Holley EFI/DIS Conversion
#13
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BUP, They make both. I used a belt driven pump, they also sell reverse rotation if your running a serp setup.
Liquid, Thanks! I put a lot of work into the set up and harness. CMI built the tails for me off of PVC mockups. I have a 4" long piece of hose that connects directly to my transom mounted tips. Since my tips are below the water line this was the closest I could get with dry exhaust. The upside is its quiet at idle. My engine didn't like to idle at all with a dominator and exhaust back pressure from the tips underwater. The EFI made a drastic change in idle quality, its as good as the stock 496 now.
Liquid, Thanks! I put a lot of work into the set up and harness. CMI built the tails for me off of PVC mockups. I have a 4" long piece of hose that connects directly to my transom mounted tips. Since my tips are below the water line this was the closest I could get with dry exhaust. The upside is its quiet at idle. My engine didn't like to idle at all with a dominator and exhaust back pressure from the tips underwater. The EFI made a drastic change in idle quality, its as good as the stock 496 now.
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Is this what's needed to do a crank trigger? I guess I would have to pass in that case. Good for you though, as I would love to run that set up. It would just have to be easier than new brackets, shimming accessories etc. I've seen the distributor mounted ones, but why bother; the crank trigger is going to read with better precision.
Last edited by DesertRage; 06-09-2015 at 12:08 PM.
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No, but that's what's great about efi. You can put it where ever your comfortable in running. I run 13.5 all the way up through my light cruise speed ~3500rpm and then start to richen to 12.8 at WOT. My compression is 10.5:1, the orange motor is just over 10:1. Both have cams to run at 6400rpm.
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No, but that's what's great about efi. You can put it where ever your comfortable in running. I run 13.5 all the way up through my light cruise speed ~3500rpm and then start to richen to 12.8 at WOT. My compression is 10.5:1, the orange motor is just over 10:1. Both have cams to run at 6400rpm.
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The big advantage of this ECU is that once you load a base tune, it will correct to your commanded AFR. If you've ever sat on the floor of a boat and tuned MEFI you will appreciate the hours it saves! I'm not discounting MEFI's they are great systems. Just not as user friendly.
The ignition can stay very simple with a Merc efi distributor and single coil or you can move to DIS with cam sync & coil packs or somewhere in between. A cam signal is only needed if you want to run sequential fueling. The DIS isn't bad if your using the Holley wheel and kit. It can get a little more involved if your using different brands of crank triggers, coils or cam position sensors. If your comfortable reading a schematic it will go smoothly. There is also Holley Tech support, they are very helpful with software settings and pin out questions.
Last edited by DesertRage; 06-09-2015 at 04:30 PM.