Upgrade rear swaybar only?

As the DE season approaches, thoughts naturally turn to upgrades. The only suspension upgrade I've done so far is to install H&R springs. I think the next step will be to upgrade the sway bars, both to decrease body roll and also to dial out a bit of the stock understeer. Since I'm on a very limited budget, can I begin with upgrading only the rear sway bar? (With the front to follow when my budget allows.) As I understand it, a stiffer rear SB will dial out a bit of understeer. I'm also looking at an adjustable one. Is it a bad idea to upgrade only one? Thanks, David

Sway bar wise, I have 3way adjust eibach rears only. It makes a big difference on the streets so I'm sure it's better at the track.

You can go with used GT3 bars and aftermarket drop links.

For DE upgrade the front only (stiffer). Leave the rear stock...

I did F & R on my C2, with adjustable on the rear. I went with the softest setting on the rear, then bumped it one stiffer. It transformed the car and eliminated a lot of the front end push (understeer). I'm confident you could go a stiffer rear only and it work work well. That's my plan for my Turbo.

If your budget allows for only one, I would go up front first.. Also consider changing the bushing front and rear as that is quite a reasonable enhancement.

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x2

Recommendations on where to purchase F&R bars with bushings?

Thanks everyone. I was hoping for a consensus, but some of you said rear only is okay, others said get the front instead, and I've read elsewhere the importance of doing both at the same time. I'm still confused about how to dial out some of the understeer; whether I should increase relative stiffness on the rear or the front. Opinions seem split on this, but since this is basic physics there must be a correct answer. I suppose I'll just have to bite the bullet and order a matched set. I'm off now to look for a good suspension book. Cheers

I just saw the Eibach front bar on sale somewhere cheap, cheap, cheap. I think it was @140 with bushings?

Hey David...Hope you are well. I would look at the front sway. Maybe a used GT3 sway. They have been popping up in FS area lately. I missed one for $250. My X74 has a 030 set but I would like something adjustable for the front. See you at Putnam soon.

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Don't bother with Eibach front. There's a reason why it's so cheap(because no one is buying them). Eibach 24mm Stock 23.1mm Factory m030 sport suspension 23.6mm Hardly a difference and not worth it IMO. There's an auction now(eBay) on GT2 sway bars starting at $200 each which is a steal.

Please help me understand...if you increase rear sway stiffens, you increase oversteer=dial out understeer. No? If you leave stock rear and upgrade front sways, you're increasing understeer...no? Assuming suspension/wheel size/tire size etc etc is all the same

You are correct in your thinking, in theory if you stiffen the rear you can dial out some of the understeer, but I think why some of the guys here are suggesting do the front bar is because it will get rid of some of the roll in the front which is causing the roll induced understeer ... So in this case, although counter intuitive, stiffening the front may actually lessen the understeer. That being said if it were me I’d save up until you can afford both bars to keep the car balanced. There are other options you may consider like trying different tire pressures, adjusting your line, throttle application and apex to get the car to rotate. Investing in a driving coach may go a long way in getting rid of understeer …

Harder sway, less grip on that axel. However, if you stiffen the front you get less roll and reduce lifting the inside wheel while hard cornering, maybe moore grip..... But normaly, harder sway ,less grip, moore responsive....

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This is correct. The inner wheel can lift thus sacrificing some mechanical grip with just a rear sway bar. Also when driving anything above 8/10's around a track, I would actually prefer a bit of understeer so I can approach the limits more confidently and ultimately go faster. Coupled with the fact that you have increased spring rate in the rear from your H&R's, I would dial in more rear tire pressure effectively increasing your spring rate even more if you still need to dial out understeer. Some guys choose to increase their spring rates rather than sway bar size. There are two schools of thought in regard to more spring and less sway and vice versa. I've driven with just an upgraded rear sway bar and it felt a bit weird to a point where it actually slowed me down around the track. I know quite a few dedicated track guys that have been known to even disconnect their rear sway links for this reason. But as others have said, I would rather save an get a complete set if you can.

We carry H&R sway bars and the GT3 kit that includes everything. For more information Click Here. H&R Front Non-adjustable: 26mm H&R Rear Adjustable: 23mm

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Agree with disconnecting the rear sway bar. As stated, stiffen the front first. Try that. Then you can stiffen the rear, but (depending on the spring rates of those H&Rs) you probable will not need too....

Not to question this swaybar discussion but hasnt actual testing proven that tire upgardes show a much more drastic improvement in handling or increasing resistance to G forces than a swaybar diameter/stiffness upgrade? Or,, are you assuming someone has already maxed out the tire factor with upgrade?

Also, diameter doesn't tell the full story. IIRC, even though the front M030s are only 23.6mm, they are thicker wall (they are hollow), than OE 23mm ones, so stiffer than the diameter changes suggest. Have to look at force ratings. I agree with KK also, tires before ARBs, but a single ARB is of course a lot cheaper.

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Hollow sway bars need to be significantly bigger in size to offer the same roll resistance of same sized solid bars. IIRC, the M030 are still solid. It was the Cup Car's that were hollow. I have one. With that said, there isn't one magical formula that will work with everyone's driving style and setup. You really have to get out on the track and experiment and see what works best for you. All of these suggestions should only be taken lightly as a mere starting baseline to begin with. Tire Pressures are one cheap and effective setting that anyone can do. Start off with the simple stuff first if you don't have the funds to do a full setup.

Im building the perfect track car setup (in my head). I Might do the swaybar/link mods to improve handling. I have the Mich Pilots already. The GT2 front bar sounds interesting.

Just to clarify things in this thread... NB vs WB have different sways, so a GT2 will not fit a C2 M030 is hollow (I have it). Eibach is solid (I have it). A slightly stiffer FSB can help improve front grip by reducing dynamic camber loss and roll which reduces lap time, but ultimately the car will still understeer. Also, too stiff a FSB will worsen understeer I've posted this before, but here's the sway bar info I gathered before getting mine. C2/GT3 Sways Normal front 23.1mm x 3.4mm / rear 18.5mm x 2.5mm ROW M030 front 23.6mm x 3.6mm / rear 19.6mm x 2.6 mm GT3 front 26.8mm x 4.0mm / rear 20.7mm x 2.8 mm (5 way adj front, 4 way adj rear, end links needed) Eibach C2 front 24.0mm x solid / rear 19.0mm x solid (only rear 3 way adj) H&R C2 front 26mm / rear 23mm - rear only adj RUF resells Eibach sways (painted green) Gemballa resells H&R sways C4S/Turbo C4S/TT front 23.6x 3.5mm/ rear 21.7x 3.0mm GT2 front 26.8x 4.0mm/ rear 20.7x 2.8mm Eibach TT front 24.0mm x solid / rear 23.0mm x solid (only rear 3 way adj) H&R C4S front 25mm / rear 24mm - both adjustable TechArt TT front 23.8mm x ? / rear 23 mm x ?? (front and rear 3 way adj, end links may be needed)

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You sure about that? First off you're probably getting mixed up as the GT2 is RWD and not awd like the C4S and Turbo models. NB and WB doesn't really have anything to do with it. It's the drivetrain layout that determines sway bar compatibility. For example, the GT2 swaybars both f/r are exactly the same as the GT3 bars. We know GT3 bars fit C2 models(have them on my car) so GT2 bars should fit. After all, they are the same part #'s. Secondly, if the M030 are indeed hollow then the 23.6mm sizing compared to the solid 23.1mm sizing of the normal sways, that to me would indicate a less effective roll resistance with the 23.6mm as you would need significant larger bar size given the hollow nature to be as effective as a solid 23.1mm. Do you know how much your hollow M030 bar weighs?

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the stock and M030 sway bars are both hollow, but the M030 bar is slightly thicker with a larger diameter... i have never heard of a NB with a GT2 sway, but I suppose it is possible. The GT2 shares suspension bits in addition to the chassis with the 996 WB / TT cars, but as you point out, the GT2 is RWD. I would be happy to be wrong as that would provide another sway bar option for me.

If your goal is getting better time on the track then get better tires before sway bars. Also it sounds like you have installed sport springs without upgraded shocks which is not the best idea for a DE car. I would rectify that before sway bars. Some cheap things as other said to dial out understeer is play with tire pressure and try to get as much camber in the front. Some toe adjustments help too. Bars does help stabilize the car making the driver feel more confident in the turns and it can be used to tune out over/understeer, but you have other things to take care of such as shocks and better tires hat would benifit you more.

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My row 030 has hollow swaybars. I didn't check the weight of the rearbar, but it is very light... There is more factors on the swaybars than just diameter, steel's do have diffrent tensilestrenght's And for the hollow vs solid, outersurface of tube/rod takes the most of the torgue. Closer you get to the center, less it resist's. So becouse of that, the hollow doesn't need to be much larger in diameter. To OP, stiffer front sway will make your inner tyre to lift easyer. So I would go with the rear sway first.

Correct rII. Stiffer front will lift inside wheel as disconnecting rear SB will do the same...

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When you guys say lift inside wheel, are you talking about front or rear?

The inside front tire. I dont see how you could cause the inside rear to lift.

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Ok, too early in the morning. I misread this an was a bit confused. In theory yes but in reality I guess it depends on other variables such as the tires you're using, spring rates, etc. It is not a guarantee that everyone will have inner wheel lift and this is important to point out. Another point to note is that some of the fastest guys on the track have inner lift which doesn't seem to affect them. Can they go faster with 4 wheels on the ground? Most likely but they have it setup where it suits their driving style and ultimately let's them drive their car faster around the track. Back to the OP, the only thing we know so far is that you have H&R springs which have a higher rate than stock. What we don't know is if you have stock shocks, sport package, tires, alignment specs, LSD, driving style(Jenson or Lewis? ), etc. So although we can discuss various theories, I'm not sure if any of us can make any concrete suggestions based on the little info.

Thanks everyone for the info. (Been a busy week and just now getting back to this.) I haven't upgraded shocks yet, though those are on the list as well. I am running PS2s and am not willing to go to track tires yet. My goal isn't ultimate grip/corner speed but overall feel and balance so I can continue to improve my skills. I now have a better understanding of how the sways affect the car--I hadn't been considering how the rears affect the front and visa versa. So it looks like I'll get a matched set rather than just one. GT3s definitely sound like the hot ticket, but they're out of my price range (unless I find a smoking deal on used ones). Basic H&R's with rear only adjustable might be the way to go for now. Pete--I'll keep a look out for used GT3s. I'm heading to Mid-Ohio with MORPCA in April. Are you going to that one? Thanks again for all the help, David

p.s. Definitely Jensen and not Lewis.

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Wow...53 signed up so far...including 3 Owens'. Thinking hard about it. Where are you staying? Never been there but have always wanted to go.

Hey Pete. You should do it--it's reasonably priced too! Kevin is my brother (don't know Scott), and he made hotel reservations. I'll find out where and pm you the info.

I decided to go with the gt2 bar up front instead of the eibach. Is anyone using the gt2 on front only? It should be here in a few days. Cant wait to try it.

KrazyK: Did you pick that up off ebay? I tried to buy a set of used gt2s on Sat, but got skunked on the front bar. I bid on the rear before knowing the front was sold. I hear you really should have a matched set for balance. Let me know if you need one...

Sorry, yes it was me.

PM me if you're interested in picking up the rear. I'd be happy to sell it since it'll just be sitting in my garage until I can find a matching front.

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Don't you have a c4s?

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Good point......GT2 = Turbo.......C4S = Turbo suspension.........yes?

Gt2 front sway bar is different from c4s front sway bar. 27mm vs 24mm. Will probably use the 24mm eibach for rear.

Forget everything you think you know! Stiffen the front and un-stiffen the rear. And change the stock struts to a minimum of PSS9's or 10's (for cost).. If you are running hard track then change the spring rates on the fronts of the PSS9/10. Or change the coilovers to XXX. However, the PSS9/10's are pretty good with replaced's front springs... Unless you are really into track and then you would want to replace your entire suspension.