2008: no more rear sway bar.

[shomesomesho]

I'm going to run this year without a rear sway bar.

After autocrossing this weekend in the cold bitter rain, I am reminded once again of the most common mode of wiping out in the SHO - no, it's not the front end pushing like a plow into cones, it's the rear end breaking loose culminating in a spin. A tailspin.

Even though she's running the smallest rear sway bar I could find in the (18 mm), the rear end is still too unstable for me to really be able to push this car as hard as I can. There's been this gnawing fear in the back of my mind that the rear will break loose, resulting in somewhat less aggressive driving and slower times. Slippery conditions seem to accentuate this weakness even more.

(For reference, last year's setup: coilovers 450/350, Koni's, 18 mm rear sb, no front sway bar; -2.6 deg & 3/16" toe-out in front; -2.25 deg & zero toe in the rear; 245 width tires)

Preliminary testing without the rear SB shows (subjectively) that the rear feels more stable, is less likely to spin, and actually feels faster through tight turns (since the rear tire aint scrubbing so much speed), without sacrificing too much of the car's ability to rotate.

So here's to planting the rear end, a more stable SHO, and faster autocross times. Bye bye rear sway bar, bye bye. :ciao:

Will let you guys know how it goes, but I'm feeling pretty optimistic about it already. :zoom:

 

[K-Dawg]

Plus, you lose some more weight. Good luck.

 

[NoSHOAllGo]

Sounds like a good set-up.

This is gonna be a stupid question, but is the sway bar also called a tower brace?

 

[greenbeanmtx]

Sounds like a good set-up.

This is gonna be a stupid question, but is the sway bar also called a tower brace?

Thats not a dumb question. A tower brace or strut tower brace is what physically goes from the tops or the strut towers and is a pipe or solid piece that connects them to add some ridigidy to the platform. It would be under the hood and in the trunk on a sho. The sway bars are underneath connects to the sides of the struts. -Karson

 

[sho_bc]

Hey Fred, I was just reading up on the Prepared rules cause I'll most likely be running Prepared next week (taking out my headliner to fix it up, may as well leave as much out as I can), and there's a whole lot you can do in that class that I had no idea about. How much room do you think you have left within the rules to max out the car's potential? Have you thought about removing the lights/harnesses, or trying to one-off some wheels that are wider and chopping up the fenders? Get yourself some 10" wide wheels!

 

[shomesomesho]

Ran this weekend without the rear swaybar. It was just a practice session so I could focus on tuning the car.

All I can say is. . .. WOW. What a difference. Rear stayed planted and I could really toss the car at will, and she would stay with me the whole time. Found that I could brake later into turns with more confidence, and I could really flick the steering through the slaloms without losing it. Didn't spin out once the entire 8 runs. All these benefits without significantly exacerbating understeer. For now, I think this is a setup I could live with. :sun:

I ran both morning and afternoon sessions. In the morning I ran street tires (Continental ContiSportContact3 245-40/17) and was actually beating a number of cars that I could only run with if I had R compounds on. The afternoon I ran R compounds (Kumho V710's). Interestingly, the Conti's were only about 1 second slower than the V710's.

 

[shomesomesho]

Hey Fred, I was just reading up on the Prepared rules cause I'll most likely be running Prepared next week (taking out my headliner to fix it up, may as well leave as much out as I can), and there's a whole lot you can do in that class that I had no idea about. How much room do you think you have left within the rules to max out the car's potential? Have you thought about removing the lights/harnesses, or trying to one-off some wheels that are wider and chopping up the fenders? Get yourself some 10" wide wheels!

Yep, you could pretty much do anything in Prepared except for forced induction. I'm almost at the weight limit for V6 sedans (2550 lbs.). You can always add more displacement. "There's no replacement for displacement."

3.4 or 3.6, anyone? Maybe in the future, as this car is definitely an ongoing project.

In terms of rims, I would have no problem chopping the fenders to run wider rims, just that I haven't been able to find anyone who will make them to our specs, without costing more than what the car is worth, plus an arm-and-a-leg. If you have any luck, let me know.

 

[sho_bc]

In terms of rims, I would have no problem chopping the fenders to run wider rims, just that I haven't been able to find anyone who will make them to our specs, without costing more than what the car is worth, plus an arm-and-a-leg. If you have any luck, let me know.

Just let me write up a group-buy feeler thread. I'm sure we'd have TONS of biters.

 

[K-Dawg]

Tires don't do any good when they are hanging in mid-air.

 

[Mike Kopstain]

Fred, Instead of removing the rear bar altogether have you considered adding a front bar to flatten the car out a bit and also neutralize some of that oversteer?

 

[shomesomesho]

Yep, tried that. Even with a teeny front swaybar, was getting too much corner exit wheelspin. (Car is Quaifed with coilovers.)

 

[Shoaz]

Something seems very odd to me about this.

Usually FWD cars get the rear stiffened up substantially to get it to turn, you're going the other way. And you had a wheelspin problem with the Quaife?

I'm wondering whether there's not a problem of some kind lurking somewhere, like a failing bushing in a strut rod or something?

Color me puzzled.

 

[dohcsable]

Something seems very odd to me about this.

Usually FWD cars get the rear stiffened up substantially to get it to turn, you're going the other way. And you had a wheelspin problem with the Quaife?

I'm wondering whether there's not a problem of some kind lurking somewhere, like a failing bushing in a strut rod or something?

Color me puzzled.

well, from experience of driving a cooper S, with a quaife, the wheels do spin at different ratios, so it is logical he's getting wheelspin....I think the quaife is a 1/3 ratio vs a torsen's 2/3 or it was something like that, I need to quit staying up all night.

SHOmesomesho, hope you do even better this year!!!

I really want to join in the fun, but I won't touch ground controls with a 10ft pole....I suppose I'm waiting to find real threaded bodied coilovers...

Andrew

 

[shomesomesho]

Something seems very odd to me about this.

Usually FWD cars get the rear stiffened up substantially to get it to turn, you're going the other way. And you had a wheelspin problem with the Quaife?

I'm wondering whether there's not a problem of some kind lurking somewhere, like a failing bushing in a strut rod or something?

Color me puzzled.

Yep, it does seem counterintuitive, but keep in mind the car has been lightened extensively (2600 lbs), and has fairly stiff rear springs (350) for the limited amount of weight back there (~950 lbs.).

The rear end is so incredibly light compared to the front (which is also fairly light), that the back end has no problem at all moving itself around. I also think due to the lack of weight back there, the rear tires never really heat up to optimum temp, especially given the short < 50 sec autocross sprints. Add to that the rear SB that tends to lift the inner tire in a hard turn (while trailbraking, with further weight shift forward), and you have even less rubber in contact with mother earth, and wham . . . tailspin city.

On warm sunny days, to minimize weight, I usually run with less than 1/8 tank of gas. On really cold days, the oversteer problem gets magnified (less heat to the rear tires, less rear grip), and to counteract that I'd fill the gas to about 1/2 tank and it would help some, although that probably slows it down a little in the straights.

Now with no rear SB, both tires stay planted, and there's more stability. The car still rotates quite well, but is more tolerant overall. I'm pretty happy with the way it behaves right now.

 

[somedude_001]

are you running a rear strut tower brace and or subframe connectors?

you did remove the factory tow tie downs on the bottom rear of the car right? I would imagine so being a gutted car but i'm just looking out for you

 

[shomesomesho]

are you running a rear strut tower brace and or subframe connectors?

you did remove the factory tow tie downs on the bottom rear of the car right? I would imagine so being a gutted car but i'm just looking out for you

Yep, has RSTB and SFC's.

No, hadn't thought about the tow tie downs. Great idea!

But wait, what am I gonna use to secure the car when I trailer it??

 

[SinisterSHO]

The one or two times I've put something on that tow tie down it bent

 

[sho_bc]

wrap the wheels down like tow trucks do?

 

[shomesomesho]

How bout this: