For anyone out there at high elevation - Colorado, Idaho, etc. I installed a prosport boost gauge, however, it's not zeroing itself out. Instead it starts at -6 just when the power is turned on (car not started). I am at 4400 ft above sea level. Porsport is supposed to be getting back to me. Just wondering if anyone else has dealt with this issue. Thanks

 

Usually there is a way, by means of fiddling with the gauge's button, to set the "0" point, so Progauge should get back to you with a simple procedure/set of instructions.

 

Your gauge is probably calibrated for sea level. Because of your altitude, the atmospheric pressure is lower than at sea level. Your gauge thinks its in a vacuum. You need to get yourself instructions on how to recalibrate it.

 

You were right. The electronic gauge cannot be recalibarted though The gauge company recommends using a mechanical gauge when at elelvation. Great Anyone else with any ideas?

 

There may be something else wrong with your gauge. The difference in atmospheric pressure between sea level and 4,500 feet is only 2.25 psi.

You'd have to be up around 14,000 feet for the gauge to be 6 psi off solely because of altitude-related inaccuracy.

 

^ Scott is correct - I thought the same thing when I read this earlier.

 

Prosport says there should be a 4.5 psi difference in atmospheric pressure at 4500ft - mine still reads 6 so something is amiss. Prosport is sending me a new internal sensor that can possibly be adjusted

 

Well, they're wrong. Atmospheric pressure drops approximately 0.5psi per 1,000 feet of altitude.

http://www.engineeringtoolbox.com/ai...ure-d_462.html

 

I believe you but how do you read that chart and get 2.25 at 4500??

 

At 0 feet (sea level), atmospheric pressure is 14.696 psia (the fifth column).

At 4500 feet, it's 12.46 psia, which is about 2.25 psi lower.

 

The column you're interested in says has the heading "psia" - that's atmospheric pressure in pounds per square inch.

Atmospheric pressure at sea level is 14.696 psi, at 4500 ft it is 12.46psi

"Boost" gauges are adjusted to read "zero" boost at the actual atmospheric pressure at your altitude - so they read out the pressure ABOVE your local atmospheric pressure as the boost pressure.

 

Jinx! Simulpost.

 

This gauge can be recalibrated daily, if you like, at the touch of a button:

http://www.veisystems.com/bhm-m.html

I use it and it works great!!



http://www.youtube.com/watch?v=C9YCRGPRAmQ

 

If they knew it couldn't be calibrated for altitude why didn't they tell you that when you called to order? You think they would have said something to you when you gave them your high altitude shipping address. Plus they are giving atmospheric pressures from another planet? lol

I hope you paid by credit card. I would return it and call my credit card company and dispute the charge.

How much was this boost gauge?
Joe

 

-6 in/Hg = -2.9467 PSI.
Vacuum is commonly measured in Inches of Mercury. Your gauge is working properly. Welcome to Altitude.

 

Good call! I totally forgot about the change in units from psig to inches of mercury when the gauge gets into the vacuum range.

 

So, if my gauge shows 12 psi of boost when driving, does that mean the engine is producing 12 or 14.9467 or 18 psi??

 

About 14-15psi

 

Alright - I received a new sensor I am able to calibrate to zero from Prosport. I put it on this afternoon, calibrated to zero, and went for a spin. My question pertains to my new boost readings. Again, I have an 07MCSm with the mods listed below. I was continously reading 16 psi at WOT and a couple times hit 18.5 and 19psi in overboost. These seem a little excessive compared to other threads on here, especially without any tune. So does anyone have an idea on this? Does anyone think the gauge may be misreading due to the altitude?? I'm just not sure how the physics behind the gauge works in altitude? Maybe I just have a strong engine