Over 30 PSI with 3 bar map...what happens?

[MSDGN]

What happens if you run over 30 PSI boost with a 3 bar map using XFI...I'm assuming the settings at 30 PSI are used...so basically if you run 32 PSI the VE table settings from 30 PSI will be used...so you can't tweak anything over 30 PSI...it that correct?...also just curious what static fuel pressure is good to use...the FAST XFI guide says 45 PSI...I need to check mine pressure but can't remember what I had set it at...thinking around 43 PSI...is it that important since XFI will compensate anyways?

 

[BEATAV8]

you are correct. If the sensor stops at 30, then that's where you will stop in the table.

 

[Otto J]

Yes,the top line will be the tune for anything over 30#s.
There are 3.5 bar sensors available to tune up to 37.5#s of boost.
Dont worry to much about the base pressure,if its between 42-45
you will be fine and tune from there.

 

[johnplogii]

The check engine light will come on when you max out the sensor, mine goes to 30.6

 

[HighPSI]

The check engine light will come on when you max out the sensor

Now, how did you know that j/k

You can also turn the check engine light off for that sensor if you want.

 

[MSDGN]

You can also turn the check engine light off for that sensor if you want.

How do you do that Cal?...so it turns the light off just for that sensor and nothing else?

 

[lazaris]

Go into view, system config, fault detection and uncheck Map fault enable.

 

[johnplogii]

Now, how did you know that j/k

Only because you told me Well maybe I set it off once.

 

[Pittsburghkid]

Yes,the top line will be the tune for anything over 30#s.
There are 3.5 bar sensors available to tune up to 37.5#s of boost.
Dont worry to much about the base pressure,if its between 42-45
you will be fine and tune from there.

AEM makes a 5 bar map sensor which might work for you. Here's what they said about the two. Hope it helps

AEM 5 Bar Map (75 PSIA) Sensor Kit. This is a pressure sensor that will read boost in a supercharged or turbocharged vehicle. A smaller 3.5bar map sensor will read ~36psi of positive boost pressure. If you need to read more than 36psi of boost, you would want to use the 5bar map sensor which will read to 58psi of positive boost pressure. When selecting a map sensor, bigger is not always better. A bigger map sensor will allow you to read more boost pressure, but a bigger map sensor uses the same 0-5 volt output as a smaller map sensor, meaning the smaller map sensor would have a better resolution. So the best way to pick a map sensor would be to determine how much boost you will max out at, if it is 36psi or below, get the 3.5 bar. If it is over 36psi get the 5 bar.

 

[HighPSI]

I'm pretty sure he was more concerned about the resolution of the table then the resolution of the sensor. So far I haven't seen a resolution issue with using a 5 bar sensor. Most of the aftermarket ecu's we sell use either a 3 bar or 3 1/2 bar. Very few customers order a 5 bar.
WARNING: The AEM 5 bar sesnor calibration is quite a bit diferent than the FAST 5 bar calibration.

 

[Pittsburghkid]

I just remember reading that about the 5 bar and copied and pasted it in case it was of any help.

 

[TurboTR]

If you go a couple 2, 3, 4 psi or so over the 3 bar limit it doesn't really seem to matter much in real racing use. The top row is then just tuned to support your max boost. And you generally pass through the top so quickly (on the way to max boost) that you don't even notice a momentary over richness.

It's kinda like the old days when we had to tune past the stock 255 MAF count limit.

Much more than a couple few psi over 3 bar though and it's maybe time to consider a higher bar sensor.

TurboTR