[fred56]

I am thinking of putting a 2.5 turbo into a Model A. The problem is that it is still in the donar which is a 1989 Dodge Shadow and it has a problem. Everytime you get on it the boost flashes to 15 lbs rather than stopping at 10 lbs. I have checked the routing of the hoses, the wastegate seems to be working but I'm not sure. Does anyone have an idea or can lead me in the right direction to fix it before I think about relocating the motor into the Model A?

[TurboS10]

Check the wastgate for sure. This is about the only thing that will cause it to overboost unless the turbo is undersized and it is experiencing boost creep. If it is the oem unit I my bet is the wastgate.

Chris

[BOBCRMAN@aol.com]

before you decide to swap that motor try to find rear wheel drive parts for it starter bellhousing trans etc. around here they are like non existant. good motor though, especially after they went to roller cam followers.

[drgnwgn289]

I'm with TurboS10, the wastegate is about the only thing that would make that happen if all else is stock.

[crshrmn3]

Check the vacuum hoses, especially the one going to the MAP sensor. I have ran many 2.2/2.5 turbos and had problems on many occasions with only a slight crack in a hose or elbow in the vacuum hoses. When the lines pressurize some of the pressure can bleed off and the computer doesn't get a good vacuum signal and causes an overboost. Something worth looking at.

Also, some models with the 2.5 turbo will run an increase boost pressure for a something like a 5-10 second period then back off a few pounds to reduce the risk of detonation. Most performance computers will eliminate this feature and give maximum boost at all times.