I think i might have a small boost leak or something else, i checked all the hoses and no leaks, got it pressure tested and no leaks,no codes either. the situation is that i peak at like 21-23 psi (depending gear) and settles at like 15 psi sometimes lower, im starting to wonder if it could be my 710n DV, N75 or my VDO boost gauge is just inacurate.I have a 2000 1.8T with APR91 any suggestions would be great thanks.

 

no thats normal. its your turbo running out of boost. you need a larger turbo to hold the boost tell redline

 

Iknow with GIAC, and badluckaudi can back me up on this, I hold 17-20 psi in all gears up till redline. The N75 race valve has helped with spiking and an extra lb or so of held boost. Also check your turbo outlet hose from under the car to be sure that it is tightly clamped on. Myself and others have checked on this hose and found the clamp to be lose and hose not slipped on all the way. After tightening it up I noticed boost was more consistant and when i replaced my DV vac line I noticed it held even better/longer in the rpms. Its hard to spot a leak in the dv vac line if you dont do an underwater test so id suggest just replacing it and check that turbo outlet hose too.