Boost Loss, PLEASE HELP!!!!

--------------------------------------------------------------------------------
Hi Everyone,

I have an issue
my 04 G35 Built shorblock, Vortech S/C with only 1,500 miles on it, 2.87 pulley.

I just rebuilt my engine and finish my break in of about 1,500miles, and the S/C is new as well with only 1,500m

I went to tune my car and am hitting 11psi at 5500rpm on the dyno and then my boost will drop to 7psi , just snaps from 11 to 7psi.
we tightened the belt down and it is extremely tight and still lost psi.

compression test & leak down test are good.
we smoked it and did a boost leak test, system is tight.




i am stumped at why my boost drops down and my power is lost,



any advise is greatly appreciated,
thanks.
Jim

 

Did you lower the C/R? Otherwise I'd say you're running somewhat lean.

Belt slip is the cause 9 times out of 10. What else can it be if you pressure tested the system?

 

Manual or automatic?