UUC SwayBarbarians now available for our cars!!

[mikeo]

That's interesting, Prince ///M. In the U.S. it's not just autocrossers but also road racers that profess the advantages of large front swaybars on BMW McStrut cars. The MWerks article is a good read, but they were building a mild suspension upgrade for a street car with OE size street tires, and while I'm not arguing that a larger rear bar doesn't help somewhat with underesteer, racers generally want to work on the end (front or rear) that is having the handling problem. Really stiff rear bars tend to limit laying down big power early on corner exit for most BMWs. I think the 135i is too new at this point to determine what works best and have the information filter down to non-pro enthusiasts. But there are two or three 135i racing efforts underway so I expect the picture will become more clear over the next few months.

[larryn]

Prince, I don't anybody was implying that this should be done with standard runflats, no additional camber, and stock dampers/springs, for the purposes of making your car more STREET worthy. In that case, you may be right (to a point), though I'm not an expert on track suspension. I am pretty knowledgeable about autocross setup.

The reason I say "to a point" is because the e90 (which is the same basic suspension layout as the e82/e88) does benefit from a stiff front bar for street/autocross/track purposes.

Mike and I are both avid autocrossers and that would be our sole reason to tweak the suspension to begin with. Mike's stating fact about BMW's being set up with a fat front back, and the rear pretty much stock (or disconnected) as the defacto setup for national champion caliber autocross drivers. It just works.. regardless of any link you can come up with.

Everybody knows (I would hope!) that a good track suspension setup and a good autocross suspension setup are pretty different. We are talking about one, and you are arguing with the other.

Bye.

[Prince ///M]

Originally Posted by mikeo

Really stiff rear bars tend to limit laying down big power early on corner exit for most BMWs. I think the 135i is too new at this point to determine what works best and have the information filter down to non-pro enthusiasts. But there are two or three 135i racing efforts underway so I expect the picture will become more clear over the next few months.

This is true, and I reported it in a previous post, but it does not represent a big limit in most of european/italian road and tracks, so generally our setups are more "neutral" (also with a bit of understeer) in order to maximize mid cornerering speed.

In addition, let me explain that in Italy we can only use the original tire size on the road. So we need (as week end racers) to optimize the handling on the tiny front 215.

For the anti roll...
Plase correct me if I'm wrong, but the stock BMW e92 M3 (very sharp turn in respect to the 135i) has 22mm front and 20mm rear resulting in a more neutral setup.
Ok, bushing are more rigid and it has also -1deg of camber (almost unrelevant) at the front, but the kinematic is very, very similar to the .35 one. So I tink that close front and rear bar diameter (read "equilibrated front and rear roll stiffness") have a geat influence on overall vehicle handling.

Of course, in particular situation/track (autocross with 245/35 on 4 corners, for example) a lager front bar can be the best solution.

Bye.

[stefan]

Attractive looking kit.. however if the purpose is to reduce body roll, wouldn't one simply swap out suspension/springs? From what I hear about the labour on the rear sway bar, it might just be cheaper and easier to replace the suspension all around, which should clean up the body roll nicely, shouldn't it?

As for simply pushing the car to tend to oversteer, I've always been told to avoid the front sway bar on newer BMWs and stick to the rear.

[larryn]

I already have springs swapped and camber added. This is for the added touch. :wink:

[adc]

Originally Posted by stefan

however if the purpose is to reduce body roll, wouldn't one simply swap out suspension/springs?

There is an additional benefit - it's adjustable. So you can use these bars to fine-tweak the setup, even having different ones for street and track.


I've had very positive experience with UUC bars on stock suspension on my E46 (with OEM staggered setup). I don't know if constant-radius constant-speed cornering speeds went up (in other words if outright mechanical grip was increased), but the car was easier to adjust and more balanced.

[larryn]

I'm just excited because they made a huge handling difference on my e36 332ti, my, 99 e46 323i, 2002 e46 330i, and my 2006 e90 330i.

Although they are adjustable, I've always set the front on full stiff, and adjusted the rears only.

[adc]

Originally Posted by larryn

Although they are adjustable, I've always set the front on full stiff, and adjusted the rears only.

Weird... On my 03 330i ZHP with 225/255 tires I set the front to medium and rears to full stiff. Big difference. No auto-x, just track.

[larryn]

I had mine set up for Autox, which I primarily do (couple times a month), compared to track events ~2-3 times a year.

[mikeo]

So Larry, how did the front bar perform at the autocross yesterday?

[larryn]

It was horrible. :wink:

I thought it felt good. Seemed like much more controllable turn in and more lateral grip. It was ~90 degrees out, sunny, which usually leads to some slickness.

I try to keep tread temps under 120, even across the tread, and play with pressure. I noticed that the tires were heating more evenly, which means less pushing. They worked great with my Star Specs.

I still won my class (I think), but I don't know by how much.

I also switched to 245F/275R Hoosiers for a few runs. STOCK ZHP WHEELS allowed no spacer fitment with that setup. There was room for more in front too. I'll post impressions in a different thread about that though. It was interesting though. :biggrin:

[mikeo]

Great, thanks for the feedback. I ordered Koni Sports and H&R OE Sport springs today. Springs won't be available for 8 weeks (that's OK with me, allows me to finish the season in DS ;-)

So the OE 330i ZHP wheels worked with 245/275 Hoosiers? Awesome! What are the offsets?

[cpt97m3]

Originally Posted by mikeo

So the OE 330i ZHP wheels worked with 345/275 Hoosiers? Awesome! What are the offsets?

Seems like a 345 would a tad much for an OE 330i front wheel.

That is good to know a 245/275 combo works though. I'm running the 245/35's on my E36 M3.

[larryn]

I posted a Hoosier thread in the photos forum, with pics and video, but the Hoosier setup was:

F 18x8 ET47 245/40/18
R 18x8.5 ET50 275/35/18

ZHP wheels are very heavy though (like out stock wheels), although they do fit. My car is lowered, and there was a good bit of room up front on the fender side of things for a wider tire (as incredible as it sounds...)

[mikeo]

Originally Posted by cpt97m3

Seems like a 345 would a tad much for an OE 330i front wheel.

That is good to know a 245/275 combo works though. I'm running the 245/35's on my E36 M3.

Damn my fat fingers! Of course 245.

[Misterkris]

In regards to the bmw strut lowering camber gain comments from before. All i really know is VAG mcphearson suspensions, and those suffer from large amounts of +camber gain when lowering. But i see these 1er specific susoensions from everyone pretty much slamming the car. Any idea of why this is? Is the suspension geometry not compromised by lowering the cars to these extents?

[Charles1]

Originally Posted by MisterKris

In regards to the bmw strut lowering camber gain comments from before. All i really know is VAG mcphearson suspensions, and those suffer from large amounts of +camber gain when lowering. But i see these 1er specific susoensions from everyone pretty much slamming the car. Any idea of why this is? Is the suspension geometry not compromised by lowering the cars to these extents?

Over lowering is bad... That said I don't think anyone knows the limits yet. That would require a lot a track logging time.

[Charles1]

I agree with Mikeo and Larryn on this one. The stiffer front bar works.

Note, Stock class racing does some crazy things with shocks and sways. Unless you are running a stock class get your car a close as possible with springs then use sways to tune roll angle for balance.

[aus]

Do you guys think the rear sway's will cause rear sub-frame failures like in the E36's, if installed with the stock supension? It was putty too much stress on the bar mounting points with the soft stock suspension.

[nordique14]

Originally Posted by aus

Do you guys think the rear sway's will cause rear sub-frame failures like in the E36's, if installed with the stock supension? It was putty too much stress on the bar mounting points with the soft stock suspension.

I am not aware of the larger way bars causing the subframe issue on the E36. The subframe issue was caused by the crappy subframe bushings. They would rip causing play in the subframe which led to tearing metal. The sway bar mounts on the E35 were crap and a larger bar would cause them to fail. They needed to be reinforced before putting on a larger rear bar. A larger sway bar should not cause any subframe issues,

[larryn]

E46's had the same issue too. FWIW, the E9X/E8X cars have a vastly different multi-link rear setup compared to either the e35/6 or the e46.

[aus]

Originally Posted by nordique14

I am not aware of the larger way bars causing the subframe issue on the E36. The subframe issue was caused by the crappy subframe bushings. They would rip causing play in the subframe which led to tearing metal. The sway bar mounts on the E35 were crap and a larger bar would cause them to fail. They needed to be reinforced before putting on a larger rear bar. A larger sway bar should not cause any subframe issues,

My bad. I should have said the sway mounting points were weak and would tear with a stock suspension. Any chance of this happening with the 1-series?