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CONDYBOY
Friday 11th July 2008, 23:51
okay guys I was just wondering, as my boost pressure is controlled by the ecu which opens a vacuum valve to the stock bov whenever it feels like it will an mbc do any good or is it a waste of time? will the ecu just apply more vacuum until the bov drops the pressure to whatever it wants at the time? Having fitted a boost guage Its been interesting to see the boost pressure change depending on throttle postion, and also whenever the ecu decides it's too high, i.e full throttle pressure drops from 27psi to around 10psi at 2700 rpm and then builds again with the revs all without changing throttle position but does feel like a flatspot!

PNuT
Saturday 12th July 2008, 07:10
27 psi?

brett craig
Saturday 12th July 2008, 09:04
my gauge only goes to 20pi !! with a mbc it starts a -20 on tickover, and max of +14psi before fuel cut kicks in, still getting cut in anything higher than 2nd

CONDYBOY
Saturday 12th July 2008, 10:03
I've got a diesel that runs more pressure standard. as the crankcase is vacuum ventilated only I've had to invent my own way of reading boost pressure see my post v40mods pics in the 40/50 series forum (this site), at tickover it drops to about 3hg vacuum as the turbo aint giving pressure and the engine has to suck its air in. my guage reads to 30psi an 30 hg on the vacuum side (again see other thread).