P3 Vent Gauge - Interpreting Read-out Values

[cmcgonag]

Did you guys have to install the boost sensor to get boost readings. I really dont want to do that...

[ozinaldo]

Originally Posted by cmcgonag

Did you guys have to install the boost sensor to get boost readings. I really dont want to do that...

Installed mine yesterday. N54 engine does need that to get the boost data unlike N55 which gets it through OBD port connection. So the answer depends what car and which engine you have. Check the company web site there are install videos there which are quite helpful.

[cmcgonag]

I have a 1M....N54T, I need to put an OBD scanner on it. The AWRON guage doesnt need a sensor so I dont think this one should either.

[ZIPNBYE]

Well, it does. The total boost gauge plumbing job took about 10min total...so what's the issue?

[flzrider]

Can someone with a boost gauge observe the difference in boost with the M button ON vs. OFF? There was some talk before about the M button keeping the waste gates closed which, if true, should be observable in boost behavior.

[ZIPNBYE]

Originally Posted by Ian///M

Let us know if you buy one. I'd be keen, just not sure I can live without the vent in summer

The P3 gauge display / unit doesn't take the use of the vent away, it merely reduces the size (potentially speeds up the air).

[flzrider]

Originally Posted by Ian///M

There is no difference. This has been thrashed out in many old threads. All the M button does is change throttle sensitivity and adjust wastegates. The car is limited to 14.5 PSI in stock form.

What do you mean by "adjust wastegates"?

For the record, I have always been skeptical of the M button's effect beyond throttle sensitivity adjustment.

[cmcgonag]

Ian let me know how the AWRON turns out...if you dont need a boost sensor it lets me know the P3 is improperly designed and I will try to get them to revise the code.

[ozinaldo]

Question: Is there anyone with P3cars digital interface and the boost seems to appear higher than it should?

I am seeing 17s and 18s like all the time as I configured the device for metric units in general other than the boost which remains psi.

The rest of the functions seem to be very much as I expected and I am sure the boost tap to diverter valve is attached allright (checked again anyway), install perfect etc.

Most of you guys know what I have as mods, or you can see from my sig, nothing really to have higher than stock boost.

It was the same high values before I configured it as well, it comes configured with psi-miles configuration not metric.

Any similar experience or ideas?

[MDORPHN]

Mine is spot-on.

There is a procedure for calibrating the P3 vent gauge. Have you tried that?

Neil

[Harlequin]

Originally Posted by ozinaldo

Question: Is there anyone with P3cars digital interface and the boost seems to appear higher than it should?

I am seeing 17s and 18s like all the time as I configured the device for metric units in general other than the boost which remains psi.

The rest of the functions seem to be very much as I expected and I am sure the boost tap to diverter valve is attached allright (checked again anyway), install perfect etc.

Most of you guys know what I have as mods, or you can see from my sig, nothing really to have higher than stock boost.

It was the same high values before I configured it as well, it comes configured with psi-miles configuration not metric.

Any similar experience or ideas?

Have you calibrated it for your atmospheric pressure with the engine off?

[ozinaldo]

Originally Posted by Harlequin

Have you calibrated it for your atmospheric pressure with the engine off?

Nope! Didn't see this in their web site or probably just missed it, can that explain the over-reading?

I will try to find how I do that but if there is an easy link or so that you can direct me I will apreciate it a lot.

Thanks.

[MDORPHN]

I believe it depends on which version you have. On the older, version 2.0 gauge, it is calibrated each time you enter the configuration menu and then exit.

I'm not certain, but believe that the newer, version 2.1+ versions have a calibration function (Cal. b?) in the configuration menu.

Also, I believe that boost is read in PSI by default (and vacuum in Hg). However, boost will be in BAR if you configure the gauge to metric.

Hope that's helpful.

Neil

[Nugget]

Also if you are just hitting the max recall button it may just be reading a quick spike which happens on throttle closure.
I am on stock tune right now and was wondering why it was reading over 12 psi when I hit the recall max button. But watching it properly it was only hit 10ish then a quick spike when I got off the throttle. Not sure if this applies to N54s.

[Harlequin]

Originally Posted by ozinaldo

Nope! Didn't see this in their web site or probably just missed it, can that explain the over-reading?

I will try to find how I do that but if there is an easy link or so that you can direct me I will apreciate it a lot.

Thanks.

You have to go into settings mode and then flick through to Cal.b

This setting is used to calibrate the analog boost sensor to your ambient conditions.

- Tap left button to select it
- It will tell you to make sure your engine is off
- Tap left button after confirming engine is off
- Gauge is calibrated

[ozinaldo]

Thanks guys! While you were posting the last few useful advices I went down to my garage (after finding the relevant part in p3cars web site quickly which simply tells what Harlequin told before) and did as it is written and the device instructed me; I have the newer version 2.1+ whatever and just chose the config. menu and when I found the "cal.b" then I shut the engine off, as the device asked me to, and then tap the first button...then well nothing, it just goes off. Because I was not sure if that is it, calibration is done, I repeated it again (they could have add something reading like done or calibrated or bravo! etc.). I see that when idling at the garage the gauge still shows high value like 15s and 16s but this is less so than before. Maybe I had to do this when engine is absolutely cold (was not) or something like that or will just show correct values when I drive the car next time, don't know, will see this later.

Thanks everyone.

[ozinaldo]

Originally Posted by MDORPHN

I believe it depends on which version you have. On the older, version 2.0 gauge, it is calibrated each time you enter the configuration menu and then exit.

I'm not certain, but believe that the newer, version 2.1+ versions have a calibration function (Cal. b?) in the configuration menu.

Also, I believe that boost is read in PSI by default (and vacuum in Hg). However, boost will be in BAR if you configure the gauge to metric.

Hope that's helpful.

Neil

This newer version that I have also has a third option which is metric reading for all functions other than the boost (which remains psi not bar). Found it best for me but now I am thinking that if the issue persists I will go try the default and metric options as well to see what happens.

[Harlequin]

Originally Posted by ozinaldo

Thanks guys! While you were posting the last few useful advices I went down to my garage (after finding the relevant part in p3cars web site quickly which simply tells what Harlequin told before) and did as it is written and the device instructed me; I have the newer version 2.1+ whatever and just chose the config. menu and when I found the "cal.b" then I shut the engine off, as the device asked me to, and then tap the first button...then well nothing, it just goes off. Because I was not sure if that is it, calibration is done, I repeated it again (they could have add something reading like done or calibrated or bravo! etc.). I see that when idling at the garage the gauge still shows high value like 15s and 16s but this is less so than before. Maybe I had to do this when engine is absolutely cold (was not) or something like that or will just show correct values when I drive the car next time, don't know, will see this later.

Thanks everyone.

Are you sure it's not reading NEGATIVE 15-16 PSI at idle?

If so then that's completely normal.

[MDORPHN]

Originally Posted by Harlequin

Are you sure it's not reading NEGATIVE 15-16 PSI at idle?

If so then that's completely normal.

Yep, I'm thinking same. It's reading vacuum, not boost, at idle.

Also, engine temp should have little effect. Ambient and altitude have greater effect.

Neil

[ozinaldo]

Yeap, you guys are right of course; I simply confused the negative reading (vacuum) at idle after doing the calibration with my previous boost reading while I was on the run, and the device was not calibrated back then

Later, I will see if boost is precise at stock values (max 14.5 psi, right?).

I got to play with this fun thing and forget about it after a while, too much data, too many numbers in what should be an analogue car

[1MOz]

Originally Posted by Harlequin

You have to go into settings mode and then flick through to Cal.b

This setting is used to calibrate the analog boost sensor to your ambient conditions.

- Tap left button to select it
- It will tell you to make sure your engine is off
- Tap left button after confirming engine is off
- Gauge is calibrated

Thanks for that Angus. I didn't know the P3 needs calibration. After calibration, my boost reading at idle is now around -20psi, used to be around -15psi. Is there anything I should be concerned? Peak at is still the same around 18-19psi with Cobb Aggressive +FMIC OTS map.

[Harlequin]

Originally Posted by 1MOz

Thanks for that Angus. I didn't know the P3 needs calibration. After calibration, my boost reading at idle is now around -20psi, used to be around -15psi. Is there anything I should be concerned? Peak at is still the same around 18-19psi with Cobb Aggressive +FMIC OTS map.

No problem mate... Always happy to help...

Mine idles around -17-19 so seems pretty normal to me...