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jwasbury jwasbury is offline
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Join Date: Jan 2008
Location: Weehawken, NJ
Posts: 3,369
I recently installed the boost/vac gauge from NHS in the clock location (gets boost signal off of brake booster hose). My observation in comparing the two is that my tach gauge is reasonably accurate at telling me full boost level...But it reads very different from the mechanical gauge when the boost is building. For example, the tach gauge will show .2 bar while the mech gauge shows that manifold pressure is at atmosphere (0 bar) or even a slight vacuum. My understanding is that this difference is due to the fact that the mech gauge reads after the throttle plate, and the factory tach gauge sender is before the throttle plate. I do think that factory boost gauge sender in my car is not original (looks too shiny so must have been replaced at some point).
Current: 1983 911 GT4 Race Car / 1999 Spec Miata / 2000 MB SL500 / 1998 MB E300TD / 1998 BMW R1100RT / 2016 KTM Duke 690
Past: 2009 997 Turbo Cab / 1979 930
Old 11-07-2008, 01:56 PM
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