This topic is inspired by comments from shelbydoug and zray in the thread on “Recommendations on Street/Track Tires”.
"........Also, regardless of what the factory did with the Boss 302's, a rear anti-sway bars on these cars is a no-no. ......."
I have yet to see a rear sway bar (on a 65/66) that actually helped anything.
My input seemed to be a bit off topic there, so I thought I’d start a new and more generic one. Since many Shelby owners are unmotivated to modify their cars in this manner, I thought it more appropriate to put this in the Replica/Tribute section.
I autocrossed my 65 Fastback in the 80’s/90's and it initially had stock-suspension with the classic vintage Mustang understeer. It was, by far, the oldest and slowest Mustang in the class.
One of the club guys suggested I contact a “vintage” Mustang racer that he knew in California by the name of Frank Stagnaro and gave me his phone number. I didn’t know him from Adam. One evening, I called him out of the blue. He was very gracious and over next 2 hours, he gave me tons of info – much of which I had insufficient background to appreciate. Note that Stagnaro’s car was (and still is) technically light-years ahead of mine.
Based on his suggestions, I made a number of suspension changes: Shelby/Arning drop, stiffer/lower front & 4.5 leaf rear springs, bigger front bar, 5/8” rear-bar, Panhard rod, Koni shocks and of course, better tires. I know I should have made changes one at a time, but then again, in autocross, you don’t have a consistent track to quantify the changes.
The car performance improved considerably and the balance went from understeer to oversteer. The changes didn’t shoot me to class champion, but I was thankfully now less slow and almost mid-pack. (Driver skill is likely a constraint here
) It’s difficult to conclude that the rear anti-roll bar is responsible for the oversteer, but I’ve heard from several sources that it definitely contributes (as the gentlemen above have inferred). The biggest benefit (for me) is that driving an oversteering car is a hell of a lot more entertaining than an understeering one, if not necessarily faster.
I’m currently completing more upgrades to the car, aiming for better balance. Adjusting/disconnecting the rear bar will be one of the tuning variables. There’s tons of info available now on suspension physics and setup, but it is geared mostly for modern cars. I’d be interested to see what others have done to their vintage Shelby Mustang suspension and what experience they’ve had.
Thx,
Jim