taller springs (than my h&r sports) so if you know if any, i'm all ears.

From what I have read some people say both some say just front. I am still running the stock bars. My inside rear tire sometimes comes off the ground so I was going to try just the front.

The X-brace is definitely worth it. Unfortunately for you, it is illegal in ST.

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

Have one of these sitting in my garage right now awaiting installation:

Not cheap... but light and really easy to adjust. Available as front only. Might be overkill for a street car, it's bigger than I really wanted for the M3 but I'll be giving it a shot. I think the bar itself is 6lb.

http://www.ground-control-store.com/pro ... I=499/CA=9

Chris Brown · **Posted:** Fri Jan 25, 2008 3:22 pm

MikeWhitney wrote:

Have one of these sitting in my garage right now awaiting installation:

Not cheap... but light and really easy to adjust. Available as front only. Might be overkill for a street car, it's bigger than I really wanted for the M3 but I'll be giving it a shot. I think the bar itself is 6lb.

http://www.ground-control-store.com/pro ... I=499/CA=9

with all the other junk i'm NOT doing, i don't think spending an extra $200 would be worth it.

so...i'm assuming based on your comments that i'm ok with going with just the front...i like that.

now, for springs...i was thinking of getting the gc conversion kit, but what spring rates for use with koni yellows? i don't mind a harsh ride on the street if i get the performance at an autox

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

Chris Brown wrote:

now, for springs...i was thinking of getting the gc conversion kit, but what spring rates for use with koni yellows? i don't mind a harsh ride on the street if i get the performance at an autox

Something like 450F 550R would be a good starting point. Shouldn't be too bad on the street. Check out this thread, the STU guys have the specs:

http://forums.bimmerforums.com/forum/sh ... hlight=stu

Suspension
17x9 SSR Comps
255/40/17 Yokohama Advan Neova AD07s
-3.5 deg camber, 0.10 deg toe out front
-2.5 deg camber, 0.20 deg toe in rear
adjustable coilovers (GC/koni, bilstein, AST, etc)
at least 500# front springs and at least 25mm sway bar up front
between 450# and 650# rear springs (depending on driver preference) stock size rear bar, or small adjustable rear bar

Weight Savings
LTW sport or race seats - 80# savings
LTW battery - 30# savings
replace exhaust with custom 2.5" or 3" single exhaust - 60# savings or so
get a non sunroof car - 45# savings

Power
cold air intake and tune

MarcusMcRae · **Posted:** Fri Jan 25, 2008 5:23 pm

450/550 is what I am using with koni sa's from GC. It is not the greatest ride when you get on a pot holed street.

RodneyWright · **Posted:** Sat Jan 26, 2008 11:51 am

Chris Brown wrote:

so in an effort to keep up with rodney's modding, i need a front sway...i think...the thing is, everywhere i look, i see them sold as front/rear packages but from what i understand, i really only need the front.

any opinions? front only or get both?

also, is the x-brace worth it?

i'm also shopping for stiffer and taller springs (than my h&r sports) so if you know if any, i'm all ears.

What mods

H&R will sell their sways separately. I currently run both their front and rear bars, but initially started out with the front bar when I was running DS.

An x-brace is not an allowed mod in STS, but your welcome to install so I can protest and kick your fast butt out :twisted:

. You can run a strut tower brace. Depending on what you read, opinions are all over the board. In talking with Dave Davis, he said there is inherent body flex on the e36. I bought the cheap sparco unit. I can't honestly tell you if there's any difference in the way the car handles. I will state that all M3's include a factory strut tower brace....I'm just say'n...

I'm running the H&R sports myself right now, but next year I'll be looking for some coilovers. Already spent my budget this year on those damn high $ camber plates.

Chris Brown · **Posted:** Fri Feb 01, 2008 2:21 pm

RodneyWright wrote:

I'm running the H&R sports myself right now, but next year I'll be looking for some coilovers. Already spent my budget this year on those damn high $ camber plates.

yeah, i saw the price of the plates and opt'd for some $25 shimms that have so far treated my nicely.

i'm going with the 450/550 combo plus the h&r fsb...i'll skip the strut tower bar for now. i think my next purchase would be either an intake or exhaust, but that won't be for a while.

Kevin Allen · **Joined:** Thu Aug 28, 2003 6:42 pm **Posts:** 3479

Those are more than double my spring rates. :lol:

DanDurusky · **Joined:** Sun Apr 10, 2005 7:31 pm **Posts:** 686

probably not at the wheel

BriceJohnson · **Joined:** Thu Apr 13, 2006 7:33 am **Posts:** 2230

Kevin Allen wrote:

Those are more than double my spring rates. :lol:

haha, if I upgrade springs this year, then that'll be about double my spring rates. Right now its about 4 times my [stock] spring rates.

Kevin Allen · **Joined:** Thu Aug 28, 2003 6:42 pm **Posts:** 3479

Quote:

probably not at the wheel

In the front, probably so. In the rear, maybe. What's the correction factor for a BMW? I think a Subaru is pretty close to 1.

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

Kevin Allen wrote:

Quote:

probably not at the wheel

In the front, probably so. In the rear, maybe. What's the correction factor for a BMW? I think a Subaru is pretty close to 1.

0.94 front
0.65 rear

WHEEL RATE = SPRING RATE x (MOTION RATIO)^2

Chris Brown · **Posted:** Sat Feb 02, 2008 10:49 am

this brings up an issue i've never understood...how can you quote a spring rate for a progressive spring? linear i understand as it's the same force across the range of the spring, but not true for progressive springs.

Chuck Branscomb · **Posted:** Sat Feb 02, 2008 11:24 am

Chris Brown wrote:

this brings up an issue i've never understood...how can you quote a spring rate for a progressive spring? linear i understand as it's the same force across the range of the spring, but not true for progressive springs.

You basically can't, but it depends on the type of progressive spring design. For example, some designs (mainly older ones) use two different springs and depend on the softer spring going into coil bind to start compressing the stiffer spring. Motorcycles were famous for such in the old days. Then you could quote the spring rate for each spring (i.e. 200/450), but that still doesn't tell you much about the true nature of the spring since you also need to know how many coils each of those rates has.

Some coilover kits these days use "helper" springs to hold the main spring in its perch under full droop, and they work the same way.

A true progressive spring has a continuously varying spring rate as it is compressed under load, so the only real way to describe such a spring is with a force/deflection chart.

That's my swag at it anyway...

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e36 front sway and/or rear sway

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