[Fraggy]

Well, yesterday they were installed as many of you know. It was a great install as another suspension related problem was fixed in the process. Between the two, the now car feels awesome!!!

Missing Spring Tops: The rear of the car now feels right. There is FAR less bounce over bumps, and less oscillation in the rear. Now it bounces once, and thats it, its very well controlled. I just had a sinking feeling that there was no way that BMW would allow their upgraded suspension feel the way it did, and I was right. The rear is certainly more firm and you feel bumps more firmly, but it actually feels better because the bumps come and go, and thats it, no residual bounce.

A poor install messed it all up. Word to the wise, spend the extra money and get it done at a higher end shop if you dont have the skills to do it yourself, like me.

M3 Sways: They feel perfect. The best part is that you cant really feel them working at all. Its hard to describe. I had an H&R 20mm rear bar on my E90 325. And when I drove into a turn, you could really feel it working. You could feel it pushing in the rear, it was quite distinct.

With the M3 bars, you dont really feel them. Yes, the car corners flatter but still allows some lean for feel, the car has sharper turn in, and it just seems to point where you are wanting it to go. The bars just work smoothly and seamlessly. They feel fully integrated with the car and with the performance suspension. Side to side mushiness has been sharply reduced and the whole car feels tighter, smoother, and more aggressive.

I did not have the tension rods installed as the installer ran out of time. Im not even sure I want them now, I like the feel that much. But since I have them, Im sure I wont be able to hold out for long before having them installed. This car is starting feel as it should have right from the factory, and Im enjoying it more and more everyday.

I really want a tune now I may have to try and get a JB+, but money is a bit tight right now, so I might have to choose between keeping the tension rods or selling them and getting a low end tune.

Overall, Im very happy with the sways! A perfect addition to the performance suspension, especially now that the install is fixed and it working correctly.

[Orb]

Originally Posted by Fraggy

Well, yesterday they were installed as many of you know. It was a great install as another suspension related problem was fixed in the process. Between the two, the now car feels awesome!!!

Missing Spring Tops: The rear of the car now feels right. There is FAR less bounce over bumps, and less oscillation in the rear. Now it bounces once, and thats it, its very well controlled. I just had a sinking feeling that there was no way that BMW would allow their upgraded suspension feel the way it did, and I was right. The rear is certainly more firm and you feel bumps more firmly, but it actually feels better because the bumps come and go, and thats it, no residual bounce.

A poor install messed it all up. Word to the wise, spend the extra money and get it done at a higher end shop if you dont have the skills to do it yourself, like me.

M3 Sways: They feel perfect. The best part is that you cant really feel them working at all. Its hard to describe. I had an H&R 20mm rear bar on my E90 325. And when I drove into a turn, you could really feel it working. You could feel it pushing in the rear, it was quite distinct.

With the M3 bars, you dont really feel them. Yes, the car corners flatter but still allows some lean for feel, the car has sharper turn in, and it just seems to point where you are wanting it to go. The bars just work smoothly and seamlessly. They feel fully integrated with the car and with the performance suspension. Side to side mushiness has been sharply reduced and the whole car feels tighter, smoother, and more aggressive.

I did not have the tension rods installed as the installer ran out of time. Im not even sure I want them now, I like the feel that much. But since I have them, Im sure I wont be able to hold out for long before having them installed. This car is starting feel as it should have right from the factory, and Im enjoying it more and more everyday.

I really want a tune now I may have to try and get a JB+, but money is a bit tight right now, so I might have to choose between keeping the tension rods or selling them and getting a low end tune.

Overall, Im very happy with the sways! A perfect addition to the performance suspension, especially now that the install is fixed and it working correctly.

The tension rods are the one thing you will kick yourself for not doing. It is ther number 1 on my list of things that has to be fixed. It is the feeling you get from them that makes them great and what you should have gotten in the first place from BMW.

After all this your done.

Orb

[Fraggy]

Originally Posted by Orb

The tension rods are the one thing you will kick yourself for not doing. It is ther number 1 on my list of things that has to be fixed. It is the feeling you get from them that makes them great and what you should have gotten in the first place from BMW.

After all this your done.

Orb

Im sure I will do them. Heck, they are sitting in a box in my guest room. Im sure $100 will get them installed. Is kinda hard to pass up, especially since I have them already

[tomtom]

Originally Posted by Fraggy

Well, yesterday they were installed as many of you know. It was a great install as another suspension related problem was fixed in the process. Between the two, the now car feels awesome!!!

Missing Spring Tops: The rear of the car now feels right. There is FAR less bounce over bumps, and less oscillation in the rear. Now it bounces once, and thats it, its very well controlled. I just had a sinking feeling that there was no way that BMW would allow their upgraded suspension feel the way it did, and I was right. The rear is certainly more firm and you feel bumps more firmly, but it actually feels better because the bumps come and go, and thats it, no residual bounce.

A poor install messed it all up. Word to the wise, spend the extra money and get it done at a higher end shop if you dont have the skills to do it yourself, like me.

you were missing spring tops?

[jcarlucci1]

How much does install usually run for swaybars?

[Mr. 5]

I'm glad you like them Fraggy!
Isn't it nice to know your car is tip top now?

I'm still thinking that the rear M3 bar may be too much for me, but the thought enters my mind every once and a while.

How is your acceleration out of turns?

[mwahlert]

Originally Posted by Orb

The tension rods are the one thing you will kick yourself for not doing. It is ther number 1 on my list of things that has to be fixed. It is the feeling you get from them that makes them great and what you should have gotten in the first place from BMW.

After all this your done.

Orb

do the tension rods alone make a noticeable improvement? or is it the combination of them w/ the front lower wishbones?

i will be installing my kw street comforts next weekend and if you think the tension rods would help out even when just having fun on back roads i might do them...

[Fraggy]

Originally Posted by tomtom

you were missing spring tops?

Yup, the moron a different shop did not install them. I suspect that you are supposed to reuse the stock ones, but since I had already installed PSS9s before upgrading to the BMW Performance, the stock ones were not available for him to use. I can understand that. But he didnt say "hey, I cant install this suspension with the part missing". Or "hey, I installed it without the tops, but make sure and order some and we can put them in later".

He never let me know at all that something was not right with the car. Its just luck that I wanted the sway bar they were found to be missing.

[Fraggy]

Originally Posted by Mr. 5

I'm glad you like them Fraggy!
Isn't it nice to know your car is tip top now?

Yup, were almost there. The rods are next and then I think Im done with the suspension.

Originally Posted by Mr. 5

How is your acceleration out of turns?

Its hard to say so early, but in street driving Ive not encountered anytimes yet that Ive been concerned about the car behaving as it should. Maybe I dont drive aggressive enough But I dont think so

The rear is very subtle compared to the H&R rear sway. Maybe because of the M3 front sway its more balance than the H&R rear alone, or maybe its just better made, and more integrated with the car.

Id be happy to let you drive my car sometime to see for yourself if you think it works for you or not. I know meeting up is hard due to busy scheduls.

[mwahlert]

there are so many sway bar options...i am thinking about upgrading the bars next weekend while installing my kw street comforts - but i have no idea which setup to choose....

[Orb]

Originally Posted by mwahlert

there are so many sway bar options...i am thinking about upgrading the bars next weekend while installing my kw street comforts - but i have no idea which setup to choose....

There is more bad options than good....this one is good one.

Orb

[Gen_E92]

Originally Posted by Orb

There is more bad options than good....this one is good one.

Orb

how does it compare to H&R? just curious...

and are you going with the M3 sways since you're selling your H&R?

[mwahlert]

Originally Posted by Orb

There is more bad options than good....this one is good one.

Orb

it would be well matched to the kw street comforts you think?

[Orb]

Originally Posted by mwahlert

it would be well matched to the kw street comforts you think?

Much more so than the H&R bars.

[mwahlert]

Originally Posted by Orb

Much more so than the H&R bars.

i need to pull the trigger on this so i have them in time... but i don't want to make the wrong decision.

i have had kw v1, now eibach pro kit and koni fsd and now switching to street comforts - looking for more suspension travel and more linear spring - hoping to make the car more controlled and comfortable, and consistent.

this is my second rear drive car so i don't mind a bit of understeer to keep myself out of trouble.

will adding the front and rear m3 sways cause oversteer or snap over steer? i'm sure the spring rates of the kw street comforts also play into this equation.

what about ride quality/comfort... will it be decreased by going to the larger bars?

i'm really just looking for flatter cornering... if i can manage to make the car more neutral without being oversteer biased i'd be very happy..

just need some help and guidance here thanks guys...

[Orb]

Originally Posted by mwahlert

i need to pull the trigger on this so i have them in time... but i don't want to make the wrong decision.

i have had kw v1, now eibach pro kit and koni fsd and now switching to street comforts - looking for more suspension travel and more linear spring - hoping to make the car more controlled and comfortable, and consistent.

this is my second rear drive car so i don't mind a bit of understeer to keep myself out of trouble.

will adding the front and rear m3 sways cause oversteer or snap over steer? i'm sure the spring rates of the kw street comforts also play into this equation.

what about ride quality/comfort... will it be decreased by going to the larger bars?

i'm really just looking for flatter cornering... if i can manage to make the car more neutral without being oversteer biased i'd be very happy..

just need some help and guidance here thanks guys...

I not sure you will be totally happy with the end results with out taking care of the fundamental bushing problems with this car. As soon as you change the tires, damper, springs and sway bars you going to change how the car behaves as a system. The stock bushings are no doubt finally tuned for the stock suspension and tires. Change one of these variables and it will upset the balance and the tuned frequency of the suspension as system which is expected. In this case, the added stiffness for either stiffer springs or roll bars will add substantial deflection to the bushing which translates into harshness, less traction and more roll. Isolation system like these are very difficult to tune and when they are this soft and you go out of range you actually make things a lot worse and this is indeed the case. I have already made the mistake of trying to tune the suspension with this problem and was futile…it can’t be done. The stiffer you go the worse the problem is and you will hit a resonance frequency with many setups. The offending isolators are the rear sub frame bushing and the tension strut. Replace these items and you have the ability to create a firmer compliant suspension which will exceed the OEM ride quality on non RFT.

Snap over steer is caused by large load transfers at high rate. You are actually more likely to get in trouble with a car that has more understeer as the actually amount of load transfer is more and at a higher rate and it very difficult to recover. Snap over steer is a tuning condition not an inherent flaw in balanced setup. A balanced car allows control of under steer and over steer conditions safely especially give the weight balance of this car. The whole subject is pointless with traction control on or partly disabled. You be amazed how difficult it is to over steer this car under any conditions. In a wet parking lot I tired very hard to over steer the car will traction control partly disabled. It wasn’t until I went full bore into a corner at 60 MPH lift the throttle and then turned the wheel almost to full lock before I could get the ass end to swing out and it was still easily recoverable. I was unsuccessful in losing control of this car after 20 attempts. This was with my H&R bar setup. This is yet another made up problem that doesn’t exists and it is nonsense statement that is never supported!

The whole subject of inside wheel spin is yet another unsupported statement by the truly clueless!!! We have a very high powered car for open differential so traction will always be an issue under acceleration with out a LSD. We have to look at how traction is generated which is by friction and forces on the tire. The friction is the nature of the tire compound while the forces are generated by the weight of the car, load transfer and external forces like acceleration. If we look at this stock car load transfer under a 0.9 G load will see the car has about 450 lbs on force on inside wheel. The same car will M3 roll bars will have about 350 lbs of force on the inside wheel. Give the low forces on the inside wheel we are not gaining much for traction and there not much point looking this as ratio either. The real thing you want to measure against is an LSD. A LSD driven car has 1700 lbs on the out side wheel combined with the inside wheel weight of 350 lbs under no acceleration. When it comes to traction it is in the order of magnitudes difference between the two systems. What does this all mean to open differential. It means you with the stock suspension you put down at extra 35 ft-lbs of torque when compared to M3 roll bar setup….you never put any real power down compared to LSD so you will have accept that you will be a cripple on the track no matter what. On the street not much of an issue in the real world and most will never notice. If we add acceleration to this scenario we naturally increase forces to outside wheel; hence, more traction…not so on the inside wheel so yet another loss for open diff’s.

There are ways to deal with inside wheel spin with open diff but you better be prepared for the nose dive of comprises and ride quality will be as bad as you can get it with no hope of improvement. I really don’t even like discussing this hack but anyone can get this to work with out any for thought. If you put a big enough front bar (28 mm solid or bigger) you will change the way load is transfer which is favourable to help reduce initial understeer (it will still understeer no matter what) and increase the force on the inside wheel. To really get this to work properly you should remove the rear roll bar…yes remove. Most think this will improve understeer and traction because of favourable camber profile but it is not the case it to do with how load is transferred. Your roll is dictated by the sum of reactions from the spring and roll bars as system not discreetly. Rest assured most of the load will be now on 3 wheels not 4 and the inside front wheel will become air born. It will make the car far less stable and you will be susceptible to snap oversteer and massive understeer. The car will never take set in corner so thinking it will is pipe dream but this is okay for autocross. Massive understeer will happen on any bumpy corner but can be compensated with the right dampening but will result in a massive loss in pitch control. Will we need to dig into dampening and roll bars for on a side bar on more negatives of this setup coming next.

One of the key setup parameters of car is selecting the spring rate. Spring rate are selected based on desired natural suspension frequencies. Almost all BMW are set with a natural frequencies 10-15% higher in the rear than the front since it allow for a flat ride. The reason this is so is when you hit bump the front and rear suspension return to static position at the same time. The effect of this setup is that it gives you comfortable ride. Pitch is very important in balancing the car but for most it is the key in giving you great ride quality and you know when it not right because human find it very uncomfortable more than anything else. On a more performance setup we can change the natural frequencies to equal front and rear up to 10% higher in the front. KW would be an exception at they will typically set the front frequencies 10-15% higher than the rear. We can do this on performance setup since with can compensate with dampening to achieve the same flat ride qualities. Spring rates are selected with purpose and for a desired result. For example, I select my frequencies at 4% higher on the front than the rear. My setup gaols was specific, as I wanted the front and rear of the car to take set in corner at the same time with minimal damping influence.

The sway bars have a massive influence on how the car handles in single bump and roll. Many think that coil spring rate have major effect on roll but it not the case unless we are talking about true race cars. The sway bars on average add 3X the stiffness over springs. The effect that sway bars have on the suspension is in single bump and roll. In single bump the stiffness of the sway bar plus the spring is you spring rate. In roll the stiffness of the sway bar x 2 plus the spring rate is your spring rate. For example, a front spring rate is 285 lb/in and the roll bar is rated at 300 lb/in I single wheel bump. The overall rate will be 585 lb/in as the spring rate. In roll, it would be 300 lb/in x 2 plus the front spring at 285 lb/in. The overall spring rate would be 885 lb/in. If we consider the basing of sway bar stiffness front and rear that can change the frequency of the suspension and this will effect pitch and thus ride quality as I already mentioned. We can compensate with dampening but it will affect our pitch control just the same. In the end, we our compromising pitch control vs in roll and single wheel bump. The more unbalanced your car the more you will comprise ride quality and handling.

Sidebar: Back to the big front bar with no rear bar

Now we know something about pitch and sway bar stiffness we understand some of the compromises. If we take the example of 285 lb/in front spring with a big front roll bar rated at 500 lb/in we are going to have a overall spring rate of 1300 lb/in. We are going to have to compensate for this with less compression dampening and a lot more rebound dampening. Guess what….you can not do it. When you drive the car straight it will always be over dampened and in roll in will be under dampened. The car will never take set because of lack of rebound dampening in roll. Okay, throw pitch control in to this equation….we have none what so ever as we had to compromise our dampening to control the car in roll and that was never meet. Think about what 1300 lb/in spring rate will do for traction over bumps. Go with this setup and you can expect very bad ride quality for this magical 3 wheel wonder.

If you want a fun good ride quality car go for a balanced setup. The trade off of small amount of loss of power to the ground out weighs all the compromises for any other setup and is why I will always recommend it.

I would go with the KW street comfort with the M3 roll bars, sub frame bushing and tension struts. Change the rear damping to 1-2 clicks stiffer and possible the front dampening one click softer to correct pitch control.

Orb

[mwahlert]

wow - well that was some response.... i liked the cliff notes at the end...

i'm worried about adding the m3 tension rods, and rear sub frame bushings....they are not cheap and i'm very sensitive to NVH....

would rear sub frame bushings really make a big improvement even for just driving around town? isn't the weak link still the lower factory mount on the e9x? i notice the m3 damper mounts directly to control arm - not to control arm via bushing...

[Orb]

Originally Posted by mwahlert

wow - well that was some response.... i liked the cliff notes at the end...

i'm worried about adding the m3 tension rods, and rear sub frame bushings....they are not cheap and i'm very sensitive to NVH....

would rear sub frame bushings really make a big improvement even for just driving around town? isn't the weak link still the lower factory mount on the e9x? i notice the m3 damper mounts directly to control arm - not to control arm via bushing...

NVH is relative to a tuned system. A sloppy un-tuned system can be far more noisy and damaging that a stiffer one because they are susceptible to resonance frequencies. You are close to having a system that has resonance. It is hard for me to explain thing like this in simple terms.

You have stiffer input for the springs and roll bars. You need to control and dampen those loads with the correct amount of resistance at the sub frame bushing which transfer that load to the chassis.

Orb

[mwahlert]

Originally Posted by Orb

NVH is relative to a tuned system. A sloppy un-tuned system can be far more noisy and damaging that a stiffer one because they are susceptible to resonance frequencies. You close to have an system that has resonance. It is hard for me to explain thing like this in simple terms.

You have stiffer input for the springs and roll bars. You need to control and dampen those loads with the correct amount of resistance at the sub frame bushing which transfer that load to the chassis.

Orb

i never thought suspension tuning required so much thought.

i'm just going to trade the car in for an m3.

how difficult is it to install the subframe bushings?

if i leave the stock roll bars in, and leave everything else alone....is the car going to be very unbalanced w/ just the street comforts?

[Orb]

Originally Posted by mwahlert

i never thought suspension tuning required so much thought.

i'm just going to trade the car in for an m3.

how difficult is it to install the subframe bushings?

if i leave the stock roll bars in, and leave everything else alone....is the car going to be very unbalanced w/ just the street comforts?

LOL, you do know I barley scratched the surface on suspension tuning.

Putting in the KW only will just help reduce the rate of roll. The mushy feeling will stay contrary to what others may say. The KW springs are stiff for what you want so not sure you’re going to be happy with it and said this to you before. You are asking for something you can’t get from this car but it can be improved upon and even better than M3 but only with stiffer springs.

Honestly, I think you be much happier with M3 EDC system for what your saying than anything you can buy for this car.

Orb

[mwahlert]

Originally Posted by Orb

LOL, you do know I barley scratched the surface on suspension tuning.

Putting in the KW only will just help reduce the rate of roll. The mushy feeling will stay contrary to what others may say. The KW springs are stiff for what you want so not sure you’re going to be happy with it and said this to you before. You are asking for something you can’t get from this car but it can be improved upon and even better than M3 but only with stiffer springs.

Honestly, I think you be much happier with M3 EDC system for what your saying than anything you can buy for this car.

Orb

i think i am just going to stuff the street comforts in - your right - i'm not sure i will even be happy at that point.....so before i spend an additional 1200 bucks on roll bars, etc, etc i should make sure i'm close to happy w/ the feel of the car.

i change cars very very quickly....i am 24 and this bmw is my 14th car....i have had 5 in the past 2 years alone.

i love this car and the power plant but always have the urge to try something else (135, or m3). maybe used m3 will be available soon with DCT and i can upgrade. there are always used c6 vettes and 09 cts-v's should be available used soon too.

[stressdoc]

I think Orb made an excellent suggestion: test drive a M3 with EDC. Alternatively, you could get the Bilstein EDC for your 335, which are fine for the street. Street comforts should be OK too.

The 335 suspension is engineered for high speed luxury touring on rfts. Some of us go to a lot of time, trouble & $ modding to emulate what the M3 does stock.