Opinion on wheel and tires for cheap autocross

[erratic50]

Being as open and honest as I can here...... four lug brake parts cost 2-3x more and are vastly less effective. If autocross is your goal dump the Stock crap as soon as reasonably possible.

Focus on removing unsprung weight.

i would not waste one penny on 15” or 16” rims. The volume of 17” that’s out there is insane if you look. Unfortunately most are 5 lug but no big deal

83 Ranger 2WD front rotors fit on spindles like those found on an 86 and older or 87-93 4 banger car. Stock bearings and seals work, stock dust caps do not. A 1/4” spacer MAY be needed depending upon how your spindles ride on your struts.

out back, get an 8.8 out of a 94-95 Mustang as it’s the cheapest way to go 5 lug via full rear differential swap. Added bonus is frequently you can get 3.27:1 or 3.55:1 rear gears. I hate the wider rear diff under a fox, but that can get corrected later with an axle swap.

Junk source 17x8 5-lug tribar wheels from a 94-95 GT with tires. These are the lightest rims available unless you drop a wad of cash on exotic stuff.

Most any 245/45/17 tire you get will be better than the 225/60 you are talking about running because you have 2” less sidewalk to flex and way more rubber on the ground

Ceramic and/or carbon fiber blended pads - especially in front - and you’re in business.

M1858 master cyl and an LMR plug and an adjustable proportioning valve will help

If you can get to a 255/40/17 tire do it

A lower friction balljoint in front will help immensely. SN95 or if you don’t mind a bit wonky bumpsteer then X2 will drop the car 3/4”. Source caster/camber plates - certain ones like old HP Motorsports plates will drop you another 3/4”

in back toss the factory spring perch rubber rings and substitute some thin rubber from the local plumbing store.

dump the stock rear swaybar and ideally get a Maximum Motorsports adjustable swaybar that doesn’t cause rear suspension bind

SN95 rear shocks with Fox bumpstops removed help huge

front and rear springs are a mismatch on the fox. If all you do is corner carve increase the front spring to around 800 like the 1993 Cobra R and leave the rear GT spring.

if you also drive on the street, swap rear springs to 4 banger LX as they are the same rate as the street version of the 1993 Cobra

Just my honest thoughts. Good luck


this focuses on the most bump and droop travel while dropping the car significantly for better handling


those who have read my build thread know the above is about to the letter what I did initially to my car. Then I went back and added 95 spindles and a bumpsteer kit and new A arm bushings, etc.

Once I put on my panhard bar and buy a torque arm I may add some more rear spring.

Its about the cheapest way to outstanding handling and street manners.

dont forget strut tower brace, lower K brace, and subframe connectors and a street cage from Kenny Brown.

[flyin5-o]

Being as open and honest as I can here...... four lug brake parts cost 2-3x more and are vastly less effective. If autocross is your goal dump the Stock crap as soon as reasonably possible.

Focus on removing unstrung weight.

True, 4 lug stuff is more expensive and less effective. 5-lug is the way to go, but I think the OP just wants a little performance bump and to have fun a couple of times a year with less cost and hassle than a 5-lug swap.

If he adds some SS caliper sleeves, braided stainless lines, EBC Red stuff or similar street pads and the Maximum Motorsports rear shoes. That along with the much improved tires will yield some improved performance, pedal feel and fun without breaking the bank.

[emerygt350]

Yeah, in the long run doing some of that would be nice but it is primarily a cruiser. Surprisingly my stock brakes have been more than adequate but that may change with stickier tires. Although the drop in tire diameter (3 inches) should increase the stopping power of what I have. Kmember and strut towers would be nice but I don't want to do permanent stuff like drill holes in sheet metal yet. She still has dreams of remaining relatively stock. We will see how I feel in the future though...

[xctasy]

Yeah, in the long run doing some of that would be nice but it is primarily a cruiser. Surprisingly my stock brakes have been more than adequate but that may change with stickier tires. Although the drop in tire diameter (3 inches) should increase the stopping power of what I have. Kmember and strut towers would be nice but I don't want to do permanent stuff like drill holes in sheet metal yet. She still has dreams of remaining relatively stockIts not endurance, so four studs can remain, and you'll get good results with better pads, and occasional changes of freash discs and drumns,. We will see how I feel in the future though...

Its not endurance racing, so stock four stud discs and drums can remain. The hub adaptors allow any kind of cheap wheel to fit any kind of cheap tire. Offsets allow the use of shallow E35/E36 offsets, effectively the track is increased, and the hub adaptors are stronger than any other 5 stud system. Shear forces are shear at the hub face, not at the bolt. A set of race wheels are around with your name on it, and 245's at the front will work if you get someone to help you with the offsets. Some Borbet looking mock BBS rims with real hex center nuts are the best, least cost option because the Fox is 4 on 4-1/4", a common as dirt size for those ancient Richard Craniums who go all gooey over TR6's and MGB GT's and Midgets and other useless English crap that wet driveways with oil and used more fuel than a US V8 to go slower than Italian Twin Cam Four. I'm a total six cylinderEnglish sports car fan. It feels good, but where is the Boss Mustang grunt, and American reliabity. Nowhere man!

And your GT350 is a rag top.

Look to the Ford, not to the back.
Look to the Apex, and be finished with all that turbine stuff,
and think like a racer.

One part, the hub adaptor, lets you do all else. Adding things to go with things, its backwards, and not as safe as getting the tire footprint, track and ride height with the wheels correct. Thae brake system is okay for repeated stops in the kind of work your doing.

I've picked 240/45 VR415's and 285/40 VR 415's on Ferrari 400I and TestaRosa rear rims for both my RAV4, and a future Mustang. Everyone want's out of old tires. The Stagea will get some LMR TRX's redrilled to a 5 stud PCD with LSC centrecaps.

The hubs can be redrilled 5 stud easily, or the poorman 5 stud conversion can be done. Think outside the box. If the engineering is sound, go for a better step ahead than just Turbines.

[erratic50]

New 5 rug rotors (83 ranger) - $50
Used 5 lug 8.8 rear diff - $250
Used 94/95 17” tribars with good 245/45/17 - $200
LMR plug - $25
adjustable proportioning valve $50
MM caliper shims - $50
Carbon/ceramic pads - $12
4 cyl LX rear springs - $50
spring perch washers via plumbing dept at big box store $ $8.00
New quad shocks - $50
———————-
$745.00

Ive had subframe connectors and a strut tower brace since I don’t know when.

I dumped the rear swaybar which removes a ton of rear suspension bind, great results.

This is what I had in mine. Worked very well even though my springs were broken (literally) and my shocks/struts had nearly 300K miles on them.


Round 2 I rebuilt the frontend.... this would be your “future” type update
94-95 spindles - $200
99 GT dual piston calipers - $100
Baer slotted rotors - $125
X2 balljoints - $100
Stock replacement struts - $... free, a buddy upgraded
SN95 shocks $.... free, same deal
M1858 Master cyl - $50
new A arm bushings (I’ll just buy replacements next time!) - $50
—————-
$625

I also added a freshly rebuilt power steering pump and trans cooler to replace the cooling loop and an in-line filter and synthetic PS fluid and UPR underdrive pulleys with a Summit Racing cobra style waterpump overdrive pulley to get it back to 1:1.

I wouldn’t have had to but I put a bumpsteer kit on it from MM

i had some HPM caster/camber plates on the shelf so I put those on. Maxed out caster, set camber via camber bolts, set to zero toe.

steering feel is outstanding


i sources low mileageOE V8 springs for the front


For what it’s worth, that’s basically what I’ve done to mine. And anyone familiar with Stock handling and braking - I’ll scare the ever-loving hell out of you with this setup.

My 60-0 distances are about stupid, and the speeds it will take a 90 degree corner at without oversteer or pushing is quite enjoyable. Very unexpected for the parts in the car. Fade could be better but that’s what Cobra brakes are for if I care.

Ride height at all 4 corners is 1 1/2” lower than stock. The 245/45/17’s just barely rub at lock.

I built it to do some SCCA Classic American muscle stuff in my area but I haven’t had time to get very involved. A good friend has an 86GT also and he was class champion and moved away. we built mine so an 86GT could continue to terrorize the other entries.

The brake upgrades as it sits now saved my life. I would not be here with any less brake than it has.

If I had it to do over again I’d do more or less the exact same thing


I sorta wish I had the 5 lug stuff on my Saleen build but 5 lug mesh wheels that fit are stupid expensive and impossible to find

someday after this car is restored it might go 4 lug as the Saleen goes 5. Or 10 hole rims might get welded up and drilled for 5 lug.

[emerygt350]

Very cool. As I get into it more I may do some of that. New shoes and drums today before I put the new rubber on. The car rides surprisingly well and handles very nice. Tires are really sticky. Not noisey at all. Yet.


There will be no tire rub... Ever. Not the most attractive stance but that isn't the point. Definitely lowered the center of gravity a good 1.5 inches.

[emerygt350]

I think if I go hard core into this I will pick up a cheap beat fox, then I can go crazy stiffing the frame etc. Hell I see half baked foxes on Craigslist everyday that people are just trying to get off their yard. Not pretty, but it doesn't have to be, course for cam the interior has to be intact etc...

[erratic50]

Just about to push off at LGA..... another very rapid trip for work. Good luck!

[emerygt350]

Have fun if you can! Next race is early October, I hope the weather holds. Going to be interesting.