The FXX?
Dude, that's essentially a full-out race engine in a $2,000,000 track test car.
That is the creme-de-la-creme version of their V12, and I'm sure every single part and piece is lightened to the extreme. The fully assembled 6.2L V12 must be lighter than a shortblock of our 3L I6...
It has a paddle-shift gearbox that changes gears almost as fast as the F1 cars, so I'm sure the flywheel's nearly non-existant.
Guide? Follow physics, man. Lighten the rotating assembly as much as possible. Get air into the engine as quickly as possible, get air out of the engine as quickly as possible. Look at the pedal, cable, and throttle assembly and remove as much slack and as many pivot points as possible.
Everything in this situation is a supporting mod; there won't be a single part you'd point to and say "THAT was responsible for the zippy".
Now, proof of each mod's effects? Even if somebody demonstrated the difference lightweight pistons make, I don't think you'll be impressed.
All of these things we've listed are going to make a change in response measured in the *hundredths of seconds* each. It's the sum of the mods that will make a difference, not any single one.
You could turn your 7M into a lean, light machine, and still have a worn throttle linkage adding a half-second delay.
That being said, its not impossible, not by a longshot. There's no curse on the 7M, and you're not at a severe disadvantage by using it.
The 7M is NOT a massively oversquare engine, not even close. With a bore and stroke of 83mm x 91mm, we have a B/S value of 0.91.
Audi's brand new R8, which uses the 4.2L V8, has a bore and stroke of 84.50mm × 92.80mm, for a value of ... 0.91. The R8 has been described as having "throttle response sharper than a Ginsu knife".
Go read the ITB thread over in the N/A section for starters, tons of interesting stuff going on in there.
