Logged boost vs mechanical boost.

[darkness]

I recently was able to hook up my mechanical boost gauge. It reads 50% higher boost than what my cts3 gauge reads thru the whole range. Cts3 gauge reads what the tune is commanding. Mechanical gauge was checked for accuracy. I’m at a loss of what could be wrong. MAP sensor? Seems it would follow the tune if it was bad.

 

[2004LB7]

PSIA or PSIG?

 

[darkness]

Both readings are gauge. Cts3 does the ecm math off of the MAP I’m assuming.

 

[JoshH]

Is your CTS3 gauge an add on EAS device or is it reading the stock MAP sensor?

 

[darkness]

Is your CTS3 gauge an add on EAS device or is it reading the stock MAP sensor?

Stock MAP.

 

[JoshH]

Have you verified the CTS reads the same as a scan tool or other datalogging system like EFILive?

 

[darkness]

I don’t have an obd2 splitter to do that, but could check certain areas I know what the cts3 reads. I know for a fact at max boost, the cts3 was reading what the tune was calling for. I was operating on boost map b and my max boost is 37psi. Boost was 24 on the cts3 and baro was at 13. And the mechanical gauge was 35psi.

 

[darkness]

Going to do a log now…

 

[2004LB7]

I was operating on boost map b and my max boost is 37psi. Boost was 24 on the cts3 and baro was at 13. And the mechanical gauge was 35psi.

37 - 24 = 13
Baro reads 13
Looks good

37 will be psig
24 is psia
13 is psia

34 looks like psig which is only 2 psi off the 37 psig. Might be a small error in either or both gauges/sensors. Nothing to worry about