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

is there any way to controll boost with megasquirt II so i don't have to buy a boost controller. i would rather keep everything to one unit. thanks for any input

is there any way to controll boost with megasquirt II so i don't have to buy a boost controller. i would rather keep everything to one unit. thanks for any input
frank dunker


Posted by email.

scir16v88,

If you need 'on/off' boost control for an external device, you can use the spare outputs (see the manual table of contents). These can use the MAP (boost) as well as coolant or air temp as conditions, etc.

If you want fuel cut, you can put in the top row of your VE table to be 1 kPa higher than what you want (which would be in the next row), and have the VE in that row all equal to zero. So, for example, you might have a 200 kPa bin with a normal VE row, and a 201 kPa bin with all zeros. The fuel drops off so rapidly that it creates a very lean mixture that won't burn, and shouldn't cause engine problems. That is effectively a hard fuel cut boost limiter.

Obviously you can do the same with spark retard, though this might lead to dangerously high exhaust gas temperatures.

If you need a PWM device, then you need to do some coding. If this were mine, I would use the FIdle output and the PWM Filde circuit, then adapt the FIdle code to activate when you prefer.

The plan is to have PWM boost control as part of the GPIO set of functions.

Lance.

scir16v88, If you need 'on/off' boost control for an external device, you can use the spare outputs (see the manual table of contents). These can use the MAP (boost) as well as coolant or air temp as conditions, etc. If you want fuel cut, you can put in the top row of your VE table to be 1 kPa higher than what you want (which would be in the next row), and have the VE in that row all equal to zero. So, for example, you might have a 200 kPa bin with a normal VE row, and a 201 kPa bin with all zeros. The fuel drops off so rapidly that it creates a very lean mixture that won't burn, and shouldn't cause engine problems. That is effectively a hard fuel cut boost limiter. Obviously you can do the same with spark retard, though this might lead to dangerously high exhaust gas temperatures. If you need a PWM device, then you need to do some coding. If this were mine, I would use the FIdle output and the PWM Filde circuit, then adapt the FIdle code to activate when you prefer. The plan is to have PWM boost control as part of the GPIO set of functions. Lance.
Forum Rules --- No responses to your posts? See this. MegaFAQ --- MegaManual


Posted by email.

scir16v88, If you need 'on/off' boost control for an external device, you can use the spare outputs (see the manual table of contents). These can use the MAP (boost) as well as coolant or air temp as conditions, etc. If you want fuel cut, you can put in the top row of your VE table to be 1 kPa higher than what you want (which would be in the next row), and have the VE in that row all equal to zero. So, for example, you might have a 200 kPa bin with a normal VE row, and a 201 kPa bin with all zeros. The fuel drops off so rapidly that it creates a very lean mixture that won't burn, and shouldn't cause engine problems. That is effectively a hard fuel cut boost limiter. Obviously you can do the same with spark retard, though this might lead to dangerously high exhaust gas temperatures. If you need a PWM device, then you need to do some coding. If this were mine, I would use the FIdle output and the PWM Filde circuit, then adapt the FIdle code to activate when you prefer. The plan is to have PWM boost control as part of the GPIO set of functions. Lance.
Forum Rules --- No responses to your posts? See this. MegaFAQ --- MegaManual


Posted by email.

scir16v88, If you need 'on/off' boost control for an external device, you can use the spare outputs (see the manual table of contents). These can use the MAP (boost) as well as coolant or air temp as conditions, etc. If you want fuel cut, you can put in the top row of your VE table to be 1 kPa higher than what you want (which would be in the next row), and have the VE in that row all equal to zero. So, for example, you might have a 200 kPa bin with a normal VE row, and a 201 kPa bin with all zeros. The fuel drops off so rapidly that it creates a very lean mixture that won't burn, and shouldn't cause engine problems. That is effectively a hard fuel cut boost limiter. Obviously you can do the same with spark retard, though this might lead to dangerously high exhaust gas temperatures. If you need a PWM device, then you need to do some coding. If this were mine, I would use the FIdle output and the PWM Filde circuit, then adapt the FIdle code to activate when you prefer. The plan is to have PWM boost control as part of the GPIO set of functions. Lance.
Forum Rules --- No responses to your posts? See this. MegaFAQ --- MegaManual


Posted by email.

James and I also plan on making boost control an option in MS2/extra. The main limitation will be the number of these other features that you can use at once without getting the GPIO board. The MS2 is very short on extra outputs.

James and I also plan on making boost control an option in MS2/extra. The main limitation will be the number of these other features that you can use at once without getting the GPIO board. The MS2 is very short on extra outputs.


Posted by email.

Thanks for the input, i found a PERRIN Electronic Boost Controller Solenoid and plan to use that and make another pwm fidle circuit like i did for my bosch 3-wire fast idle controll valve. Once i get that built i will see how changing the code goes. thanks