Sway bar or not?
Sway bar or not?
(OP)
I've raced IMCA Modifieds successfully for decades, both pavement and dirt tracks. I've NEVER used a sway bar on the car, front or rear. I look at the big hunk of steel (bar) and the added weight, so off they come when I buy a chassis. Am I wrong to dump the bar? What do I lose? I know the bar allows using the left spring rate to allow for a softer right spring, but is it worth the extra weight? In my mind, I just spring/shock the car based on tire temps, weight at wheel and wheel travel, and save the bar weight. Your info/advice is much appreciated, thank you.





RE: Sway bar or not?
Regards
Pat
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RE: Sway bar or not?
There's your answer.
I'm guessing that the mental effort of worrying about when to tweak the ARB and in what direction and how much might distract you from just racing with whatever car you have at the moment, and the weight savings therefore pays off.
... at least for you.
If you start losing, consider adding ARBs.
... or washing the car.
Mike Halloran
Pembroke Pines, FL, USA
RE: Sway bar or not?
But I bet you can't set up a typical road car without some front bar.
Cheers
Greg Locock
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RE: Sway bar or not?
articulation and, to a lesser extent, sway bars increase the chance of rollover if one experiences unwanted bit when drifting through a high speed corner. Now I believe that 7S and IMCA are different primarily because IMCA is not requiring 2 feet of suspension travel, and the terrain is nowhere near as unpredictable as in the desert racing world.
With all due respect to the previous posts- yes, one cannot argue with results, if you've been successful with your current suspension combination then you may consider leaving it as is. However, racing is not about remaining complacent with moderately good results (in my humble opinion). Sway bars can significantly improve the contact patch of the tire while cornering because it reduces the car from swaying like a boat. Your suspension becomes predictable and allows for fine tuning from one track to another.
That being said, the traction benefits a sway bar can offer far outweight the added weight to a 2,000-3,000 lb car. I say give it a shot, in the worst case scenario youll find that your first instict was right, but at least you fed your curiosity for a relatively low price.
Alex Esteves, Pasadena CA.
RE: Sway bar or not?
Pretty sure the ARB will decrease the available grip at that axle by transferring more load laterally. If he can live with a softer car in roll then no bar could be beneficial.
As someone else mentioned, the ARB is good for adjusting the roll rate distribution with changing tracks and conditions.
RE: Sway bar or not?
RE: Sway bar or not?
On race cars, any race car, the bars are their because they are just another tuning aid. If they were not necessary, trust me, they would not be there. If you are in a car that has acceptable cornering and transitional handling with springs only, you are the one that has the edge. Smooth tracks, big springs, fat tires...that's the ticket. However, in my little cars, smooth track is usually an oxymoron...I have a bar at the back of my Mini because otherwise I would need to dicker with toe out to get the darn thing to rotate into a corner under power and that makes powering out a problem. The bar corrects that little handling deficiency well enough. It can also be made cockpit adjustable to correct for little on track changes like less fuel or weather. Digging deeper into the question, what about putting a small damper as the connecting link of the ARB? It's done in some racing classes. Makes the bar "work" entering a corner but "go away" exiting. Just a tuning aid. Man, if I could do without one, I would!!!
Rod
RE: Sway bar or not?
The dynamic is stiff across the rear (less body roll) and little ARB or no ARB in the front give you a great sense & feel weght shift for steering with the throttle.
The rear being "loose" allows slide the rear turning in (less steering input) and to control that slide you apply throttle and transfer weight to the rear causing the tire to grip slowing the slip rate. This is modualted with the throttle. You are able to aim the car & throttle out of the turn sooner.
I removed the front bar & added more spring allowing the RT & LF to compress independently to manage weight shift balance front to rear. With this type of set up you must be on the throttle all the time in a turn or the cart beats the horse out of the turn.
You want about 30% to 50% less spring in the rear relative to the front to allow weight to swat the rear as the weight transfers on throttle up. Better dampening in the rear than the front.
RE: Sway bar or not?
track is only 8 deg bank, sweeping turn, so not a lot of side g's, but lots of speed around turns. I spring the car pretty soft.
only gotta turn left. about 60 pct left side weight, wheel travel on all corners I keep at about 2 inches..so there's not much body roll at all...car is nice wide track. With this info, If I follow some of the comments, seems like the sway bar is just along for the ride...extra weight. Likely why I've done fine without. With the additional info, I'd appreciate your comments, thank you.
RE: Sway bar or not?
RE: Sway bar or not?
The key is to understand the right 'numbers' for your tyres: aero balance, roll balance & weight distribution.
Regards, Ian
RE: Sway bar or not?
Regards
Pat
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RE: Sway bar or not?
RE: Sway bar or not?
Corollary to Murphy's Law..If a race car is infinitely adjustable, there is a 100% chance that something is always in need of adjustment!
AND...
Nothing is so out of adjustment that $$$ cannot fix. ;o)
Rod
RE: Sway bar or not?
Another jewel of wisdom.
Regards
Pat
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RE: Sway bar or not?
RE: Sway bar or not?
Someone mentioned F1 - did anyone else notice they run camber now. Maybe it's old news and I haven't noticed but it looked like 1.5 or so degrees.
RE: Sway bar or not?
Norm
RE: Sway bar or not?
Has been that way since 1998 at least...
Regards, Ian
RE: Sway bar or not?
Rod
RE: Sway bar or not?
I like the in car camera shots from above and behind the driver where you can see from the marking on the tyre, what part of the tyre is in contact with the road at what time and I dont remember ever watching the tyres on the straights with only 3/5ths of the tyre in contact with the road.
Maybe I am nuts or maybbe they just run more now.
RE: Sway bar or not?
BTW, based on the adjustable bars I have on one of my cars, adjustable bar stiffness steps would seem to be about 15% - 20% apart, or about the difference between 25mm and 26mm solid bars bent to the same shape. That's probably fine enough for most folks until they have a sponsor or two buying stuff for them. I suspect that your ride height change approach also tweaks the rear roll- or toe-steer, so it isn't just the LLTD effect you're getting.
Norm
RE: Sway bar or not?
This last year the Yokohama 032R tire that I normally use was out of production and I was forced back to the old Hoosier bias TD's. Just temporary as the radials are back on the shelf (thankfully).
One thing I noticed is that I tend to 'flat spot' the fronts a bit less often with the bias even though corner speed is down and I'm pushing a bit more to make up for it. The radial race tires are simply better overall. Ya just gotta pay attention to what your foot is doing to that brake pedal...;o)
Rod
RE: Sway bar or not?
Now, road sensing active suspension keeps my 14 yr old Cadillac very level in cornering & gliding as soft as a marshmellow at speeds under 40mph, its too soft but still corners level.
The anti sway bars are so tiny they really have no business being on a 3800lb vehicle with 4 foot of axle/body overhang on both ends. Its rather amazing the complexities that are employed in this suspension.
The struts are electromechanical-hydraulic valved & work off data from steering, ABS, powertrain, utilizing wheel position, wheel speed, accelerometers & yaw sensors. The strut valving operates in 3 states-soft, normal, firm. It is fully automatic and there are no settings.