The Quest for Traction: Wheels, Slicks, and Fender Flares

Since the motor was rebuilt and the interior gutted, the car had become a complete animal to drive.  With over 550ft/lbs torque and no weight to wrestle it down, it would get wheel-spin all the way up to 90mph.  While it was immensely entertaining, smoking the tires at highway speeds wasnt going to break any lap records.  The 275 front and 285 rear tires were as large as the fenders would allow, so once again it was time to start chopping away at Porsche's unique design... but more on this travesty later.

In order to have any chance at getting this monster to hook up, it was going to need a .50 cal size wheels and tires.  A call to Tire Rack and a (once again) empty bank account later, some beautiful OZ Alleggerita HLT wheels arrived at my doorstep.  Tire Rack didnt have an obnoxiously wide rear wheel for a 928 (big surprise there...) so the 18x10 and 18x12 wheels were originally designed for a 996 GT2.  Despite the 200 hours I had worked to pay for these, the car still needed tires... yeah, that was a bitch of a realization.  Thankfully, some lightly used Hoosier A6's were available for a reasonable price.  The fronts are 295mm and the rears 335mm.  I could bore you with why I chose those sizes and the weight reduction of these featherweight wheels minimizing the rotational mass and unsprung weight by 4lbs each, but honestly, who gives a crap?  This was the result:

 

Mounted and Balanced 

 

After some measuring and oddly satisfying chopping of the fenders, the wheels were bolted up.  The new wheels/tires stuck out about 2" past the fenders in the front and back.  This setup would be ready to go at an autocross, but actual race tracks and circuits dont allow this.

 

 
The rear width now measured 78.5"

 

The front width now measured 75"

  

Several hours on the forums and ebay later, I found these Datsun ZG fenders were just large enough to shroud the enormous tires.  The other requirement which these fenders filled was the "bolt on" aspect. Perfectly fiber-glassed and blended fenders look stunning on show cars, but they have no place on a racetrack, especially when they are destined to get obliterated by a competitor or wall of tires.

  

Being fiberglass, they were easily bent to match the contours of the hand bent aluminum front fenders.  Installation was as simple as drilling holes and filling them with rivets.  RTV sealant was used to fill any gaps where air or water might penetrate. 

  

 

  

 

 

 

Final words:   The car is currently barely capable of driveway egress, but it still may need a bit more fender trimming once it's fully lowered.  Regardless, it looks much better with black wheels and it's now as wide as a Lamborghini Countach.  Will the quest for traction be successful? Probably... since F1 cars use the same size rear tires, but it'll be interesting to test once it finally hits the track.