I would definitely only have the flywheel lightened by someone who has done this before and has been taught how to do it properly though. At my old place there is a guy with 1 arm as a flywheel broke up at only 1500rpm and smashed through the wall of the test cell and ripped it off. Dave!
I trust mine will be ok, as it gets used at up to 7k on track, been fitted for a year - Mart knows what he's doing anyway, working where he does..
heres a pic of my flywheel against a std one,as said above ive noticed no problems with lack of torque,stalling ect.
Well, I spoke to the engineers this morning and they told me that they do lighten flywheels. Unfortunately, when I had the flywheel couriered round to them they took one look at it an said 'oh dear'. It seems that this type of flywheel isn't very straightforward when it comes to lightening (i.e. how much to take off and from where) and they weren't prepared to chance it considerring they hadn't done one like this before. So considerring the time constraints (the car being 'in the way' at my mechanic's, with its engine out) I've had to dispense with the idea of getting the flywheel lightened/balanced for now. [:^(] Guess I'll have to leave it until I can get one from somebody like HotGolf, who've done it all before.
