Sway Bars?
 

Hi, just wondering, do you guys run with

a) stock rear sway bar

b) aftermarket rear sway bar

c) no rear sway bar

thanks

okay, which car? FB, FC or FD?

-bill

I'm running an FC with RB sways front and rear. They make a substantial improvement in body roll, but can be harsh if its your daily driver. The resulting chassis performance tends more toward oversteer due to the increased rear stiffness, but if you are running any decent tire, it should be progressive and controllable.

I'm building an FC for scca IT-s, thanks

Im most likelly gonna get a RB front bar, but ive seen a few people running ITS cars without any rear sway bar at all, and I was wondering if this was the norm amongst the FC people. Theres no use in buying an aftermarket rear bar if its gonna induce so much oversteer it slows me down. All in all what were your experiences with sway bars.......any input would be very helpfull and thanked!!

It's really tough to say. The sway bar interacts heavily with your choice in springs.

My ITS car started with 350lb front and 250lb rear with ST sway bars all around. Handling was balanced but the car leaned enough to need 5 degrees of camber all around to get even tire temperatures.

I upgraded to 450lb front and 325lb rear with the same ST sway bars. The car is still balanced and it only needs 3 degrees camber all around. (corner weighting is critical at high spring rates)

Some experts have recommended no rear sway bar with low rear camber. I have not tried that but I don't really understand the advantages of that setup.

Currently my car understeers mildly under acceleration and oversteers mildly under deceleration.

ed

designfreak,
no rear bar, 500/300 lb springs, Call Mike at ISC Racing for the front bar. a little toe out up front, a smidge of toe in rear. That should take car of it.

When you get that thing on the track, look me up.

Jim

This is a really subjective topic. It is very dependent on the track you are running on, how much travel you have, camber gains and bump steer you are willing to live with and driver technique. I can give you a couple of setups that I have run and the tracks that they work extremely well on. I run a data logging system that I use to validate actual corner G-forces, as well as suspension movement. I also compare camber settings/ toe settings to wheel spin and tire temps.

At Mosport, a really fast smooth track like Road Atlanta (avg. 89 mph+), I am running 550 lb Front - 400 lb rears (front crossmember 5" off the ground). The bars are RB front and stock rear with additional holes to stiffen the rear bar slightly. With this set up I almost run out of travel in the front and get a ton of rear movement, but still have about an inch of travel left in the rear. This generates almost 1.2g's steady and 1.4g's peak cornering load. Based on some outside video, for this year we are going to try a slightly stiffer bar set up.

For Shannonville a rougher tighter track (like Nelson Ledges, we run the car an inch higher, soften the rates to 400 lb front and 250 lb rear. Keep the RB bar on the front and no rear bar. This seems to work well, however I have had better feel in the rain with the front bar removed. This year will try stock bar in front to soften front.

These are my settings and toe tends to be very close to zero front and rear. Camber is dependant on suspension bushing compliance and type of tire. These work very well for me, however I am an old Formula A direct drive karter who really likes to "feel" what the suspension is doing and who prefers a nailed down nose and a slightly slidey (?) rear. I also run some effective aero that really helps in the fast stuff to keep the car nailed.

True on the Subjective bit. I guess I should have said that this is my set-up and it seems to work well for me. I'm getting about the same data as you on the smooth tracks and/or quck transitions. Slightly less on bumpy stuff. This is with Hoosier R3S04's on Florida tracks (Daytona, Sebring, Moroso).

I like the same feel you describe. Controlably loose. With the rear bar, the rear seemed to want to snap around, and was much harder to "catch". :bigthumb:

No issues at all. Suspension setup is very subjective. You know, someone could write a whole bunch of books on setup. I have a ton of seat time in many different cars and have found out that it really ultimately depends on what you feel comfortable with. What I like and what the data logger likes, you may hate as it either feels sluggish or nervous to you.

I am also really interested in that we both generate the same g's. I run Toyo RA1's and the only way I get there is with a monster splitter and a rear wing 12'' high off the rear deck. The WC cars also generate a max of 1.4 g's on Toyo RA1's as well with some (I will assume far more effective) aero. I will have to think about this a bit, but the Hoosiers generate as much side grip naked as I do/ WC does with a bunch more aero download. HMMMMM.

I have as deep a splitter as I can run legally. Stock rear spoiler. I'll see 1.0 to 1.15 in steady state, or even carousel type turns. On a quick transistion, I'm between 1.20 and 1.31 max. These numbers are pulled off a Pi System 2 traces. My numbers are slightly less, but similar. Maybe the Hoo's help make up for that big ole' splitter. (or maybe my Pi needs recalibrating..I've never compared it to other cars, just against myself)..

Jim

Like everyone said, depends mainly on your spring, and damper selection. I'm running Advanced Designs with 600ft/400rr, other rates I have are 700/450, and 500/275 for the bumpy stuff. I use RB bars, with the middle hole in the rear, and the inner hole in the front(been known to lift a front wheel on occasion) I have a huge splitter, and a huge wing combined with no other useful data ;) Car is fast, and easy to drive but I have not run it yet with the stiffest combo yet. 500/300 is a bit soft, but close to what AWR recomends for EP FC cars. I know other EP cars run with rates close to my higher rates. I run an unlimited class, thus the wing, and splitter. Carl

for Mosport, what length of spring you run with 550 front and 400 rear? what camber you set at?
what about for Shannonville?

thanks

I run 8" springs front and rear. This may not be of any help to you as I have modified spring perches on the front struts and rear shocks. My suggestion is to first determine how you are going to locate the coilovers on the stock struts, then determine the the free length of spring you require to get the ride height you want.

As to cambers, it varies depending on the tires (manufacturer) recommended range. As I have to run Toyo RA1's based on my series rules, Toyo recommends between 2 1/2 - 5 degrees negative. I try to keep my rates between these extremes and adjust according to temperature, conditions, track and length of race. I always check the camber against tire temperature spread.

thanks,

got any pic of your set-up?

did you lower your bottom perch? what about upper cap, did you move it up and closer to the tower?

thank again.

regards

oh by the way, I am also running RB front sway-bar and stock rear bar, and I am happy with this set up. and will try a second hole for the stock rear to see if there is any gain there.

I have lowered the lower spring perches down to the top of the spindle mount flange. The upper spring perch is a flat Bicknell 2 1/2 coilover top. The top mount butts against a camber plate that is 5/8" thick. This is all pretty standard for a coilover converted strut using camber/caster plates. Go to the ground control or tien sites and they sell the whole thing as one kit.

with your 400 front spring(8 inch too?), how much travel you have in compression in the front, do your car hit the bump-stop with your sway bar in 400 lb spring under braking and corner entry phase?

thanks for sharing info with fellow canuks,

Regards

Almost hits the bump stops with the Bilsteins. Pounded them hard with the Koni's. Seeing approximately 4 inches of travel in the front 5 inches in the back.

FWIW, with Konis/GC coilover kit, ran 450 (6")/275 (8") with 235-40-17s. This worked very nicely with the RB sways set full stiff front, and middle in the rear. The front rate really needed to be higher, but the Konis maxed at 500, so I did not up them. Jay(GC) stated that fresh Konis can handle 500, but older ones ought to be revalved. My new set-up with GCAD runs 8" fronts, and 10" rears. Rates were listed previously. Carl

There are so many factors involved with selecting the right swaybar. I am honestly considering going with a custom made fully adjustable one. I am sure it has been said already but car weight, rim size, tire type, spring selection, shocks alignment.... everything will affect each other. You might have to trial and error it.

I currently have the racing beats front and rear and I am seriously considering trying the stock up front and see what happens. If it helps with rotation I might get a custom one made so I can tweek it more.