1.8t how much boost can I run question

[S-Express]

Hi guys, although not a 5cyl issue, its still Audi and turbo'd so I'm begging the collective for some guidance!
I have a 1.8t AMK engine that has had a lot of money spent on it by previous owner but then neglected and abused and I am now picking up the pieces and trying to make it good again.
Brief spec:
AMK block
AGU head
stainless inlet valves
iconel ex valves
Wossner rods
IHI VF34 turbo
ME7.1 Bosch ecu
Greddy BC
uprated fuel pump & injectors (unknown spec at present)

Now when I got it, the car wasn't boosting right, turns out the spring and sealing cup of the diverter valve were missing completely! So after replacing them, putting your foot down felt like a mule was kicking you in the backside. However, the Greddy was all over the place, peak boost was (according to the Greddy) 2.75 bar (40psi!!) anyway, played with the parameters and got boost down to around 1.3 bar and no harm seems to have been done to the engine.
Car is obviously nowhere near as quick as it was, pretty sure the engine mods are good for 400+bhp and the IHI turbo good for 340+ bhp.
Now just in the process of fitting a wideband lambda gauge (Stack) to ensure I don't run lean.
So my questions is; Once I have the ability to monitor by AF ratio, is there any reason why I cant just keep turning the boost up? Surely if I keep the AF richer than say 11.5, then I should be able to run the turbo to whatever boost it will let me have? Or am I going to grenade the engine? I can't help but think the turbo will run out of puff before I stress the engine too much, after all, the rods and valves are done?
Oh and engine has (some time ago) been mapped by jabbasport so hopefully timing etc is OK.
Would love someone with the knowledge to let me know please!

Thanks guys....

[mac2226]

Hi what housing is on the ihi p18/20 stamped on inside has it got cut back blades as this will determine how much power it can do 340bhp is really limits on p18 and p20 cut back blades 370bhp if your after more its ihi vf22 that holds boost all the way till redline 8000rpm and it could do 155mph in 5th in 6th still pulling strong till I back of because ran out of road

[S-Express]

Hi what housing is on the ihi p18/20 stamped on inside has it got cut back blades as this will determine how much power it can do 340bhp is really limits on p18 and p20 cut back blades 370bhp if your after more its ihi vf22 that holds boost all the way till redline 8000rpm and it could do 155mph in 5th in 6th still pulling strong till I back of because ran out of road

Ooh good info - thank you. I will take a look at the turbo.

[prj]

Remove the boost controller. It is not needed and it will never work right with ME7. Use someone who knows how to map the stock ecu properly and control the boost with the ecu.

[S-Express]

Remove the boost controller. It is not needed and it will never work right with ME7. Use someone who knows how to map the stock ecu properly and control the boost with the ecu.

That's what that little niggling voice in the back of my head was saying...
Are you volunteering?
Where are you based?

Thanks

[prj]

Hover over my flag...

I can't help, too much to do.

[S-Express]

Hover over my flag...

I can't help, too much to do.

No worries - thanks for the advice though - helped me make my mind up!