How many UTEC users have removed their MAF sensor? Not sure if I'm understanding correctly. Documentation says that if you have the MAP sensor for speed density fueling, you can remove the MAF for more air flow.

 

No, not true. You still need your MAF for when you are just cruising and not WOT. The UTEC is not controlling the car 24/7, it is a piggy back that takes over at a certain throttle percentage (or boost level) and rpm. You car won't even idle without the MAF, try it and find out for yourself .

 

^^+1

Utec only kicks in when your in boost. ECU is still controling everything with the MAF sensor when your not.

 

you can setup the UTEC to control fuel and timing from startup. I've never tried it, though. If you want to do it, you need to change you lowest open loop fueling parameter to probably "-12" psi. that way, as soon as the car starts, you'll be in the 10% load column.

of course, you'll need to redo your entire map!!!

 

Just keep in mind that your car idles at -21 psi so it is still not 100% possible for the UTEC to have full control. But with any throttle input (even slight), you are usually at -15 psi or higher anyways so it will work for you. Just set the map initiate threshold to the lowest (which is -15) and tune away!

 

You must have a special car if yours idles at -21 psi!!!!

I think you are confusing inHg (inches of Mercury) with psi. They are not the same. 1psi is approx equal to 2 inHg. So, you car actually is idling at -10.5 psi (but your gauge has a scale in inHg on the vacuum side), not -21 psi.

 

Remember the Earth's standard supercharger is +14.7 psi [+29.92" Hg].

Mechanics assume this is Zero, ENGINEERS KNOW that there is never a vacuum just a lower than atmospheric pressure.

Drives me nuts, the use of the word "vacuum gauge"


18" of so called vacuum is 14.7 minus 6 or POSITIVE 8.82 psi in plenum

 

Lol, thanks for the correction quadcam, that is what I meant .

 

this is all true, but we are talking about tuning the UTEC which refers to pressures less than standard atmospheric as a negative PSI value.

The UTEC does offer a choice of choosing between absolute and gauge pressure readings on its logging display, though.