1972 Track Rat vs 918 vs 991 at Big Willow
 

http://flatsixes.com/cars/tuned-pors...vs-918-spyder/

Kind of cool, with video and data...

If I missed this discussion already, please excuse the double post.

Cool but all it really proves is that track prepped car is faster than (most) street cars. Even in autocrossing a lowly "street prepared" honda civic will have a worse pax multiplier than "super stock" Z06/porsche (forgive me if my autocrossing classes are old - its been a few years.)

I thought excellence did an article where 3.2L carrera spec track cars were faster than new (997 vintage?) GT3s a few years back.

I suspect an aggressive track only alignment on either the 918 or 991 would lower lap times a bit. Throw a couple aftermarket suspension bits in and it would be no contest.