Can someone please explain offset and scale
 

I have just recently installed a GM 3 bar map sensor, and was looking for the correct way to set up the scale and offset. However, after doing a search on the forum, I see that several different people have used several differnt settings.

Can someone explain exactly what setting the scale and offset is supposed to accomplish?

Additionally, can someone tell me how to determine the optimun setting for any particular setup?

:)

yes,

in Max's post, he wrote what offset and scale to use.. Steve (pluto) also responded with a different one. basicly, its different for all cars and what you do is set it and hook up a boost pump (like the one that you have) and pump it to a set PSI and see what the pfc is reading.. if its right on the dot, it fine, if not, try other settings until the pfc boost reading and the guages are as close as possible.. Thats what i understood for reading other posts..


btw, SEARCH!! hhaha... :)

I don't think it should be all that different from car to car, so you should just be able to get some numbers and plug them in.

You know the line equation y = ax + b ? Scale is a and offset is b, as best I can figure.

-Max

It shouldn't be but I have 3 different figures being throw around on the forum.

41800 offset 0 Tworx7
43500 offset 320 ccarlisi
44000 offset 357 pluto

the forumla is familar, but I do not remember what it was used for. too long ago. :p:

I guess I should have read your thread a little closer. I went back and re-read it, and noiw the dense fog has turned into a mushy kinda haze. :p:

Anyways, can you tell me if I have this right.

With the key in the in the on position, I hook up a pump to the boost sensor. Pump, and make sure that what is reading on the pump is also reading on my commander?

If not adjust the option 2 with one of suggested numbers and offsets, until everything is reading correct?

Can this all be done with just the commander?

You can use any of the settings or come up with your own. There's not much difference and if you tune the entire map anyway it really doesn't matter much.

Many stop short, just tune full throttle and live with the rest of the map, those that have taken the time to tune it all know what I am talking about. If you pay someone to tune the entire map it can cost some jack, takes lots of time and IMHO several sessions under different ambient conditions and different tanks of fuel to optimize.