Boost / Vacuum question.

[Thaddeus]

While at idle i have -.69 hkPa or 10psi. This seems like low vacuum to me. Just wondering what everyone else is getting at idle. I've only been KA-T for two weeks.

I also get a surging or bucking when I get on and off the throttle while cruising down the road. When I put in the clutch from a higher RPM the RPM's will bounce after dropping lower than usual, like 400 or 500 RPM's.

[Razi]

Around -20 psi seems like the norm.I idle at around -21 or -22 psi vacuum.

[Thaddeus]

Ok, I must have a leak somewhere. Thank you.

[D-UNIT]

blow off valve might be opening when idling.

[Doya]

Blow off valves are s*** IMHO. You are not going to mess up your turbo not using one. But if you're running high levels of boost, I would use a bypass valve.

[Chris28]

If you are running anything more than say 6 psi, I would highly recommend a blow off valve unless you feel like replacing your turbo frequently.

Back on topic though, I idle around -25 psi. During decel I'm certainly pulling more than 30 psi of vacuum, but my gauge maxes out there.

[Razi]

Ok, I must have a leak somewhere. Thank you.

No problem, I idled around -10 psi and I did a boost leak test and I found a lot of leaking areas and that fixed the problem.

[neverlift]

If you are running anything more than say 6 psi, I would highly recommend a blow off valve unless you feel like replacing your turbo frequently.

very debatable.

I beat the s*** out of my car the week or two I had no bov installed, at 11psi, had to replace a turbo to manifold gasket and inspected the turbo, it has the same amount of play it had prior(none lol). I think around a bar I would start to be concerned with the ill effects of no bov, I reinstalled mine cause the flutter was screwing with my n60 giving me a worse stumble than suck through and vta bov was Any who BB turbos are less prone to a failure related to no bov.

op unplug the bov and see if your reading goes up

[Chris28]

Yeah I've heard both sides of the argument, but I don't something spinning as fast as a turbine wheel should change directions that fast.

Why are BB turbos less resistant to lack of bov's? Not trying to argue, just wondering lol.

[neverlift]

when I can be shown a turbo stopping from flutter I'll buy into it being bad, dont get that statement twisted, I dont think its good for a turbo to have to chop up the compressed air. But unless its a lot of air I dont see it being a big problem.

Something I cant recall atm, I remembered it this morning but atm my brain is lagging.