Over boost valve

[Guest Muddy 1]

Hey all, just wondering if anyone has gotten around the overboost valve on a td27 diesel engine and if so how they did it? I cant wind my boost past 10psi before it bleeds off. The part in question is on the top of the intake manifold and is a round disc that sits about 30mm high and feels like there is a spring underneath it (its not the wastegate). Ive already done everything else(exhaust, intake, intercooler, boost controller ect) this is the only thing ive had trouble getting around.

Any help is appreciated

Cheers Matt

[geordie4x4]

Matt,

first be careful how high you go, it is there for a safety valve. It should blow at about 12psi. The spring can get weak and the valve can stick. You could try cleaning the valve.

 

I have blown mine off a few times and it seemed to stick open till the boost dropped to about 6psi then close. I cranked the boost up to a max of 12 to 13 using the link to the waste gate. The valve first blew black crap all over the manifold, so I assume it had not blown off for a while. I removed it and cleaned it out thoroughly. The boost now will go to 12 psi at full throttle and I have cranked the waste gate link back so not to go over that.

 

There is no reason that you could not fit a large pipe fitting then an aftermarket adjustable blow off from a performance shop. They are a bit expensive but might give the control you need.

 

There are guys that say they can get 15psi out of the factory turbo but that is a bit of a risk. The TD27 is an older style motor with a pre-injection chamber. I have heard that high boost can cause pre-detonation and damage, but I do not know what is the limit.

 

G