M30 Turbo Valve Spring Pressure

[Klassic]

Hi all,
I know its a bit "left of field", but does anyone have some knowledge as to what valve spring pressures are good for an M30 turbo set up running 20lbs boost?
I've seen dual springs being used, so I bought some, but this works out to be 287lbs at full lift when measured.... far too high??

Any input would be appreciated.

 

[sfdon]

I have adjustable wastegates made for me for the 745i engine. I prefer the m102 spring (provides higher initial pressure over the m106 spring) and then the adjusting screw sets final pressure. Then we use a small valve to control total air pressure to the diaphragm so that you can have an adjustable wastegate on the fly. I used to run my 745i up to 22 pounds of boost with some added 110 octane.
Bill Smith is my machinist - he can make you one if you want.

 

[sfdon]

I have one newly built adjustable wastegate left in the shop if you want pics.
I will be driving in France until the 28th.

 

[Klassic]

Thanks for the replies. I wasn't clear in my description. I'm referring to the inlet and exhaust valve springs in the head. Sorry about that.
However, interesting the boost pressure at 22lbs. Must have made good numbers!

 

[sfdon]

Crazy Numbers!

 

[sfdon]

I would think that either m30b35 oem stock double springs or Schrick double springs would do. Stock m106 turbo engine had max torque at 2000 rpm.
max Hp at 4900 rpm

 

[Klassic]

Had a chat with a turbo specialist last night about spring rates/tension, he reckons 287lbs/inch is quite within range for the M30 engine running turbo. It seems from what I can work out that the factory duel spring set up is in fact about that tension.