I have a 1994 wrx wagon, which i think is great, the only mod as far as i know is an ITG panel i fitted 4 months ago. The problem comes after a longish run about 40/50 miles i seem to lose the punch from the turbo, allthough i can still feel the turbo come in and pulls well, its nothing as violent as when the car is much colder. Im running optimax, as i have for the last six months, can anyone please give me some advice.........thanks Compo.

Sounds lke it could be heat soak on the intercooler..
Just an idea...
Rob

Could you get a Boost gauge to see if its going into safe mode when you feel the power drop off, or even an AFR gauge to see if its fuelling properly when hot?.

I've been looking but still havent seen you round Swindon.

My 94 WRX wagon has been doing the same thing for the last 3 years I have had it. My local garage hasn't a clue, and due to its intermitent nature its been impossible to sort out. If you do manage to cure it I would be very interested to find out what it was.
Sorry I can't be more help.
Mark