[HP Autosport]

Originally Posted by HighVoltage

You needed one of these... http://www.turnermotorsport.com/html...=100-100-00008

You can get a Quaife for much less:


http://www.e90post.com/forums/showthread.php?t=70397

[Gen_E92]

Originally Posted by Kit523

damn i confuse right now....
i am either getting the UUC, hotchiks or the OEM M3
but i need more info before i do some stupid things!
anyways....will i able to get the same installion cost ?

the UUC one needs to be serviced regularly...dunno about the details though.
i dont like the idea of getting oem m3 bar at all, since it's 20mm(same as h&r) and only the rear is available.
if you think h&r set is overkill then go for hotchkis, or just get the 14mm m-sport rear for a mild upgrade.

of course you'll get the same price from Advance...w/o the front it's probly $250.

Originally Posted by Orb

I think most will be disappointed with KW and H&R sway bars without modification as it will induces under steer at 9/10 driving. The problem with a rear bar is that the load transfer is not balanced. With the rear bar, the outside rear wheel load more which in turn unload the inside rear wheel. Now throw is some dynamics such as trail braking in a corner and out side front has to much weight transfer due to cross load from the inside rear and changes in the roll center. The fix is a stiffer front springs (60 N/mm) which correct the roll center migration. I am now running KW v3 / Clubsport hybrid with far less front camber than most.

Orb

Do you think a front strut brace will help with my currecnt set up of eibach prokit / koni fsd and h&r sway bars? btw I want slightly lower than stock linear spring and can't find any

[leftcoastman]

Originally Posted by Gen_E92

Did leftcoastman ever mentioned that he only got the H&R rear sways? IMO getting the front sways would help quite abit with the problems he experienced before. Even though the H&R front is only 0.5mm thicker than OEM, the stiffness multiplies. Since he has LSD now I think the H&R would match well, this is the set up Orb is running with KW V3.



$300 front and rear

Sorry if I wasn't clear.

Regardless of what you do in front, the rear bar will effectively make the rear end more like a solid rear axle (that's what antisways do).

If you just do a rear anti-swaybar, you will get tons of wheelspin.

You can put a 1,000 mm bar up front, as long as you thickened your rear anti-sway, you will still get tons of wheelspin.

But like I said, go for it. Please video it though and post up a video of a stock Honda Civic accelerating away from you at corner exit, because it can actually put some power down, lol.

[flukey]

so upgrading just a rear bar is BAD or GOOD? i'm talking about street driving...

sorry for being such a noob, but ive searched and havn't found a clear answer for this. i have an E90 335xi with KW V3. I noticed that there was a pretty significant amount of under steer. I'm under the impression that installing a H&R rear sway (i rear sway fitment is same as xi rear sway fitment) should help reduce the under steer, thus inducing more over steer.

I'm interested to hear some comments on just a rear sway bar upgrade alone...

Thanks.

[Kit523]

mr.5 thanks for creating this thread
lol...should be putted into sticky

[leftcoastman]

Originally Posted by flukey

so upgrading just a rear bar is BAD or GOOD? i'm talking about street driving...

sorry for being such a noob, but ive searched and havn't found a clear answer for this. i have an E90 335xi with KW V3. I noticed that there was a pretty significant amount of under steer. I'm under the impression that installing a H&R rear sway (i rear sway fitment is same as xi rear sway fitment) should help reduce the under steer, thus inducing more over steer.

I'm interested to hear some comments on just a rear sway bar upgrade alone...

Thanks.

XI is a whole different story. You'll be fine lifting your inside rear tire, because you have your fronts to help accelerate!

Plus, you're just going to be boulevard cruising, so it should be fine.

That said, as if it hasn't been made obvious already, I believe antisways should be the very last balance tuning tool used (TC Kline and various race teams believe the same).

I cannot opine on whether or not it will cause you to snap oversteer, especially if the XI is veryveryvery heavily balanced toward push.

[jimmy330xi]

I was thinking about the UUC sway bars for my car (330xi) and after reading this thread I have mixed feelings, I think I will leave the sway bars alone. I just ordered a set of KW V3 and the OEM front Strut Brace, I was asking myself if it would be a better option to go with the Hotchkis Chasis brace to tighten things up without having to mess with the Sway Bars. My reasoning is that if the M Sport sway bar is only available for the rear, then the Chasis Brace will take care of getting everything dialed in back there without having to mess with anything else. Please let me know if that's a better, easier and cheaper option without risking to loose the BMW feel of the car, which with sway bars I will loose most of the OEM feel.

[Mr. 5]

I'm confused man.
What do these numbers mean exactly?
Also, Do you know that the Hotchkis bars are not solid?
They are hollow, so do these numbers take that into consideration?

Originally Posted by Orb

Mr 5...it is much stiffer than you think so here are the numbers

13 mm = 28561
16 mm = 65536
20 mm = 160000
26.5 mm = 493155
27 mm = 531441
32 mm = 1048576

Bar Roll couple:

- Stock: 521716
- H&R: 691441
- Hotchis: 1114112

Orb

[Mr. 5]

Originally Posted by Orb

These are stiffness number. You can see that Hotchkis stiffness numbers correlate closer to solid bar so a good assumption is they are not hollow or they just invented a material called Unobtainium. Use the numbers to do percentage ratio. The variation will be connection length.


Orb

So you're saying that they are using false information to sell their sway bars?
They say tubular steel.
http://www.hotchkis.net/p-800-bmw-e9...sway-bars.aspx
I don't believe that H&R use tubular steel do they?

[wrh3]

I have been running the H&R bars, front and rear, with my OE sport suspension for a few months- long term I will get some Koni FSDs to go with the Sport Package springs. This is my wife's car (family car on weekends) so I am not looking for it to be a track car but wanted to be able to have fun with it in the mountains. I have found the H&R setup to be fairly neutral with some understeer at the limits, but much more solid than the OE sway bar setup.

I am an avid DIY guy, but decided to let my local shop do the H&R swaybar installation. They did not drop the rear subframe but loosened the bolts enough to maneuver the bar in. After watching them do the install I would gladly pay to have it done again- my next house will have a lift but I would not want to do this on jack stands in the garage.

FWIW, I wouldn't go back to OE after having the H&R bars and I think the sport package springs rates are great but with less than optimal dampers.

[Gen_E92]

Originally Posted by wrh3

I have been running the H&R bars, front and rear, with my OE sport suspension for a few months- long term I will get some Koni FSDs to go with the Sport Package springs. This is my wife's car (family car on weekends) so I am not looking for it to be a track car but wanted to be able to have fun with it in the mountains. I have found the H&R setup to be fairly neutral with some understeer at the limits, but much more solid than the OE sway bar setup.

I am an avid DIY guy, but decided to let my local shop do the H&R swaybar installation. They did not drop the rear subframe but loosened the bolts enough to maneuver the bar in. After watching them do the install I would gladly pay to have it done again- my next house will have a lift but I would not want to do this on jack stands in the garage.

FWIW, I wouldn't go back to OE after having the H&R bars and I think the sport package springs rates are great but with less than optimal dampers.

well said...and you are gonna love the FSD with your current set up

[stressdoc]

The elasticity modulus of different steel alloys varies a little bit, but my guess is that there is nil difference among the materials for the solid bars. Might be a slight difference for the Hotchkis hollow bar because there are somewhat different constraints for extruded materials. In comparing the properties of the different bars, there are so many variables -- shape, hollow/solid, bushing materials, pre-load, and so forth -- that I can't imagine the complexity of predicting their effects. Bottom line is you need competent tuners to go out and test, test, test. Change combinations of sways, springs, dampers, camber, tires, etc. And remember that different conditions/tracks will require adjustments. Think Nascar -- those guys live on a very fine tuning line, with changes from minor stuff like track temperature, weight balance from how much fuel they have, etc. So the input of members like Harold (HPAutowerks) Orb, Ray, SR4to335, leftcoastman, et al is extremely valuable. Read through it and remember that there is no singular best set of mods, because you are unique. Figure what will best suit your needs. Use the power of the forum and its many contributors.

Coming from a rallye background, the goals are so different -- independence of wheel movement, and lots of wheel travel, are key to maintaining contact. This is very different from auto-X and other track demands. Similarly, street conditions also have different demands and constraints. And low vs. high speed.

Strut and chassis braces will influence handling a bit by changing how much chassis flex you have. In general they are a good investment if you are stiffening up the suspension, because that will transmit more strain on the chassis, and you want to reduce that wildcard. Imagine the chassis as a rubber band that is getting twisted and then responding by untwisting back when unweighted. Bad things can happen. This is why stiffer bushing can help as well.

[Mr. 5]

So now I just learned by one of the other threads that the XI has a 15mm rear sway bar.
Does anyone know if this will fit on the regular 335i?

So, 14mm or 15mm if it fits?
Hmm...the discussion goes on.

13mm stock 335:
http://www.realoem.com/bmw/showparts...80&hg=33&fg=45

15mm stock 335XI:
http://www.realoem.com/bmw/showparts...80&hg=33&fg=45

[leftcoastman]

Originally Posted by stressdoc

So the input of members like Harold (HPAutowerks) Orb, Ray, SR4to335, leftcoastman, et al is extremely valuable.

LOL, I didn't know he used to have a Dodge Neon SRT-4. That explains a lot!

[flukey]

Originally Posted by Mr. 5

So now I just learned by one of the other threads that the XI has a 15mm rear sway bar.
Does anyone know if this will fit on the regular 335i?

So, 14mm or 15mm if it fits?
Hmm...the discussion goes on.

13mm stock 335:
http://www.realoem.com/bmw/showparts...80&hg=33&fg=45

15mm stock 335XI:
http://www.realoem.com/bmw/showparts...80&hg=33&fg=45

Based upon this fact: the UUC Rear Sway developed for the RWD E9X's fits the AWD E9X's (http://www.e90post.com/forums/showthread.php?t=150049), I would assume so. I personally just purchased a H&R rear sway. It will be installed in the next month.

Also, if you notice the other part numbers (minus the stabilizer items because of the different diameters) that are used in conjunction with the sway bars, they are the same.

I'm guessing the AWD models have a larger rear sway because they in fact do suffer a greater degree of understeer. Also, I would be willing to bet that the material used in the M-Sport rear sway is stiffer than the stock XI rear sway....

[HP Autosport]

Originally Posted by flukey

so upgrading just a rear bar is BAD or GOOD? i'm talking about street driving...

sorry for being such a noob, but ive searched and havn't found a clear answer for this. i have an E90 335xi with KW V3. I noticed that there was a pretty significant amount of under steer. I'm under the impression that installing a H&R rear sway (i rear sway fitment is same as xi rear sway fitment) should help reduce the under steer, thus inducing more over steer.

I'm interested to hear some comments on just a rear sway bar upgrade alone...

Thanks.

By installing just the rear bar you are in theory reducing the amount of traction available. Without a good LSD, you may experience more wheel spin exiting a low speed corner under power.

[Mr. 5]

Alright guys, even though I had a great deal lined up with the Hotchkis sway bar kit, I went with just replacing the rear 13mm sway bar to the OEM BMW 14mm (Part #33556764426) bar used with the M package in europe.
The 14mm BMW sway bar is only $85 and comes with the rubber mounts needed for installation.
http://www.trademotion.com/partlocat...&siteid=214672

In addition to ordering the sway, I placed the order for the BMW Performance Suspension.
I'm 99% sure that I've made the correct decision for my daily driver that I occasionally take to the track.
A big thanks goes out to Evan at Tischer for making this kit affordable, and for dealing with all of my questions.

I'll provide a review, after everything is installed, and thanks to those who participated in the discussion.

[S4to335]

Originally Posted by leftcoastman

LOL, I didn't know he used to have a Dodge Neon SRT-4. That explains a lot!

I didnt know either...I did have a 1976 MGB roadster though...boy was that sweet...NOT.

[pittyinSC]

So I should be fine with just KW V2's on the street even if I want to
be pretty stiff/neutral?

[stressdoc]

Really looking forward to your review!!! Details regarding what is included in the Performance suspension would be most appreciated!

Originally Posted by Mr. 5

Alright guys, even though I had a great deal lined up with the Hotchkis sway bar kit, I went with just replacing the rear 13mm sway bar to the OEM BMW 14mm (Part #33556764426) bar used with the M package in europe.
The 14mm BMW sway bar is only $85 and comes with the rubber mounts needed for installation.
http://www.trademotion.com/partlocat...&siteid=214672

In addition to ordering the sway, I placed the order for the BMW Performance Suspension.
I'm 99% sure that I've made the correct decision for my daily driver that I occasionally take to the track.
A big thanks goes out to Evan at Tischer for making this kit affordable, and for dealing with all of my questions.

I'll provide a review, after everything is installed, and thanks to those who participated in the discussion.

[Mr. 5]

Originally Posted by stressdoc

Really looking forward to your review!!! Details regarding what is included in the Performance suspension would be most appreciated!

Will do man.
It looks like I'm going to get it some time next week.

[stressdoc]

Maybe Harold can chime in on the Hotchkis sways and tell us firsthand how they feel.