I finally got my XJ6 out of storage and I need to upgrade the tires. I am also going to put on 16" wheels. I test-fit a rear wheel today and measured for the tires. The tire I want to run, a 245/50-16, will interfere with the bump stop by about 1/8". I've heard of people shaving down the bump stop, and I was thinking about trying this. If I do, how much clearance should I plan for between the bump stop and the side of the tire?

A couple things to consider: First, I know the IRS will move around a little when taking turns, accelerating, braking, etc - the tire travels with the IRS, but the bump stop is fixed to the chassis. I measured the suspension while it was bottomed out, and when the suspension travels up, it (slightly) travels away from the bump stop. The bump stop is 1.5" thick. I also suspect the tire will change shape during different driving conditions, but I do not know exactly what it will do.

Anybody have experience with this? I heard it was something popular to do on E-types?

 

How did you go with your problem did the larger wheels fit?

 

I didn't do anything all that adventerous. I wound up getting a nice set of used 16x7" wheels from a 1998 XJ8. They are getting powder coated now - I should have them back in a week or two. I bought a set of 225/55-16 Bridgestone Potenze RE760 Sport tires. They should give me plenty of clearance on both the front and rear of the car. I think they're going to be a nice compromise between being connected to the road and having a comfortable ride.

I'll post back when I get the new wheels and tires on!

 

Excellent I look forward to seeing the results

 

You can run it pretty tight. I run about 5/8's of an inch at normal ride between the sidewall and dump stop. I'd say you could go a bit tighter at normal ride height. As the suspension compresses the wheel will move outward because the control arm straightens out, increasing its effective length, because the control arm moves in an arch perpendicular to the near center line of the vehicle. As rear suspension gets fully compressed, the effective length shortens again and the wheel will begin to move inward a bit. You can fairly quickly jack the car up, un-bolt the shock/spring from the control arm and cycle the suspension by hand and visually check for clearance. I don't think the IRS moves from side to side in any significant way. I had clearance issues with the fender lip running 235/55/R17's with an 8 inch wheel. I rolled the lip for clearance but its still not enough traction for my setup so I've got some 9.5 inch wide wheels that will take a 275 series tire but this will require a fender flare. The work never ends!

 

What model were you running the 8 inch wide rim on icsamerica?

 

'76 Xj6c

 

Here the my wheels. I had them stripped and powder coated silver. They are 16x7" and from a 1998 XJ8. The powder coated just finished them - can't wait to see them in person and put them on the car!