Own a 97 impreza turbo,When going to overtake foot hard down get to about 3,500-4000 revs and the car just seems to stop as if hitting a wall,lunge forward and then picks up again as though hitting a rev limiter.Have recentley fitted prodrive back box and forge motorsport dump valve could this be related.
Cheers Gareth.

 

Sounds like fuel/boost cut!!!
Do you have a boost gauge fitted? What is the boost peaking at?

 

No i havent got a boost gauge so havent got a clue what boost pressure is ,
thanks gareth.

 

Does it do it more in the cold weather?

I wouldn't have said the mods would cause the problem, though they could have pushed the boost up a little and over the edge!!

Do a search for cleaning the boost solenoid (It's the cylindrical thing mounted in front of the drivers side suspension tower).
Cleaning it out would be the first step. (It gets contaminated if you over fill the oil on a service!!!)

If that doesn't cure it. It's time to fit a boost gauge for a bit of diagnosis! It's advisable to fit one anyway
You can get a gauge for about £40 and pod is about the same.

Hope you get it sorted,
Iain.

 

Ok Thanks Iain will try that tommorow then look about for a boost gauge.
Cheers Gareth.

 

Forget to say no being cold makes no difference.
Cheers Gareth.