Vacuum reading at idle

[benoitthegr8]

I bought this GN about a month ago, completely bone stock. So far I've put on a K&N air filter, adj wastegate, volt booster, new alternator, calibrated the TPS, and the TV cable. The car still has slight turbo lag, so I hooked up a boost/vacuum guage. I'm reading between 15/20 in. HG at idle.... When I'm putting the car under boost it is topping out at around 10 lbs, and the dash boost is reading 15 lbs. I'm wondering if I have a vacuum leak, I've got all new vacuum hoses to replace the vacuum lines, and I'm also going to hook up the ole knock guage. I'm just paranoid of over boosting the car, but if the boost guage is right I should be able to get around 4-5 more pounds of boost safely. I've never had the vacuum reading on any of my prior cars...what am I missing here?

 

[Roc87]

15" vacuum at idle is great for these motors. The stock boost gauge is basically an 80's gimmick, it may have worked good when it was new, but the technology isn't in it to make it reliable. That being said, don't put any trust in the stock tach either.

 

[QUIP'6']

I bought this GN about a month ago, completely bone stock. So far I've put on a K&N air filter, adj wastegate, volt booster, new alternator, calibrated the TPS, and the TV cable. The car still has slight turbo lag, so I hooked up a boost/vacuum guage. I'm reading between 15/20 in. HG at idle.... When I'm putting the car under boost it is topping out at around 10 lbs, and the dash boost is reading 15 lbs. I'm wondering if I have a vacuum leak, I've got all new vacuum hoses to replace the vacuum lines, and I'm also going to hook up the ole knock guage. I'm just paranoid of over boosting the car, but if the boost guage is right I should be able to get around 4-5 more pounds of boost safely. I've never had the vacuum reading on any of my prior cars...what am I missing here?

the factory bost gauges are old and never work right they just usually peg at 15 i would trust your aftermarket one but to be safe i would get a scanner of some sort and gradually bring the boost up to around 15 to 16 depending on chip and octane

 

[benoitthegr8]

I'm gonna hook up the caspers knock guage tomorrow, and adjust the wastegate slowly. If the car is still only at 10 lbs of boost, the motor still pulls really good. Hopefully there will be a bit more to get out of it...