Imports
- Thread starter Puffy
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- Marin County, C
How the boost gauge is mounted is a personal preference, and people shouldn't complain about it. Just get over it, they obliviously put it like that for a reason.
- 1,035
Just like everything anyone has ever done to a car. Ever. Personal preference.
People express their opinions on forums. Their opinions might differ to yours. Get over it.
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Thing is, you can. Your analogy is horrible because Psi and in Hg are used to measure the thing same... in fact, you could use Psi for the whole thing... and have it start where it should at 14.9 psi, which is atmospheric pressure, rather than zeroing at it. Or you could just have negative Psi, which is basically what the in Hg are.
Atmospheric pressure is about 15 PSI, and the VAC is using Mercury based barometer readings to do the same. Inches or mm of Mercury (aka Torr) are just another unit for measuring pressure, along with bars and Pascals and atmospheres. A vacuum gauge is just checking the loss of pressure versus the standard atmospheric, which means to get the true pressure, you would subtract the reading on the boost gauge from the atmospheric pressure. Standard atmospheric pressure in inches of Mercury is 29.92, which is also why none of those gauges read higher than that.
http://en.wikipedia.org/wiki/Pressure#Pressure_Units
1 atm = 101,325 pascal = 1.01325 bar = 1.0332 at = 760 mm Hg = 14.696 psi
Basically, you could do it with any of those units, all the way across. I personal prefer the Bar, just because its about 1 bar to 1 atm. And look! Boost gauge thats all in Bar...
- 17,865
- 509
Did you read my post? The zero value is the actually at 1 bar, which is atmospheric pressure. True Zero is at -1 bar, at which point there is NO PRESSURE on anything. The inches of Hg on US boost gauges should actually be a negative number as well...
- 2,312
- Misnblu
- Misnblu
All cars operate on vacuum but boosted cars will go higher because the air is being forced into the cylinders as opposed to being drawn (vacuum) into cylinders with a normally aspirated engine.
Even with the right cam selection and exhaust, a n/a car can still produce as much as 1 or 2 psi above atmospheric pressure due to exhaust scavenging effect along with the right cam profile, timing, and other things.
That would usually occur at full throttle but any other time, you'd be in a vacuum state with n/a.
Turbo cars also have a vacuum state until they get into the revs which will them get them into boost or above atmospheric pressure.
And zoxxy, yes I've skated.
Ramps, street, vertical, and have pretty much done most everything in the extreme sports world.
I don't skate now but have an admiration for Ryan Shecklers ability and obsession to be the best at what he does. 👍
Even with the right cam selection and exhaust, a n/a car can still produce as much as 1 or 2 psi above atmospheric pressure due to exhaust scavenging effect along with the right cam profile, timing, and other things.
That would usually occur at full throttle but any other time, you'd be in a vacuum state with n/a.
Turbo cars also have a vacuum state until they get into the revs which will them get them into boost or above atmospheric pressure.
And zoxxy, yes I've skated.
Ramps, street, vertical, and have pretty much done most everything in the extreme sports world.
I don't skate now but have an admiration for Ryan Shecklers ability and obsession to be the best at what he does. 👍
- 17,865
- 509
Last post here I'll make on this probably, then I'll get Famine and or do a different thread 
20 in of Hg is roughly 10 PSI. This is based on the fact that 1 atm = 29.92 in Hg = 14.69 PSI.
Negative pressure, from what I understand, really doesn't exist. Its kind of like having negative velocity... its relative to the point of reference.
A good example would be this... lets say your room temperature is normally 70 degrees F. So you decide to make that your zero point, so at room temp, thermometer reads 0. So when it reads +10 degrees F, you would be at 80 degrees F, and -10 degrees F, you'd be at 60 degrees F. Now just change what is being used for negative values to Celsius. Thats kinda whats going on here.
Inches of Mercury was used often to describe pressure due to the Mercury barometer, with millimeters of Mercury being more of the international unit.
Most units have a absolute negative. Temperature is at -273 degrees C, or 0 Kalvin. Nothing can go lower than that. In a normal, science usage, 0 PSI, atm, in Hg is the absolute pressure. However, for some unknown reason, the US automotive people decided to use 0 being normal atmospheric pressure... 1atm, 29.92 in of Hg, or 14.69 PSI. Which means at negative 29.92 in Hg (or 14.69 PSI), you are at absolute zero. By convention, anything below the surrounding pressure is a vacuum, but a vacuum is still measured in the same units everywhere BUT on US boost gauges it seems.
So its hardly impractical to measure vacuum in PSI... its just not the convention you are use to seeing on boost gauges, for the US market.
20 in of Hg is roughly 10 PSI. This is based on the fact that 1 atm = 29.92 in Hg = 14.69 PSI.
Negative pressure, from what I understand, really doesn't exist. Its kind of like having negative velocity... its relative to the point of reference.
A good example would be this... lets say your room temperature is normally 70 degrees F. So you decide to make that your zero point, so at room temp, thermometer reads 0. So when it reads +10 degrees F, you would be at 80 degrees F, and -10 degrees F, you'd be at 60 degrees F. Now just change what is being used for negative values to Celsius. Thats kinda whats going on here.
Inches of Mercury was used often to describe pressure due to the Mercury barometer, with millimeters of Mercury being more of the international unit.
Most units have a absolute negative. Temperature is at -273 degrees C, or 0 Kalvin. Nothing can go lower than that. In a normal, science usage, 0 PSI, atm, in Hg is the absolute pressure. However, for some unknown reason, the US automotive people decided to use 0 being normal atmospheric pressure... 1atm, 29.92 in of Hg, or 14.69 PSI. Which means at negative 29.92 in Hg (or 14.69 PSI), you are at absolute zero. By convention, anything below the surrounding pressure is a vacuum, but a vacuum is still measured in the same units everywhere BUT on US boost gauges it seems.
So its hardly impractical to measure vacuum in PSI... its just not the convention you are use to seeing on boost gauges, for the US market.
- 834
Next up, JUN's AWD VQ-TT 350Z 
man that thing is SICK!
man that thing is SICK!
- 834
- 2,312
- Misnblu
- Misnblu
Dude, Jun is one of the biggest tuners there is.
SuperStreet had an excellent article about the car.
Going from a rearwheel drive format to an allwheel drive is something that only Jun could do.
The parts used from multiple vehicles says alot about the tuner.
Here is a quote directly from the SuperStreet article and should give you a little heads-up on their specialties.
"Jun Auto has made a career of kicking ass and taking titles in every single prefecture of tuner town-from the 1/4 mile to the JGTC and everthing in between."
"Koyama-san selected the ATTESA E-TS AWD system from a R32 GT-R because frankly, it's less complex than a R34 with all of its additional electronics bells and technological whistles.
The front differential case is from a JDM M35 Nissan Stagea AWD and the front subframe was liberated from a V35 Skyline AWD or our (U.S.) G35.
The front axles are one part BNR32 Skyline and one part M35 Stagea. The Z-33 rear axles were spared the ignominy of the scrap heap, but the front and rear suspension arms were plucked from a PY50 Nissan Fuga (think Infiniti M) and the front upper arms are JUN adjustable units. "
Susumu Koyama is one of the premier tuners in the world.
I would'nt diss anything about the car or say it's rice.
This is one car to completely drool over with all of the specialty work done.
Simply stated, awesome. 👍
- 834
Well I said what I said because there is video of it going around Tsukuba but I don't know what kind of class it would run in and not to mention it looks super clean and has a show car look to it.
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- Midship_Express
Thats a repost of a repost of a repost of a repost... and the car has since been wrecked...
ND4SPD
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