The great sway bar debate: Front or Rear

After much deliberation, I have chosen to stay in HS for the foreseeable future, mostly because my STX funds have been sent to Carnegie Mellon University. (no complaints, my daughter is a rock star!)

So that means that I will be trying to max the car out for HS. Lightweight wheels? Check. Lightweight lug nuts? Check. (I hear you snickering) 200TW tires. Check. Shocks? Check. Now it comes to the sway bars. I have Eibach front and rear bars on the car now, but can only keep one per HS rules. Common wisdom is to add a rear bar and keep the OEM front bar, it's a FWD car after all. But there are two things that give me pause.

One is the difficulty of swapping out the front bar. It's an afternoon to do it, not a deal breaker, but if I don't have to than why mess with it, all the better. The rear is 5 min without a jack.

The other is articles that I have read from folks like GRM writers and FiST drivers at Nationals that say a front bar is the way to go. From what I have read however, this is because it reduces body roll which is helpful for steady-state cornering like on a track or a big course like at Nationals. The downside is loss of traction to the inside wheel under acceleration when pulling out of a hard, tight corner...which is most of the courses that I run. Doh!

So what would the hive do? I'm swapping out the struts, so the front bar won't be too bad actually. I am willing to adjust my driving style (read: learn to corner properly) to compensate for either setup.

There is only one answer, test! Otherwise you are guessing.

I assume you're generally trying get rid of a tendency to push? If that's the case then you generally need more rear bar. YMMV

FWIW I know nothing about FWD CARS.

Anything to prevent the FiST from rolling onto it's roof. I hate to say it but as a safety steward the car that gives me the shivers more than any other is the happy little ford. Good luck finding the right bar solution.

In reply to KyAllroad:

Even on 200TW tires? I have been up on two wheels and came close to going over in my Mini, but I was running F500 bias ply Hoosiers. With regular tires, the best I could do is lift the inside rear tire. I've not driven an FiST, but like the platform from my various times in them as rentals.

https://grassrootsmotorsports.com/forum/grm/non-st-model-fiestas-banned-from-autocross/97668/page1/

I see more problems for the FiST as 200TW tires keep getting better and better.

T.J. wrote: In reply to KyAllroad: Even on 200TW tires?

Yes.

2 wheeling on Dunlop Z2s

TiggerWelder wrote: There is only one answer, test! Otherwise you are guessing.

Clearly, this! Of course, you could try swapping out the rear bar first and maybe you'll decide it's so awesome there's no need to muck about with the other end...

Could the solution be to disconnect the front bar and test it with just the rear bar? It wouldn't be actual auto-x ready testing, but it would give a feel for what the car would be like with less up front and more in the back. Then do the same on the other end.

Testing is the only way to be sure...there are ways to make a decent educated guess without swapping out bars a million times though.

How is the handling balance right now? Does it lift a rear wheel in the corners? How is your corner-exit traction right now? Do you think it has too much body roll at the moment?

If the rear bar is that easy, swap it for the stock one and see how it feels at an autocross. If you like how it does, keep it. Otherwise spend some time to swap the front. I agree that testing is the only way to be sure.

GameboyRMH wrote: How is the handling balance right now? Does it lift a rear wheel in the corners? How is your corner-exit traction right now? Do you think it has too much body roll at the moment?

These are good questions but they can lead you down the wrong path.

example: car balance is good, and it doesn't feel like it is rolling too much, but in truth the camber on the front and rear outside tires is going positive mid turn and the OVERALL cornering forces are much less.

bmw e36 is a great example - many people thought that it needs a bigger rear bar to decrease understeer, (and that works by reducing traction at the rear to match the front) but a much better solution is WAY MORE front bar to keep the front contact patches flat and therefore decrease understeer by increasing front traction to match the rear.

If I were op, this is what I would do:

1. swap rear back to stock.
2. Go to local autox where lots of runs are likely.
3. make a couple runs with upgraded front and stock rear.
4. remove one sway bar link in front to simulate upgraded rear and stock front (stock rear + no front is as close as stronger rear and stock front you will get without actually doing the swap).
5. READ TIRES, and LAP TIMES.
6. If lap times somehow do not plummet and tires are still reading ok, then I would look into upgraded rear and stock front testing. If they do plummet, I'd stick with the upgraded front.

The general wisdom of FWD is BF bar in the rear and little to no bar up front.

Since it's only 5 minutes, you should try at least one event with front only before committing to the front removal.

On my MKII GTI I ran the Shine Street suspension setup. Tall stiff springs, big rear bar, and no front bar. That car handled incredible.Very neutral and was easy to induce oversteer for drifting on course

My experience with my ZX2SR. Stock front bar and BIGGER rear bar. More negative camber on the front. More caster on the front. The Eibach springs and SR spec tokikos helped.

Fellow SER driver noted, "your car doesn't lean."

Note: on any strut car, lean is a bad thing.

FWIW, the car I drove at nats in 2015 only had Konis and wheels/tires. We just cranked the front shocks all the way up and about half way up in the rear. The car felt great and I beat every Fist there except for one.

The car owner had driven a Fist with a front bar and he didn't like the pushy nature and the fact that it had a harder time putting power down.

I'm sure it comes down to driving styles and driver preference, but I never felt the need to add a bar.

Generally, you want more bar at the non-drive end. But sometimes a poor camber curve and the corresponding need to reduce body roll can over-ride that.

Ovid_and_Flem wrote: I assume you're generally trying get rid of a tendency to push? If that's the case then you generally need more rear bar. YMMV FWIW I know nothing about FWD CARS.

See "testing" above. If the car corners on three wheels, adding more front bar will reduce understeer since it is keeping the tires flatter. Moreso if the front end is riding the bumpstop, adding front bar will actually make the effective spring rate softer on the outside front.

Once you lift a tire, adjusting the suspension stiffness differential is meaningless as you already have 100% weight transfer on one end.

Tried different combinations(3 fronts and 3 rears) on my supercharged 2001 Focus with complete SVT suspension setup. Ended up with the stock(non SVT) front bar and a 25mm Eibach rear bar. Stock front was the lightest of the fronts and the Eibach rear was the middle of the 3.

Great advice all. The issue with testing is that I can't actually test my two setups easily. I can take off the rear bar and run only the front, or disconnect the front bar and see how it handles with only a rear bar, but I have to actually swap the front it to test stock front with a rear bar.

I ran front only last year and struggled with traction out of corners, so I am familiar with that. When I swap in the Konis, I think that I will go back to stock front bar and keep the rear on. I will play with tire pressures and settings on the shocks, and after running that if I feel like I need a change, I have the front bar waiting.

If the local SCCA has a test-n-tune, I will be happy.

In reply to pinchvalve:

I've said this same comment before in every other thread like this, but on a car with similar architecture to older VWs(Mac strut front/torsion beam rear) you should at least research and consider a setup similar to what Jason Saini ran on his Corrado. I owned the car for a few years and it was simply amazing. The basic setup was the largest front bar possible, and custom-valved Konis with increased rebound damping, particularly on the rears. The front bar kept the car flat, while the rear of the car would still rotate.

With a bit of toe-out up front the car turned in very well, transitioned great, and was not twitchy. Yes, you had to have some patience on corner exit, but not any worse than any other open-diff FWD car. Although one significant difference between the Corrado and your FiST is the VW could get about 3-degrees of negative camber up front. Still, it's a setup technique that worked exceptionally well, yet few people seem to want to follow.

can you disconnect the front sway bar links with out removing the bar completly, that'd be the same as no bar then install the rear,also a stiffer spring on the side of the most turns make that tire/corner have more weight and more grip. this is where scales come in to play and a note pad write down EVERYTHING but a light rear bar is enough to keep the back Hung out /aka oversteer

rear bar with soft shock settings and front shocks turned rock hard is how i'd try it

I was taught that a Spring Holds the weight and a Shock Controls it's Movement, But I'm OLD and things Change.

P.S. a sway bar is also a Spring, think about it Like it' a torsion bar.