I'm curious if anyone has gone full race car route on their r55 and how you went about it. So far I've done the following to my 2011 r55s:
catless dp
aem intake and strut bar
helix intercooler
manic stage 2
megan coilovers
hotchkis 25.5mm rear sway bar
and of course some visual things like bbs wheels and custom trim.

Just looking into what others might have done and how it's working out.

 

You're pretty far from race setup.

I too am running intercooler, JCW intake, JCW tune, Alta turbo inlet, hot side boost, Megan Coilovers, AC Schnitzer exhaust, Hotchkis rear sway bar, OZ Supertuismo wheels, NO DP here. It's more like a hopped up street/mountain twisty fun exhilarating smile on your face hotwheels go cart. Next project...Brakes! Trying SS lines first then maybe to 6 piston wilwoods.

 

When you say "full race car", do you mean a dedicated track car (not street legal)? What race classification are you targeting?

In general, you'll be doing exactly the same things as for an R56. For example, roll cage, race cam, ECU tuning, racing tires, limited slip differential, racing seat and harness, engine mounts, etc. Don't forget driving lessons.