Efficiency potential of the L28 (MegaSquirt)

[Zed Head]

You can buy degrees of completion ranging from a bill of materials to be assembled yourself, up to essentially complete boards and wiring harnesses.

I'm sure you've seen this company's site but I'll post it for the record - http://www.diyautotune.com/ They seem to be the most established for Megasquirt, although there are others out there.

[Mikes Z car]

There is an HHO mileage improver that has been around for a while. It is nothing more than oxygen and hydrogen gas from electrolyzed water fed into the air intake. I know three people who claim to know someone who had one of these and two of them said they were getting 50% mileage improvement. I have read that it works better with carbureted cars rather than ones with O2 sensors. I ran across the owner of a local auto repair shop recently who says he saw an HHO device hooked up to a truck that was run on a dyno. I gather the usual dyno test is to run the RPMS up and back down to determine peak HP and torque. They observed a 20 HP increase with the HHO device though I don't know if that would translate to a mileage improvement. One of the reasons I bought my 240Z was to verify claims for the HHO device but I have been so busy rust proofing it and making it closer to stock I haven't done that yet. Anyone else tried the HHO device or have an opinion on it?

Mike

[Z train]

You can buy degrees of completion ranging from a bill of materials to be assembled yourself, up to essentially complete boards and wiring harnesses.

I'm sure you've seen this company's site but I'll post it for the record - http://www.diyautotune.com/ They seem to be the most established for Megasquirt, although there are others out there.

Good reference.ANother neat thing about MS,is that you can get the box with all the whisltes & bells and add features as you can afford or want to.Other (some)systems DO NOT have this feature.

[madkaw]

Sarah,

you might think about installing a wideband and see what's happening with you mixtures. My car got 30mpg going to Zcon at nashville with a 3.7 LSD and the T-5 trans. I didn't have the wideband then. NOW I have the wideband I realized that my car was running very lean, thus the great MPG. I have dialed the motor in much better with the wideband and still get great mileage. I have to measure again, but now with a 3.54 diff I think I am still around 30 running about 15.0afr at cruise.

The wideband will also hook up in conjunction with your MS unit, so you need to do that anyway

[FastWoman]

That sounds like a good idea, Steve! I might just do that.

I looked at the MS equipment on the DIYAutoTune website and have to say all the bells and whistles were dizzying. I see I can do everything from basic fuel control with banked injector firing to ignition control with advance and sequential injection. (How important IS sequential injection?) I can see I'll need to do quite a lot of studying just to determine what it is I might want to buy/do.

But the O2 sensor is certainly a good start. I think I'll ruminate on that a bit.

[Z train]

That sounds like a good idea, Steve! I might just do that.

I looked at the MS equipment on the DIYAutoTune website and have to say all the bells and whistles were dizzying. I see I can do everything from basic fuel control with banked injector firing to ignition control with advance and sequential injection. (How important IS sequential injection?) I can see I'll need to do quite a lot of studying just to determine what it is I might want to buy/do.

But the O2 sensor is certainly a good start. I think I'll ruminate on that a bit.

For sequential,you cam postion sensors.Really overkill requiring over engineering.But the other stuff is usefull.Example:

Start out with just the fuel.

Then the timing.

Then coil packs

Then elimiante the distributor altogether

[madkaw]

Z trains right-don't even bother thinking about sequential. You can do one step at a time. I suggested the O2 sensor because it gives you a lot of info right away and it looks cool to. It's essential for your MS to work also.

For me the next stage is timing-or a way to monitor timing for the eventual MS install. Your MS will need some input on engine rotation, then you will have rpm and AFR info to combine.

It's a little bit of a learning curve, but SARAH, you seem to have a handle of things from the posts I've read. I'd predict that you will be helping others with their install in no time.

[FastWoman]

Thanks Ztrain and Madkaw! So sequential isn't that big a deal... I can believe that.

So for the ignition, is the distributor gutted/modded to be a cam angle sensor? Are there kits for that?

Having the ignition under ECM control certainly sounds like the way to go.

[cygnusx1]

My L28ET will not run smoothly at anything much above a 14.5:1 AFR with megasquirt. If I try REALLY hard, I could manage about a 22mpg. That's about it. The L motors LOVE to run on the rich side. They really don't seem to run smoothly, or make any smooth power/torque unless you feast them with gas. It might have everything to do with combustion chamber design. I am using 440cc Ford Lightning injectors made by Bosch.

My megasquirt box happily runs a Ford EDIS-6 crank triggered ignition with no distributor of course. A nice healthy spark for sure.

Edited July 19, 2011 by cygnusx1

[FastWoman]

Dave, I think what you say is true. I've got my EFI tuned (via potentiometer) a bit on the rich side, and it seems to like it there. I'm sure I get at least 22 mpg on the highway. In fact I'm sure I'm fairly certain I'm in the mid 20's, but I'm perhaps tuned leaner than you are, and I probably drive a bit slower. The next time I'm on a good stretch of highway (which is very seldom these days), I'll have to determine exactly what I do get.

So I'm still on the fence about MS. Instead, I'm wondering whether I could preserve my antiquated analog AFM system and get the greater efficiency by rigging an accessory circuit to tweak the tuning of the EFI in real time, based on the output of a wide band O2 sensor. Or maybe I could have a mixture selection switch that would switch me from rich (performance) to lean (for cruising).

But I suppose it all starts with the sensor. How much should a muffler shop charge me to weld on a bung?

Any great ideas about where to mount the extra gauge? Pull the clock, perhaps? (I kinda hate to do that.)

And where should I mount the flux capacitor? Should it go in the rear of the center console area? (I have a high voltage relay that looks a lot like the doodad in the movie. I'm often tempted to mount it under the hood somewhere as a lark -- to see how many questions I get about it. )

[robftw]

I gotta say im pretty jealous.

I get about 10mpg but i have all of my emissions stuff removed, along with charcoal can etc... if i keep it under 3000 i can get MAYBE 15mpg..

[LeonV]

Sarah, go standalone, you will not regret it! You will have control over the whole fuel map (and spark, if so desired) with the flick of a finger. No need to mess around with different circuits and try to make an ancient EFI system more adjustable and efficient. With MS, set cruise leaner and higher load operation richer and voila, it's that easy!