So I got my Nistune done a couple days ago, spent about 3 hours on the dyno.
My mods
-blitz intake
-blitz front mount
-blitz front pipe
-blitz cat back
-blitz SBC
-no cat (test pipe)
-splitfire coils
-stock turbo
When we did some load pulls on the actual road the car blew off a vacuum line on the manifold. We fixed this leak and all seemed good.
At idle the car reads -19 vacuum, and on decel off the pedal i get -23 vacuum ....the car is tuned for a max of 13.5lbs of boost, but I turn it down to around 12lbs boost.
I ran into an issue the other day that anytime around 4000rpm in 3rd, 4th, or 5th the car would completely loose power. I can creep into 12psi by using partial throttle but full throttle and the car cuts.
So today I take it back and they boost leak test the car, do some smoke to help find the problem but not much luck. Then we take a look at the stock bov, we T into the vacuum line running from the manifold to the bov, and un hook the recirc side of the bov that goes into the intake tube. Apply some air and the BOV starts leaking like crazy, and there is maybe 2-3psi running through it.
Its evident the BOV needs replacing, but what gets me is why the car runs well still and how it can even make any boost with the BOV not being able to hold any pressure and leaking like that.....would it be because the turbo is compensating and spinning even faster to achieve its target boost level?