To all of you who have aftermarket boost gauges, how does the in-dash OBC boost reading compare to the real reading? Higher than true boost value, lower and lags behind, or spot on?

 

mine shows consistently .1 bar higher compared to the greedy
tim

 

Tim -- Thanks for the fast reply and the information!

 

My OEM gauge displays the same as Tim's - about .1 bar over the greddy.

 

Interesting....the boost gauge shows .1 bar over....and the speedometer shows 4 miles faster.....I guess that's sort of built in psychological marketing? You think you're going faster and at a higher boost than you actually are? Is this is the psychology used to keep your speeds slower, boost lower....and possibly add a little longevity or less warranty claims due to lower power thresholds? I've read on these forums that almost universally, the speedo's are 4-5 miles slower....why the built in inaccuracy? I mean Porsche is supposed to be a precision German engineering. Where's the precision in instrumentation?

 

I've noticed that my speedo is 1.5mph faster than my Pbox. I don't have a boost gauge, so I can't tell if that is off.

 

You mean I'm not crazy???????? My speedo reads 3-4 MPH higher than my GPS--I thought maybe the GPS was off (and maybe it is), but if these speedos are notoriously high, then I feel a little less crazy Maybe I'll borrow a friend's portable GPS and see which two of the three are the same...

 

My HKS boost gauge registers and retains (until reset) the peak boost for a particular segment of time as does the Greddy. It is about equal with the factory gauge but when I look at the computer data logged for the whole run, the HKS number is 0.1 bar higher bc the HKS reads and displays the spike.

My Performance box shows my spedo 2mph fast at 60 mph with OEM diameter tires.

 

The dash gauge and an ebc take readings from different places w/ respect to the manifold, leading to the dash reading a little higher

 

My Pbox takes the reading from my cigarette lighter, thats probably why mine is off...

 

I guess it depends on what sort of stuff you're smoking