boost/vaccum? and vent bov?

[tkhaab_94]

hey guys. well i just got a vac/boost guage from autozone and it appears that im only getting about 15-16 vac HG or what ever you guys call it and im boosting about 10 psi. is that correct? could my stock bov be leaking boost? right now im all stock with a open cone air filter and how about venting the bov what do i need for that? i vented my stock bov just to see how it sounds like and it is sound crazy loud. too bad it made my car run like crap. died like 10 times. i heard you need like a GM MAF and a transmitter or somthing like that. any help would be great! thanks.

 

[sax_man]

Yes, you will need the GM maf, translator, and some way to tune it (DSMlink, safc, ect).

When you vent your BOV you run rich between shifts and the car will die.

 

[tkhaab_94]

ok cool. well what about the 15-16 vac? is it my bov?

 

[knochgoon24]

No, it's not your BOV. Vacuum is produced post throttle plate. Do a boost leak test and see if your injector seals, throttle shaft seals, or throttle body gaskets are leaking.

Normal seems to be right around 17inHg, so you're not too far off. Still, routine boost leak tests are always a good idea on a turbo equipped car.

 

[tkhaab_94]

well. i seen that this one guy that had a greddy type s bov. it was leaking boost and he was getting 15 inHg and then when he put the new NGR type s on he got about 18-20 inHg

 

[knochgoon24]

well. i seen that this one guy that had a greddy type s bov. it was leaking boost and he was getting 15 inHg and then when he put the new NGR type s on he got about 18-20 inHg

inHg is a measurement of vacuum.
psi is the measurement for pressure (boost).

There is no way a BOV can affect vacuum, unless there's a hole somewhere in the vacuum hose that goes to the BOV.

His improvement came under boost. His old BOV would start cracking open at 15psi. The new one held 18-20psi before it would start to crack open.

 

[tkhaab_94]

YouTube - NGR Type S vs Greddy Type S (Customer Review)

check that video out.

 

[knochgoon24]

Then the diaphram in his BOV must have been torn and was leaking air back in through the vacuum hose.

 

[tkhaab_94]

yeah so can my stock bov's diaphram be torn? it can my my shitty boost guage thats reading wrong..

 

[knochgoon24]

The stock 2g BOV is a piece of crap. It could be damaged, but I doubt it. If you want a some piece of mind, get a 1g BOV with an adapter. With the adapter, it's a direct fit and should cost you less that $50 total. As soon as you start running more boost, the 2g would leak boost back pre-turbo anyway.

Chances are, your throttle shaft seals are leaking. Those tend to get hard and lose their ability to seal. Do a boost leak test and check/listen near the throttle. Move the throttle a little bit, too. You can replace those seals for ~$15.

 

[tkhaab_94]

is it easy to replace? what has to be done? the throttle shaft seals.

 

[zhjiln]

hmm..that video of the NGR vs greddy is mine... yeah that greddy was bad.... NGR BOV is nice ...


check you hoses near the intake manifold etc, for little tears or rips.. and yeah the throttle body area is a pain ... tiny leaks is common..

 

[tkhaab_94]

yes i know its yours. i will check that out tomorrow.

 

[tkhaab_94]

ok so today i got the TB gaskets. replaced it and i still get around 15 inHg. it sometimes goes lower than 15. how do i replace the throttle shaft seals?

 

[2gGSX]

15 inHg is fine.

 

[giovanniv]

There could be a boost leak anywhere. Do a BLT and see where it's leaking. Sure the TB is a common place to leak but what if it's leaking through one of the other million little hoses?

 

[toxicity883]

15 inHg is fine.

True I put a cam and a new set of heads on my RAM and now im lucky to get 12hg, but it runs fine.