The Mustang Forum for Track & Racing Enthusiasts

Taking your Mustang to an open track/HPDE event for the first time? Do you race competitively? This forum is for you! Log in to remove most ads.

  • Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!

Whats a typical rear coilover spring diameter

My apex 18*11 wheel rubs on one side against the rim against the coil over spring.. I have a few things to check, like the panhard is centered, that the shock hasnt moved from being centered in the top hole.
However the coils measure 86mm, my other 2 cars I checked ( not mustangs ) and both are 60. Im thinking whats on the car is larger than normal, and therefore the cause of my problem.
What do your rear coil overs measure in as?
Thanks
 

Mad Hatter

Gotta go Faster
4,788
3,605
Santiago, Chile
Which coilovers do you have?... If they are cortex remember that the go in upside down. Usually the spring diameter diameter is 2.5" or 63.5mm.

I have apex 18x11's and they have plenty of space with 2.5" springs.
 

APEXRaceParts

Race Proven, Street Approved
Supporting Vendor
653
968
Exp. Type
Time Attack
Exp. Level
5-10 Years
Bay Area, CA
I'm late to the party but to follow up here, there are a lot of variances in rear coilover setups that come into play with wheel fitment. OD of spring, preload, ride height, shock orientation, and more all have some effect on inner clearances. We always recommend that if you are running 11" wide wheels (from any company, any 11" wheel that fits the rear will have the same issue) with a rear coilover, check check and check clearance around the spring and/or perch. Both on the ground and in the air.

If there is a clearance issue, you can add a spacer to gain some space, or you can redo the spring stack to move it out of the way. I wouldn't suggest going more than a 5mm or so on the rear, otherwise it begins to push the wheel/tire too far outward.

- Cory
 
I have determined that my rear axle is not centered, its out by at least 1/2 inch. Im waiting for my k-link so I can center it. I believe that will solve my problem as the one shock stands more upright than the other. I am a little concerened about the axle ( stock setup ) being that far off center.
 

Mad Hatter

Gotta go Faster
4,788
3,605
Santiago, Chile
Is it touching only on one side?? Do you have and ajustable panhard bar?? When the car is lowered the axle gets pushed to one side and needs to be centered with a ajustable panhard. The K link will fix that since you wont need a panhard anymore....:rolleyes:
 
5,623
6,702
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
It’s stock rear suspension until the k-link arrives. I have not even looked if the stock piece is adjustable. Car is on the trailer I have another issue to sort out asap :(
Stock piece is NOT adjustable. Lowering the car usually causes this, that's why adjustable panhard bars are needed.
Won't matter with the K link. FYI Most coilover springs are 2 1/2" ID. Some are 2 1/4" ID.
Are you getting the KB coilover setup that goes with the K link? It requires a very different shock/spring package.
 
5,623
6,702
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
interesting that the rears are so stiff.
The extremely low roll center generates a ton of side bite, so they have to throw some of that away to balance the car.
However, when the body is no longer in roll, forward bite suffers due to the extremely stiff springs.
A lower HP car is probably not as much of an issue but for a higher HP car this could be a problem.
I'm watching anxiously for someone to come out with one of these and see how this all pans out.
Of the few that I have seen, they were push monsters and not very fast.
Not to disparage the system, just pointing out some concerns and sharing my observations thus far.
 

TMO Supporting Vendors

Top