68 Camaro Ridetech coil over ride height

[brickyard69]

Seeking advise from you guys. I have a 68 Camaro with a ridetech front and rear coil over set up. The front tires are rubbing and I want to raise the front end about an inch. I have run the preload up probably farther than recommended. See photos. Tires are 245 40 18. Should I try and find a different spring at this point?

The rear also rub going down my driveway on an angle and tore up the quarter lip. I have also run up the preload on those. Can I move the shock mount up one to the mono leaf holes or do I need new spring on the rear too? See photos.

[stab6902]

The root cause of your issue is your wheel/tire fitment. Raising ride height and spring rates would help to some degree, but there will always be a driveway or road undulation that will use up your available suspension travel and cause issues.

[oleyeller]

Yup the 4 link rear does not like to articulate. It goes straight up and down just fine, but jack one side and the rear moves fore and aft a ton. You have to take driveway approaches straight on not at an angle. In reverse you can rip off fender mouldings and cut tires....Not the greatest setup. The design issues have been argued to death in previous posts.....Brett and an Aussie..

[brickyard69]

I can roll the back lip and live with that but any suggestions for the front? I need another inch of height.

[dhutton]

Alignment specs? Looks like you could benefit from some negative camber. -.75 degrees or so. That will pull in the top of the tire.

Yes you can raise the rear lower shock mount.

Don

[brickyard69]

Alignment specs? Looks like you could benefit from some negative camber. -.75 degrees or so. That will pull in the top of the tire.

Yes you can raise the rear lower shock mount.

Don

Good advise. I will remove a shim on the front to go a little more negative. I also am going to contact ridetech about getting one level up on stiffnesss so I can run proper preload. Thank you.

[brickyard69]

I ran my coil over almost to the top threads. I have good ride height but is that too much preload on the spring? 26 inch front and 27.5 inch rear ride height.

[68conv455]

You're running too much tire with not enough offset. I'm guessing those are 18x8's with 1mm offset. not enough. Especially with the wilwoods that likely moved your mounting surface outward 1/8 inch. Great looking wheels but USmags doesn't provide the best offset.

[brickyard69]

That is exactly the wheel specs. I will have to to make it work with camber and ride hight as I am on a budget and don’t want to buy new wheels until I mini tub the car. Good insight though. Thank you for the info. Appreciate it.

[marolf101x]

First. . .wheel/tire fitment:
As stated, your real issue is wheel offset. The tires are pushed too far out for proper clearance under full compression/full steering lock in the front, full compression/articulation in the rear.

Since you cannot change the wheel/tire at this time we have to put a few band aids on the setup to get it drivable.
These are as follows:
1a-increase camber in the front
1b-roll the fender lips in the rear
2-increase ride height
3-increase spring rate

Second. . .preload:
You can spin the adjuster all the way to the top of the threads without issue. As you can see the threads do not go all the way to the top of the shock.
I designed these so when the adjuster is all the way to the end of the threads and the shock is fully compressed the spring is only compressed 80% of full travel. (If you go beyond 80% compression you can hit "coil bind" which damages the spring and causes "sag". Under 80% and you're fine.) So if you run an 8" spring in the front there's no way to reach coil bind as you physically cannot compress the spring enough.

Third. . .spring rate:
This really depends on what you think of the ride quality. Increasing spring rate will decrease the chance of the tire getting into the fender, but it will also cause a stiffer ride. If you are ok with that you can increase spring rate.

Fourth. . .4-link articulation:
The statement "Yup the 4 link rear does not like to articulate" is incorrect. The tire rubs (primarily due to improper backspacing) but also BECAUSE the rear articulates. If the rear did not articulate, the tires would remain perpendicular to the wheel opening and the tires would never rub.
The wheels/tires are always perpendicular to the axle (|---|). So when the rear is articulated (at the extreme one side is fully compressed while the other side is in full droop) the axle is at an angle to the horizon, so the tops of the tires are tipped "in" on the compressed side, and "out" on the droop side. This can cause the compressed tire to rub the inner fender well, or the droop tire to rub the fender lip.

[streetk14]

There’s guys way more experienced with this stuff than me, but a few things I’ll comment on as I have all the front ridetech stuff on my ‘68.

On the front, it’s got to be your offset and added width with the Wilwoods. I’m right at 25.125” from ground to fender lip with the same height tire. I’m using a 245/45/17, but it’s the same height. My wheel is an 8” with 4.8” backspacing, and my Baer brakes do not add any extra width vs stock.

On the rear I’ll just mention you’re running a taller tire that might be contributing. I’d do a 275/35/18 myself if I were doing 18s.