Which is Correct: Boost Gauge or Turbo-Link?

[Who Needs 8]

So, when I make a WOT run, my boost gauge will say it's running 20psi but my boost harness on the Turbo-Link says 25-26 psi I am having some knock issues, but if I turn it down to where the gauge says 17PSI, the knock goes away (on 104 or 110) but the TL says 24-25 PSI.

Sometimes when it's on 93 octane and the gauge says 17 psi, I have Knock. Which makes me think the gauge is wrong. The gauge was on the car when I bought it.

Which do I believe?


INFO: 1989 Turbo Trans Am
ATR intake pipe, K&N cone-type filter
38 lb/hr Fuel Injectors
Elect. Walbro 340, adj. regulator, stock line size
21° Timing
Stock manifolds, 3" ATR exhaust and single muffler
Precision Industries GT 3255 Turbo
Tial external wastegate with adj. boost controller
Vigilante, 3,200 stall

 

[Who Needs 8]

Oh yeah, I'm also using an Auto Meter boost gauge.

 

[ijames]

You need to borrow a second, "known good" gauge, and tee it into the hose in your engine compartment that goes to your boost gauge. Then use a bicycle tire pump with one of those conical adaptors you use to inflate air mattresses and pump up your system while you watch both gauges and turbolink. Anything short of that is just us consulting a Ouija board .

 

[GNguy]

from my experience, autometer gauges suck

 

[jpratt]

Did you calibrate TL before the run? You need to calibrate a few times a day to give acurate readings.