Rear Sway Bars, who has run without them

As the title says, I read a while back the DAL? racing notes as I am sure some of you have as well and I am pretty sure from memory they ran without the rear bars and noticed no real difference to running with a rear sway. Most people here myself included run with a lighter rear bar on the softest settings or keep the OEM one and go as big as they can or want on the front.
So my question is has anyone run without a rear bar entirely, the Porsche guys over here do all the time especially in damp conditions so it is a lot more common than I thought.
Anyone with any experience on this care to comment

notes for those that haven't read them item #6 talks about sways https://web.archive.org/web/20110310192308/http://www.dalmotorsports.com/cars.asp#Sway Bars

Remember, he was tuning with R compounds and huge camber numbers up front and unknown spring rates on his Motons. I have never tracked without the bar myself; and it may be the best set up in certain situations.. just keep in mind that Your mileage may very from his. A cheap simple way you can find out for sure is to log tire temps using a tire probe type thermometer. Once you have collected sample data try running without one and chase the balance using spring rates first, then air pressures. I bet you can find something that will make it work.

I have always used a rear bar, but if memory serves certain purpose built track cars with 1200-1000 front springs and slicks also did not use them...vassos built a car like that and I think old #42 ran without one.

yeah interesting, I will try a few setups when I get my car back on track and compare but was curious as to anyone here trying this since those days.
I am not running R comps as the class I am in next year is street tires only no semis allowed so my NT01's have to go and I have upgraded to heavier springs recently and that has helped my lap times cant see myself buying Motons anytime soon tho...

Interesting discussion, my progression with the NSX has gone from soft stock setting to an ever increase in stiffness of the chassis and suspension. As I've turned up the power meter, I've turned up the stiffness. Now that I've pretty much maxed out the power, tire/wheel width and spring rates, I've backed off from Dali Trophy bars to Dali track bars. The more experience I acquire with this car, the less compliance I require. With my latest round of power upgrades I very well may have reached the tipping point in that regard. I never track in extreme conditions wheather they be wet or extreme heat, barring the rare afternoon rain shower.

I tracked my car once with the equivalent of no rear sway bar given that the mechanics had forgotten to bolt one of the clamps...
The car felt very loose from the rear and I noticed immediately that something was wrong.
My setup was Bilstein shocks with Zanardi springs and 22 mm Dali bars on the middle hole.
I also remember the difference between my Porsche 944 S2 with no rear sway bar and my 968 CS with a rear sway bar.
Gone was the understeer so as the body roll.
I don't understand why many Primers drive with such strong front bars and don't seem to understeer???

The Real Time Racing And Honda R&D Pikes Peak NSXs both do not have a rear sway bar. Like what Will said, maybe it just works with some set ups.

RTR


Honda R&D

I use a Dali track bar in the front and no rear bar.

'94 alignment specs
Kumho Ecsta V720 tires, '92 OEM sizes
10kg/mm front springs, 8kg/mm rear springs
Small (1") front splitter with a ducted hood and blocked AC vents, massive exhaust-blown rear diffusor
OEM LSD
400 ft-lbs of torque at the wheels for instant vehicle rotation <--- That might be the key for all the vehicles running without a rear sway!

CB72 said:

Gone was the understeer so as the body roll.
I don't understand why many Primers drive with such strong front bars and don't seem to understeer???

Click to expand...

I don't either. I am understeering with 850/500# springs. Roughly 13/10KG front/rear. dali front track bar in stiffest setting, OEM rear bar which is basically a Zanardi bar in an 05 car. 225/40/18 front and 275/35/19 Pilot super sports. I understeer. I really feel I need more rear bar. I am baffled about the DAL motorsports "no front bar is thick enough" comment. It was the basis of doing what I did but the result is fairly heavy understeer.

I run a Dali front track and Zanardi rear bar on 9k front and 7k rear springs. Since the OSG LSD 1.5 install I'm fighting some on-throttle understeer. There's a lot more grip in the back and the car is more sensitive to throttle steering in general, both on accel and decel. It takes some getting used to.

I am leaning towards a heavier rear bar and or a less front biased spring setup.

After the various setups I've had on my car I really can't comprehend not running a rear bar. My brain is too small

- - - Updated - - -

Btw... It hasn't bothered me as much because my JRZ dampers seem to have enough range to counter balance the understeer with damper adjustment. It felt better at Sears Point last wknd but I still prefer to have some more front grip. I think I need to sort out my front camper issues first. The alignment shop was only able to dial in -1.7° up front this time.

My front camber is around -2.3 I think. I wonder if the OSG would improve over an 05 diff. I keep reading the diff differences and I forget again. I know the 05 diff is different than the early 90's ones.

TURBO2GO said:

My front camber is around -2.3 I think. I wonder if the OSG would improve over an 05 diff. I keep reading the diff differences and I forget again. I know the 05 diff is different than the early 90's ones.

Click to expand...

I usually get -2.3° but I went to a non NSX shop so...

The difference with a OSG LSD is substantial especially under forced induction. I should have done it 10yrs ago.

I've run both an OS Giken 1.5 diff and the OEM 5 speed dif upgraded to NSX-R specification.
There's not much difference in terms of roadholding in my view except of course when the diff really locks under acceleration and pushes the front out.
I believe that those who run with very little rear sway bar compensate with lots of rebound damping in the rear.
This decreases the body roll when initiating the turn just like the sway bar would.
Of course the action is only temporary but probably enough to load the outside wheels.
Those of you who can adjust the rebound damping might try this out?

Talking autox setup so take it for what it's worth. I'm running the Dali 1" front/rear bars. On 650f/550r# springs I test stock bars. Then went to the 1" rear bar and I had oversteer everywhere, way too much. Threw the front 1" bar on and the car became more neutral. Both bars on their softest setting. Will likely leave the rear on softest and need to test the front bar adjustment. I think front bar with middle setting might give me the best balance. Right now, I can throttle rotate/pivot around cones with ease, so setting up for exits works out really well. Car is putting power down well.

Anyone consider that maybe some of these known track cars aren't running rear bar but with high spring rate compensation to possibly help allow better contact for rear grip?

Also taking alignment into consideration... running -2.1* camber, max caster and 0 zero toe front. -2.5* and 0.15* total toe rear.

Dry grip and rotation is phenomenal now that I'm a lot more confident with the car.
https://youtu.be/r519AlY2Fm8

Wet grip on oily slick pavement is just laughable...you'll see my nice spins
https://youtu.be/ocKtbmEi3S0

^ nice videos I must get out on a carpark one day and some of that fun
I now run a 657/457 spring rate and recently installed the OSG my OEM diff had the type R pressure washers in it and I noticed the difference when exiting the corners and I'm only NA, mind you its a 4.4 final drive so I should feel something.
My camber is -2.5 with the comptech kit and I have played with my rear rebound a lot and I think I am 2 clicks off full but better check that before confirming and with my new homemade splitter I am not pushing the front through the corners at all its more the rear I want to work on, after discussing this with a couple of race car drivers they said to try it without the rear bar, we also just fabbed up a new exhaust ourselves and thought it would be easier without that bloody bar in the way.

You're confirming what I thought: Rear rebound damping can substitute for less sway bar.
Another advantage is that the car should be safer (more understeer) under slippery conditions.
I believe many of the Lotus cars came with no rear sway bar.
Was it only to reduce weight and cost or also to help reduce wheelspin with an open diff?

What are everyone's rear toe settings?

I'm running a toe at the rear of
0°13' on eitheir side or a total of 0°27'
The rear camber is -2°21' on one side and -2°44' on the other
The camber upfront is -1°54' on one side and 1°46' on the other.
The toe upfront is -0°07' and -0°08'

Some takeaways based on my car's setup. YMMV

* I tried 0 toe in the rear. It felt really wobbly/loose under hard acceleration at turn out. I basically hated it. I'm at .75-1mm of total toe in in the rear. I think I need more. Maybe 1.5-2mm total toe. [MENTION=25108]illwillem[/MENTION] is ridiculously fast with zero toe so goes to show how good of a driver he is!
* With the JRZ RS Pro's i'm starting to prefer an even softer spring setup. My old setup on the DG5s were 9k/11k. Then when I first got my JRZs I ran 11k/9k. Now i'm at 9k/7k. I'm considering running 8k/8k or even 8k/7k to go softer still. Letting the damper do its work is really confidence inspiring. Things happen so much slower and the mechanical grip really shows. The extra range they provide helps with setup issues at the track too. I found adjusting sway bar or spring settings was unnecessary. Would love to know if anyone has tried JRZs and KWs back to back.
* The OSG 1.5 LSD has changed the behavior of the rear end. Even at partial throttle I can feel the rear's influence on the front end. On-throttle i'll get mild understeer then quickly off-throttle i'll experience the rear want to come around similar to the feeling of trail braking or having too much rear brake bias. It's all very controlled and confidence inspiring but requires some getting use to. I think stiffer rear springs or perhaps more rear toe in would help. I'm not sure if this is a sway bar issue or a spring issue. Feels more like a spring issue since there's a lot of squat when I put the power down? This is where my lack of setup experience really shows.

I routinely removed mine, as I've always overpowered the car and as a result, removing the rear sway helped to settle the rear of the car.

Cody@LoveFab said:

I routinely removed mine, as I've always overpowered the car and as a result, removing the rear sway helped to settle the rear of the car.

Click to expand...

so more power was the catalyst for removal

- - - Updated - - -

Mac Attack said:

I use a Dali track bar in the front and no rear bar.

'94 alignment specs
Kumho Ecsta V720 tires, '92 OEM sizes
10kg/mm front springs, 8kg/mm rear springs
Small (1") front splitter with a ducted hood and blocked AC vents, massive exhaust-blown rear diffusor
OEM LSD
400 ft-lbs of torque at the wheels for instant vehicle rotation <--- That might be the key for all the vehicles running without a rear sway!

Click to expand...

so what made you decide to run without the rear, too much power based on your last comment

I initially took it off about six years ago when I started designing my naturally-aspirated exhausts and needed the layout space:
https://vimeo.com/user1744194

That need for space carried over to my current semi-sequential twin turbos.

Mac Attack said:

I initially took it off about six years ago when I started designing my naturally-aspirated exhausts and needed the layout space:
https://vimeo.com/user1744194

That need for space carried over to my current semi-sequential twin turbos.

Click to expand...

Holy Sh*t.. was that really 6yrs ago! How time flies

Yes it does....

Have you worked on your trail-braking? Reduced rear toe-in? Played with a front splitter?

The OSG is nice, but made it worse with your power level, right? With the power level I'm at now, I would certainly benefit from one on the track at corner exit, but I'm not ready to loose the civility around town.

You control roll with the end opposite your drive wheels. The Elise has similar corner-exit understeer issues as they have a front ARB from the factory but no rear. The general consensus for them is trail-brake or go for more power.

My $0.02.

Dave

Still playing with all those things

Though, in all honesty there have been no drawbacks to the LSD. There's been zero noise going slow or fast. If anything I have to have more control of the throttle. If I'm midturn accelerating can induce understeer. Decelerating induces what feels like trail braking situation. It all happens very slow and controlled. It's been more of a learning experience than maybe a setup flaw. I still have a lot to learn! Maybe I can fast track my learning ramp up if someone more experienced can drive my car and give me feedback. For now it's still a fun journey.