i just installed my Defi-D boost guage.
at idle it reads 20 vacuum. (-20)?
and when i'm at full throttle 3rd gear it only goes up to around 10-12 psi.
is this how it's supposed to be?

with my perrin mbc supposedly it's set to be around 20psi but the guage never goes up that high.
the car doesn't seem to be going slower either... it actually seems a bit quicker.

 

ok either i installed mine wrong or the perrin mbc is labeled incorrectly but hell it seems to work the way i did it.

on the mbc it looks like this:


<-- (-) boost (+) -->|||||<Screw)

and the screw is on the right side.
sooo... logically you should UNscrew to get more boost?
but according to the manual, it shouldn't be unscrewed more than 5 grooves. and 5 grooves is stock boost.

then that means i'm stuck at stock boost?
noo....i will not live with that.
i thought my boost guage was reading wrong but no....
i screwed the MBC IN to the amount i wanted and BAM!
21psi drop off to 19psi.
so according to the MBC i have to add more (-) boost to get more psi.
retarded...

only problem left, my Defi D guage won't illuminate.

 

Exactly 1psi here or there especially off of a gauge is meaningless. The only accurate way is to go off logs anyway.

 

normally on mbc's you turn clockwise for more boost or toward the +(positive sign) for more boost... but if it works going to the neg...whatever....

gauge wont illuminate? check your ground and get one of those testers to see if you tapped into the right line for power to light up your gauge

 

i tapped into gauge fuse and grounded to chassis right around the fuse box.

and then i tried tapping into cigarette lighter fuse... still no light.