I would like to get some help.
I did the first a-x since I installed UUC AntiRoll bars Front and Rear.
Now the car understeer a lot.

Current setup:
Suspension - H&R COs with 375lbs front/450lbs rear
Bars - Front UUC full stiff / Rear UUC full soft
Front Camber -1.3 / Rear Camber -1.9
Tires 225/40/18 front / 245/35/18 Rear on 18x8.5" wheels

What would be the best way to correct this.

1. Set the front bar to middle or soft
2. Set the rear to middle (I only have 2 holes each side, so one of the link will be on the front hole, the other on rear hole) or full stiff.
3. Get a camber plates that will allow more negetavi camber up front.

I really need your help.

Thanks

So you're saying that the car understeers more than it did with stock swaybars? I would keep the front in the stiff setting. Experiment to see if anything makes it better. Camber plates do make a huge difference in the handling of the car, they are well worth the money IMO, however if you are having understeer problems, I would try to fix it with your existing suspension than try to put a bandaid on it with camber plates.

^ so you suggest to get camber plates and possible set the rear to stiff so that why I will eliminate the understeering?

You need more front camber (among other things).

Fix that, make sure your tire pressure is set right, and go from there.

No need to buy camber plates right now. Make changes to what you have first. Softer the front sway bar first, then try stiffer the rear. Play with tire pressure too.

should I go full soft, or try middium first?
Next a-x will be after 3 weeks so I won't really know how the car will feel.

^ so you suggest to get camber plates and possible set the rear to stiff so that why I will eliminate the understeering?

well, I think we need to optimize what you have now before putting on any camber plates.

For the front bar, I would keep it at the stiffest setting. On most cars this increases understeer, but due to the crappy camber curve of the mcpherson strut, a stiffer front bar actually helps oversteer on M3's. I used to have my front bar on soft, but tried it in the hard setting and prefer it that way. JMO.

Overall, just experiment with the settings on the bar and see what you like best.

I agree that you should play around with tire pressures as well.

When you mean it understeers....explain that better. What type of turn do you feel more push on, slow tight corners or long sweepers.

A stiffer front bar will help the car a lot in transitions and slaloms but will make it push more on steady state cornering and certainly makes the car unhappy in tight small radius turns. Essentially you have to a compromise you can live with, varialbles being tires, surface grip and course layout.

Having more camber in the front than the rear is a no brainer and it will help with tire wear but you will also have to adjust your driving style and make sure you slow down enough entering the tight turns.

You might also try making the rear stiffer to get the car to rotate more willingly.

should I go full soft, or try middium first?
Next a-x will be after 3 weeks so I won't really know how the car will feel.

Try middle setting first. If it does not help, put the front back to full stiff and change the rear. Don't make mutilple changes at a time because you won't know what made it better or worse. Log everything in a book to keep a history.

2 items that haven't been mentioned yet.

Driving style and tire stagger

Do you know what trail braking is? Try turning AS you are letting up on the brake. Don't treat the brake pedal as a switch, ease off it as you turn in.

BMWs generally (at least close to stock) don't like to be driven hot into a corner. Unless you have massive amounts of camber and a good shock/spring setup, it will push. Trade a little corner entry speed for a LOT more mid and exit speed.

Tire Stagger:
If you want to get more competitive, get rid of the 225/245 tires. You want the same section width front and back, even if the rims are different widths. So 235/235 or 245/245. 235/245 as a fallback. But you need to be carefull of pinching or stretching the tires too much. Tire rack or another performance tire house should be able to get your sizes right so you don't mess with the sidewalls too much and get close enough in diameter so you don't mess with ABS or ASC.

^ that is how I got best time,
Stoping earlier, slow in fast out, at least I was trying but still.
I put the front bar to midium today, will order some camber plates soon, and see how is going to be on next a-x

swap your strut moutns for camber

i just finished up an event w/ my new TMS bars (full stiff 27mm front, full soft 24mm rear) and the car did great. i might go a notch stiffer in the rear since rear traction wasnt an issue.

but i am running -3 camb up front and -2 in the rear. it makes a huge difference

I will just get camber plates, because I want max of -2.3 to -2.5 camber , I am running -1.9 rear

I will just get camber plates, because I want max of -2.3 to -2.5 camber , I am running -1.9 rear

Most plates can get you -3.5 or so. -3.5 would be fine with that much front camber, it works well for me.

You need more camber.

If you're running street tires, set the front bar to medium.

Most plates can get you -3.5 or so. -3.5 would be fine with that much front camber, it works well for me.

I don't want that much neg. camber:) the car is daily driver too, something in the middle should be fine for the beggining, that is why I said I am looking for -2.3 to -2.5.


You need more camber.
If you're running street tires, set the front bar to medium.

I am running Dunlop Super Sport Race, not the best r-comp but those work much better them my street Pirelli P7000.

I set the bar to medium today and left the rear to soft, will try to see how the car will feel tomorrow.

i ive been dailing driving on my azenis w/ this alignment since january and my treadware is amazingly even. its perfect front and back.

i'm running -3, 0 toe up front, and -2, 1/8th total toe in rear. well behaved on the highway/track, and rocks for autox. its the toe thatll make or break your tire wear

Bars - Front UUC full stiff / Rear UUC full soft
Front Camber -1.3 / Rear Camber -1.9
Tires 225/40/18 front / 245/35/18 Rear on 18x8.5" wheels


I would make some changes on these three items.

1) I'd say almost swap the swaybar settings... full stiff in the rear, medium in the front.

2) Even thought it's a street-driven car, -1.6 or =1.7 won't be too bad on your tires and works very well.

3) Go with 245s all around. The staggered setup is practically designed to cause understeer, too little tire in the front trying to stick, turn, and slow all at once.

I don't want that much neg. camber:) the car is daily driver too, something in the middle should be fine for the beggining, that is why I said I am looking for -2.3 to -2.5.

But this is the beauty of camber plates, you can set it to -1.5 for the street, and then when you get to the track, it only takes 5 minutes to adjust it to -3.5. Believe me, all it will take is one day at the track with the plates at -3.5 and you won't want to go back to anything like a -2.5, etc.

More camber adjusment and whatnot will definatly help..... but not as much as driving technique.

Practice, practice, practice, practice, practice, practice.....

Better yet, ask a more experienced guy to ride along and give you some feedback.

I bet I can make my mom's mini-van oversteer with the proper technique.

osborni,
I am sure there is nothing better then practice.
I am not expert by any means and I am not the best driver, but I did drive my car before and after the sways and those are the difference.
However are much more experience drive ride with me, and even I was taking the lines right his impression was like mine, the car has too much understeering, the same guy rides with me almost all the time, he is giving me advices about my driving, so definitely is not only the practice.

300ZXNA,
That is the reason I want camber plates, not just swapping the strut hats.
Since I will be doing some track day, I want to be able to have much more negative camber for that and put back to more reasonable camber for daily driving.

Thanks for all inputs guys.
I really appreciate it.

You're running full stiff front full soft rear.... that's as much of a bias towards understeer as you can possibly get with sway bars. As someone above said I would definitely switch that. Maybe not all the way... but medium front, stiff rear? soft front, medium rear?

I'm running -3.4 front -2.2 rear camber on a dedicated car and I still understeer with a front swaybar being too stiff.

You're running full stiff front full soft rear.... that's as much of a bias towards understeer as you can possibly get with sway bars. As someone above said I would definitely switch that. Maybe not all the way... but medium front, stiff rear? soft front, medium rear?

I'm running -3.4 front -2.2 rear camber on a dedicated car and I still understeer with a front swaybar being too stiff.

I already switch the front to medium, and will try the car like that, if the car understeer, I will switch the rear to full stiff.

In the mean time I will try to get my hands on camber plates.

I have the UUC bars, -3.5 front, -2 rear with realtively soft H&R OE Sport springs/Koni SA, 255x40 Azenis all around. I've been running the front bars at medium, rears full soft (the rear UUC bar is stiffer than most after market bars). In this configuration the car felt very neutral in all but the tightest turns. This past weekend I tried the fronts at full stiff for Saturday's auto-x and did not care for the result--it increased understeer in corner entry, mid-corner and exit. Went back to medium front setting for Sunday and the balance was back. This suprised me some as most people on this board say that full stiff front is the way to go. Well, I don't after trying it--not for my driving style anyway.

mileo,
You are not running spaces on front right?
I have to run 10mm with my RC to clear the big brakes otherwise I would go with 245 all around.
Now the bar is set to medium see how is going to be on the next one.

mileo,
You are not running spaces on front right?
I have to run 10mm with my RC to clear the big brakes otherwise I would go with 245 all around.
Now the bar is set to medium see how is going to be on the next one.

If you have sufficient negative camber you can easily fit 245's on the front of the car, even with a 10mm spacer on larger wheels.

How about swapping your strut mounts? (if you cant get camber plates)

If you have sufficient negative camber you can easily fit 245's on the front of the car, even with a 10mm spacer on larger wheels.

How about swapping your strut mounts? (if you cant get camber plates)

Hi Rich,
How was the Adwater?

I am getting camber plates for sure, just not right now.
The reason I am not swapping the mounts is because I want no more then 2.5 neg. camber.

Then I will try 245 tires on front.

Right, no front spacers, because I'm running BBS RK 17x8, not the 18x8.5 BBS RCs in the sig.

Hi Rich,
How was the Adwater?

Atwater was a blast despite the fact I was a bit dissapointed in my performance. Going back again this weekend to get my butt kicked even worse!:buttrock

Right, no front spacers, because I'm running BBS RK 17x8, not the 18x8.5 BBS RCs in the sig.

Ahh, well I am running RCs that is why I asked.
Have to try and see if I can fit them.


Atwater was a blast despite the fact I was a bit dissapointed in my performance. Going back again this weekend to get my butt kicked even worse!


Rich,
Good luck to you and Edge Team this weekend, I guess I will see you either on May 14th with SCCA or May 20th with BMWCCA

I have the UUC bars, -3.5 front, -2 rear with realtively soft H&R OE Sport springs/Koni SA, 255x40 Azenis all around. I've been running the front bars at medium, rears full soft (the rear UUC bar is stiffer than most after market bars). In this configuration the car felt very neutral in all but the tightest turns. This past weekend I tried the fronts at full stiff for Saturday's auto-x and did not care for the result--it increased understeer in corner entry, mid-corner and exit. Went back to medium front setting for Sunday and the balance was back. This suprised me some as most people on this board say that full stiff front is the way to go. Well, I don't after trying it--not for my driving style anyway.

despite all the advice saying full stiff front, i have a much more neutral car with my uuc's stiff rear/soft front. it suits my style. in advanced groups, i'm one of the faster bimmers on track hanging with the r-comp guys. i'm using street tires.