boost issues grrr

[nixy]

Car in question is a A3 1.8T AUM, when i first got it car was spot on had previously been remmaped etc. After about a couple weeks it developed a flat spot at about 3.5k revs where it felts boost was dropping off then back in. It then quickly changed to the boost only spiking at 14psi dropping down to 10 psi and surging up and down between 10 and 12 psi.

I then did the N249 bypass and the boost then spiked to 18psi and came in much stronger but still drops off to about 12psi and surged. I had car serviced and today put on a Forge 007 dv plus a spanking new N75 and now the boost spikes to 18psi some times but other times only 16psi or 14 psi. It still drops straight off but now no surge!

Also if I changed gear at high revs the boost only goes up to 10 psi with no drop off or surge!

Getting annoyed now and just want it fixed now!

Any help much appriciated

Nick

 

[camscockle20vT]

If its hesitating then it might be a weak coil pack or sparks, also pipes under inlet corrode and cause problems.

 

[<tuffty/>]

Log it with VCDS and check for fault codes is first step in this case... you will have something to work back from...

Have you checked for the usual split pipes etc?

Maps don't change, mechanical stuff does however... if it was fine before then something has changed in the engine bay somewhere...

<tuffty/>

 

[badger5]

split pipes, error when doing bypass, n75.... etc etc

 

[nixy]

as said new n75 on and bypass made it better lol. IF the forge dv has the wrong spring could it cause problems like this? Which pipes exactlly am i looking at under inlet manifold would it be the oil breather pipes?