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View Full Version : Boost Gauge install reading 0 at idle???



dieseldom
11-13-2008, 08:01
newbeeee...
I have installed a autometer pyro and boost it looks like the pyro works fine but the boost gauge is not, not sure if this is right.
At idle it reads 0 and as I drive it will move up but not fast and will read up to 15 if I'm at about 15-1800 rpm's and when I stop will read 0.
I have an 05 silverado DMAX and have tapped the line into the passenger side intake manifold just ahead of the rubber boot. no kinks and all tight.
This is new to me so if I can get some help from some one who has one installed it would be great to hear from you. Thanks

:confused:

Kennedy
11-13-2008, 08:20
Boost is more load dependent. At idle it will typically be nothing. Smash your foot to the floor and it should see 20 or so. I haven't been a big fan of the Auto Meter gauges (aside from nice styling they tend to suck) but it sounds like yours are working fine.

Mark Rinker
11-13-2008, 08:35
Wouldn't vaccuum gauges suck? And boost gauges ... blow? :p

dieseldom
11-13-2008, 08:36
Thanks for the reply Kennedy, this gauge should read about 28-30 at highway speeds under load? can you elaborate on this.

DmaxMaverick
11-13-2008, 09:18
Without a significant load, you won't see much boost activity. A load can be actual cargo, loaded bed or towing, hard acceleration, or ascending a grade. You should never see 28-30 PSIG with a stock truck, 20 to 25 PSIG is about max, and that's at a specific RPM, WOT, under a significant load. Highway cruising on a flat road should show less than 10 PSI. Temperature, humidity, and barometric/atmospheric pressure also play a part in how your turbo performs. In any case, you should never see more than 0 PSIG at idle, or easy acceleration off idle.

The turbo is a passive device. It isn't mechanically driven, like a supercharger (blower). To create intake boost, you need exhaust gas energy to drive the turbine, and intake restriction (more pressure than the engine RPM can consume). At lower fuel input, there isn't much exhaust gas energy to drive up the intake pressure. More fuel with a lesser climb in engine RPM will increase the boost, and power. More fuel is more power and more boost (potential), which in turn, creates more exhaust gas energy to drive the turbine. Your turbo performance is also controlled electronically by the PCM, so you will not see the same performance curve of previous wastegate turbo models. Good or bad, depending on how you look at it.

dieseldom
11-13-2008, 09:40
Thanks for the info. DmaxMaverick. You have explained this well. I have not hauled or put any strain on the truck since I've installed this gauge and now knowing this, has given me an understanding on how it should be.
Thanks again
:)