rims and tires

[mkcobra]

Don or DV what size rims and tires are the best combination for the CR. Don i have the 8.8 ford solid axle with disc brakes now and 15 inch rims. can you tell me about the rims. they are Halibrand knock offs i think. Can i go with a 17 inch rims and if so what kind of backspacing do i need/ have at this time. what is the widest tire you can get under the CR with out serious rubbing. mostly the rear the fronts are 15 inch 245/60 and seem ok. but i would like to have wider rims if possible.

thanks Mike

[Jack21]

Used 17's on mine. Since the factory 15" wheels were 15 x 8 w/ 4" backspacing, and it fit OK, used is as a starting point for 17's.

Compomotive had 17's at $500 apiece. TeamIII had just introduced their 17" at $300 apiece, but I had to wait for them. Ordered in November '00, got them in April '01. Initial production problems. But the wheels are fine.

Fronts. Using 11" Grenada rotor. Went with Team III 17"x8" w/ 4" backspacing. The original fronts were 235/60R15, went +2 with 235/45ZR17 tire. Only the wheel diameter changes, the tire diameter remains 25" - 26". You get a little more treadwidth, and a lot less sidewall bulge. The 17" tire is actually smaller across the middle than the 15, so there's more fenderwell clearance.

Initial reluctance to put what looked like forklift tires on car, but did it anyway. (Virtually everything I read on performance tires said go with 17") Looks very natural. What looks odd now though are the diminutive 11" brakes. Car stops on a dime, and they are the largest you can put behind a 15" wheel, but can go 13" brakes with the 17's.

One more brake upgrade I used was the Stainless Steel Brakes 4 piston caliper instead of the mid sized '78 -'83 GM. These are the same calipers used on '66 - '67 Mustang GT's and (I think) Shelby GT350's. Copies of Kelsey-Hayes calipers. The brakes work well. SSB Tech Support had a really bad attitude when it came to helping with Cobra specific problems. The unused lower bleeder screw pad hits the strut rod and limits total steering travel. In use, it isn't enough to be concerned about. To do over, I'd look at Baer 13" front & 12" rear that will fit 17's, but not 15's.

What would really look nice, would be the late Mustang Cobra R brakes used on 17" wheel late Mustangs that say COBRA on the side of the caliper.

Rears. Used SVO M-2300-C '79 up Mustang rear disk brake conversion kit. This is the '87-'89 T-Bird Turbo Coupe setup. Has single piston calipers, 10" rotors, doesn't change the rear wheel location, and includes a 4wdb master cylinder that bolts right up to the MII power brake booster, and brings the brake lines out on the engine side. (Although those 10 inch rotors look really small behind the 17" wheel.) TeamIII 9 1/2" w/ 5" backspacing. (Could have just centered the offset witth 4 3/4" too).

Tires are 275/40ZR17. Used Falken FK451's all around. (vulcantires.com, $495 for the set, including shipping) Runner up was Bridgestone RE730. (tirerack.com, $650 for the set).

Afterthoughts with a little over 3000 miles on them? Originality? No, but you wouldn't be building a CR if dead nutz originality was a concern. They do look like they belong there. They ride a little firmer than the 15's. But traction and handling is a whole nuther ballgame. Like night & day. You'll have to get on them a whole lot harder to make 'em smoke. There's no squealing in corners, car just goes where you point it. And if it starts to rain, you just keep on driving. I wouldn't put 15's back on after this.

[brandonF]

TTT

Well I would like to know the same information.

[dscott]

Brandon, The setup I use is 15" wheels. 7 1/2 or 8" on the front. The 8" needs a 3 3/4 backspace, the 7.5 can be 3 1/4 to 3 1/2. I use a 245x60x15 on the front. The rear can be 8, 9, 9.5". The wheel backspace is 3 3/4 for the 8", 4 to 4 1/4 for the 9", 4 1/2 for the 9.5". I use a 275x60x15 on the rear. If you use a 50 series tire you can go to a 255x50 front and a 295x50 rear. I haven't used the 17" wheels but the backspacing would be the same. A good tire shop can tell you which tires would be similar in height and width to the 60 series. I am talking about overall height since the 17" tires are generally a 40 or 45 series. The backspacing is assuming the stock width 8.8 rearend with drum brakes. If you use the newer 8.8 with the ford installed rear disc the rear is 1.5" wider and the backspacing would need to be adjusted.
Don

[jwinkler]

Nothing like straight up info - I just copied Don's note straight into my "CR futures" file!

Also need to say I had the opportunity to see a Don Scott-built CR at the Texas Cobra Club annual gathering. I had considered mine to be well built in most ways (CR factory built circa 1992) but his was really something else! Details that stand out were of course fit and finish, but his door handle solution was too cool too. Instead of the car-mounted used-to-be-a-bike-gear-lever door handles, he had devised a setup that put the latch mechanism in the door. He also had four point harnesses mounted where I've got commuter car inertia-lock 3-point belts. On the other hand, given the quality of help he's given on this forum (and me in particular), I shouldn't have been surprised - never the less, very nice.

Another well-done CR I saw was one of Jay Nordstrom's cars, and in a wheel-related note, it was rolling on the CR-standard centerline wheels, but with plastic Halibrand-look wheel inserts that passed everything but the "tap" test (you had to tap them to know they were plastic!). Given my current budget restrictions, it was a very appealing wheel option! According to Jay, available from Snakebite Performance.

Jay's CR also had an "ooh, cool" touch - he had his body man (I think that's what he said - Jay?) add a hint of a flare to the rear fenders. Really nice, but not an option for me currently.

JLW
(soon to be at a reasonable ride height, thanks to Bill Emerson)