What do you all think about an ultimate wheel/tire advantage going 13" wheels vs. 15" wheels? For AX or track? This would be for a second set of race only wheels+tires.

I know a local guy who did the mods to use 13" wheels on a 914. This is the first I have seen it done, but I don't have decades of racin experience either.

13" seems to have plenty of available race tires that are cheaper (very cheap as race-track throw-aways). Getting wheels may be a custom job, that's what my friend did, but maybe there are VW bugs or other 4x130s (or 5-lug P-car) racers that have used wheels?

Very interested in your insight into physics and experience of 13s vs. 15s.
I have seen lots of fast SCCA cars with them.

Happy New Year!

First: you better check your rule book if you're going to a/x w/ 13" wheels. You just moved into the modified class.

Second: On the track you will change your gears so much you'll probably be slower overall.

Chris, to touch on one of Paul's points.
Zone 7 PCA does not have any rules currently that address wheel diameter, only wheel width.

With the carbon fiber body parts I have, I already land in modified. No worries!

As DanT knows, I am usually at the PCA events, hoping to be in the top half.
I would do this to be faster at AX, have wheels+tires that fit inside for transport better, and because faster wheels are cheaper than a faster motor right now.

top half is what I have in mind for my stock '75 on street tires for next season....should be great for my PAX results.
see you out there Chris...
the 13" wheels/tires are definitely an interesting mod.

Wheels & tires are lighter...if ya don't buy steel wheels. R25 Hoosier cantis are available. Good grip but quick wear.

Will a 13"'wheel even fit over the stock brake caliper and disc?

caliper needs to be changed
see a thread here
13" wheels and tires on a 914