Rear Sway Bar Delete

[SCFD]

I'm new to the platform and need a bit of help deciding how to setup my car for next year as a dual purpose SCCA D Street and time attack car.

Rules allow for 1 bar change so my original plan was to pick up a Hotchkis FSB and run it on the softest setting. However, I recently started leaning towards deleting the RSB after encountering inside rear tire spin a few times.

As a stock car, I feel like the BRZ already has pretty good roll resistance where I might be able to get away with removing the RSB. Any feedback on how the car performs with either setup (bigger front bar vs deleting rear bar) would be appreciated.

Planned mods:
OEM crash bolts, 0 toe all around
225/45R17 200TW tires

[DarkPira7e]

Removing the rear is fine I removed mine in winter to help with snow and ice traction. Didn't notice too much until I put the 200tw tires back on

[strat61caster]

Front stiffness helps the car transition more quickly in slaloms and a little help in terms of reducing camber loss due to body roll in steady state. You can try no rear, I have, but I don't think it helps as much as a stiffer front.

[ZDan]

For a street car, stiffness is OK. For track, stock suspension is way too soft. I'd go the stiffer front-bar route and keep rear bar. And anything you can do to get more front camber would be for the best... I don't think just camber bolts will get you where you wanna be. CAn you run offset top mounts or camber plates?

[ML]

shits gonna push (understeer)

[steverife]

Frankly, rear bar delete on a stock sprung car sounds awful.

You won't be able to reduce camber loss and you are giving up overall roll stiffness, both of which are at a premium in Street. Additionally, I think you would introduce some nanny interference weirdness.

With that said, it is free to try (outside your time to disconnect/reconnect and your opportunity to try/learn something else during those runs), so go for it.

[norcalpb]

Originally Posted by steverife

Frankly, rear bar delete on a stock sprung car sounds awful.

You won't be able to reduce camber loss and you are giving up overall roll stiffness, both of which are at a premium in Street. Additionally, I think you would introduce some nanny interference weirdness.

With that said, it is free to try (outside your time to disconnect/reconnect and your opportunity to try/learn something else during those runs), so go for it.

I’m curious about this, aren’t the trailing arms responsible for holding camber steady in the rear? I’ve always been under the impression it was just macpherson that had camber loss problems.

[steverife]

Originally Posted by norcalpb

I’m curious about this, aren’t the trailing arms responsible for holding camber steady in the rear? I’ve always been under the impression it was just macpherson that had camber loss problems.

I was speaking to camber loss at the front of the car.

You are allowed one bar change, so by focusing on the rear bar, you are giving up the opportunity to run a larger front bar to minimize camber loss up front.

[ZDan]

Also note that by reducing rear roll stiffness, you're going to get more roll at the rear *and at the front*. Since it sounds like you're gonna be very front-camber-limited, that's not so good. Much better to INcrease front roll stiffness which will reduce front camber loss.

FWIW I've never had serious inside rear wheelspin issues at the track with ~60% stiffer lowering springs and stock swaybars, on RE71Rs. I do get some rear wheelspin out of some lower-speed 2nd gear corners but always both rears.

[strat61caster]

Inside rear wheelspin on Street class ax setup sounds like a lead foot overwhelming the torsen, won't be able to do much to fix that without going up to STX and getting a clutch type diff. You'll have to change your drive style. That being said unhooking the rear bar is free so just go try it before buying a front bar and see if you like it.

[SCFD]

Thanks for all the feedback. This reminded me of a setup I previously ran on a FWD car without a front bar. The car was sloppy even with quite a bit of toe-out and heavy springs (suspension frequency of ~2.2Hz).

I think running no rear bar on the BRZ will probably hurt more than help.

[norcalpb]

Originally Posted by steverife

I was speaking to camber loss at the front of the car.

You are allowed one bar change, so by focusing on the rear bar, you are giving up the opportunity to run a larger front bar to minimize camber loss up front.

Oops sorry, misread that!