cleckner04

when you read peoples set ups and they say that they have a gm map sensor. does that mean they acually have a general motors map sensor. is that real. and what is the propose of it. is it for boost or what.

Fabrik8

Yes, it's a General Motors MAP sensor. The ones that people use are meant to measure higher pressure (often 2 bar) than the OEM Honda sensors, so they are used for boost. The GM ones are convenient because they are cheap and are somewhat convenient to retrofit into most cars. Not the greatest sensors out there, but they do their job.

If you use a GM MAP, you'll have to get tuned because the sensor is scaled differently. Say the stock sensor is 1 bar, and the output is scaled between 0.5-4.5V. If you use a GM MAP, it might be a 2 bar with the same 0.5-4.5V output, so it has a higher pressure measurement range but the same voltage range to go to the ECU. SO all of the pressure readings will be at a different output voltage than the OEM sensor, which is why you need to be tuned for the different MAP. In most cases that is really easy though; the GM MAP is so common that most of the tuning programs are already pre-configured for them and you just have to select the GM sensor from a dropdown menu or check a selection bubble, etc.

If you're looking to buy one, the GM part numbers are really easy to find, they're listed on tons of DIY turbo sites and forums. You can usually buy them off of a lot of vendor sites too, you don't have to get them from a GM Parts counter.

cleckner04

oh i dont need one but i just read that people use them and wondered why.