ITR Mustang

[Ron Earp]

The 1995 cars are classed in ITS, at a new attractive weight I might add.

Ron

[billf]

Let me chime in here, and possibly answer a few questions.

As noted, the '95 is classed in ITS. The '99-'02 is classed in ITR...but in both classes the allowed weight is probably WAY lower than physically achieveable, regardless of what components can be deleted, or replaced. Although I'm glad SCCA is approaching classification in IT with a plan in mind, this particular car is classed too light for reality. It probably should have ended up in ITA at a more realistic weight.

Having had a few years experience with the Fox in ITB, I have thoughts on how to make the chassis work better, and eliminate some of the undesireable characteristics of its handling. Incidentally, I'm working on an ITR, which has parallel issues, and the weight sensitivity part, too (I don't expect to make anywhere close to the allowed weight). Therefore, what I'm saying is: You might want to be VERY judicious in adding any component that is not manditory for safety. Specifically, I'm thinking of Panhard Rod, or Watts Links, or added roll cage bars due to the added weight. Try to solve the problems with bushing selection (in the rear, very soft, or very mechanical), to reduce/eliminate the bushing-bind that is the source of the handling quirk.

At the front, the same philosophy everyone else who uses struts, will apply to this chassis. Try to find hollow sway bars instead of solid bars.

Cage: be very careful where the bars are located, and if you really need/want them. Tie into the chassis at the spring mounts in the rear, not the shock mount. In front, tie to the firewall where the upper frame extends off to the core support.

Plan to remove any and every component allowed to lighten the car. Lose a few pounds, yourself (difficult, but possible...and allowed by the rules!!!).

Happy holidays.

Bill

[cjb25hs]

Chris Dercole has one and he is on the board, it is a 99 and up though. His handle is RedMisted on here.

[Jethro]

Thanks Guys

I've been talking with Chris and he's a wealth of info.
Looks like I'll have to run 15" tires, yuk!
stock size is 205/65x15, and looks to me like the only popular racing size is gonna be 225/50x15, this make sence to anyone?
Any tips on strut manufacturer choice, even from the 79-94 guys?

[cjb25hs]

Thanks Guys

Looks like I'll have to run 15" tires, yuk!
stock size is 205/65x15, and looks to me like the only popular racing size is gonna be 225/50x15, this make sence to anyone?

You can go to a 245/50/15 in the Hoosier. I would also suggest you talk with Sam Strano from Stranoparts. He is a wealth of knowledge when it comes to Fox Body Mustang setups.

[billf]

ITR allows the cars to weigh a few pound more, so additional suspension parts may be more desireable, and less injurious to performance. For ITS, I'd think even more critically about added weight.

Personally, I'm a fan of smaller wheel diameters with generous width, to reduce the rotational mass of the wheel assembly. Aftermarket/racing lists have 15's avaiable in various offsets. What you will have to pay for is lightness, not the size. Additionally, the handling can be enhanced by the placement of the lower A arm (smaller diameter wheel assemblies put the ball joint closer to the ground), giving you the opportunity to have an up-ward angled lower arm. This will give you enhanced camber change during bounce.

Differential gear set ratios available (stock and aftermarket) for the 7 1/2 inch, are 3.08, 3.27, 3.4, 3.73, and 4.1. I prefer the lower gears with the second, third, and fourth transmission gears being used.

What you want to concentrate on is how to enhance the handling without adding to the weight of the car. Aftermarket parts all weigh pounds and ounces...from which the car/engine combination cannot benefit. Hollow sway bars are available, too.

Start your project with a through reading of the Mathias book on Mustangs ("chassis", actually number two). It will give you a grounding in the four link design, and its consequences. Solutions are proposed which work, but all add weight. There is one concept that is not in that book that will lessen/eliminate the problem. That is to replace the source of the problem (the rubber bushings), with spherical bushings. This is the major solution in the rear of the car. Peruse the AS sites also...they have delt with the problem for years, although their solutions are added mechanicals (weight).

Good luck.

Bill

[RedMisted]

Bill:

I really don't know about using 15" wheels on such a heavy car shod with horrible brakes. I use the airier 17" rims with all the brake tubing I can cram into the wheels. Our rotor sizes are 11"--pitiful by ITR standards. At tracks like Watkins Glens or Nelson, brakes are not a major issue so I guess you could run the smaller wheels. But at a Gingerman or a Beaverun, that brake pedal is gonna be down on the floor before you know it. I'd rather have the weight of the larger wheels knowing that my brakes are getting all the cooling possible.

Another reason to optimize brake cooling: The ITR Mustang is equipped with PBR aluminum front calipers, unlike the earlier SN-95 cars that came with cast iron bits. This is great for weight, but these calipers deform like crazy in the heat, even at the easy tracks. It's normal for me to replace the front calipers (at about $65 a pop)about every other event. If I don't, I'll be wasting box after box of $200 brake pads. So running the larger wheels helps me to minimize an economic issue.

Just my $.02