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boost gauge?

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Old Jul 2, 2005 | 03:24 PM
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boost gauge?

well i was wondering where can i get digital boost gauges? i been looking around for while but i havnt been able to find one. i perfer brand name. the reason i want digital boost gauge is because i heard autometer tends to be +-1.5psi off
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Old Jul 2, 2005 | 03:32 PM
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rynberg's Avatar
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digital boost gauges suck....

What you are looking for is an electrical boost gauge, although mechanical ones can certainly be just as accurate.
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Old Jul 2, 2005 | 03:34 PM
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well i was reading on this site http://www.turborx7.com/recomend.htm he said digital. i guess electrical boost gauge would be it if he means digital
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Old Jul 2, 2005 | 04:11 PM
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any1
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Old Jul 2, 2005 | 05:11 PM
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Get a mechanical gauge. Digital gauges look terrible in an FD.
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Old Jul 2, 2005 | 06:24 PM
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There's a difference between "digital" gauge and "electrical" gauge. A "digital" gauge is one that displays the readout as LCD numbers, ie, not a needle sweeping around a dial.

An "electrical" gauge has a sensor placed to measure something and it sends a signal through a wire to the gauge which sweeps the needle with an electric motor -- an electrical boost gauge would have a vacuum tube running from the intake manifold to a pressure sensor mounted in the engine bay. A wire would then run from the sensor to the gauge in the car.

A "mechanical" gauge actually samples whatever you are measuring at the gauge itself -- a mechanical boost gauge would have a vacuum tube running from the intake manifold to the gauge itself.

I far prefer electrical gauges to mechanical gauges. Digital gauges can work ok for things like temperature readings. But when it comes to measuring pressure, especially boost pressure, it is far easier to read a needle sweep than quickly changing numbers on an LCD.
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Old Jul 2, 2005 | 07:26 PM
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Function before form.

I have the same sentiment as Rynberg. The passive eye cannot detect minute changes in a digital number gauge. Also, such a gauge requires mental processing and that thinking time slows you down as your eye pans back to the road. Even dial watches are faster to read than digital watches. What was that number again? 1.21 or 1.12? Oh crap, now I have to take another look. Oh, so it is 1.12. No wait. Now it's 1.13. Watch out for that tree!! BAMMM. CRASH. Another FD bites the dust.
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But atleast I knew the exact decimal pressure in the manifold before I totalled my car!

With a sweeper gauge, you could just put a sticker on it that marks the low point and high point and be assured that as long as it's somewhere in between you're okay (in the case of temp). For boost you can just mark the high point and transition point and check to see if it's touching. Function before form.
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Old Jul 2, 2005 | 08:24 PM
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so what you guys think?which one should i get guys then? need your guys is opinion because you guys have more experience
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Old Jul 3, 2005 | 12:37 AM
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Pretty much what Rynberg says. The term "digital gauge" usually refers to the display, in this case digits. A digital gauge is, in all cases that I know of, an electronic gauge. The advantages to a digital display are an increase in resolution (reading precise digits vs. interpreting between two divisions on an anolog display), and a lack of the bad qualities of an analog display which are basically hysteresis and paralax error. An example of hysteresis would be a gauge that reads a 20 psi input as 19.5 on increasing pressure and 20.5 on decreasing pressure. Paralax error would be a gauge that reads 20 psi if viewed directly head on but if viewed from a slight angle might appear to read something different, say 19.5.

The disadvantages to a digital gauge are that they don't give you a sense of scale and are difficult to read when your input is changing rapidly. When you read digits, You must process the number and apply a sense of scale. A quick glance at an analog gauge will tell you if you are good to go just by the position of the pointer, without knowing the exact value.

An analog gauge can be mechanical, electronic or sometimes a combination. Your basic mechanical gauge uses a Bourdon Tube (a tube shaped like a question mark that will try to straighten when internal pressure is greater than the external pressure-usually atmospheric, or curl with vacuum). A pointer is connected to the tube via mechanical linkage. I have never opened one up, but my guess is that all the mechanical boost gauges work this way.

With electronic, a sensor will convert physical (pressure, temperature, etc.) to an electronic signal that can be used with analog or digital displays. These will usually be the most accurate. The problem with electronic boost gauges from the various companies is you have to also buy the processing module, IE "Defi Link II" unit.

I have tested a Defi D Gauge and Auto Meter mechanical boost gauges on a dead weight tester in a Metrology Lab and believe it or not, the Auto Meter kicked Defi's ***. I believe Defi no longer offers a D Gauge mechanical boost gauge.

If I were you, I would get an analog electronic gauge that comes the closest to the style and backlight color of the stock gauges. The problem is I don't know of any that match both criteria - I am looking for one myself
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Old Jul 3, 2005 | 11:46 AM
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what brand should i go with then? i am probly going to need air fuel ratio gauge and boost gauge and their is one more i cant remeber which one was that lol
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Old Jul 3, 2005 | 07:34 PM
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Any1
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Old Jul 3, 2005 | 07:38 PM
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Greddy, HKS, Apex-i, Defi, whatever your wallet can take. I prefer the Defi gauges.
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