losing boost? Please help
Has anyone ever encountered this before?
Vehicle setup:
stock 60K mile shortblock
AFR 165 heads
B303
GT40 intake with 1" spacer
42# inj's
no fmu
255 lph pump
Snow water/meth inj
MSD 6BTM
spout out set at 30' always with 1' pull out per pound
BD11A with 11 # pully that has never made 11#'s max ever of 10
BOV - 1st Gen DSM
Pro M 77 cali'd for 42's
blower has about 4k miles on it. the car is only a weekend car.
Best time to date:
11.7@118.59mph
Here's the deal:
last year - made 9-10 psi depending on temperature outside. If i step on it at about 2500-3000 rpm the boost would instantly jump to 5 psi and climb to max boost as rpm increases.
this year: (beginning of the summer)
max boost about 7.5 psi. 2500-3000 rpm full throttle amybe 3 psi and slowly builds to 7.5
now - (end of the summer)
max boost 4.5psi 2500-3000 rpm tromp and it jumps maybe to 2 psi.
I took the blower off the car last week to check it out. Internal belt looks like brand new. opened up both sides. nothing looks wrong. dam! i was hoping to find the problem.
I tried another boost gauge, and it reads the same. (did not use the same vac line, i ran it off the back of the intake.
The car feels flat when it is under full throttle. when i say flat, it feels and sounds as if the car was tuned for boost and none is here to save the day... just like the time my serp belt flew off. Just flat. no power
Vacuum is same as normal and steady at about 12" (B303 cam)
The serp belt last year was loose as heck (thats why the belt flew off - ONLY once though and that was while passing someone on the way back from the track after running repeated high 11 sec passes).
With my boost problem i went and got a new belt. Its tight.
Replaced the discharge tube with the factory plastic one with no BOV just to see if the 1st gen DSM BOV was leaking. Nope same crap.
Off bost, the engine runs just like normal. Not boost it just doesn't seem to do much more as little to no boost is happening.
I don't know where to look next. I planned on upgrading to an S-Trim, BUT if i can just figure out the damn problem with this BD11a i can sell it to help fund the S-trim.
Anyone got an S-tirm for sale ?
