For me it would be:
1. Sequential gearbox with a massive STICK (gumpert style)
2. K20 mounted in the boot
3. Full carbon fibre shell
spaceframe chassis, 4wd, turbo conversion, 500bhp, sequential box, hmmmmm good real good!
billet tall deck block, 92mm bore, 75mm stroke with a 150mm rod.
Flat top pistons 10.0:1 cr.
Billet 'soft head' cylinder head with servo actuated valves for infinitely variable valve timing.
Variable geometry intake and exhaust manifolds.
Should produce a nice flat 160lbft torque curve from idle to 12000rpm with insane throttle response.
Then i would bung that all through a custom 6, no sod it, 7 speed box.
:d
my ultimate mods would have to be done to ef8 crx.
B16 bored out to 86mm but destroked to keep it 1600cc (you need the really short stroke to rev really hard) producing between 280 and 300 bhp at around 11000 -12000rpm also reverse the head so engine can be put as close to bulk head as pos
loads of carbon light weight panels to get weight down to about 750 kg
super touring car spec chassis
sequetial gearbox
full blown race car basicly
super amounts of money lol