With those injectors you must be planning to run E85

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It's a Slant thing. Even I don't understand.

1974 Duster, EFI /6 soon to be turbo...

Get that Monkay! Get that nasty thing!!

Yesterday I was running on the stock coil. Tonight I went out and ditched the stock coil, ballast, and 100 percent of the stock ignition system. I wanted to try the coil off a Magnum 318 I happened to have in the shop. It was very simple to wire, no ballast, just a 12v connection to the orange wire and my ignition control wire from the MS to the brown-ish wire.

Fired right up and sounded very crisp but not running as it should, which is not surprising. I have not adjusted the timing at all. I shot the timing light at it and it was about 40 degrees advanced Not really the best. I'll adjust it tomorrow as my kid had my serial cable for the laptop.

Here's kind of a look at the adjuster I made for the contact plate. By loosening the jam nut and turning the bolt I can move the plate significantly in both directions. My plan is to retard the timing this way until I'm as close as I can get to what MS is saying, and then lock it down. Should not mess up the phasing - right?



I also bought a new cap, so I'm going to sacrifice the old one and cut a hole in it to check the phase when it's running.

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It's a Slant thing. Even I don't understand.

1974 Duster, EFI /6 soon to be turbo...

Get that Monkay! Get that nasty thing!!

That's gasoline and assuming there is room to grow.

Used this site and a friend to help calculate. Inputs = 600HP and .65BSFC 80%DC
http://www.witchhunter.com/injectorcalc1.php4

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11.02 @ 120.56
http://www.youtube.com/watch?v=EAxRmoDgsdY
Chassis dyno
http://www.youtube.com/watch?v=wd6hFGzLJMc

When you rotate the dist. body,both the cap and pick-up coil move equaly in unison. I think you're confusing late model cars with ign. pick-ups that measure off the crankshaft. It is true that you can goof up the dist. phasing on them.

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V8?? We don't need no stink'n V8!!

Phasing is the relationship of the rotor to the cap. Turn the cap, change the relationship.

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It's a Slant thing. Even I don't understand.

1974 Duster, EFI /6 soon to be turbo...

Get that Monkay! Get that nasty thing!!

Got the ignition tuned up much better. I adjusted the pickup plate until I could get the timing mark under the timing light to agree with what the computer said I had for timing. I have no issues that I can tell with phasing; however, I have not run it under load yet.

I had to play with the pickup offset some to get the timing to finally come in the last little bit. It's a software setting that's a bit like turning the distributor by clicking the mouse. I think I ended up with something like 8 degrees of offset. Not sure if that's good or bad. The Megasquirt example uses 10 degrees so I must be in the ballpark. Now the computer says 18.3 degrees at idle and the timing light says 18.3 degrees.*

It now runs and sounds very crisp and throttle response is very good. I'm sure my plugs need changed, and I expect it to improve even more after that. I really am not crazy about the TBI with a cold manifold. Once it warmed up it was fine, but at first I had liquid fuel running out the exhaust. Last time I ran it, it was August. A 40 degree manifold is drastically different. I think I will make a heater block out of aluminum and run the heater hoses to it. If nothing else it will keep the manifold a constant temperature.

* as far as I can tell. The limits of the distributor become readily apparent with this setup. The timing varies about 5* at idle. I'm sure it's backlash in the timing chain, which is new but is a standard (not roller)chain, and the backlash inherent in the system from the cam through the distributor to the pickup. I took pains to eliminate all the play I could in the distributor itself, after locking the weights and the pickup plate, I also filled the slots in the cross head with silicone to dampen the tiny play that was in there. The timing is rock steady at anything but idle. A roller chain setup may help, but I think an EDIS system is not too far in this engine's future.

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It's a Slant thing. Even I don't understand.

1974 Duster, EFI /6 soon to be turbo...

Get that Monkay! Get that nasty thing!!

Do you have a rumpy cam the timing bouncing around at idle could the be the lope of the cam fluttering the rpm?

Kev

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No, cam is stock. Actually, I'm not sure it's all caused by backlash. I need to look at the spark table again. I think I need to flatten the advance out at idle some more. It may be hunting around.

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It's a Slant thing. Even I don't understand.

1974 Duster, EFI /6 soon to be turbo...

Get that Monkay! Get that nasty thing!!

I may be wrong, but I may be the first to run timing on the slant with the MS II. I'm learning some interesting stuff.

I've perused the many timing curve threads on this site. There is a lot of information here. I've been trying to build an advance curve using the data I've looked at. I used the spreadsheet on this thread: http://www.slantsix.org/forum/viewtopic.php?t=38471 and build a curve using Doc's suggested inputs.

Here's the thing: most discussion revolves around the limitations of advance weights and vacuum governors to bring in advance when desired. In Megasquirt, I have no such limitations. I have a 12x12 matrix that I can set up at will to provide the exact advance at the RPM *and* manifold pressure I want.

Using "Doc's suggested settings" on the spreadsheet, I built the matrix below:



Here it is in 3D:



Manifold pressure (MAP,) in kilopascals (KPA) is on the left side and RPM on the bottom. 35 KPA is about 19 in/hg of vacuum, 90 KPA is about 3" for reference. 100 KPA is approximately WOT. The 200 KPA line is the max boost I plan to make, approx 15 PSI.

As you can see, I'm pulling 7 degrees of timing out under boost. I can take more or less simply by adjusting those cells. Once again, I have not run with this table and the turbo is not installed yet.

So... assuming you had no limitations, what would the ideal advance look like on the slant? I have not driven with the above table so I don't know where it pings or not. For sure I will have to experiment with this.

But, what should the base timing be, ideally? How much timing in, how fast? I have no limits... within a 144 cell matrix that is.

Current progress pic:

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It's a Slant thing. Even I don't understand.

1974 Duster, EFI /6 soon to be turbo...

Get that Monkay! Get that nasty thing!!

Hmm sorry I got no ideas to shoot out i've only worked with carbs never touched the software stuff.

Kev

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Never mind the software, just imagine what the ideal curve would be. I'll put it in the software. What advance are you running under boost?

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It's a Slant thing. Even I don't understand.

1974 Duster, EFI /6 soon to be turbo...

Get that Monkay! Get that nasty thing!!

25* might be ambitious under full boost and pump gas. I would take that number to something between 15-20* and work up.

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11.02 @ 120.56
http://www.youtube.com/watch?v=EAxRmoDgsdY
Chassis dyno
http://www.youtube.com/watch?v=wd6hFGzLJMc

I agree. 20 deg max under full boost.

I would smooth the transition between idle and 3000 RPM too, too much of a step around 2000. At 100 kPa I would start at 28-30 deg and go from there. Also, I've found in my dragstrip tuning that a bit less timing at higher RPM and WOT is good. Try peaking the timing around 3000-3500 and drop 1-2 deg per 1000 rpm above that.

Get that thing bolted together so we can duke it out at Kearney!!

Happy tuning,

Lou

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Home of Slant6-powered fun machines since 1988

Yep, I agree about the boost setting. I just threw that number up there to look at the map. As far as the transition from idle to 3000, that's actually how the numbers work out following the spreadsheet curves. I'm using "Doc's" numbers (and assuming that's DD).

On smoothing, Lou:

One thing to note is the software interpolates the numbers. So for example at the 90 KPA line, the computer has 500 rpm between the 1500 and the 2000 columns to advance the timing 10 degrees. Then another 500 to go another 5 degrees from 2000-2500, etc. By 3000 it's basically all in.

That makes 17* @ 1600, 19* @ 1700, 21* @ 1800, 23* @ 1900, 25* @ 2000.

Then, 26* @ 2100, 27*@ 2200, 28* @ 2300, 29*@2400, 30* @ 2500. It does work this way as verified with the timing light.



One thing to watch out for is that boost retard. The same principle applies to taking timing out. So if I set 18* at my max boost, 200 KPA, then the software has from 100 to 200 KPA to go from 30* to 18*, which may leave me on the high side somewhere in the middle. I may need to change the 100 KPA bin to say, 105, and set the max timing there to 25 or something, so there is only 7* to go between there and max. My math has me at 24* at around 7.5 PSI boost which is not likely good.

More stuff to play with. As Shaker said, start conservative and work up.

I'm scared I'll be in the exact same position I was last year, with it bolted together but not enough time to tune it in properly. I guess I can run it with everything set rich and retarded (like me, except rich) and just have a good time. I don't expect to set any records. I WILL be there come hell or high water.

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It's a Slant thing. Even I don't understand.

1974 Duster, EFI /6 soon to be turbo...

Get that Monkay! Get that nasty thing!!

I'm 10deg initial like shaker said 20degree under boost.

Kev

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