Wow, I never realized how inaccurate my Autometer gauges were.
I took them out of my TSI the other day, to swap them into the AWD; and noticed that the vac/boost gauge was sitting a little low in the float block.
I work at a gauge warehouse, and I'm the calibration tech. So I brought them to work with me. This morning, I put them on the test bench. Here's the numbers I came up with.
Environmental Conditions:
Temperature: 73.9°F
Relative Humidity: 42%
Barometric Pressure: 30.028 inHg
Gauge Reading..... Calibration Bench (standard)
-20.................... -19.882
-10.................... -9.878
0........................ 0
10...................... 13.5117
20...................... 25.1447
30...................... 36.032
20...................... 24.949
10...................... 13.468
0........................ 0
-10.................... -9.87
-20.................... -19.97
I was boosting 16.5 psi according to the gauge. On the calibration bench, that turned out to be approximately
22 lbs. With a Walbro 255 and 450's, that could have toasted my motor...
I was unaware of how inaccurate these gauges were, anyone know which gauges are the most accurate? (at least a 2A according to NIST, even a 1A if I had to).
Looking at the build quality of the autometer, it looks to be a grade B (2-3-2%). That's not going to give me enough peace of mind when trying to set boost (without a logger/DSMLink).
Edit: An interesting article I found since posting this:
http://www.autospeed.com/cms/article.html?&A=1008
(Written in 2001)