Mpi standalone efi

[rxrider]

so true

 

[desperado]

The challenge at getting better fuel economy on a SC setup is much more closely related to perfecting the boost map than the fuel map -- the two obviously go hand in hand. Most SC setups put out too much boost at part throttle and the increased air charge pressure must be compensated with additional fuel at part load where the engine does not make full use of the corresponding absolute manifold pressure.

For example, reducing midrange absolute manifold pressure, say at 7,000rpm, from 160kpa to 130kpa will reduce fuel requirement by 30% at that engine speed. This is because a properly setup MAP compensation table will double fuel flow for every 100kpa. Trying to achieve the same thing by going from lambda 0,80 to lambda 0,85 (12.0 afr to 12.5 afr) will only net around 5% less fuel requirement. All oem supercharged jetski manufacturers (Yamaha, Seadoo and Kawasaki) understood that a long time ago and have engineered SC systems that can pump 180kpa boost (12psi) while allowing cruising at boost anywhere between 90kpa to 110kpa.

 

[gunnerthesnowman]

The challenge at getting better fuel economy on a SC setup is much more closely related to perfecting the boost map than the fuel map -- the two obviously go hand in hand. Most SC setups put out too much boost at part throttle and the increased air charge pressure must be compensated with additional fuel at part load where the engine does not make full use of the corresponding absolute manifold pressure.

For example, reducing midrange absolute manifold pressure, say at 7,000rpm, from 160kpa to 130kpa will reduce fuel requirement by 30% at that engine speed. This is because a properly setup MAP compensation table will double fuel flow for every 100kpa. Trying to achieve the same thing by going from lambda 0,80 to lambda 0,85 (12.0 afr to 12.5 afr) will only net around 5% less fuel requirement. All oem supercharged jetski manufacturers (Yamaha, Seadoo and Kawasaki) understood that a long time ago and have engineered SC systems that can pump 180kpa boost (12psi) while allowing cruising at boost anywhere between 90kpa to 110kpa.

So you cycle your blow off valve to give a set boost at a set RPM

 

[desperado]

Exactly, best method is to use a pulse modulated solenoid and a 3D map using rpm and TP as the X and Y axis. Using TP as an axis allows to anticipate driver power requirement and control the BOV faster for even greater throttle response.