FIA Sway Bar Rubbing

[Historic Hp]

Have any ERA Cobra racers experienced tire rubbing on the front sway bar? I started racing my FIA (chassis #2150) this year at BIR in Minnesota and at Blackhawk Farms in Beloit, and visually noticed the rubbing on both sides after the first race. I’m running the normal 26.5 x 8 x 15 Billboards on the front, giving me about two inches clearance between the tire and the sway bar at full lock.

Seems like a lot sidewall flex to contact the sway bar, considering I’m not anywhere near full lock on even the tight corners. I’ve tried increasing tire pressure in small increments from 23 up to 32 lbs, with only marginal improvement. The sway bar is ERA standard issue, and fits fine.

Any other ERA Cobra racers out there experience this? I know I can run a skinnier tire, but it sure seems lots of guys are running the same tires I am.

Thanks,

Don

HistoricHorsepower.com

[1795]

Have not raced an ERA, but on my vintage MGB race car I went to solid aluminum sway bar mounts, as the rubber mounts can allow for more travel of the sway bar on hard corners. Also, check the mounting bolts for the rubber mount to make sure that they are tight.

would be interested in hearing what others who have raced an ERA have to say.

[DanEC]

I certainly don't have any racing experience and wouldn't mislead anyone on that. I suspect the contact comes from when the suspension travels up and down - probably when the suspension is compressed in a hard corner the tire camber change and arc of the a-arms moves the tire closer to the bar would be my guess.

[1985 CCX]

Looks like you are using billboards.
They may be too big for 289.
I run 427 BB fronts on my rear.

[Historic Hp]

Yes, they're Billboards. ERA recommends 235/60-15, so the 26.5 x 8 x 15 Billboards are a bit taller and about 1.5 inches wider than the recommended tire. I'm sure the smaller tire would make a difference. I'll probably have to give it a try.

Anyone racing an ERA FIA running 26.5 x 8 x 15 Billboards?

Thanks,

Don

HistoricHorsepower.com

[ERA2076]

Don, a couple of things. As already stated, the the swaybar can walk in the bushings depending on suspension movement. You can purchase nylon split collars from McMaster-Carr to trap the swaybar against the bushings. I had this problem off roading a Wrangler and we used the clamps to correct it. We have since added them to our SN95 track car.

https://www.mcmaster.com/#split-shaft-collars/=163hzxg

The original cobras ran narrow wheels compared to section width. I would not want to run 1 1/2" difference between the section width and rim width on a track car. The car is going to drift thru the sidewalls. If the class you are running allows it, it would be nice if you could get it down 1/2". If I could not get a wider rim I would opt for a narrower tire. Either way I would want to stiffen that system.


chr