Front Sways, Rears Sways, or Both?

[BMW86]

What will improve handling the most? Front sways, rear sways, or both?

It seems like only doing the front is the most popular choice but why is nobody doing both? What is the effect of doing this on an otherwise stock car? At this stage I can't afford to invest money in some coilovers so springs will have to do for now.

What does everyone recommend? I would appreciate hearing as many informed opinions as possible to help me make the right choice. My car will be 95% time on the street.

For those of you that have already given me some insight, I really appreciate your help.

[rodi]

http://www.1addicts.com/forums/showthread.php?t=302722

did you read this thread? lots of info and answers to your questions.

[BMW86]

I've read through that thread a few times. I just wanted more insight in front sways vs both sways. I've seen someone mention that by putting on the rear sways it will induce snap oversteer?

[Bobbo]

My car is stock apart from Yoko AD08's (Best tyres I ever used).

Got H&R sways installed on Monday.

Well it is like driving a different car. Roll induced understeer is almost completely eliminated. Rear bar is around 5 times stiffer.

It still wobbles a bit but only when you really chuck it around which I couldn't at all before. Still needs dampers to be changed and M3 bits to help get rid of the chassis slop after changing from RFT's.

Ride is actually better than before as it doesn't jiggle side to side anymore over our crap Aussie roads.

Get em.

[Bobbo]

Oh my car feels really balanced now.

So i think you need both sways. One only will fix half the problem unless you do something else to counter it. Like getting front bar but increasing rear spring rates heaps to stop roll but this will ride pretty average.

[BMW86]

Thanks for the input, the H&R's sound like a really good option. What was the install like? I've heard that the rear is a pain to install and very time consuming. Did it cost you much or did you do it yourself?

[Bobbo]

Cost $300 mechanic did say it was a pain had to drop subframe to slide the rear in. Not really a diy job for me anyways.

[BMW86]

Originally Posted by jbgti

Cost $300 mechanic did say it was a pain had to drop subframe to slide the rear in. Not really a diy job for me anyways.

Sweet. That sounds fairly reasonable. I keep changing my mind but I'm set on the H&R Sport Springs and H&R Front and Rear Sway Bars unless somebody can tell me otherwise. I would think these parts would work well together.

[cpt97m3]

I've added the Hotchkis front sway bar only, and it did help reduce body lean a lot. But I'm thinking about adding an H&R rear bar at some point to further help the body lean. I've still running stock springs an shocks, and I'm not looking to have a real aggressive suspension setup yet.

So I'd say go for them both, and let us know how you like them.

[jibaholic101]

would it be a good idea to mix and match the hotchkis front with the h&r reaar?

[BMW86]

Originally Posted by jibaholic101

would it be a good idea to mix and match the hotchkis front with the h&r reaar?

I don't see why not

Although, I read somewhere that the Hotchikis bar is hollow and the H&R is not so I don't know what effect this will have. I'm pretty sure Hotchikis make a rear sway bar anyway.

[BMW86]

Does anybody know how much weight the sways will add to the car? In particular, the H&R's ??

[AtomiK]

Originally Posted by BMW86

Does anybody know how much weight the sways will add to the car? In particular, the H&R's ??

I don't believe weight should be an issue since the H&R sway bar does not look to be much larger than the OEM sway bar.

[arrutled]

IMO just get the front sway. Front sway reduced understeer by not allowing the front to roll over into positive camber. The rear actually does not roll into positive camber due to its geometry (read J tylers thread in the autocross/drag section). Also the Front bar moves weight to the inside rear tire on a turn which allows you much greater exit speed. I dont think you will actually gain anything from the rear bar at all. It will only reduce rear grip and what you really want to do is increase front grip. Think about that......reduced grip......you dont want that! Not only that theoretical BS, but today I finished 1st or 2nd (don't know exactly which one yet) in class C, normally of which I finish 7-8 (middle of the road) after only swapping out the front sway with the 26.5 mm M3 bar. so smoke on that.

[nordique14]

I installed just a front sway and ran with that for around 4 months (and several autox) before I installed the rear bar. I found the rear bar balanced out the car. Just the front bar made for quicker initial turn in but made for more understeer at corner exit. Also, several people watched me while autox and they said I lifted a wheel with just the front car. Adding the rear bar removed the corner exit understeer caused by the front bar only and now all 4 wheels now stay on the ground around the corners.

I have the UUC sways. Install of the rear bar was $400.

[jthorst75]

I have both F&R H&R sway bars. I intstalled them myself and it didn't take too long to do them. Most people shy away from doing the rear but it wasn't a big deal to do. I have read where most install the front but still want to do the rear, IMHO do both and enjoy.

[BMW86]

Originally Posted by arrutled

IMO just get the front sway. Front sway reduced understeer by not allowing the front to roll over into positive camber. The rear actually does not roll into positive camber due to its geometry (read J tylers thread in the autocross/drag section). Also the Front bar moves weight to the inside rear tire on a turn which allows you much greater exit speed. I dont think you will actually gain anything from the rear bar at all. It will only reduce rear grip and what you really want to do is increase front grip. Think about that......reduced grip......you dont want that! Not only that theoretical BS, but today I finished 1st or 2nd (don't know exactly which one yet) in class C, normally of which I finish 7-8 (middle of the road) after only swapping out the front sway with the 26.5 mm M3 bar. so smoke on that.

Firstly, congrats on coming 1st/2nd that's a huge improvement from the sway bars. Are you suggesting that having the rear bar would induce a hint of oversteer because it reduces grip in the back? If so, by how much? The general consensus I'm getting from everyone who has both is that it neutralises and balances out the car.

Originally Posted by nordique14

I installed just a front sway and ran with that for around 4 months (and several autox) before I installed the rear bar. I found the rear bar balanced out the car. Just the front bar made for quicker initial turn in but made for more understeer at corner exit. Also, several people watched me while autox and they said I lifted a wheel with just the front car. Adding the rear bar removed the corner exit understeer caused by the front bar only and now all 4 wheels now stay on the ground around the corners.

I have the UUC sways. Install of the rear bar was $400.

Thanks for your input. Firstly, do you have any other suspension mods in addition to the sways? When you said you encountered understeer during corner exit, how bad was this understeer from just having the front bar installed? It sounds as though the front and rear bar completely neutralises the car and balances it out making it feel more planted.

Do you experience any oversteer at all or does the car turn in and turn out perfectly now similar to that of AWD? I've never tracked my car before but at times I do drive aggressively and take corners pretty hard but I would rather be on the understeer side than the oversteer for safety reasons until I gain some more experience at the track.

Also, can you please confirm that the $400 installation was just for the rear bar itself?

Originally Posted by jthorst75

I have both F&R H&R sway bars. I intstalled them myself and it didn't take too long to do them. Most people shy away from doing the rear but it wasn't a big deal to do. I have read where most install the front but still want to do the rear, IMHO do both and enjoy.

How does your car feel with the front and rears? Does it feel more planted or does it induce snap oversteer if you are not careful?

[nordique14]

Originally Posted by BMW86

Firstly, do you have any other suspension mods in addition to the sways? When you said you encountered understeer during corner exit, how bad was this understeer from just having the front bar installed? It sounds as though the front and rear bar completely neutralises the car and balances it out making it feel more planted.

Do you experience any oversteer at all or does the car turn in and turn out perfectly now similar to that of AWD? I've never tracked my car before but at times I do drive aggressively and take corners pretty hard but I would rather be on the understeer side than the oversteer for safety reasons until I gain some more experience at the track.

Also, can you please confirm that the $400 installation was just for the rear bar itself?

$400 install was for the rear only. I did the front myself.

My car has stock springs/shocks. I do have the M tension rods front and rear. On the street you would probably be happy with just the front but at the limit you need the rear end to rotate. The rear bar does not cause any oversteer. It just helps neutralize the late corner understeer from the front bar only.

I know most people have said that adding the front bar will reduce understeer. My experience is that it reduces understeer on initial turn in but is the same (or worse) on mid-corner and corner exit. Again, that is just me at the autox. I could have lived with that but the lifting of a wheel was what made me put the rear bar on. IMO, the car needs to be balanced front and rear when driving at 10/10ths.

[BMW86]

Originally Posted by nordique14

$400 install was for the rear only. I did the front myself.

My car has stock springs/shocks. I do have the M tension rods front and rear. On the street you would probably be happy with just the front but at the limit you need the rear end to rotate. The rear bar does not cause any oversteer. It just helps neutralize the late corner understeer from the front bar only.

I know most people have said that adding the front bar will reduce understeer. My experience is that it reduces understeer on initial turn in but is the same (or worse) on mid-corner and corner exit. Again, that is just me at the autox. I could have lived with that but the lifting of a wheel was what made me put the rear bar on. IMO, the car needs to be balanced front and rear when driving at 10/10ths.

That makes sense. I will definitely go down this route now, my only big concern was inducing oversteer from the rear sway bar but you have confirmed that this is not an issue. I may have to find a decent workshop that will work out some kind of a package deal for installing the whole lot seeing as though the installation will be very expensive due to the rear bars. However, from what you've said the car will feel a lot more balanced and neutral so it will be worth it.

[arrutled]

Originally Posted by nordique14

$400 install was for the rear only. I did the front myself.

My car has stock springs/shocks. I do have the M tension rods front and rear. On the street you would probably be happy with just the front but at the limit you need the rear end to rotate. The rear bar does not cause any oversteer. It just helps neutralize the late corner understeer from the front bar only.

I know most people have said that adding the front bar will reduce understeer. My experience is that it reduces understeer on initial turn in but is the same (or worse) on mid-corner and corner exit. Again, that is just me at the autox. I could have lived with that but the lifting of a wheel was what made me put the rear bar on. IMO, the car needs to be balanced front and rear when driving at 10/10ths.

I would agree that you might want the rear bar if you track your car often for balancing the car at 10/10s. For autocross purpose though I think the initial turn in plus corner understeer (less donuts) is a net gain for a novice (like myself) not to mention its way cheaper. I have heard from a few people that the car can easily spin with the a bigger rear sway without a true LSD with just a little throttle input, which I think would be very annoying to a novice (like myself). What if you dont like it? another 400 to remove the damn thing. At least try it in stages or call someone who works on suspension a lot (ie. TC Kline). Also , I got 2nd today by .003 seconds but had FTD in class C as an update.

[BMW86]

Originally Posted by arrutled

I would agree that you might want the rear bar if you track your car often for balancing the car at 10/10s. For autocross purpose though I think the initial turn in plus corner understeer (less donuts) is a net gain for a novice (like myself) not to mention its way cheaper. I have heard from a few people that the car can easily spin with the a bigger rear sway without a true LSD with just a little throttle input, which I think would be very annoying to a novice (like myself). What if you dont like it? another 400 to remove the damn thing. At least try it in stages or call someone who works on suspension a lot (ie. TC Kline). Also , I got 2nd today by .003 seconds but had FTD in class C as an update.

Thanks for your input and well done on your placing!! I've decided to go with just the front sway bar because the installation expense has put me off and as you said, I may not even like it as my only driving experience is spirited driving on the streets. This way I can do it in stages and be able to tell difference if I do get rear sway bars. Now I'm back to square 1 because I was going to get the Oem M3 front sway if I was only getting the front and the H&R front and rear sways if was getting both bars. The idea of having oem M3 parts appeal to me but the M3 rear sway doesn't seem like the best suited rear bar hence the H&R sways. The only problem with the M3 parts is they were never specifically designed for the 1 series and they just happen to fit... However the H&R and other brands are designed for this car only. Decisions...

[Dr3K0]

I have been debating on the same situation. So I try something different, I start playing with suspension settings on GT5P. I know is not a real car but outcome should be close.

After a lot of different sets of configs pretty much all ends on how you like the car to behave vs. you driving style.

Explanation.

I had good success by power slide thru corners to get better lap times. The settings were stiffer rear. Obviously I lose traction so the car over steer and then gun it. With some practice I got to time it perfectly but I would not dare to do it on the streets (I don’t have a track close by), plus I would eat the tires. Also noticed that if I were driving using grip I could not accelerate strong enough(in turns) w/o under steer; really frustrating.

Then change to stiffer in the front. Wow, really different. Now the car keeps the desired path during the apex and can gun it for a fast exit (using grip). The power slides are more difficult to execute, I have more grip so had to go like a mad man to pull the slide all the way thru the turn. But is easy enough to get the proper angle and fly thru the turns (less dramatic slide). Over all had better, more consistent times.

Then stiffen both. Now the car felt more like default, can’t drive fast enough in turns due to over steer. Had more traction than default but less than the front alone.

As far by my tests I had better results with just the front, it felt like another car. It’s not a real life test but is a good synthetic benchmark. All depends on what you like, I believe.


Dr3K0