Anyone compare boost readings off of the ECU (EvoScan w/ Mod23) vs a traditional boost gauge? The reason is that I recently installed a Greddy Infometer touch with an external boost sensor adapter and have been noticing peak boost of 28.9lbs as compared to my 24.9lbs that was logged while getting tuned. Unfortunately, I do not have the Evoscan software to do back-to-back runs but was was wondering if anyone has any feedback.

Thank in advance!!

 

Hmm right after posting this, I just had an idea. Since the infometer can display multiple readouts at the same time, I was thinking I should use the intake manifold pressure readout and display that at the same time as the external boost readout. Although the ECU provided readout would be peaking at 22.3lbs (Infometer can read the boost off of the CAN output but the Infometer will only show up to 22.3lbs via the ECU), this should be a fare comparison up until that point. I'll post again later tonight with the results.

 

So the Infometer has its own sensor and isn't reading off the factory MAP?

 

I can read off the factory MAP but for some reason the output of the ECU will peg at 22.3psi. The Informeter touch allows for add-on sensors for boost, temp, and pressure readings.

 

First of all, they have to be reading from the same place. Secondly, you have to make sure the external sensor is properly calibrated.

 

The OBD-II MAP signal is capped at ~37 psi. Assuming barometric pressure of 14.7 psi:

37 - 14.7 = 22.3 psi

 

I think OBD2 programs are capped at 22.3 psi or so but the Mode23 in Evoscan 2.6 b16+ should read much higher. My gauge has always read about 1-2 psi higher than actual so when I see 29 psi while my ECU logged readout is 27 psi I don't panic but I can understand your concern. The first issue I've noticed with my autometer gauge is that it sits at 1-2 psi when the car is off depending on high or low barometric pressure. Yours seems to be much bigger of a difference but something to think about.

 

Thanks for the feedback. I wasn't concerned with the reading but just curious as to how/why they would be different. In the end, if the A/F ratios, knock logged, etc show that the car is running safe/fine; then regardless of the "boost", there's nothing to worry about. I am curious as to which is the "actual" though... But consistency is what matters more if you ask me.

My thought process goes like this:
Say we are at the track. It would be like me giving someone a tire gauge that read 5psi higher than it really was and telling them that when that tire gauge read 28psi; the laptimes would be the most consistent/fastest. If this was true, then regardless of the actual pressure, as long as the gauge always read the same thing and everything else was "safe", it wouldn't matter... Same would apply to the boost reading. If the boost always read 29psi but was really, 26psi and safe, in the end it doesn't matter.


All that said; anyone else notice differences with their gauges?

 

Can you confirm that the informeter can only show max 22.3 psi reading off the CAN? I just installed the informeter today & thinking of getting the sensor adapter with the external boost sensor if it can't read beyond 22.3 psi.

 

If your logging with Evoscan look at your table for PSI. Comes with 14.7 in the formula. Me being at around 5000ft im at 12.3. Best way make it read 0 turn key on (not the engine) and see where your Psi level is at. if its not zeroed out play with formula make it read zero. Then should be dead nuts.

 

is there any way to but the 14.7 psi correction factor into the informeter?