Sun Jan 04, 2009 11:53 am
if that's an EVO2 you won't need 48mm throttles to make more power. EVO is the only M3 engine which makes the power BMW claims IMHO. All others (including the mighty Sport EVO) are down on factory power.
EVO2 throttles are the most difficult bit to source! Don't give them away. Difference is the casting towards the head which is larger than the "standard" 46mm throttle bodies. Evo2 inlet ports are same size as 215bhp engine, hence the larger throttle casting.
I would put the cage on the list of modifications BEFORE the engine. It will transform the handling of the car if done right and will make you faster on track even without fiddling with the engine.
If the engine is healty (or near) I would NOT touch it till a full rebuild is on the cards. (start saving, it will cost a bomb)
My list would look like this:
take care of rust
weld in cage (which may well go hand in hand with rust repairs)
fit buckets and 6 point harness (if you have a cage)
STRIP interior and whatever you don't need/want (removing weight is the cheapest power upgrade)
sort out suspension (Bilsteins and H&R race springs, or do a DIY coil over conversion for decent track handling)
sort out brakes (300x32mm Merc disks front with E34/E32 calipers)
and then drive the car for a season.
you may well start off with a "milder" suspension setup for a year (Billies and H&R) and then move on to the more hard core stuff (which is unsuitable for the road, full stop), give yourself time to grow WITH the car. Don't build an all out track monster with all the bells and whistles and you don't like it afterwards.
The suspension I am driving now would have not been suitable for me 3 years back, I just wasn't fast enough for it.
It doesn't make much of a difference on track if you have 220 or 250 bhp but it will make a huge difference on your credit card. I would spend the money on handling and braking, that's where the fun comes from (and the lap times.....)