boost issue

[2.5bluenob]

Hi All, my car has a small problem at the mo. im only able to unleash 500 horses as high boost isnt working too well.
low boost seems ok i think its hitting about .8 bar of boost but high boost isnt as it should be. If im already on full boost on the low setting and i hit the high boost button the boost seems to only increase slightly and steadily. im sure before it used to go to 1.2 bar on high boost and the needle used to fly round to 1.2 now it just creeps up.
Does anyone know what the problem could be?
Cheers
Steve

[andygtt]

Sounds like you could have a boost leak to me, turbos don't have trouble overcoming the leak and producing the low boost, but max out on high boost hence you only slowly overcome the leak?

Check the hoses for leaks and the intercooler for cracks... Anything after the turbo.

[Blu3R]

I'd suggest a vac hose leak. Sounds like you're making actuator pressure but barely anything more.

[YellowShed]

Agreed. Check all the small-bore tubing - sounds like one turbo is on wastegate only....

YellowShed

[2.5bluenob]

ok cheers guys i will take a look. are there any tricks for finding such a leak?

[Blu3R]

Bike pump with that lilo adapter you always lose. Get some pressure into the lines and get busy with your fairy liquid in a squirty bottle. You'll need to bung some ends so have a few bolts lying around for the job.

[2.5bluenob]

ok thanks Rob.

[jl34]

Im guessing it could also be a faulty boost controller that isn't overriding actuator pressure, so its just working on standard actuator pressure

[2.5bluenob]

This fault turned out to be a faulty alternator and st wiring to the plug. after changing the car was back to full power.
Cheers Steve