Page 1 of 1
MAP sensor placement
Posted: Sun Feb 03, 2008 5:54 am
by 1365keith
I am having trouble finding a place to put the controller under the dash of my car. Just not enough room and still be accessible. I am thinking of putting in the trunk. First of all, an pros and cons of putting it in the trunk? Second of all, with that long of distance between the MAP sensor and the engine, will response time or distance be an issue? Would it be better to place the sensor on or close to the engine and run wires back to the controller?
Posted: Sun Feb 03, 2008 8:17 pm
by obxer
From the manual - right under the MAP sensor info:
Don't worry about how long your MAP sensor vacuum hose is. Intuitively it seems that shorter should be better. However, a few people have done tests to see how bad the effect of a long hose was on vacuum signal propagation. With a ~100 foot (~30 meters) coil of rubber tubing in between the MegaSquirt® and the engine, the result was that no delay was apparent. This was with about a 10 millisecond resolution clock. The reason for this is that air has so little inertia that it moves very quickly in response to a vacuum (this is how we fill the cylinders, after all!).
Had this worry myself - ended up putting my Microsquirt behind the passenger seat.