Wiring Question

[Bob Cowan]

I have a question about switch wiring for two seperate but related circuits.

1. A negative/ground circuit from the ECU to ground. Closing the switch changes a function in the ECU (switches between gasoline and E85).

2. A dash lamp, indicating the ECU is running on E85.

The two circuits need to be operated by the same switch, but they need to be completely separate. There can't be any bleed over.

I'm thinking that a single throw, double pole switch will manage this task. Is that correct?

16A 125V or 10A 250V DPST AC On/Off Round Rocker Switch : Rocker Switches | RadioShack.com

[sharkx]

Yep, that's what you want. It's really two separate electrically isolated switches in one case with a common lever.

Bruce

[Bob Cowan]

Thanx. That's what I thought, but wanted to be sure.

[mlewin]

Nice Bob, so you are using the map switching feature in Megasquirt? Do you plan to run E85 at the track for increased power or knock resistance?

[Bob Cowan]

That's exactly what I use it for with the street tune. On hot days - especially at low altitide - I can fill it with E85 for high octane and cooler running. I was in Moab in June, and it was really hot - like Africa hot. But on E85 it ra smooth and cool, just it should. When I got back to Grand Junction, CO, I filled it with gasoline and flipped the switch. Worked like a charm.

On the track I have a different tune that I load with the lap top. I use open trumpets there instead of air cleaners. That provides for better air flow, so I need more fuel. The engine runs better on E85 than it does on Sunoco 110.

[mlewin]

That awesome. I am glad the system is working so well for you. Now all you have to do is get the accelerometer on there and get some good G data. hahah

[Bob Cowan]

That's my next big project, I think. I'd like to add a data acquisition system, with video, GPS, accelerometer, etc. Not cheap, but could be very helpfull.

[tweeker]

You could use diodes to prevent bleed over.