Excellent....thanks.
Here is an excerpt from the post concerned for anyone who's interested.
"In the meantime, just so you guys can get some facts.
The engineering firm is certified, therefore the mods are legal.
They slice the inner part of the rim off close to the wheel centre, then obtain a sacraficial 18" wheel that has the same taper and thickness etc, which they also slice on the inner, with 1" extra width, which is then double side welded to the factory rim. Then they machine the finish.
Many race cars are modified this way when they are playing with offsets and widths for handling.
The join is perfectly legal and every bit as strong and safe as the original wheel. I once had a corvette where I widened the 9.5" rims to 11" exactly the same way. They performed (track days included) perfectly.
The 4mm offset that is required is provided by a 4mm spacer plate, either welded to the rim or simply placed between the rim and axle hub.
the law requires a minimum of 6 x 360 degree full turns from the lug nuts for safety. The 4mm still allows over 8.
Looking at the finished article I probably did not need to roll my guards, however, with cornering forces flexing the tyre I think it is a good safety idea.
The inner clearance issues relate to the lower control arm bolts, which are cleared more than adequately with the 4mm offset. In fact, looking at the end result, the rims would probably clear enough without the spacers.
After completion we braced the car and jacked the rear wheels individualy to check clearances for full up and down limits in the suspension travel. No problems.
My car is also lowered 1" all round with King Springs. The combination of lowereing, 275's out back with 8mm overall added offset is 'FAT'. Definetly gives the car the look and GRIP that it should have had from factory. The machine polishing also looks great.
The costs are.
Widening of wheels $220 each.
Spacer plates $22 each.
Full machine polishing $110 each
There may be an additional $50-$60 per wheel if they have to buy 'brand new' sacraficial 18" wheels for the inner ring."
Bob
