Car holding back in 5TH?
 

Yesterday I took my car out and ive only just noticed it seems to be holding back slightly on boost in 5th gear. It pulls well through all the other gears but in 5th on the motorway the whoosh noice from the air filter seems to flutter slightly instead of a constant boost noise if that makes sense. Im thinking maybe upgrade or change the injectors but would like some more input before I go spending moneys, thanks in advance, Leon

Is it a newage impreza ?

facelift classic 2.0 turbo with apexi ecu vf43 turbo, yellow injectors, front mount mapped to 352bhp

I've got a bug eye sti that was doing the same thing my turbo intake pipe was split which I changed that improved it but it still flutters a tiny bit does yours do it all the time or only when u put your foot to the floor ?

Has it always done it since it was mapped ?.

Speak to your mapper

never use to do it, used to pull real hard on boost in 5th but lately seems to have a slight flutter to the boost when you give it full loud pedal in 5th, any other gear is fine. Still reads 1.4 bar on the fc commander and the gauge so im thinking its fuelling

Fuelling wouldn't cause air filter flutter noises.
More likely boost control related. Give the boost control solenoid a clean through with carb cleaner.

Are you running a 2-port or 3 port boost control solenoid.

Could be weather/temp related as the car will try and produce more boost in the cooler weather and the boost control may be a touch high, hence it gives a quick spike and the ECU is trying to get it back under control, hence is flutters/stutters.

As an aside, I hope your running a high pressure FPR if your pushing 352BHP on Yellows and maybe even a wideband AFR permanently installed.

would I benefit from upgrading my yellows then? its all running sweet its just in 5th it seems to do it