Sway bar upgrade: E9X or E93

[SDS135]

Looking to upgrade my front sway bar. I've got a guy who can sell me a used E9X M3 front sway bar (good price) or I go with a new E93 M3. Is the E9X M3 front sway bar going to be noticeable or should I just go with the new E93 which seems to be the norm if I'm going to upgrade. I read all about the differences here but looking for some input!

http://www.turnermotorsport.com/t-tech-e90-e92-sway-bars.aspx

Thanks.

[RimasRS]

read more about M3 sway not everybody likes it...

[1Pirate]

I have the E93 M3 FSB on my car and have been happy with it. Definitely an improvement over the stock FSB. I also have the other M3 front suspension upgrades (as well as the rear M3 upgrades). I chose the E93 M3 FSB because it was slightly larger than the E92 M3 FSB.

[HP Autosport]

There are a lot of variables that go into a front sway choice. In my opinion, unless you have a fully built coil over kit you really won't notice a big difference between the two choices. I don't know what suspension setup you have, but it is important to find a balanced setup in terms of spring rate, dampening, compression, and then choose a sway bar based upon the characteristics of your car. If you have a pretty tight setup with high spring rates, you might not need the larger sway for it will induce understeer. If you have a looser setup just for daily driving, a larger sway (e93) would help manage body roll up front and help with turn in and overall handling. It really all depends and that is the fun part. Hope that helped a little bit!

-Mike

[SDS135]

Right now I'm on the stock suspension and this would be my first suspension mod. I still need to do my research but I figured I'd start here and I've heard that's where most people start

[RimasRS]

again.... read more

[GermX-85]

Originally Posted by HP Autowerks

There are a lot of variables that go into a front sway choice. In my opinion, unless you have a fully built coil over kit you really won't notice a big difference between the two choices. I don't know what suspension setup you have, but it is important to find a balanced setup in terms of spring rate, dampening, compression, and then choose a sway bar based upon the characteristics of your car. If you have a pretty tight setup with high spring rates, you might not need the larger sway for it will induce understeer. If you have a looser setup just for daily driving, a larger sway (e93) would help manage body roll up front and help with turn in and overall handling. It really all depends and that is the fun part. Hope that helped a little bit!

-Mike

i was going to add my 2 cents but i think you covered all the points.

[Focusedintntions]

I'd say do dampers before the sway...much better investment. Larger sway will only increase the understeer. Sure your car feels more responsive and flatter, but you get less balanced handling.

[1Pirate]

The dampers are, in my opinion, the weakest link in the stock suspension. Replacing them is a must to really improve the car's handling.

[RimasRS]

Originally Posted by 1Pirate

The dampers are, in my opinion, the weakest link in the stock suspension. Replacing them is a must to really improve the car's handling.

+1
I replaced mine with Bilstein B12 Eibach pro kit and it is the whole different car its more stable in the first mm of dampening is even softer quieter less sway its a must

[John_01]

Turner motorsport have a comparison of the sway bar stiffness on their website. They say its around 7% difference between the two. To be honest I'm having doubts about that figure and I think there must be a bigger difference to create a useful difference in tuning. Is anyone able to confirm or dispute it?

[TS135i]

I was thinking of going with the E92 M sway, but is it worth it at a 7%, how does that 7% translate for daily driving vs stock M-sport sway...

[froop]

Originally Posted by HP Autowerks

There are a lot of variables that go into a front sway choice. In my opinion, unless you have a fully built coil over kit you really won't notice a big difference between the two choices. I don't know what suspension setup you have, but it is important to find a balanced setup in terms of spring rate, dampening, compression, and then choose a sway bar based upon the characteristics of your car. If you have a pretty tight setup with high spring rates, you might not need the larger sway for it will induce understeer. If you have a looser setup just for daily driving, a larger sway (e93) would help manage body roll up front and help with turn in and overall handling. It really all depends and that is the fun part. Hope that helped a little bit!

-Mike

Hi Mike,

I've purchased some Moton Clubsports (used) with 560lb front and 800lb rear swift springs from HPA. What would be the best option for sway bars (both front and rear) in this case? I'll also be doing an M3 rear end sway with the LSD, subframe, suspension arms etc and it comes with an E90 M3 rear sway.

Is it best to just leave in my stock 135i sway bars or should I upgrade both the front and rear sways to either E90/92 or E93 sways?

I'm probably looking to get the most grip I can when I'm out on the track. With those springs rates I can't see it making a huge difference in reducing further body roll.

Thanks,

Alex

[CJ421]

I had the M3 front and rear sways installed before I upgraded any other parts of the suspension (installed at the same time w/ Quaife LSD and M3 rear subframe bushings). They noticeably reduced body roll on turn-in without affecting ride quality.

Sway bars are tuning tools (and relatively barbaric ones at that). The ideal way to upgrade suspension as noted - with better control and performance as the goal - is to start with the tires, then the dampers and springs. You may not need to upgrade the sways at all if you get the spring rates right.

[HP Autosport]

Originally Posted by froop

Hi Mike,

I've purchased some Moton Clubsports (used) with 560lb front and 800lb rear swift springs from HPA. What would be the best option for sway bars (both front and rear) in this case? I'll also be doing an M3 rear end sway with the LSD, subframe, suspension arms etc and it comes with an E90 M3 rear sway.

Is it best to just leave in my stock 135i sway bars or should I upgrade both the front and rear sways to either E90/92 or E93 sways?

I'm probably looking to get the most grip I can when I'm out on the track. With those springs rates I can't see it making a huge difference in reducing further body roll.

Thanks,

Alex

Hi Alex,

In my honest opinion I would just go to the track with that setup and see how the car behaves. You might just be happy with those spring rates and no sway (front or rear). My car (turb0mike's e90 335i) has the AST 4250s with 400/800. I like the rear end characteristic even without a sway bar. The front end needs a little work for it rolls quite badly in sharp high speed chicanes. I plan on going to 560 and testing it on the track. With all that being said, it all depends on driver preferences; I like my car a little tighter so I can rotate the back end to counter understeer. Some people want it a little looser because oversteer can be scary if you don't know how to control it. Hope that helps a little!

-Mike

[froop]

Originally Posted by HP Autowerks

Hi Alex,

In my honest opinion I would just go to the track with that setup and see how the car behaves. You might just be happy with those spring rates and no sway (front or rear). My car (turb0mike's e90 335i) has the AST 4250s with 400/800. I like the rear end characteristic even without a sway bar. The front end needs a little work for it rolls quite badly in sharp high speed chicanes. I plan on going to 560 and testing it on the track. With all that being said, it all depends on driver preferences; I like my car a little tighter so I can rotate the back end to counter understeer. Some people want it a little looser because oversteer can be scary if you don't know how to control it. Hope that helps a little!

-Mike

Hi Mike,

Thanks so much for the reply. That definitely helps.

I think I'll keep the front and rear OEM bars in that case and not install the rear M3 bar that comes with the subframe. I just hope I don't change my mind later as I'd hate to have to pay for the labour to change the rear bar...lol

Thanks,

Alex

[HP Autosport]

Originally Posted by froop

Hi Mike,

Thanks so much for the reply. That definitely helps.

I think I'll keep the front and rear OEM bars in that case and not install the rear M3 bar that comes with the subframe. I just hope I don't change my mind later as I'd hate to have to pay for the labour to change the rear bar...lol

Thanks,

Alex

I would track the car first without the subframe bushings to see if you really need the sway... then when you install your bushings you can make an educated decision.

-Mike

[froop]

Originally Posted by HP Autowerks

I would track the car first without the subframe bushings to see if you really need the sway... then when you install your bushings you can make an educated decision.

-Mike

Thanks Mike,

Yeah I plan on taking it out with completely stock suspension in the next month. I have a private track day at a private track. Looks epic!



It's just that when it comes to installing the suspension upgrades, the coilovers, subframe, LSD, bushings, rear suspension arms are all going to have to go on at the exact same time. The rear bar requires dropping of the subframe as well to install which is why I'm tossing up whether to install it all with or without the M3 rear bar. Don't want to have to pay ridiculous labour costs just to change out the rear bar. Hopefully I make the right decision the first time around.

Alex

[HP Autosport]

Originally Posted by froop

Thanks Mike,

Yeah I plan on taking it out with completely stock suspension in the next month. I have a private track day at a private track. Looks epic!



It's just that when it comes to installing the suspension upgrades, the coilovers, subframe, LSD, bushings, rear suspension arms are all going to have to go on at the exact same time. The rear bar requires dropping of the subframe as well to install which is why I'm tossing up whether to install it all with or without the M3 rear bar. Don't want to have to pay ridiculous labour costs just to change out the rear bar. Hopefully I make the right decision the first time around.

Alex

That track looks positively delicious... wow. I honestly think with your setup you won't NEED the rear sway. The 1ers already have a considerably smaller wheelbase than the e90. So the car will just be 'tighter' in general and easier to rotate around a corner if you need. You also don't want your car to be 'too' stiff on the back end, because if you are putting down some power (400whp+) you will want some give and torque. If it is super stiff the power won't be able to be applied to the tarmac and you will drift around smaller corners. Go track with stock suspension, find your driving style, and hit me up. Your setup looks mighty good at the moment though.

-Mike

[TS135i]

Originally Posted by SDS135

Looking to upgrade my front sway bar. I've got a guy who can sell me a used E9X M3 front sway bar (good price) or I go with a new E93 M3. Is the E9X M3 front sway bar going to be noticeable or should I just go with the new E93 which seems to be the norm if I'm going to upgrade. I read all about the differences here but looking for some input!

http://www.turnermotorsport.com/t-te...sway-bars.aspx

Thanks.

Back to the original question.. I just installed the E92 M3 FSB, my suspension is totally stock M-Sport.
The front end has flattened out somewhat around slow hairpin bends, but the main benefit I feel is quick S-bends and lane changing, the steering feels that little bit crisper, bearing in mind my car is a daily drive.
It's not a day & night difference like some here on this forum may claim it to be, but a worthwhile street mod, I am pleased I did it.
I have M3 rear sub-frame bushings and rear control arms sitting my garage waiting for the RFT's to wear in order to replace them with PSS, so I'm hoping to rid the dreaded rubberband rear end.

I'm hoping I can live with stock springs & dampers providing I adrress the tires, bushings, arms and front swaybar. If this setup fails my expectations, then plan B is BMW PS.
Now before someone says "but the stock dampers/springs are the weakest link" I don't mind them for the street and our local councils obsession with speed humps.

[froop]

Originally Posted by HP Autowerks

That track looks positively delicious... wow. I honestly think with your setup you won't NEED the rear sway. The 1ers already have a considerably smaller wheelbase than the e90. So the car will just be 'tighter' in general and easier to rotate around a corner if you need. You also don't want your car to be 'too' stiff on the back end, because if you are putting down some power (400whp+) you will want some give and torque. If it is super stiff the power won't be able to be applied to the tarmac and you will drift around smaller corners. Go track with stock suspension, find your driving style, and hit me up. Your setup looks mighty good at the moment though.

-Mike

Thanks Mike! You're a wealth of information! I'll and hold off doing any suspension mods until the track day.

Yeah I can't wait to head out there. It was built by the ex CEO of Coke because he lost his license and had nowhere to drive his mclaren race car around . That's passion.

[yawn]

Originally Posted by TS135i

Back to the original question.. I just installed the E92 M3 FSB, my suspension is totally stock M-Sport.
The front end has flattened out somewhat around slow hairpin bends, but the main benefit I feel is quick S-bends and lane changing, the steering feels that little bit crisper, bearing in mind my car is a daily drive.
It's not a day & night difference like some here on this forum may claim it to be, but a worthwhile street mod, I am pleased I did it.
I have M3 rear sub-frame bushings and rear control arms sitting my garage waiting for the RFT's to wear in order to replace them with PSS, so I'm hoping to rid the dreaded rubberband rear end.

I'm hoping I can live with stock springs & dampers providing I adrress the tires, bushings, arms and front swaybar. If this setup fails my expectations, then plan B is BMW PS.
Now before someone says "but the stock dampers/springs are the weakest link" I don't mind them for the street and our local councils obsession with speed humps.

This rubber band effect you mention, does it happen when putting the power down on the straights or round the bends?