Rear Wheel Clarence

[gasfumes]

How much clearance is need between frame rails and outer rear quarter? Wheel are 18 by 12 inch wheels.

[gasfumes]

Trying to measure for rearend

[dhutton]

Depends on the car - shape of wheel openings and also ride height. No easy answer that I am aware of.

Don

[csouth]

As Don said there is now easy answer to this question. It might help if people knew what type of car?

[Schwartz Performance]

12 inch wheels are actually 13" wide.. 335 tires are just a tiny bit wider overall, so figure a minimum of 14", but preferably more to allow for suspension movement and tire sidewall flex.
But yes it does depend on the car.. A lot of quarter panels are deceiving, and ride height is a factor.

-Dale

[BMR Sales]

Car? Year? Tires? Lowered?

[gasfumes]

1969 camaro 18 wheels with 335 tires ridetech coil over suspension.

[cwylie]

Do you already have the wheels? I have about an inch of clearance to the inner and 1/2 an inch to the outer. As the rear axle articulates it pulls the tire towards the inner and away from the outer so keep that in mind.

[Carl @ Chassisworks]

With that tire, that car, and a stock/modified stock frame rail you don't really have an option for clearance. You just have to center it in the wheelhouse as best you can.

If you are cutting out the floor and backhalfing the car with new frame rails, then you have a lot more options. We typically recommend two inches on either side. The taller the sidewall the more it will deflect under cornering and move toward the inside of the corner.

My best recommendation is to measure the car and the wheel/tire combo that you're going to use. EVERY car is slightly different. We have a worksheet that has a lot of math that double checks itself. (http://http://www.cachassisworks.com/cac_worksheets.html)http://www.cachassisworks.com/cac_worksheets.html
https://static1.pt-content.com/images/pt/2015/06/cac_worksheets_fab9-1.gif (http://http://www.cachassisworks.com/cac_worksheets.html)