MicroSquirt.com read only forum (Jan.15,2018)

heres what i got

81 yamaha xj650 stock engine
turbo kit i built running 9psi
gm coolant temp sensor
gm air temp sensor
gm 3 bar map sensor
microsquirt

this bike has been running for about 7months without really any problems but im trying to find out how to fix my rich spot on interstate see the problem im having is my map reading is on 90-100kpa on the interstate which is causing a rich spot so what ive done to kinda get around the problem was to lean out just the spot at 65-70mph which is 5k-6k but if i want to really get on it from 1st which doesnt really build boost ill get a lean dip at them rpms anyway to fix this ?? i have the map sensor tapped into all 4 itb's by itself and the other vacuum stuff is tapped of the intake manifolds which is all tie together. thanks

A datalog and msq file would be helpful.

A few years back there was a design plan (mentioned here and there on the various Bowling and Grippo websites) for a small do-it-yourself analog circuit board that was called a "synchro-map circuit". I think the circuit was the brain child of guys who were trying hard to make Speed Density fueling work on small ITB engines rather than just giving up and going to Alpha-N fueling.

On engines with short, independant throttle bodies, especially small displacement engines that tend to generate really jagged and jumpy MAP signals, the synchro-map circuit could be used to smooth out the vacuum signal reported to the Mega/Microsquirt. The way it worked was this: you installed a separate MAP sensor on each intake runner (that would be 4 total map sensors on a 4 cylinder motorcycle) and ran their outputs into the synchro-map circuit. The synchro-map circuit looks at the inputs from all the MAPs and only delivers the lowest of the MAP input signals it sees at any given point in time as output to the Mega/Microsquirt.

I know your turbocharged situation is more complex than a naturally aspirated engine would be, but if having a smoother MAP signal that's more honestly representative of the actual amount of vacuum your engine is pulling (or the level of pressure the turbo is pushing) at any given moment is helpful, maybe the synchro-map circuit might help you out a bit.