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| MegaSquirt EFI Computer and the /6 https://www.slantsix.org/forum/viewtopic.php?t=4665 |
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| Author: | Thropar [ Tue Apr 08, 2003 5:31 pm ] |
| Post subject: | continued learning... |
... i'm trying to learn about fuel injection and some is a little foreign, but thanks for the info... maybe I should get a book on fuel injection basics to understand the lingo... hey, you know, the TBI unit on my 4.3 Chevy Astro looks exactly like the Holley Projection unit... also, i think buying parts at Radio Shack for my /6 would be really cool! I would pay $20 bucks for a simplified write up on how to do this whole deal...tips etc... TBI or Multiport... 
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| Author: | Bob D [ Tue Apr 08, 2003 8:21 pm ] |
| Post subject: | |
Have you read my EFI conversion article in the "articles" section? http://www.slantsix.org/articles/dibias ... ersion.htm Bob D |
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| Author: | Thropar [ Tue Apr 08, 2003 9:44 pm ] |
| Post subject: | wow! efi article rocks..! |
Thanks Bob! I guess I owe you $20  !!!!!!!Man i want to go to the junkyard right now!!! .. or maybe i'll tear into my Astro.. no wait that's got the TBI... at least i'm familiar with a Chebby...! I have messed with my ECM in the Astro many times, checking codes, etc... ...maybe i can make friends at a junkyard here in Orlando to get deals..! cool man, that article is great... So would this setup be more "tuneable" with the Megasquirt controller? or is it easier to stay GM because of all the matched up wiring? and, are you going to a turbo? |
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| Author: | Bob D [ Wed Apr 09, 2003 2:50 pm ] |
| Post subject: | |
The set-up described in the article is not "tuneable" the way that the Megasquirt controller is. They aren't interchangeable because the Megasquirt is a speed density system while the set-up I'm using is based on mass air flow. I am doing a turbo and expect to have it running in a few weeks. For that I'll be using an ECM for a Buick turbo. It essentially plugs directly in place of the one I'm now using. This ECM (1227148) is available in junk yards from any '86 3.8L Buick or Old although you will need a turbo EPROM for it to run a turbo. The EPROMs are available on the turbo Buick web sites as is just about anything else you would need. This ECM controls boost and timing and will also control detonation. You can also make it "tuneable" by getting a translator that allows you to use the later LT1 or LS1 mass air flow sensor. This MAF sensor is used on over 400 different cars and is also available in junk yards. I may eventually try this translator. Bob D |
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| Author: | Thropar [ Wed Apr 09, 2003 7:09 pm ] |
| Post subject: | good ideas... |
I like your ideas of using the stuff that's cheap and available in the junkyards Bob... the ECM info is very informative.. thanks again! Please do a write up on the turbo install when you have time 
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| Author: | Dart270 [ Thu Apr 10, 2003 6:30 am ] |
| Post subject: | |
Guys, The MegaSquirt could be used with the Buick setup since it has a MAP sensor (good to 2.5 bar, or about 22 lbs boost) as part of the computer, and you can just eliminate the Buick MAF from the system. Cheers, Lou |
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| Author: | Bob D [ Thu Apr 10, 2003 4:34 pm ] |
| Post subject: | |
Lou, When you say that the MegaSquirt can be used with the Buick set-up I assume that you mean with the Buick turbo (or for that matter any turbo) but that it won't "plug-in" in place of a GM ECM. Am I correct? Will the MegaSquirt accommodate a knock detector to control timing? Bob D PS The other thing that occurs to me is that the Buick set-up makes use of a wastegate solenoid. This solenoid is pulsed at varying pulse widths by the ECM under different conditions and is used to control boost. |
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| Author: | Dart270 [ Thu Apr 10, 2003 7:53 pm ] |
| Post subject: | |
OK Bob, you got me there.  The MS has no provisions for knock control or wastegate control at this time. It won't plug right into a GM connector, but it would be easy to wire up to the GM EFI components.Lou |
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| Author: | Bob D [ Thu Apr 10, 2003 8:17 pm ] |
| Post subject: | |
I'm no trying to "get you" Lou. I appreciate the fact that the MegaSquirt is tuneable with a lap top and that that is an advantage. I also have a great deal of respect for your car crafting abilities! Bob D |
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| Author: | Dart270 [ Fri Apr 11, 2003 6:09 am ] |
| Post subject: | |
Don't worry, Bob, I was not offended. Just kiddin' around... Thanks for the kind words, and I definitely respect your innovations too! Lou |
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| Author: | Charrlie_S [ Fri Apr 11, 2003 6:55 am ] |
| Post subject: | |
Thats the way to go, guys. Keep the info flowing. I would like to go with FI on one of my cars in the future, and I'm learning a lot. |
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| Author: | Pierre [ Fri Aug 08, 2003 2:05 am ] |
| Post subject: | |
Hey Lou, did you ever add the inline resistance? How did that work out? There is a new flyback add on board that is coming out soon for the megasquirt that is going to take care of driving the low resistance injectors... more efficent option then inline resistance. By the way, what version code & hardware are you running on it? |
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| Author: | Dart270 [ Fri Aug 08, 2003 7:14 am ] |
| Post subject: | |
Pierre and all, I may have forgotten to post this, but I am running 2.4 Ohms of inline resistance on each TBI injector. Works like a charm and no problems in 1 roadrace event, 8 dragstrip passes, and about 4k miles on the street. I will be converting over to MPI as soon as I can, so that won't be an issue. Good to know on the flyback add-on - I haven't been keeping up on the MS site. If you are referring to the V2.2 board, I have that already and it wasn't quite enough. I am running V2.2 hardware and V2 software and I sometimes use Megatune 2.14 (2.13 maybe??). I should upgrade to the latest (2.15?). BTW, I was looking at my datalogs, and I am actually running these injectors up to just over 85% duty cycle at 6000 RPM. That means I'm really on the edge with my 170 lbs/hr total on this motor. I'm in the 250-280 crank HP range assuming a 3000lb race weight. Leighton Drake mentioned this problem to me at Clay City, and this may explain my slower MPH than expected over there. The injectors may be overworked and running out of steam at the end of the 1/4. I didn't really think this would be a problem, since Holley states this system is good to 275 crank HP, but I guess I'm getting there. So I would say that 30lb/hr injectors (MPI - 180lbs/hr total) are a minimum for this motor. Lou |
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| Author: | Pierre [ Fri Aug 08, 2003 8:04 am ] |
| Post subject: | |
They are up to version 3.0 on the software, it turns off pwm while cranking and that alleviates some of the pwm issues. You'd need the Williamete or any other programmer to put the new code on the internal cpu. |
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| Author: | Dart270 [ Fri Aug 08, 2003 12:40 pm ] |
| Post subject: | |
Correction to my last post - I am only running 14 psi fuel pressure on my TBI at this point, and it will run up to 18. So, I am maxing out my injectors at his pressure, but I have about a factor of SquareRoot(18/14) = 1.1 times more total flow I can use. I will try this on the next dragstrip outing. By standard calculators, I have around 250 crank HP from this sucker. Pierre, are you saying that I can't just download the new 3.0 software and use it with my current ECU? I guess that makes sense for some functions. Any idea how hard it is to get/use one of these Willette programmers? Things are working fine for me, so I'm in no big rush to upgrade. I guess it would be easy for them to just send a new programmed PROM for $15. Injectedly yours, Lou |
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