Sway bar sizing?

[ralphie361]

Took my dart to its (and my) first autocross this weekend, and I was happy overall, I had a blast chasing my time. I only got four runs in before the rain came, but I'm already planning for the next time. It definitely under steered on tight turns, and leaned quite a bit. Front and rear traction was an issue as well. I'm not going crazy with the car right away, but I think sway bar(s) and tires and wheels will be next. Background on the car setup, poly bushings, 1.03 tb's, welded and reinforced k, stock manual box, factory front sway, welded subframe connectors, hotchkis leaves, 195/60 15 front, 215 60 rears. I have a set of 17" mustang wheels with 245's that I'm going to try, and then I think it's sway bar time. Should I upgrade the front to the biggest I can get, and then add a rear if needed? I'm a noob when going around corners

 

[autoxcuda]

Tires will be an incredible difference on the track.

Yes, put the biggest sway bar with those 1.03" T-bars. Hellwig has a hollow 1 1/4" version with a special bend in it for high backspacing rims like you will have with the mustang rims. Your 17" mustang rims have a good chance of hitting your current factory sway bar. But you have the parts now, so just put one on an check it out.

Buy just the front for now. Autocross usually uses a little stiffer rear roll resistance to help the car turn in the tight course. But trying to fine balance the car with those current tires is a waste.

 

[ralphie361]

Awesome, thanks! I was looking at that hellwig a while back and threw my original on for a baseline. I'll check out my mustang wheels and see if they go on without a lot of hassle, if not I may wait for some different wheels.

 

[Woods74]

There's no reason the mustang wheels won't work; you may need adapters, but they will work! No shame in adapters!

 

[spl440]

My 67 Dart is set up pretty good for the 15" rims I am running. Biggest sway bar up front with poly bushings, SS springs de-arched in the back. Actually both are the R/H ones for the same spring rate. Rear sway bar the smallest I could find at the time and still a little to much. As recommended on this forum, switched to rubber bushings in the back to calm it down and that helped a bit. Has firm feel P/S box and c body tie rods. As good as I could get with a mostly stock set up. K member and such. As previously suggested, TIRES are the best investment you can do. 17" rims much easier to get a good grip tire, 15" rims not so easy, I just like to run the cop wheels with trim rings for the sleeper look.

 

[72bluNblu]

Tires!!!

You'll notice a huge difference with 245's and 17" rims. The mustang rims should be a pretty good fit for the front if they're from the right model year range. The 17x8's with 5.72" of backspace are usually the best bet, sometimes a small spacer to set the bs up at 5.6" is needed, and the hub bore usually takes a little clearancing with a dremel. In the back if you have a stock A-body rear axle you'll likely need 1" spacers. Again, that will depend on the backspace on the rims and which rear axle you have, the 7.25" rears are actually a bit narrower than the A-body 8 3/4's.

http://www.ebay.com/itm/1-0-inch-5x4-5-Hubcentric-Wheel-Spacers-Mustang-GT500-Shelby-Cobra-SVT-GT-1-/380907996776?hash=item58afe2c668&vxp=mtr

With 245's up front the Helwig sway bar won't be too big at all, it should work pretty well with 1.03" bars.

The Hotchkis leafs are 130 lb/in, so you may or may not need a rear bar with 245's. Probably come down to your preference and how much grip your particular brand of tire has. Not to mention how tight the course is, how much horsepower you have, etc.

 

[ralphie361]

Awesome info guys, thanks! I will "borrow" the mustang wheels from my daily driver Dakota for track days, although they aren't sticky tires, they will help until I wear them out. I think they are the older 17x8 with the better backspace, they are the mach1 wheels. I like the idea of trying one thing at a time so I can see the improvements, plus my driving skills need to progress as well. I have an extra manual box I'd like to rebuild with a quicker ratio, in the tight turns it fleet like I was steering my heart out, lol. It and the sway bar are probably not in the budget for the next few months, so I'll get some spacers and play with the wheels I have for now while learning to drive!