Fuel Maps from my Megasquirt, the graphs are kinda cool |
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Fuel Maps from my Megasquirt, the graphs are kinda cool |
DNHunt |
Dec 7 2004, 10:10 PM
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#1
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914 Wizard? No way. I got too much to learn. Group: Members Posts: 4,099 Joined: 21-April 03 From: Gig Harbor, WA Member No.: 598 |
Here's a fuel map i preloaded for my new engine as a starting point. Certainly it's too rich but, it should be safe.
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DNHunt |
Dec 7 2004, 10:11 PM
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#2
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914 Wizard? No way. I got too much to learn. Group: Members Posts: 4,099 Joined: 21-April 03 From: Gig Harbor, WA Member No.: 598 |
Here's a cool graph of the same thing from the tuning screen
Attached image(s) |
DNHunt |
Dec 7 2004, 10:15 PM
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#3
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914 Wizard? No way. I got too much to learn. Group: Members Posts: 4,099 Joined: 21-April 03 From: Gig Harbor, WA Member No.: 598 |
Here's the ignition table
Attached image(s) |
DNHunt |
Dec 7 2004, 10:16 PM
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#4
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914 Wizard? No way. I got too much to learn. Group: Members Posts: 4,099 Joined: 21-April 03 From: Gig Harbor, WA Member No.: 598 |
And the spark graph
Dave Attached image(s) |
Dr Evil |
Dec 7 2004, 10:42 PM
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#5
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Send me your transmission! Group: Members Posts: 23,002 Joined: 21-November 03 From: Loveland, OH 45140 Member No.: 1,372 Region Association: MidAtlantic Region |
Your just cool, Dave. I'll be looking you up for graph advise when I build my DIS for the 2.7.
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drgchapman |
Dec 7 2004, 10:46 PM
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#6
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Current Stable Group: NoClassifiedAccess Posts: 922 Joined: 20-September 04 From: Portland, OR Member No.: 2,789 Region Association: Pacific Northwest |
Dave, did you use some base numbers, then allow for your particular engine set up? So as I understand the graphs, or misunderstand, as RPM increases, fuel output increases, measured as partial pressure (kPa), spark advance increases as well up to 32 degreees BTC. I assume that this is related to the torque curve and horsepower curve using some algorithm. Is the fuel delivered same as l-jet, pulse duration variable?
The graphs look really cool. When do you fire her up? Gary |
a9146luvr |
Dec 7 2004, 11:59 PM
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#7
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Member Group: Members Posts: 55 Joined: 2-January 04 Member No.: 1,495 Region Association: None |
Why do i feel i should copy those to my desk top? it'll be interesting how close you are. thanx.
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chunger |
Dec 8 2004, 01:32 AM
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#8
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Member Group: Members Posts: 409 Joined: 11-January 03 From: Albany, CA Member No.: 133 |
Is it possible to use this resolution on an earlier MS hardware? Do I need to re-program the chip itself or can it be done w/ re-loading things into memory.
-'Chung |
crash914 |
Dec 8 2004, 06:58 AM
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#9
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its a mystery to me Group: Members Posts: 1,826 Joined: 17-March 03 From: Marriottsville, MD Member No.: 434 Region Association: MidAtlantic Region |
Dave, do you really get a 115 Kpa?
I re-scaled my table to go from 0 to about 60 Kpa and RPM up to around 7000... Just trying to get more resolution to the steps... Yours looks cool though...are you using the Hi-res code? I don't get the pretty colors with my megatune... can't wait till you post the pictures of the first drive around the block... later, herb |
DNHunt |
Dec 8 2004, 07:21 AM
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#10
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914 Wizard? No way. I got too much to learn. Group: Members Posts: 4,099 Joined: 21-April 03 From: Gig Harbor, WA Member No.: 598 |
QUOTE(drgchapman @ Dec 7 2004, 08:46 PM) Dave, did you use some base numbers, then allow for your particular engine set up? So as I understand the graphs, or misunderstand, as RPM increases, fuel output increases, measured as partial pressure (kPa), spark advance increases as well up to 32 degreees BTC. I assume that this is related to the torque curve and horsepower curve using some algorithm. Is the fuel delivered same as l-jet, pulse duration variable? The graphs look really cool. When do you fire her up? Gary Guys Right now this is just a quess and I expect it to change a lot. It's loosely based on the fuel map that I ran on my 2.0 l but, I had to expand that from an 8 X 8 grid to a 12 X 12 grid that's in the new firmware. Gary both maps are dependent on RPM and vacuum. Spark is more closely related to RPM so it changes more in that axis but if you look there is vacuum advance and retard. Fuel map should really reflect the torque curve ofthe engine. This plot is pretty optimistic. If you look at around 900 RPMs and 25 kPa you'll see a small valley where it will idle and there is another valley around 3000 RPMs for cruise. I really don't expect that much vacuum but I had extra bins so I plugged them in and figured I would tune them later. The original MS started on an 8 X 8 fuel map from a 350 Chebbie so this should be closer than that. Dave |
pbanders |
Dec 8 2004, 09:23 AM
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#11
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Senior Member Group: Members Posts: 939 Joined: 11-June 03 From: Phoenix, AZ Member No.: 805 |
I would think that if the motor is stock, or nearly so, a good starting point would be to replicate the fuel map from stock by using the injection duration vs. speed mapping of D-Jetronic. See the chart near the bottom of this page: http://members.rennlist.com/pbanders/djetfund.htm
The fuel units obviously need scaling and/or transformation to your mapping. The thing you want to replicate is the curve. From what I saw of your curve, unless I'm misinterpreting it, you're not compensating for the decline in VE above 5000 rpm or so. The ignition mapping starting point can be derived from the data in the factory workshop manual on the advance curve of the stock D-Jetronic distributor. Mapping the effects of vaccum advance might be tricky, however. Vacuum retard should be fairly easy to map. |
Jake Raby |
Dec 8 2004, 09:39 AM
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#12
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
Dave, the fuel does look rich, but safe and easy to start from....
The spark could use some work. I would try using something like this.. 1000-12 degrees 1500-15 degrees 2000-21 2500-28 3000-32 3500-32 4000-32 4500-30 5000-28 5500-24 6000-22 This is the curve from an engine that I built and tested with the Kit carlson EFI that had the same cam that you have and similar port work. At high RPM pulling timing out cleans up the top end since piston speed is higher you don't need much advance to light the fire. The ability to add in more timing down low and pull it away in the top end give the best of both worlds. Have fun! |
Mueller |
Dec 8 2004, 10:23 AM
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#13
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914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None |
QUOTE If you look at around 900 RPMs and 25 kPa you'll see a small valley where it will idle and there is another valley around 3000 RPMs for cruise. my 1.8 had 55 kPa at idle, not sure why so far off from your motor and the other guys running MS on the Type IV motors...I tested it an external gauge and got the same reading... looks like you are making some serious progress Dave (IMG:style_emoticons/default/pray.gif) |
nein14-6 |
Dec 8 2004, 10:53 AM
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#14
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Member Group: Members Posts: 93 Joined: 4-October 04 From: Mount Airy, MD Member No.: 2,883 |
Dave, Sorry if you have already posted this but what components are you using for ignition this time around?
Thanks, Rob |
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