So I've been tuning my rx7 fc and its running a lt10c and the mapsensor reading in the data logs is not steady.... right now I got it right at 20psi in the boost gauge but in the data logs it show fluctuating between 15- 21 psi and its driving me nuts... anyway to kind of tame the map sensor reading? so it can show my boost pressure steady? I'm using the microtech ecu map sensor and it is hooked up to the little nipple besides the BAC valve. there is a MAPLAG factor in the ecu software and i tried playing with it but no success... any help will be greatly appreciated

 

You can try relocating the Microtech's vacuum/boost line to the front (non firewall facing) bottom nippple on the throttle body to provide a smoother signal. Dont tee this in with anything else.

Keep the line as short as possible, including the use of a small ID, thick walled hose to prevent kinks.

 

The best way to stabilize the fluctuations is fit a small fuel filter in your vaccume line it acts as a dampener and you will get a steady reading

 

Yes the onboard MAP sensor i have found in my experience to be sub standard. as quoted below a quick fix is to fit a small fuel filter to "dampen" the signal as mentioned by WJM rotaries. Just for your info the variations in this map signal will also be varying your injector pulse width so effectively you will be going rich and lean (which is dangerous in rotarys). i have tuned a car where i fitted a fuel filter damper and the car went from 210kw at the wheels with a flutter like missfire to 260kw at the wheels instantly without any change to the tune.