boost problem only on wot

[dobbin]

dont know where else to look now , no boost leaks at all , if i do a in gear pull say 3rd or 4th will hit 1.7bar but if i go through the gears might hit 1.2 max and hold boost .
read the threads about tps and altitude sensor ,adjusted both so that they are now corrected values, but still have the same fault also new fuel pump fitted and injectors cleaned and new fuel filter, any ideas ? no fault codes on vag.

[prj]

What setup are you running?

[Rusty]

The boost does change over the rev range to account for the turbo capabilities; could that explain what you are seeing? Changing gear at 7k will drop it to 5k and generally give less boost than at 3k or 3k5 in a high gear, depending on setup of course.

[dobbin]

homefries 3" exhaust and down pipe 040 pump 100 cell cat , dv007 ,
if i rev the car hard in gears its as if car retards back tries to go then holds boost at 1.2

[prj]

I personally would say that the wastegate is overtightened and boost control is way off.

EDIT:
Yeah, wind back your wastegate, 1.7 bar on stock turbo, lol.
Engine knocking it's head off.

Put wastegate back to stock, both the screw and the spring.

[dobbin]

waste gate spring i believe is stock and wound out fully i have tried adjusting but found run better fully out . poss wrong spring in car? what length should it be

[prj]

Wrong spring, sticky N75 or torn WG membrane.

[dobbin]

prj i believe map is no good for my car needs fine adjusting. can you help?
dont mind rebuilding hybrid turbo and remap to same spec as you have done recently

[prj]

This has nothing to do with the map, fix your car

[Rusty]

Whereabouts are you?

[dobbin]

ok i have taken spring out and measured it thickness is 2mm and lenght is 87mm
andy car is rs2

[Rusty]

Ah, that makes more sense - I've edited my previous reply...

If you're anywhere near Bristol then I can read codes etc. for you.

[prj]

ok i have taken spring out and measured it thickness is 2mm and lenght is 87mm
andy car is rs2

Wait, so it's an RS2? I thought it was a S2.

If it is an RS2, I think you have a boost leak.
Have you tried pressurizing the intake?

[dobbin]

ok update i read on forum spring should be 83mm and not 87mm length so i dug out cap on wastegate and adjusted screw out so length of spring would be around 83mm in length
much better in gear more of a pause before boosting, but im in work havent got my boost guage with me, andy i will take you up on your offer im in newport, prj all hoses changed including intake , no leaks found on intake or hoses going inside car to maf ect. i did have leaks everywhere before around back of inlet manifold,

[Rusty]

Cool. I'm about this weekend, if that's of any help and am over in Cardiff on monday, as I'm having my DP modified.

I have a spare WG, cap and spring here, off an ABY and can have a look at the current item that's in there - it should have a spring rate of 3N/mm approximately, so you can test it.

Do a base-boost test with the N75 ewlectrically disconnected - it should see 0.4 bar max boost.

Other than that, VAG Com should be able to check sensor readings, codes etc. and see what's up but don't be suprised if it's not that simple or obvious