In the pursuit of Lightness..., 13" Diameter wheels on a 914 Options

[Mike T]

For Autocross. Not street or roadracing. Autocrossing puts far less demands on a braking system. Fade isn't much of an issue for a 1700lb car and a 60 second run.

Why?
If you use slicks for autocrossing you may have noticed there are far more size and compound choiced for 13" diameter wheels that any other size.

13" wheels and tires are also lighter and cheaper.

Biggest problem is the 13" rim's inner diameter won't clear the brake calipers unless you use a huge offset.

I've thought of trying a more streamlined caliper like a Willwood Dynalite. Is there a mounting bracket available that would mount one on the 914 caliper mount?


Mike T

[Mike T]

I suspected that even with the smaller Willwood caliper, Dynalite II or Billet single as you suggest, I would still need the 914 rotor to be turned down to 10" -10.5" diameter and the caliper mounted closer in the radial direction to the spindle centerline.

I believe the inner bell dimension on the wheels I was looking at, Keiser, was 12.25" . I need to look at my notes.

At one time I had a Rabbit GTI caliper and mounting bracket bolted to a 914 spindle. The caliper mounting bracket bolt pattern matches the 914's caliper hole distance. I had to open the holes up in the caliper mount to fit the 914 caliper bolts. The caliper was very close to being centered on the 914 rotor and only needed 1/2 to be turned off the rotor diameter to clear the bridge. The GTI caliper is a single piston design with the piston on the inside so it clears a 13" wheel easily. Don't know about piston volume, if the 914 master cylider would be compatible. Also it didn't seem any lighter than the 914 caliper.

Mike T




Mike T