This is wild - Gasoline/Diesel mix

[pocket-rocket]

i don't see why this couldn't be done on a production engine, provided you have the controls to mix the gas/diesel blend right at the point before they're injected if you want to use the same injectors. you couldn't do this with a return-style fuel pump system since the gas/diesel would mix and not be possible to adjust the ratios.

"The new in-cylinder fuel blending strategy is less expensive and less complex, uses widely available fuels and addresses both emissions and fuel efficiency at the same time."

"Development of the blending strategy was guided by advanced computer simulation models. These computer predictions were then put to the test using a Caterpillar heavy-duty diesel engine at the UW-Madison Engine Research Center."

1) It sounds to me like the fuel systems are completely separate.

2) It sounds like they just added the gasoline injection system as a secondary to an already production engine.

3) I would hope they put some sort of primary fuel system failure detection in place... Wait a minute, carnage pics are cool, nevermind

On a side note, looking for videos on youtube of people that put gas in diesels has gotten me interested in making a small hydrogen generator for my truck...

I also typed this up way over an hour ago before posting, and now the dual tanks has come up. Why not mount a fuel cell in the trunk?

[Schmieder]

I say piggy back a PCM for the seperate fuel system, just omit the spark control, trans control, everything but fuel pulse. Just got to wire in the right sensor signals...the ECT sensor may be an issue so two would work great there.

But in that case, tuning could be a real PITA w/ two pcms.

I'm sure there are NOS controllers available. Just rig it to control an extra injector just past the throttle body.

Now I'm gonna have this in my mind tonight....and at 3am I'll have the AH HA!

[robertisaar]

1 injector for all cylinders? fuel distribution is gonna suck.

and generally, PCMs can share sensors like that.

[Schmieder]

1 injector for all cylinders? fuel distribution is gonna suck.

and generally, PCMs can share sensors like that.

Well, only 1 injector if the added gas isn't a lot. Augmenting the diesel.

I know sensors can be shared but the ECT was said to need two as two lines did something to the signal. I think cut it in half, but all the rest were fine to share.

I could be wrong though

[robertisaar]

i believe i've heard of megasquirt piggybacks that used only a single sensor... but i could be wrong.

but spraying gasoline into the diesel intake is going to be very much like a carburetor at that point....

[Jonpro03]

I know sensors can be shared but the ECT was said to need two as two lines did something to the signal. I think cut it in half, but all the rest were fine to share.

I could be wrong though

Correct! Well, as far as Megasquirt goes.

[robertisaar]

i would think IAT would act the same then....

[pocket-rocket]

Ah yeah, dual gas tank trucks. For a track car, I could mount an extra fuel tank in/under the trunk. Just cut the space needed, weld up the mounts, frame around to make up for lost frame integrity and then shield it. Heck, just a 10 gallon in the trunk should do it...lol...or a bladder fill in the spare tire area.

I think it would be a fun project. I have to consider this down the road....it would be something unique, thats for sure.

I would feel a bit safer running a 10 gallon fuel cell in the trunk over a bladder in the spare tire area, lol.

Also on the note of sensors, you don't want to run two ECMs off of resistance based sensors (like the ECT).

Why You Can't Connect Two Devices to the Same Temperature Sensor

Sometimes it may seem tempting to connect two devices, like an ECU and a gauge or an aftermarket ECU and a stock ECU, to the same temperature sensor at the same time. Resist this temptation. While you can often get away with connecting two devices to a voltage-based sensor at the same time, resistance-based sensors don't work that way. An ECU or gauge determines the resistance of a sensor using a circuit called a voltage divider, which is a circuit that uses two (or sometimes more) resistors, one being the sensor and the others being inside the ECU. Connecting two devices to one sensor ties these voltage divider circuits together in ways the designers never intended. While this usually won't damage an ECU, the calibration in the ECU (and whatever else you have hooked up to the sensor) will be very far off.

Top left of page 41- written by Matt Cramer and Jerry Hoffmann from DIYautotune.com

This is probably why GM has difference ECTs for the gauge and ECM, and eventually created the 3 wire ECT (two ECTs in one case with a common ground).

[Schmieder]

I know my cylinder heads have ports for an ECT sensor. One for each puts the total potential ECT sensors to 3. I think having a dual ECT gauge for the cylinder heads would be cool for moderate-high boost applications. But if two were needed, the PCM could be tuned to the cylinder head ECT and then have two of almost equal readings, as long as everything is operating normally.

Off topic, I wonder how feasible it would be to use a remote temp sensor to map the coolant passages in the cylinder head while at operating temp under mild rev (for stronger flow). Marking off specific locations to check temp and use the differences to port the gasket coolant holes. Basically balancing the heat load on the heads. I can't say for sure but I wonder if tuning such a thing, water flow, could bring the engine to a noticable increase in balance. As hotter cylinders change the nature of the burn and then cylinders are out of balance, however mild it may be.