Vacuum/Boost readings. What's normal?
01-29-2009, 11:26 AM
#2
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01-29-2009, 12:59 PM
#4
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I prefer a manual boost gauge, more accurate. Your gauge could be off by 1 or 2psi for all we know. Even the manual gauges have a degree of error.
21 Hg of vacuum is normal at idle. Mines 21-23 when the motor is hot, my idle is at 750rpms as i'm sure yours is to.
It will read vacuum until 50-75% throttle position, not sure the exact number.
You have the second generation whipple right? What size pulley did the non-intercooled kit come with? If you get a chance, record your MAF lbs per minute using the aeroforce gauge. Here's mine with the 3.6 (8lb) pulley. I think I got it into the 60's once.
21 Hg of vacuum is normal at idle. Mines 21-23 when the motor is hot, my idle is at 750rpms as i'm sure yours is to.
It will read vacuum until 50-75% throttle position, not sure the exact number.
You have the second generation whipple right? What size pulley did the non-intercooled kit come with? If you get a chance, record your MAF lbs per minute using the aeroforce gauge. Here's mine with the 3.6 (8lb) pulley. I think I got it into the 60's once.
Last edited by moosestang; 01-29-2009 at 01:07 PM.
01-29-2009, 03:12 PM
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01-29-2009, 04:08 PM
#7
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This is something that's been on my mind the past week, as I'm picking my freshly Hellion'd GT up anyday now.
It's been ~30 degree's down here in the lovely state of Texas, where weather does what it wants and just doesn't seem to give a f^ck. And from my buddies GT with a Novi, it pulls a bit harder and sees some higher boost. If I was supposed to be seeing 7-9 psi, how much would I be seeing under this freakish Texas weather, not much for now, since the cold has been lifting, but for future freak shows with texas weather. What sort of dangers would be associated with running into higherboost other than spinning tires, does this legitimately create too much power?
It's been ~30 degree's down here in the lovely state of Texas, where weather does what it wants and just doesn't seem to give a f^ck. And from my buddies GT with a Novi, it pulls a bit harder and sees some higher boost. If I was supposed to be seeing 7-9 psi, how much would I be seeing under this freakish Texas weather, not much for now, since the cold has been lifting, but for future freak shows with texas weather. What sort of dangers would be associated with running into higherboost other than spinning tires, does this legitimately create too much power?
01-30-2009, 02:17 AM
#8
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[QUOTE=BruceH;5890178]
True and since it is so cold out and the efficiency of the Gen 2 S/C consider it like your intercooled! 
Dont worry about the motor.....your safe at that boost levels because of the cold....your boost levels will decrease as the ambient temp rises.
You have the second generation whipple right? What size pulley did the non-intercooled kit come with?
QUOTE]
It came with a 4 inch pulley and yes it is a gen 2. I was able to calibrate the gauge to 0 with key on, motor off by changing the intercept. Still doesn't mean it's going to be more than an indicator of boost/vacuum differences rather than a precise measurement. It's also set to elevation. I'm barely above sea level.
According to some random posts obtained though google, colder denser air will increase boost. I was seeing lower numbers later today after it had warmed some. I will hazard a guess that it will be different once warmer weather gets here.
QUOTE]
It came with a 4 inch pulley and yes it is a gen 2. I was able to calibrate the gauge to 0 with key on, motor off by changing the intercept. Still doesn't mean it's going to be more than an indicator of boost/vacuum differences rather than a precise measurement. It's also set to elevation. I'm barely above sea level.
According to some random posts obtained though google, colder denser air will increase boost. I was seeing lower numbers later today after it had warmed some. I will hazard a guess that it will be different once warmer weather gets here.
Dont worry about the motor.....your safe at that boost levels because of the cold....your boost levels will decrease as the ambient temp rises.
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