anyone runnning holsets? at like 35-40psi

[autronicDSM]

I don't know about AEM, but autronic MAP sensor reads ~100kpa at 0psi on a gauge

 

[aero_sallee]

It doesn't work like that. The map sensor is affected by atmospheric pressure but not like you are thinking. At sea level a map sensor and a good gauge should read the same. At 5000ft it would be off by roughly 3 psi.

The map sensor itself doesn't measure like that though. It measures from 0 pressure, not from atmospheric like a guage. The AEM may be set up to display it that way though.

 

[40oz]

It doesn't work like that. The map sensor is affected by atmospheric pressure but not like you are thinking. At sea level a map sensor and a good gauge should read the same. At 5000ft it would be off by roughly 3 psi.

No, it works like that. Absolute pressure is pressure greater than 0, meaning there is some gaseous pressure in the volume. That's why some boost gauges have a "vacuum" display. Any pressure less than atmospheric is vacuum. There isn't even a way for a MAP sensor to measure gauge pressure, because it has no exposure to atmosphere (Not sure about ALL MAP sensors, but most, I believe). The AEM could certainly have a boost display, set up to compare the MAP reading versus atmospheric, but if it is the true MAP sensor reading, then it isn't boost, it's boost plus atmospheric. That's why some naturally aspirated cars come with 1 bar MAP sensors, because 1 bar, or about 1 atm, is all they will ever have to measure.

 

[GVR4592]

I've tuned 4 different types of engine management systems in the last few months and the datalogged values from the map sensor matched the gauge within 2 psi on all systems. My AEM 5 bar with both Dsmlink and my AEM EMS, reads identical to my boost gauge.

 

[autronicDSM]

That's because the software displays it that way!

 

[topstreet]

Unless you are traveling around the country and seeing a large difference in baro pressure then it souldnt make that great of a difference. I use an AEM ems and have seen little difference in MAP voltage from even one season to the other. Key on but not running where the gauge is going to display pressure with no engine effect.

I run 43 psi on a regular basis. ( above 0 ) The software is where the tuning takes place, so that is where I would like to see the consistancy. I dont even run a boost gauge because it doesnt really matter what it says. The point in my fuel and timing maps is what matters to me.

As far as the block, head, that kind of stuff. Talk to Darren at FFWD. Ask him for the best of the best and thats what Ive got. Head gasket is a stock mitsu. MLS.

 

[GVR4592]

I don't know about AEM, but autronic MAP sensor reads ~100kpa at 0psi on a gauge

AEM reads the same, 100KPA=0PSI