Lowering boost without power

[Jezza-7]

Im running something like 15psi at the moment, with standard charger and my full blend is going on this evening. I have been told it will rise slightly by maybe 2-3psi, im worried that running that much boost will start causing problems with gaskets, seals etc.

Whats a good way to drop the pressure and not loose power?

Would i have to go looking into porting the engine, skimming head (if that would help?), bigger pistons?

If you skim head it lowers compression ratio? What are the gains of doing that? I dont have a great knowlege of skimming heads.

[Varley]

I wouldn't worry too much about a few extra psi doing too much damage as the turbo lads run north of 20psi but basically you want to make it as easy as possible for air to get into the combustion chamber rather than 'backing up' in the boost system (which is what your gauge is measuring),

So: larger capacity (bore, stroke or both) or an easier route for the air to get in such as a larger inlet, big valve head or a larger throttle body will mean more air getting in and assuming appropriate fuelling morre power and like for like, a lower boost pressure reading on your gauge.

Maybe cam profile too? Not sure about that one though.

[Richg40]

Skimming your head wont change your ratio dude, head face is flat.

G40s are so unpredictable it's a real ball ache. Increasing the boost could blow any kinda seal on one engine and be perfectly fine on anyother. It's the risk you take.

[hayesey]

what size pulley have you got? usually get 15psi with full blend and 65mm pulley, although it also depends on the rest of the spec.  but like varley said, you'll not be blowing any gaskets (?) or anything, plenty of us running 21+ psi

[AlexG40]

My G can clock 17psi mainly due to a stock engine with a toothed belt kit and ported charger. No problems here either.

[bushyg40]

the standard map sensor in the g maxes out at 15 psi after that ur fueling will go to shit mines running 19 psi at mo but dont want to take it to that in case of melting a piston

[hayesey]

you can fit higher rated map sensors

[bushyg40]

mnes on order up to 25 psi then

[hayesey]

but I should mention, you have to have a re-map to suit, you cant just fit a bigger map sensor without getting the maps changed to suit.

[bushyg40]

mine is set up for all tha custom mapped