I'm probably over thinking this but here is my deal:

i have a '97 sedan and when i bought it had bilstein sports and H&R sport springs. I have swapped strut mounts and am running -3.0/0toe front and -2.0/1/8th'in rear. I'm running 255/40/17" Azenis on 8.5" wheels front and rear. stock sways

I autox a lot and HPDE a few times a year. daily driven.

Now, if the car had stock suspension when i bought it, id likely have gone w/ coil overs w/ a stiff rear spring rate and ran stock or no sways. But since the car has what it has and its a decent setup and definately more streetable, i'll stick with it and just add sways to control roll a bit.

So i'm leaning toward UUC bars because the price is right and i like all the info they provide. it seems the UUC bars are biased with a pretty stiff rear. 100% stiffer rear than stock and 50% stiffer front than stock.

So im wondering if this was designed more toward a stock suspension? Is this what i want for my setup? Or should i focus more on a stiffer front bar since i have a lot of camber and a softer rear? Is the adjustability of the UUCs great enough to achieive a stiff front/soft rear?

Any recommendations or ideas? thanks!

:buttrock

Rear bias is ugly.

Get the H&R bars. WAY bigger than UUC up front, slightly bigger rear. Massive rear sway bias just makes you slower and the car more difficult to drive. If you don't want H&R, get the Turner kit. If not that, get the RD bars.

does anyone recommend running just the front aftermarket bar with the stock rear bar? Or do you need to run a matched set?

I have a similar shock/spring combo as the original poster, Vogtland Club Spec with Koni SA. Daily driver with a few autox and HPDEs a year.

does anyone recommend running just the front aftermarket bar with the stock rear bar? Or do you need to run a matched set?

I have a similar shock/spring combo as the original poster, Vogtland Club Spec with Koni SA. Daily driver with a few autox and HPDEs a year.
The front bar is the important one. The rear bar is generally a matter of taste.

TXBDan,

My setup is very similar to yours (except I have camber plates and H&R OE Sport springs with 255/40-17 Falken Azenis). I have the UUC SwayBarbariabs installed F&R. I experimented last season with different settings F&R and have have settled, for now anyway, on this: Front adjusted to middle holes, both sides. Rear set at softest setting, both sides (did you know that UUC suggests fine tuning between settings of changing only side?). I took the car to a two day advanced SOLO2 school and past National Champ Tom Berry drove the car several times. He was very impressed with the handling and said the car could be driven past 10/10ths and still be recovered quite nicely. I, to, am happy with this setup and will not vary from it for my driving style--at least for the first half of the season.

The middle front setting is apparently stiff enough to lift the inside front wheel on a sweeper, according to one of the corner workers!

I run STU as well, same wheel/tire (255/40 Azenis on Koseis), but have GC/koni SA setup with Dinan adjustable sways.

Initially I installed the front sway at position 6 of 7 settings (7 being stiffest), and ran stock rear sway. I really liked this setup.

Eventually I installed the rear dinan sway (at full soft) and found I liked the stock rear sway better. So IMHO, I would just stick with stock rear sway and let the rear suspension articulate.

^^awesome

^what are your spring rates though? that seems to be the norm if you have the rear spring rate. but i dont, so thats where im getting confused.

i guess i could ask, "what rear spring rate does it take to be happy w/ the stock rear swaybar?"

i guess i could ask, "what rear spring rate does it take to be happy w/ the stock rear swaybar?"

I don't know what the auto-X guys are using, but in road-race-land it's around 800lbs befire you can do away with the rear bar entirely.
I'm using the stock 20mm M3 bar with 650lb rears. (500lb fronts with a 26mm front bar) It's probably neutral, but since I'm used/like a bit more oversteer I'm now playing with toe and camber to get what I want in the way of balance.

You guys with the high rate springs can certainly be less concerned with rear swaybars. Now, if memory serves, the H&R OE Sport and Sport both have the same rear spring rate of only 384 lbs. In that case a stiffer than stock rear bar will help, IMO. Along with the gorilla front bar, of course.

hrmm thanks, its getting clearer. but the jist of what i'm getting is i need a lot of front bar and some additional rear bar. i wonder if the UUCs can be adjusted in this manner. ill look into the H&R and turner sizings

hrmm thanks, its getting clearer. but the jist of what i'm getting is i need a lot of front bar and some additional rear bar. i wonder if the UUCs can be adjusted in this manner. ill look into the H&R and turner sizings
No, the UUCs are too skewed.

^yeh it starting to seem a bit that way. here is the data i've come up with:

<table x:str="" style="border-collapse: collapse; width: 691pt;" border="0" cellpadding="0" cellspacing="0" width="919"><col style="width: 83pt;" width="110"> <col style="width: 82pt;" width="109"> <col style="width: 74pt;" width="98"> <col style="width: 58pt;" span="2" width="77"> <col style="width: 48pt;" span="7" width="64"> <tbody><tr style="height: 12.75pt;" height="17"> <td class="xl22" style="height: 12.75pt; width: 83pt;" height="17" width="110">Brand</td> <td class="xl22" style="width: 82pt;" width="109">front size (mm)</td> <td class="xl22" style="width: 74pt;" width="98">rear size (mm)</td> <td class="xl22" style="width: 58pt;" width="77">front added</td> <td class="xl22" style="width: 58pt;" width="77">rear added</td> <td style="width: 48pt;" width="64">
</td> <td class="xl22" colspan="2" style="width: 96pt;" width="128">adjustment holes</td> <td class="xl22" style="width: 48pt;" width="64">
</td> <td class="xl22" colspan="2" style="width: 96pt;" width="128">endlinks?</td> <td class="xl22" style="width: 48pt;" width="64">price</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> </tr> <tr style="height: 12.75pt;" height="17"> <td class="xl22" style="height: 12.75pt;" height="17">stock</td> <td x:num="" align="right">23</td> <td x:num="" align="right">20</td> <td x:num="" align="right">0</td> <td x:num="" align="right">0</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> </tr> <tr style="height: 12.75pt;" height="17"> <td class="xl22" style="height: 12.75pt;" height="17">
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> </tr> <tr style="height: 12.75pt;" height="17"> <td class="xl22" style="height: 12.75pt;" height="17">UUC</td> <td x:num="" align="right">25.4</td> <td x:num="" align="right">23.8</td> <td class="xl24" x:num="0.48738542815384389" x:fmla="=((B5/23)^4-1)" align="right">49%</td> <td class="xl24" x:num="1.0053392099999998" x:fmla="=((C5/20)^4-1)" align="right">101%</td> <td>
</td> <td class="xl23" x:num="">3</td> <td class="xl23" x:num="">2</td> <td>
</td> <td>rear</td> <td>
</td> <td class="xl25" x:num="350"> $ 350.00 </td> </tr> <tr style="height: 12.75pt;" height="17"> <td class="xl22" style="height: 12.75pt;" height="17">Racing Dynamics</td> <td x:num="" align="right">27</td> <td x:num="" align="right">24</td> <td class="xl24" x:num="0.89908197869504547" x:fmla="=((B6/23)^4-1)" align="right">90%</td> <td class="xl24" x:num="1.0735999999999999" x:fmla="=((C6/20)^4-1)" align="right">107%</td> <td>
</td> <td class="xl23" x:num="">3</td> <td class="xl23" x:num="">3</td> <td>
</td> <td>rear</td> <td>
</td> <td class="xl25" x:num="390"> $ 390.00 </td> </tr> <tr style="height: 12.75pt;" height="17"> <td class="xl22" style="height: 12.75pt;" height="17">H&R</td> <td x:num="" align="right">28</td> <td x:num="" align="right">24</td> <td class="xl24" x:num="1.1964472682701968" x:fmla="=((B7/23)^4-1)" align="right">120%</td> <td class="xl24" x:num="1.0735999999999999" x:fmla="=((C7/20)^4-1)" align="right">107%</td> <td>
</td> <td class="xl23" x:num="">2</td> <td class="xl23" x:num="">2</td> <td>
</td> <td>
</td> <td>
</td> <td class="xl25" x:str="230/180"> 230/180 </td> </tr> <tr style="height: 12.75pt;" height="17"> <td class="xl22" style="height: 12.75pt;" height="17">Turner MS</td> <td x:num="" align="right">27</td> <td x:num="" align="right">24</td> <td class="xl24" x:num="0.89908197869504547" x:fmla="=((B8/23)^4-1)" align="right">90%</td> <td class="xl24" x:num="1.0735999999999999" x:fmla="=((C8/20)^4-1)" align="right">107%</td> <td>
</td> <td class="xl23" x:num="">3</td> <td class="xl23" x:num="">2</td> <td>
</td> <td>rear</td> <td>
</td> <td class="xl25" x:num="370"> $ 370.00 </td> </tr> <tr style="height: 12.75pt;" height="17"> <td class="xl22" style="height: 12.75pt;" height="17">Ground Control</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td>
</td> <td class="xl23">inf</td> <td class="xl23">inf</td> <td>
</td> <td>front/rear</td> <td>
</td> <td class="xl25" x:str="400/300"> 400/300 </td> </tr> </tbody></table>
So H&R has the biggest/stiffest front and UUC has the smallest/lightest front. they pretty much all have the same rear. Ground Control doesnt say how big their bars are so who knows. Looks like Turner or RD might be the way to go because they are at a good price and include rear endlinks

GC is 27-30 in front, and 19-24 in the rear (with three different rear bars to choose from). But they're also way more expensive than makes sense for a street car.

I got H&R springs with Bilstein shocks, x-brace and TMS Sways front and rear. Body roll is pretty much a thing of the past but I got the sways dialed in mainly for as much oversteer as possible (see sig).

Remember that the thicker rear sways can be tough on the sway bar mounts. After 3 drifting events the sway bar mounts started to tear and I had to have them welded back into a more solid piece to avoid the problem in the future. Be sure to check you mounting points periodically and especially after hard driving.

^cool. i think TMS is the frontrunner in my mind right now. do you have the newer greased up poly rear endlinks? if so how do you like them? what adjustment settings are you running? i have sigs turned off. i hate a million pictures while im trying to read :P

i have some sway mount reinforcement plates.. i just need to get em welded in someday. i'll probably take care of that when i install these.

I have had Bilstein/H&R Sports with RD bars and then on my other M3, went with the Bilstien/Eibach/UUC bars.

The H&R Sports are 200lbs front, 375 rear
Eibach were 150lbs front and 415 rear

UUC bars were designed for STOCK application and in my opinion, both H&R and Eibach are pretty much close to stock rates (stock rear is 325lbs). IMHO, the UUC bar would work better for you. Throw the front bar on full stiff and the rear (bigger 24mm prefered for soft spring rates) on full soft. The car was very neutral and I drove my then street car on the track with this suspension for 2 years and it was hauling ass.

When I upgraded to H&R Race (345lbs front, 515lbs rear), the UUC rear bars were right around at its max. I was getting mild mid corner and corner exit over steers (which made it a bit faster). The moment I went with 800lbs rear bars, the UUC rear bars were MAXED out and I coudlnt damn drive the car at all. The tail was all over the board.

At that point, I disconnected the rear bar and when I looked at the pics from Winterfest, the rear had TOO much lean. Personally, "I" would tune my car around a rear bar. At present I have a UUC front bar set to full stiff and a stock 20mm rear bar. I havent had a chance to see how this setup feels but am taking the car to wet skid pad this weekend to fine tune it before my first race in May.

Long story short, if you are using stock or barely stiffer than stock springs. Stick with UUC. If you already have a stiff enough (anything more than 500lbs rear) I would go with the RD bars.

Hope this helps

BTW my alignment was identical to yours all throughout the suspension changes.

Lutfy

yeah i got the sway reinforcement plates welded on along with the subframe reinforcement plates. I got the sways back in '04 so they are the older units but they did come with poly end links and bushings. They work well as they don't squeek like poly usually does. The added stiffness of the endlinks contributes to the wear and tear of the mounting points however. I am running the stiffest setting in the rear, not sure about the front as my mechanic said he tweeked them for more oversteer.

My sig is a pic of my e36 drifting, hence the reason for max oversteer.

^^well youre the man to talk to. hah

but, pretty much all the brands have the same rear bar. and then you said w/ UUC bars you had the front max stiff. would have wanted to go any stiffer? if i went w/ RD or Turner id be the in the same situation as UUC in the rear, but id have the ability to go even stiffer up front. i could back off a notch and probably have 'UUC max stiff' stiffness

in other words, UUC's distinctive trait is that it can go softer than the rest up front. but since you had your UUC front set full stiff you werent taking advantage of their only unique trait. so why UUC?

I should have noticed the posting on various bars above. Guess what? They are INCORRECT. Here is the correct info:

http://www.motor-force.com/tech/bars.html

RD rear bar is NOT 24MM. They are 22mm!! And Guess what? So si the Dinan bar. Ready for this? The H&R bar is only 21mm. Turner's and Eibach's rear bar are the only ones that comes close to the UUC bar at 24mm.

With the camber curves of BMW (my experience has been only with the E36 M3s), they love front bar set to full stiff. Less roll equals better camber angle (yes this is absolutely the opposite of what Carroll Smith had said but he was also refering to independent suspended cars). Another important point you want to keep in mind is that a 1mm different is cubed in a bar (in terms of stiffness). For a naked eye, the 22mm and 24mm bar would not make a big difference. However, the difference is pronoucned when it comes to performance.

I have played around with different bars/springs on my car. For the setup you have, go with UUC (again, wouldnt recommend it if you had 500+lb rear springs).

And when you do get them, set the front on full stiff and rear bar to full soft and go out and play :)

I should have noticed the posting on various bars above. Guess what? They are INCORRECT. Here is the correct info:

http://www.motor-force.com/tech/bars.html

RD rear bar is NOT 24MM. They are 22mm!! And Guess what? So si the Dinan bar. Ready for this? The H&R bar is only 21mm. Turner's and Eibach's rear bar are the only ones that comes close to the UUC bar at 24mm.

With the camber curves of BMW (my experience has been only with the E36 M3s), they love front bar set to full stiff. Less roll equals better camber angle (yes this is absolutely the opposite of what Carroll Smith had said but he was also refering to independent suspended cars). Another important point you want to keep in mind is that a 1mm different is cubed in a bar (in terms of stiffness). For a naked eye, the 22mm and 24mm bar would not make a big difference. However, the difference is pronoucned when it comes to performance.

I have played around with different bars/springs on my car. For the setup you have, go with UUC (again, wouldnt recommend it if you had 500+lb rear springs).

And when you do get them, set the front on full stiff and rear bar to full soft and go out and play :)
Out of curiosity, can you verify that list on current product? Regardless, the UUC front bar is too small (and according to your own list, the Eibach and the Turner rear bars are BIGGER than UUC). Don't buy the UUC bars. They're crap that is set up for people who like to feel the tail slide, rather than people who want to maximize grip.

Out of curiosity, can you verify that list on current product? Regardless, the UUC front bar is too small (and according to your own list, the Eibach and the Turner rear bars are BIGGER than UUC). Don't buy the UUC bars. They're crap that is set up for people who like to feel the tail slide, rather than people who want to maximize grip.

Adding to the curiosity, does anyone know the different colors for each manufacturer? I've got front and rear bars that are blue (like painter's tape blue), but the guy that I got them from didn't know the mfg. I'm wondering now because it feels like I need more bar, but I don't know if I can get one that is stiffer.

Adding to the curiosity, does anyone know the different colors for each manufacturer? I've got front and rear bars that are blue (like painter's tape blue), but the guy that I got them from didn't know the mfg. I'm wondering now because it feels like I need more bar, but I don't know if I can get one that is stiffer.
I know I need the GC World Challenge bar for my M3. 32mm isn't cutting it. Hopefully 36mm will.

I should have noticed the posting on various bars above. Guess what? They are INCORRECT. Here is the correct info:

http://www.motor-force.com/tech/bars.html

RD rear bar is NOT 24MM. They are 22mm!! And Guess what? So si the Dinan bar. Ready for this? The H&R bar is only 21mm. Turner's and Eibach's rear bar are the only ones that comes close to the UUC bar at 24mm.

The Motorforce tables do not specify that all the bars are for the E36 M3, which is where I think you are confused. Both the H&R website and Turner say the rear bar for the E36 M3 is 24 mm. The H&R rear bar for the 325i and 328i is 21 mm, and has a different part number. H&R at 28 front / 24 rear are the largest E36 M3 bars outside of GC, MASR and other race brands.

Out of curiosity, can you verify that list on current product? Regardless, the UUC front bar is too small (and according to your own list, the Eibach and the Turner rear bars are BIGGER than UUC). Don't buy the UUC bars. They're crap that is set up for people who like to feel the tail slide, rather than people who want to maximize grip.

I wouldnt go to the extent on calling them crap. Sounds like you have a personal vendetta against the company. I like having 24mm bars at the back IF you are running anything close to stock springs. In this case, the author of this thread is. He can get away with either the Eibach or the UUC bars. Oh and BTW Turner too sells the UUC bar (just and FYI).

WIth my RD bars, the exhaust would bump against the exhaust. UUC bends (rear) eliminated the problem.

And to confidently say that its for people who like to have the tail slide, have you done any testing? Data. Results?

I have played around with RD bars and UUC bars on the same setup he is currently running. If you read my post properly, you will see that the 24mm bar messes things up when you go north of 500lbs rear spring rate. Ask me how I know.

A.L.

Do I actively dislike UUC? Yes. Does that have anything to do with my position that a tiny front sway makes for marginal handling characteristics? No.

I wouldnt go to the extent on calling them crap. Sounds like you have a personal vendetta against the company. I like having 24mm bars at the back IF you are running anything close to stock springs. In this case, the author of this thread is. He can get away with either the Eibach or the UUC bars. Oh and BTW Turner too sells the UUC bar (just and FYI).

WIth my RD bars, the exhaust would bump against the exhaust. UUC bends (rear) eliminated the problem.

And to confidently say that its for people who like to have the tail slide, have you done any testing? Data. Results?

I have played around with RD bars and UUC bars on the same setup he is currently running. If you read my post properly, you will see that the 24mm bar messes things up when you go north of 500lbs rear spring rate. Ask me how I know.

A.L.
i have my uuc's set to full soft front, full stiff rear, with h&r sport springs. camber about 3.5 front, 2 rear. my car still heavily understeers. it gets even worse when i get on the gas as the weight transfers to the rear and front grip becomes less. i'm considering getting a 500# rear spring and set my front bar to stiff and tune from there.
would i have problems?
this is what i went over with the guys a tc kline on my setup after we went over ride height, camber, toe, tire temps/pressures, shock rebound settings, camber settings etc.
i have no problems with uuc products.

just to clairify, a linear 500# spring takes 500 lbs to compess an inch and 1000 lbs to compress 2 inches. am i right?
when do they start measuring the inch? from unloaded height or working height?

just to clairify, a linear 500# spring takes 500 lbs to compess an inch and 1000 lbs to compress 2 inches. am i right?
when do they start measuring the inch? from unloaded height or working height?
Linear springs are linear. Unloaded or working height doesn't change anything.

And I'll bet you that your understeer is coming from too much rear bar combined with too little front bar. I've found that that gives really, really ugly understeer on corner entry.

here is a slightly different question. We see lots of race photos with the E36 lifting the front inside wheel off the pavement. Conventional wisdom says that's a bad thing, all four tires should be planted for maximum grip. But plenty of good racers seem to have their car set up that way, and I'm betting a lot of it comes from the large front bar. (as an aside, the FWD pocket rockets, CRX and GTI and others lift the inside rear wheel, so I'm assuming the drive wheels also have something to do with it along with the suspension)

So will larger front bar cause this trait on the E36 M3, and how bad is it on handling?

Linear springs are linear. Unloaded or working height doesn't change anything.

And I'll bet you that your understeer is coming from too much rear bar combined with too little front bar. I've found that that gives really, really ugly understeer on corner entry.
i'm inclined to think otherwise. once, i was doing work on my car, and forgot to re connect one front sway link. i went to the post office and had instant oversteer on demand. i wans'nt even driving fast. this would have scared the crap out of me at the track.
earlier i was thinking, i have motorforce plates with stock-style springs. while installing the springs, i had to compress them more than with the factory perches/mounts. i'm thinking my front springs may be under preload due to the shorter max height allowed by the motor force plates. could this have raised my effective spring rate?
just stabbing inthe dark.

i'm inclined to think otherwise. once, i was doing work on my car, and forgot to re connect one front sway link. i went to the post office and had instant oversteer on demand. i wans'nt even driving fast. this would have scared the crap out of me at the track.
earlier i was thinking, i have motorforce plates with stock-style springs. while installing the springs, i had to compress them more than with the factory perches/mounts. i'm thinking my front springs may be under preload due to the shorter max height allowed by the motor force plates. could this have raised my effective spring rate?
just stabbing inthe dark.
Too little front sway means understeer on corner entry with oversteer on corner exit. NASCAR folks call this "pushy-loosy." IMHO, it's the nastiest possible setup you can have on a car. Lots of front sway means oversteer on corner entry and understeer on exit.

Set your front bar to full stiff and see what you think of how your car drives.

I'm not hearing you say that you've tested this. I've tested no front, no rear, no sways at all, minimal front, minimal rear, lots of front, lots of rear, and lots of the various shades of gray in between. If you don't try it, you can't say it won't work. Especially not when your current setup doesn't work in the first place.

Of course, it could just be a driver issue.

Oh yes, and preloading a progressive spring only affects you if the spring gets extended, or if you've got so much preload that the car doesn't compress the spring. If the car drops at all when you drop it off the jack, you have zero preload at rest.

here is a slightly different question. We see lots of race photos with the E36 lifting the front inside wheel off the pavement. Conventional wisdom says that's a bad thing, all four tires should be planted for maximum grip. But plenty of good racers seem to have their car set up that way, and I'm betting a lot of it comes from the large front bar. (as an aside, the FWD pocket rockets, CRX and GTI and others lift the inside rear wheel, so I'm assuming the drive wheels also have something to do with it along with the suspension)

So will larger front bar cause this trait on the E36 M3, and how bad is it on handling?
You can fix it with lots of spring, but that is not a good solution. I'm told helper springs will reduce this somewhat.

Let's just put it this way: PTG has had cars that lift a front wheel. It's not a big deal.

here is a slightly different question. We see lots of race photos with the E36 lifting the front inside wheel off the pavement. Conventional wisdom says that's a bad thing, all four tires should be planted for maximum grip. But plenty of good racers seem to have their car set up that way, and I'm betting a lot of it comes from the large front bar. (as an aside, the FWD pocket rockets, CRX and GTI and others lift the inside rear wheel, so I'm assuming the drive wheels also have something to do with it along with the suspension)

So will larger front bar cause this trait on the E36 M3, and how bad is it on handling?
You can fix it with lots of spring, but that is not a good solution. I'm told helper springs will reduce this somewhat.

Let's just put it this way: PTG has had cars that lift a front wheel. It's not a big deal.

I'm not hearing you say that you've tested this.

Of course, it could just be a driver issue.

Oh yes, and preloading a progressive spring only affects you if the spring gets extended, or if you've got so much preload that the car doesn't compress the spring. If the car drops at all when you drop it off the jack, you have zero preload at rest.

i have tried driving with no front sway. like i said, oversteer all the time. especially on corner entry.

it is a minor driver issue. it only understeers when i drive it.:D

i get the last part now that you explained it. thanks.

Set your front bar to full stiff and see what you think of how your car drives.



Agreed. The fastest setup is front full stiff and rear full soft. Conventional wisdom says otherwise but you have to remember that the camber curves on the E36s are not the same as the curves found on an independent suspended car. That said, (odortiz) try the above setup and I can assure you that even with those softer spring rates (you have enough camber) your car will behave much better.

Ahmad

i have tried driving with no front sway. like i said, oversteer all the time. especially on corner entry.

it is a minor driver issue. it only understeers when i drive it.:D

i get the last part now that you explained it. thanks.
Dude. No front sway is not the same as a too soft front sway. If you don't try it, you're not allowed to say that it won't work.

Moreover, the amount of time it takes for the car to roll over and set with no front sway makes it virtually impossible to oversteer on corner entry. With no front sway the transition to mid corner oversteer (basically as soon as the car takes a set) happens so fast that you THINK you're getting corner entry oversteer when you're not.

On more vote against UUC bars. I had them for the E46, and ditched them. Now I have a front H&R 27mm bar, and stock rear bar, and the car handles great. Surprisingly neutral at autocrosses -- easy to get the tail out, but allows me to put down power on corner exit with minimal inside wheel spin.

If any conventional wisdom says my setup must understeer, then the wisdom is wrong.

UUC rear bias is well marketed, but doesn't work best in practice. Go to Solo II nationals in Topeka KS and ask how many BMW drivers are running UUC bars. I doubt you'll find many, if any at all.

Dude. No front sway is not the same as a too soft front sway. If you don't try it, you're not allowed to say that it won't work.

Moreover, the amount of time it takes for the car to roll over and set with no front sway makes it virtually impossible to oversteer on corner entry. With no front sway the transition to mid corner oversteer (basically as soon as the car takes a set) happens so fast that you THINK you're getting corner entry oversteer when you're not.
ok i'll give it a shot with stiff front bar. i'll be at shenandoah this weekend.

Agreed. The fastest setup is front full stiff and rear full soft.

:buttrock

thanks for all the info. i think i'll settle on the Turner MS bars. theyre almost as cheap as the UUCs, same size in the rear and will go even stiffer up front if i feel i need to. if not ill back off a notch and be near UUC's max stiffness. and they come w/ rear endlinks unlike the H&Rs.

Agreed. The fastest setup is front full stiff and rear full soft. Conventional wisdom says otherwise but you have to remember that the camber curves on the E36s are not the same as the curves found on an independent suspended car.

It's not just camber curves, but differing roll centers between the front and rear as well. You can literally see them fighting when an E36 corners, as the front rolls more than the rear, even with higher wheel rates (combination of springs and bars), resulting in the inside tire lift. Without being able to make suspension geometry changes (i.e. PTG or BMW CCA Mod class), it's nearly impossible to solve the wheel lift problem because you are stuck with the crappy roll center up front that occurs when you lower the car. Thus, big bars, big spring rates, and lots of camber are usually the way to make grip on the front of E30, E36, and E46's (they are all essentially the same) in stock and prepared classes.

Adding to the curiosity, does anyone know the different colors for each manufacturer? I've got front and rear bars that are blue (like painter's tape blue), but the guy that I got them from didn't know the mfg. I'm wondering now because it feels like I need more bar, but I don't know if I can get one that is stiffer.

I believe it'd be Turner's: http://www.turnermotorsport.com/html/detail.asp?PRODUCT_ID=TMSSWAY

It's not just camber curves, but differing roll centers between the front and rear as well. You can literally see them fighting when an E36 corners, as the front rolls more than the rear, even with higher wheel rates (combination of springs and bars), resulting in the inside tire lift. Without being able to make suspension geometry changes (i.e. PTG or BMW CCA Mod class), it's nearly impossible to solve the wheel lift problem because you are stuck with the crappy roll center up front that occurs when you lower the car. Thus, big bars, big spring rates, and lots of camber are usually the way to make grip on the front of E30, E36, and E46's (they are all essentially the same) in stock and prepared classes.Although you were answering lufty, I think that answers my question as well. thanks Bryan.

spuds - I agree with knightpitt, the smurf blue sounds like Turner.

TXBDan - do you know if you will need the front links too? GC sells adjustable ones, but they are like $120. Just wondering if these are necessary, or whether the Turner kit comes with the necessary links.

http://www.ground-control-store.com/products/description.php/II=677/CA=9

Smurf Blue is the Turner bars...but IIRC they're just H&R bars coated blue.

My .02 on this issue...while my car is an E46 I have the H&R bar set on full stiff with the factory rear bar and it helped quite a bit. My brother's '95 E36 has a GC front bar (full stiff) and stock rear bar and feels even better than my car. These cars seem to respond well to controlling roll from the front. While I've been throwing around the idea of playing with a rear bar the only one I'm happy with the size of is the GC medium rear bar. My fear is if I put more rear bar in the car that I'll want More front to keep the current balance and I'm already maxed out on the front bar.

Andy

Conventional wisdom says otherwise but you have to remember that the camber curves on the E36s are not the same as the curves found on an independent suspended car.

http://www.merriamwebster.com/cgi-bin/dictionary?va=independent

Read 1b.

It's not just camber curves, but differing roll centers between the front and rear as well.

To take it one step further, the FRCH combined with the city bus-length FVSALs and the low roll gradients everyone targets is what causes the need for a heavy front LLTD bias.

--Matt

To take it one step further, the FRCH combined with the city bus-length FVSALs and the low roll gradients everyone targets is what causes the need for a heavy front LLTD bias.

Ha!

To take it one step further, the FRCH combined with the city bus-length FVSALs and the low roll gradients everyone targets is what causes the need for a heavy front LLTD bias.

--MattHey I'm just a track star wannabe looking to improve his street car with some off-the-shelf components, not a suspension designer trying to squeeze out the last tenth or so, so I think you lost me there. Do your acronyms mean:

FRCH: front roll center height?
FVSAL: front view swing arm length?
LLTD: lateral load transfer distribution?

I really don't know what this all means, but here's what I found in some random street rod tech article:

Front-View Swing Arm (FVSA)
FVSA is the horizontal distance from the instant center (see definition below) to the center of the tire-contact patch. This length determines the rate of camber change and how much side scrub the suspension will have. Too short an FVSA will make a vehicle feel very unstable on the road. FVSA length should be at least 100 inches for street cars.

Instant Center (IC)
The instant center is a virtual intersecting point of suspension links, including the angle of the control arms and the centerline of the contact patch. This is the point around which the spindles rotate. This rotation point itself keeps changing its location as the suspension arms cycle up and down and change their angles (that is why it is called "instant").

From a Cobra forum:

"lateral load transfer distribution", which is the complete load transfer description including the part reacted through the springs and controlled by the roll couple distribution, and the part reacted through the control arms and controlled by the roll centers.


But as Tweety would say: "ooooh, my poor wittle head!"

A basic primer on car suspensions. Ironically, it's for RC cars, but the same principles apply.

http://home.tiscali.be/be067749/58/

Go to the suspension link on the left hand bar. About 1/4 the way down and it starts to talk about roll centers, etc.

FRCH: front roll center height?
FVSAL: front view swing arm length?
LLTD: lateral load transfer distribution?

You're good on FRCH and LLTD, but FVSAL has a read-between-the-lines "V", making it Front View (Virtual) Swing Arm.

Front-View Swing Arm (FVSA)
FVSA is the horizontal distance from the instant center (see definition below) to the center of the tire-contact patch. This length determines the rate of camber change and how much side scrub the suspension will have. Too short an FVSA will make a vehicle feel very unstable on the road. FVSA length should be at least 100 inches for street cars.

Not a great definition. It's from the FVIC (Front View Instant Center) to the center of the wheel, not the contact patch. The comments about FVSA length are extremely shortsighted, so don't consider those to be good rules of thumb. Also, side scrub is determined more by FVIC location that FVSAL.

Instant Center (IC)
The instant center is a virtual intersecting point of suspension links, including the angle of the control arms and the centerline of the contact patch. This is the point around which the spindles rotate. This rotation point itself keeps changing its location as the suspension arms cycle up and down and change their angles (that is why it is called "instant"). [/I]

Another one that could be better. FVIC is determined by the geometry of the links (or LCA and strut) but it has nothing to do with contact patch. It also has nothing to do with spindle rotation.

"lateral load transfer distribution", which is the complete load transfer description including the part reacted through the springs and controlled by the roll couple distribution, and the part reacted through the control arms and controlled by the roll centers.

No, that's TLLT (Total Lateral Load Transfer). LLTD just has to do with how much of it is transferred to the front vs. rear. Edit: Actually, it's a poor definition of TLLT.


A basic primer on car suspensions. Ironically, it's for RC cars, but the same principles apply.

I don't see the irony.


--Matt

A basic primer on car suspensions. Ironically, it's for RC cars, but the same principles apply.

http://home.tiscali.be/be067749/58/

Go to the suspension link on the left hand bar. About 1/4 the way down and it starts to talk about roll centers, etc.that was a pretty good site, I actually understood most of it! thanks.

Matt, those were the results of quick googling, just to try and find some reference points.

The biggest different from RC cars to BMW (well, aside the obvious :) ) is that we have strut type front ends while the stuff on the RC car site is all about a-arm suspensions.

The roll-centers, camber curves, etc. are all different on a strut front end. The same basic principles of roll couple, IC, etc. are the same though.

Specifics on strut from ends:
http://e30m3performance.com/myths/Weight_Transfer/weight_transfer2.htm

What is done on Motorsport e30s to fix it:
http://e30m3performance.com/tech_articles/susp-tech/ft_roll_center_comp/index.htm

You can also get a-arms that have a longer distance from the knuckle to the ball joint on the suspension arm to drop the outside pivot point. Also requires a similar spacer on the stearing rod to fix bump steer. (Ground control makes that part).

Main site - really good stuff in there BTW:
http://e30m3performance.com/index.html

You can also get a-arms that have a longer distance from the knuckle to the ball joint on the suspension arm to drop the outside pivot point. Also requires a similar spacer on the stearing rod to fix bump steer. (Ground control makes that part).

In addition to spacers, you can also space out the pivot point of the control arm to give a "longer" arm. In our case, we even used the longer E46 control arms on a E36 and then replaced the outer balljoint with an offset spherical bushing to further extend the control arm length:

http://www.bryanwatts.com/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=802&g2_serialNumber=1

So, just to see if I get it right: I've got stock suspension with slightly stiffned chassis. Stock front sway bar is 24mm.

If I upgrade just the front sway to 25,5mm (sport package sway bar),what would be the effect in handling?

Thanks

In addition to spacers, you can also space out the pivot point of the control arm to give a "longer" arm. In our case, we even used the longer E46 control arms on a E36 and then replaced the outer balljoint with an offset spherical bushing to further extend the control arm length:

Cool, I didn't know what the difference in the arms was. Looked like they would fit, but couldn't confirm it.

Where do you get the spaced ball joints?

RRT can fab the arms up for you. They produce the bushing carriers and press them into the arms for you.

RRT can fab the arms up for you. They produce the bushing carriers and press them into the arms for you.Heh - should have guessed. :)

I need a suspension first for the track toy, so perhaps next year.

well i bought the Turner bars a few weeks ago. i installed the front bar first and had only that for over a week. the car immediately felt flatter and more responsive.

finally today i had a chance for a friend to come over and weld on the GC rear sway bar mount reinforcements so i could install the rear bar.

so now w/ both bars (front full stiff, rear full soft) the car is feeling awesome. w/ just the front you could feel the rear end trying to roll or something odd, but now it feels really good. i can't wait for the next autox in a couple weeks to try this out!

doh

Out of curiosity, can you verify that list on current product? Regardless, the UUC front bar is too small (and according to your own list, the Eibach and the Turner rear bars are BIGGER than UUC). Don't buy the UUC bars. They're crap that is set up for people who like to feel the tail slide, rather than people who want to maximize grip.

Please check you facts. The UUC bars are hollow tubes, therefore they have way more surface tension and do not need to be as big or as heavy as the others.

^only the E46 bars are hollow. the E36 are not. im pretty sure my list is accurate

hollow tubes, therefore they have way more surface tension and do not need to be as big or as heavy as the others.

In order to provide the same torsional stiffness as a solid bar, a tubular bar needs to have a larger OD, not smaller.

--Matt

prove it

most simply put, stiffness of a solid rod = pi*materialelasticity*diameter^4. since we're comparing (dividing) we can cancel out the pi*elasticity part and just use the arbitrary product to compare.

you can find the stiffness of a tube by subtracting the stiffness of its empty inside. so:

so you have a solid 25mm tube. its stiffness is approx 25^4 = 390625

if there were a hollow 25mm tube w/ a 3mm wall thickness we would do:

25^4-(25-3*2)^4 = 260304. so no, its not as stiff.

itd take about a 28mm hollow bar to be as stiff

Seems pretty clear that for a given diameter, solid are stiffer than tubular. But by increasing the diameter just slightly, you get equivalent (or better) stiffness and lighter weight.

http://python.rice.edu/~arb/Courses/615_sway_bar.pdf

http://www.hotchkistuning.com/bin/Misc/HollowSwayTech-D.pdf

http://www.whiteline.com.au/docs/bulletins/Hollow%20vs%20Solid%20Swaybar.pdf

http://www.theherd.com/articles/swaybar.html

A hollow bar has about 90% the stiffness of a solid one. The reason to use a hollow bar is because they are lighter weight. The swaybars on our WCTC only weigh a few pounds but are hugely stiff because of the large diameter.

The outside of a swaybar has to twist further in proportion to the metal in the inside of the bar. So by proportion the metal in the inside of the cross section will provide relatively little stiffness. Some, but not alot compared to the material on the outer edges of the bar. This is why you can basically remove the inner bit of the bar by using a hollow tube and lose little stiffness.

Either way this doesn't have anything thing to do with the front swaybar being to small.

Please check you facts. The UUC bars are hollow tubes, therefore they have way more surface tension and do not need to be as big or as heavy as the others.
That's got to be the funniest piece of incorrectly parroted marketing gibberish that I've ever read.

I came back here to find out the diameter of the Eibach sways, and discovered that they are not in the table posted earlier. So here is another crack at the Motorforce table, just for completeness:

E36 Anti-roll Bars
Manufacturer..........Front, mm.........Rear, mm..................Notes
BMW - 1995 M3..........22.5.................19
BMW - 1996+ M3........23....................20
BMW - 325/328 Base...24....................15
BMW - 325/328 Sport Package 25.5......18
Eibach M3 style..........26....................24........... .......adjustable
Eibach 325/328/318....28....................21..................a djustable
UUC Motorwerks.........25.4.................23.8...... ............adjustable
Turner Motorsports.....27....................24.......... ........adjustable
RD...........................27................... .22.2..................adjustable
Dinan.......................22.2.................. 22.2..................adjustable
H&R.........................28....................21 ..................adjustable

And as discussed above, the aftermarket bars, unless otherwise noted, appear to be for the M3

cool, thanks.

if anyone cars, my current sweet spot w/ the TMS bars is 4/5ths stiff front, full soft rear. and stiffer and i think im giving up grip.

cool, thanks.

if anyone cars, my current sweet spot w/ the TMS bars is 4/5ths stiff front, full soft rear. and stiffer and i think im giving up grip.


This may be a stupid question but IIRC doesn't the turner front bar have 3 adjustment holes?...how do you get 4/5 stiff if there's 3 holes?

Andy

you can go 'half steps' but just moving one side to the next hole. so if there are 3 holes in each side, then there are 5 steps:

soft/soft
mid/soft
mid/mid
stiff/mid
stiff/stiff

so im mid on one side and stiff on the other up front. and so there are three settings for the 2 hole rear as well. im soft/soft in the rear

This may be a stupid question but IIRC doesn't the turner front bar have 3 adjustment holes?...how do you get 4/5 stiff if there's 3 holes?

3 holes on each side leaves you with 5 possible adjustments.

1-1, 1-2, 2-2, 2-3, 3-3...1-3 doesn't matter as it "should" be the same as 2-2.

I'm not too bright sometimes... Thanks for setting me straight.

Andy