FWD Oppos, Which Sway Bar Would You Choose?

"way2blu does a rev update" (way2blu) 04/19/2018 at 15:56 • Filed to: FWD, Autocross

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Image via Megan Racing

I’ll be autocrossing a FWD car soon. The stock SCCA class allows the addition of one sway bar, either front OR rear. What are the pros and cons of each? I may make the upgrade soon...

HammerheadFistpunch > way2blu does a rev update 04/19/2018 at 16:00

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its about the front to rear balance. Typically speaking you want the front to be lighter than the rear for oversteer in FWD cars, so ideally you would change the rear bar. but it depends very much on what car and how its setup.

MR2_FTW - Group J's resident Stig > way2blu does a rev update 04/19/2018 at 16:00

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With a front wheel drive car you’ll almost certainly want to upgrade the rear bar.

LongbowMkII > way2blu does a rev update 04/19/2018 at 16:05

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that’ s a strut bar pictured

bhtooefr > way2blu does a rev update 04/19/2018 at 16:05

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Most likely, the car has a front bar already, although not as stiff as aftermarket.

So, go out and thrash the car some.

Disconnect the front bar, and thrash it some more. Ignore the body roll, pay attention to the handling balance. Feels better? Connect your front bar back up and put a rear bar (or a stiffer one if you already have one) on.

TheTurbochargedSquirrel > way2blu does a rev update 04/19/2018 at 16:07

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You are going to want a beefy rear sway bar to loosen the car up. The stiffer rear bar really helps it to turn in. Heck, the fastest guy in my region doesn’t even run a front bar.

Highlander-Datsuns are Forever > way2blu does a rev update 04/19/2018 at 16:08

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I would think with all the weight on the front of the car you would want the upgraded sway bar on the front. Maybe just do solid end links on the rear?

LongbowMkII > LongbowMkII 04/19/2018 at 16:09

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or not. its an odd looking thing. swrut bar

Ash78, voting early and often > bhtooefr 04/19/2018 at 16:16

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Good advice. I had my front sway removed for a couple years and the handling was amazing (like you said, once you get over the body roll). But you lose some ability to change direction quickly due to the suspension travel and rebound, so I’d lean toward adding a rear bar for autocross...

ITA97, now with more Jag @ opposite-lock.com > way2blu does a rev update 04/19/2018 at 16:25

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You’ll almost certainly want a bigger/stiffer rear sway bar to induce the car to rotate more on turn in, especially since autocross is all about how the car transitions.

Also within the rules, a trip to your alignment guy will yield results. If you can live with the tirewear on the set of tires you drive to work with, most FWD autocross cars at a serious level are setup with some degrees of toe out up front. It’ll cost tirewear and the car will want to hunt a lot more on rutted roads and less than ideal pavement, but turn-in is so much better with some toe out.

LOREM IPSUM > way2blu does a rev update 04/19/2018 at 16:44

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Thickest bar you can find on the rear. Be warned though, lift throttle oversteer is a thing. If it is street driven and you pitch it into a curve a bit too quickly and lift off of the go pedal, things are going to get ugly. By ugly I mean sideways, then backwards, maybe forwards again, and probably into something.

MR2_FTW - Group J's resident Stig > LongbowMkII 04/19/2018 at 16:53

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It’s probably for a twist beam rear axle FWD car like a Fiesta or Fit or Corolla.

SmugAardvark > way2blu does a rev update 04/19/2018 at 16:54

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It varies on the car. But like others have suggested, a FWD car will tend to see more benefits with a stiffer rear bar. In fact, many many years ago I had a Cavalier with a 25mm rear bar, which was enough to easily lift a tire through turns, and even resulted in a couple instances of looping the car on track until I got used to it.

Little Black Coupe Turned Silver > way2blu does a rev update 04/19/2018 at 17:03

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Drive it first stock, see how it does. Probably will want a bigger rear bar through. Do some research into your specific car and see what other people are doing.

the right pedal > way2blu does a rev update 04/19/2018 at 18:14

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Bigger rear bar, helps lessen understeer

way2blu does a rev update > Little Black Coupe Turned Silver 04/19/2018 at 19:23

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It’s a current-gen Honda Fit (with the compact but rudimentary torsion beam rear suspension) so it’s not as fancy as the Fiesta STs that dominate the H-Street class for SCCA. I’ll run it stock this weekend and then see what can be improved for next time.

way2blu does a rev update > Highlander-Datsuns are Forever 04/19/2018 at 19:24

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That’s fair, the Honda Fit I’m driving has a pretty simple torsion beam setup for the rear suspension so there’s not much to change back there. I’ll look at front options after this weekend’s event for sure.

way2blu does a rev update > HammerheadFistpunch 04/19/2018 at 19:27

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Hmm. Would the rear bar help with oversteer on a torsion-beam rear setup? It’s a 2015 Honda Fit. (first year of the current GK generation)

LimitedTimeOnly @ opposite-lock.com > ITA97, now with more Jag @ opposite-lock.com 04/19/2018 at 19:31

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Even going to zero toe helps. That is where I am set up currently.

way2blu does a rev update > TheTurbochargedSquirrel 04/19/2018 at 19:31

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I take it most FWD cars are set up for more of an understeer bias from the factory? The biggest rear sway bar I can find is a 17mm one from Megan Racing (pictured above).

way2blu does a rev update > bhtooefr 04/19/2018 at 19:35

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I’ll have to try that out. Body roll shouldn’t be too much of a worry. I learned to drive on a ‘65 MG Midget with body roll for days, and it cornered brilliantly :D

way2blu does a rev update > LongbowMkII 04/19/2018 at 19:36

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As MR2_FTW said, it’s for a torsion beam setup. My ‘15 Honda Fit was the first year they moved to that setup for increased interior space. Torsion beams are rudimentary (and not great for handling) but super compact.

way2blu does a rev update > ITA97, now with more Jag @ opposite-lock.com 04/19/2018 at 19:38

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I hadn’t considered alignment changes, but that might be very helpful. Thank you!

way2blu does a rev update > LOREM IPSUM 04/19/2018 at 19:39

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I have a ‘91 Toyota MR2 that I’ve autocrossed as well ;) I’m very familiar with lift-off oversteer...

bhtooefr > Ash78, voting early and often 04/19/2018 at 19:39

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Yeah, I just suggested it for illustrating what a rear bar will do.

“This, but with LESS body roll, instead of more body roll.”

LOREM IPSUM > way2blu does a rev update 04/19/2018 at 19:54

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Oh hell yes you are. Haha.

Just lookin’ out, but you’re all good. I put a 25mm Ground Control rear bar on my ‘00 Si(r) which I got used not long after they discontinued them and maxed them at 22mm for that application. Tight offramps and roundabouts and whatnot were a hoot, but it could get really sketchy really quickly which is never really great on the street. Probably why they discontinued that bar, but still fun as hell and glad I got my hands on one.

TheTurbochargedSquirrel > way2blu does a rev update 04/19/2018 at 20:03

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FWD cars have an inherent tendency towards understeer.

Highlander-Datsuns are Forever > way2blu does a rev update 04/19/2018 at 21:30

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I have never raced a front wheel drive car, all my experience is 1970’s Datsun Z cars. They have really thin anti roll bars so that’s the first thing you do.

ITA97, now with more Jag @ opposite-lock.com > way2blu does a rev update 04/19/2018 at 22:48

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No problem. If you can get a degree or two of negative camber at the front (and maybe a degree or so at the rear) within the factory adjustment range, that’ll really help overall grip within street class rules also.