Rear sway bar

[biggels_7]

Hewy guys just after some advice i was wondering who here runs a rear sway bar and if so has it made any improvements on the way the car turns it or does it cause more over steer. Ive heard so many conflicting stories from people just would like some more input before i look at going down this track

cheers

Richard

[d240zx2]

My experience, though limited, shows that a rear bar does increase oversteer a bit. My bar is 3/4" (which may be a bit heavy) and a smaller one might not be as severe. I had originally set the car up for Auto-X back in the '70s and it really helped there, but on track days, it can get a bit squirrelly as the speeds are considerably higher.... makes you pay attention, I'll tell ya!

[hogie]

I am hoping to hear that there isn't much point in adding one. My car came with an MSA rear bar, but none of the hardware and they want $60 bucks for that.

[tlorber]

"Only 2 things scare me, and one of them is Nuclear War". Austin Powers

The other is understeer (I added that part). That's reason enough to put the sway bar in.

[LeonV]

No, you don't need it, but as alluded to it will increase steady-state oversteer by changing your roll stiffness distribution. FYI, the US-spec 240Zs didn't come with a rear bar. It all depends on what you use the car for.

[jmortensen]

Two basic theories on sports car suspension:

1. Run soft springs with stiff bars

2. Run stiff springs with soft bar, possibly no rear bar.

The stock Z is set up with very soft springs and no rear bar. If you want it to handle you really need to control the roll, as you lose negative camber with body roll. For a street car, #1 is probably the way to go, so that means bigger front and rear bars, and in all likelihood stiffer springs as well, since the Z was undersprung from the factory.

[Jeff G 78]

My 260 has a huge rear bar to go along with the large front bar. A normal aftermarket bar set is 1" F and 3/4" R. My front is 1", but my rear is a bit over 1". The car is neutral, handles very well on the track and is super easy to control at the limit. YMMV.

[hogie]

Hopefully, this isn't too far off of the topic. Are Tokico drop springs with an MSA front sway bar considered stiff enough to fall into option 2?

[jmortensen]

Hopefully, this isn't too far off of the topic. Are Tokico drop springs with an MSA front sway bar considered stiff enough to fall into option 2?

Option 2 is more for race cars. The Tokico springs are not nearly stiff enough to control roll by themselves, and adding a big front bar with no rear will lead to even more understeer. Nobody says you "have to" do any of this, but if you just want to get Tokico springs I would suggest you either leave the front bar alone or get the aftermarket front and rear bars.

I am not a big fan of the Tokico springs though. Do a search and you'll see lots of people who have the front springs nearly coil bound.

[Jeff G 78]

I am not a big fan of the Tokico springs though. Do a search and you'll see lots of people who have the front springs nearly coil bound.

Just to be clear for future searches, only the 240Z Tokicos are progressive and have the issue mentioned. The Tokicos are linear for 280Zs and don't have the stacked dead coil issue.

[hogie]

Well crud, the cars also already had tokico springs on them. There is an autocross in a couple weeks, maybe I will actually get a chance to push it hard then.

I have heard that the coils can bottom out on the highway, but I havent experienced anything bad yet.

[biggels_7]

thanks for the info guys ,im running 280 lbs rear springs and 200lb front springs and do track and motorkhana days as well has club cruises but i suffer shocking understeer on the motorkhana tracks maybe its worth a try to run one an see what happens