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Microsquirt on 6v

Posted: Mon Jan 07, 2013 3:57 am
by wagon
Hello!

I've got a mate who's thinking about converting his old 'Condor' single-pot 350 to efi. It's a 6V system and we want to keep the old dear fairly original looking.

Will a microsquirt (or megasquirt) run OK from 6V?

It'd be a ripper little machine with decent fueling since the carby is worn out. Any small fuel pumps and injectors to suggest?

Re: Microsquirt on 6v

Posted: Sat Jan 12, 2013 3:21 pm
by bluehaze
Hey Wagon
Concerning the MS unit, I reckon the 6v fed into the voltage regulator will be too low, most linear regulators need input volts of about 2 volts greater than the output (5) volts.
I think you'd be pushing it to find an injector which runs on 6 volts, let alone finding one with the correct flow rate.
May I suggest a 6-12volt buck/boost dc-dc converter? Have a look around, you should be able to get one capable of running one pump, the MS and an injector, as well as running happily with the no doubt less than ideal 6 volts coming from the magneto on the old Duke.

Re: Microsquirt on 6v

Posted: Sat Jan 12, 2013 5:01 pm
by wagon
bluehaze wrote:Hey Wagon
Concerning the MS unit, I reckon the 6v fed into the voltage regulator will be too low, most linear regulators need input volts of about 2 volts greater than the output (5) volts.
I think you'd be pushing it to find an injector which runs on 6 volts, let alone finding one with the correct flow rate.
May I suggest a 6-12volt buck/boost dc-dc converter? Have a look around, you should be able to get one capable of running one pump, the MS and an injector, as well as running happily with the no doubt less than ideal 6 volts coming from the magneto on the old Duke.
The 5v regulator used in the MS boxes is a low-dropout type, but it still needs around 5.5V to work properly. I'm trying to talk my friend into rewinding the stator for 12V so we can run everything as per 'normal'.

Re: Microsquirt on 6v

Posted: Tue Jan 22, 2013 2:44 am
by long283
I will be interested to see how this project turns out. I just bought a CRM 250 and I am planning to put EFI on it.

Have a look into using a Bosch FRP (Fuel Rail Press.) sensor and controlling the fuel pump speed in a returnless system if you want to keep current draw low.
Here's a link with some info;
http://www.madhu.com/content/Main/FuelPumpController

And here's a boost converter if for bringing the voltage up to 12V
http://littlebirdelectronics.com/produc ... -converter