MAP Scaling Help

[lplott]

Two questions:

1. With a 2 bar MAP sensor, and 7PSIg boost, I think I should be reading about 150kPa at 7PSIg. Anyone out there witha boosted application can verify this on their car?

2. If I have the MAP sensor scaling messed up,what do you think would be the best way to get it right without having to re-install the OEM MAP sensor, read baro, re-instll the 2bar MAP sensor and re-scale.

Thanks,
Lonnie

[TAQuickness]

148 kPa would be about right at sea level.

As for the MAP scaling, page 16 of the custom OS tutorial covers scaling the 2 bar map sensor.

[lplott]

TAQiockness,
Yep, that works if you know what the MAP should put out at this altitude, 6000ft above sea level. Unfortinutely, the 2bar is already installed and I do not remember what the OEM MAP sensor read 3 months ago when it was removed. I scaled it then to what the OEM MAP read. I had a friend with a simular Vette check his MAP kPa reading at key on and he reads 80kPa, so does mine. The problem is, I am only seeing about 125kPa on the MAP log but my boost gauge says 7PSI. Something is not right here. Also, the car runs strong, breaking loose 335 rears in 1st and 2nd.

Almost sounds like above 105kPa there is a different scale being used so I am only seeing 125kPa at 7PSI.

Something does not sound right...

Any thoughts???

Lonnie

[dc_justin]

If 80kPa is atmosphere, then it would make sense to me that 125kPa would be about 7psi of boost. That's 45kPa of boost right there compared to the 48kPa that TA said would be 7psi... pretty close if you ask me.

[lplott]

dc Justin,

That is why I come to this board. Someone out there always applies a little common sense to my problems and helps me see the light.

You'd think with my math background I would have seen that... Guess I got stuck on 105kPa being atmospheric and did not apply to the equation that 80kPa is amospheric here in Colorado Springs

THANKS for a good dose of common sense.
Lonnie

[dc_justin]

dc Justin,

That is why I come to this board. Someone out there always applies a little common sense to my problems and helps me see the light.

You'd think with my math background I would have seen that... Guess I got stuck on 105kPa being atmospheric and did not apply to the equation that 80kPa is amospheric here in Colorado Springs

THANKS for a good dose of common sense.
Lonnie

[TAQuickness]

dc Justin,

That is why I come to this board. Someone out there always applies a little common sense to my problems and helps me see the light.

You'd think with my math background I would have seen that... Guess I got stuck on 105kPa being atmospheric and did not apply to the equation that 80kPa is amospheric here in Colorado Springs

THANKS for a good dose of common sense.
Lonnie

Nothing like a fresh set of eye's.

DC nailed it. The MAP reading is absolute and your boost guage is in reference to atomospheric.