The Project Pad

I'm currently running V3 coil overs. I'm not certain on the spring rates, but it does have the rear sway bar. With the 034 aluminum control arms I have to figure out a way to reattach it since the mounting points are a little different. I'm also considering adding a front sway bar. What is everyone's thoughts and opinions on sway bars? Best set up for track use?

Thanks,

Swaybars are good. Cars usually always like to be stiffer in roll than in ride, which sway bars allow you to do. That said, I've been too lazy to put them back on my car yet, and it has quite a bit of body roll even with 400lb springs, but handles really nicely aside from that.

Ideally, you'd want the front to be slightly stiffer than the rear. Running equal rate bars front and rear is nice for screwing around, but I think if you're going to track the car it makes the rear a *bit* too stiff...too much lift-off oversteer, etc. Running equal spring rates front and rear already puts the rear suspension frequency a decent amount higher than the front, it doesn't need to be much higher.

Anyways, I think what you'd ideally do is run the standard 26mm bar in front, and a 24mm bar (FWD 4k) in the back. Or you can play with motion ratios. For example; the control arm mounted swaybars have shorter arms and thus a stiffer rate relatively speaking. But, since they're mounted to the control arm, they move less than the wheel/strut does due to the lever effect, and thus the force applied by the bar for a given suspension movement at the wheel should even out to the 1:1 motion of the strut mounted swaybar.. I'm not sure if the two designs end up equivilent in rates if installed how the factory set them up, but I imagine they would be close. I've thought about playing with this to achieve different rates...attaching a strut-mounted swaybar to the control arm for a lower rate, or a control arm-mounted bar to the strut for a higher one. You may just look for different sway bars in a junk yard too and see if there is one that fits but gives you different sizing to play with.

Sam

Great question.

I've been considering this as well: my set up is v3's with strut mounted sway, using RS2 bar and forged CAs with delrin bushings.

Wanted to get a strut tower brace installed once I figure out my strut top mounts (likely K24R) but wonder if that's just going overboard with respect to bracing?

For the rear I'll be trying a front bar from a B7A4 2.0t because I have one laying around, if that doesn't work out I'll use a front 4kq bar.

I always see people talk about the strut brace and the sway bar like they do similar/same things, as I just saw a mention of it on MG the other day and was going to comment. They are completely unrelated in function and should not really be considered as complementary, although they both will affect the suspension and handling and overall 'feel' of the vehicle.

The strut brace is solely to keep the top of the towers in a consistent and stable postion with respect to the rest of the chassis, which will act to maintain consistent steering and suspension geometry while under the influence of forces, mostly the lateral direction by their design.

Also notable IMO, braces like the Jamex that have the major bend to clear the battery are garbage, as the stiffness is significantly compromised by the bend which will experience bending moments, allowing the ends of the bar to move more easily than a straight bar under pure tension/compression. I would never put a Jamex-style brace on a car. Generally, a car can feel more solid with the strut brace.

The sway bars are mainly, as Sam mentioned, to counteract body roll by effectively distributing a portion of the vertical load from the more loaded side of the car to car (typically outer when cornering) to the other less loaded side. You end up increasing the effective spring rate of a corner with the sway bars while under unequal side/side cornering forces.

You should always have a strut brace (or towers connected to the firewall, etc.) to maintain the optimal geometry. Sway bars will be more subjective, but unless running super stiff rates, most cars will benefit to keep roll under check.

I just measured and the strut bar my car had mounted in the back is the 22mm from the 4k. I have to cut the current strut bar bracket off because it completely blocks access to the nut to the tie rod. So what are the recommendations for best front and rear setup? Put 22mm on front and back or just the back? Or find the beefier bars?

Guys on S2F seem to like an RS2 front with a whiteline adjustable rear. I've been running with only a, stock 91CQ, rear and do not feel that it has significantly increased roll or made things too tail happy.

The only way I'd run bars is if they were adjustable. It's been a while since I've done anything with set up, but my memory is that you want it stiff enough to counter roll and fine tune, but not stiff enough to limit wheel travel (too stiff of a bar and you will limit travel and end up with the potential to lift a wheel off in corners). My car has only the front factory bar and 250F/300R spring rates, and I would love to have an adjustable front and the whiteline adjustable rear along with a step-up in spring rate.

As far as I can tell, the adjustability comes from extra holes in the mounting flange on the bars. What's to stop a person from drilling one hole equally spaced on either side of the OE one?

cuatrokoop wrote:The only way I'd run bars is if they were adjustable. It's been a while since I've done anything with set up, but my memory is that you want it stiff enough to counter roll and fine tune, but not stiff enough to limit wheel travel (too stiff of a bar and you will limit travel and end up with the potential to lift a wheel off in corners). My car has only the front factory bar and 250F/300R spring rates, and I would love to have an adjustable front and the whiteline adjustable rear along with a step-up in spring rate.

Other than $$$ there is not much stopping anyone from running a blade style system.

I don't believe there is enough room to drill new holes on the factory bars. But yes, Ed, time and money...

Seat cars are an essential fine tuning tool IMHO.

It all depends on the particular drivers preference for vehicle dynamics. For me I like a lively chassis ie I like to be able to Indy e under steer or oversteer at whim but I want the car dialed toward oversteer. Quartos are inherently unsdersreer pigs as that is 'safe'

Personally on my track car I run (will run as I am currently to stuff , gigity) 750f, 900r springs with Koni 8611 shocks with a lot of rebound dialed in

Fri t sway is 32mm rat is 27. Great in the dry, a little scary oversteer in the wet in R888 275s all rousing will drop sway bar size a little this year

Main target should be 7° castor

Are you running NASCAR/universal/blade bars Haydn or something adopted from the junkyard?

Sam

SEStone wrote:Are you running NASCAR/universal/blade bars Haydn or something adopted from the junkyard?

Sam

Right now just junk yard pieces.