A/F ratio
#31
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Fixx
I hear what you are saying, problem is, there are no marine engine builders around here......closest I would trust is Alex Haxby who is in Vancouver and it is major time and money to get the boat over there. I am happy with the build and happy where things stand right now but when the weather permits and I can get some water test time under my belt it will be nice to monitor the engine and make sure we got it right, if not, we can make changes based on the info we get.
I had my ECM re-flashed by Mark Boos but perhaps I did not supply him with all the info he needed, on the dyno it seemed to run a little lean, but until we run it on the water under load I don't know if we got it right.
The A/F reader I ordered comes with software and a laptop connection so I assume certain things can be changed.......as far as getting a "professional" up here to set it up for me, it ain't gonna happen unless I fly somebody in......the other half would shoot me.....
Thanks for all the feedback boys......
I had my ECM re-flashed by Mark Boos but perhaps I did not supply him with all the info he needed, on the dyno it seemed to run a little lean, but until we run it on the water under load I don't know if we got it right.
The A/F reader I ordered comes with software and a laptop connection so I assume certain things can be changed.......as far as getting a "professional" up here to set it up for me, it ain't gonna happen unless I fly somebody in......the other half would shoot me.....
Thanks for all the feedback boys......
#32
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Dyno numbers are just for a starting baseline. Load water testing is really the only way to get your A/F close. On an EFI blower engine with no boost 13-13.8 is optimum for cruising. Caution should observed if you load the engine and climb quickly in boost.
Unless you have a system that has boost reference variable corrections you can find yourself in a detonation situation. As boost climbs, your A/F should drop to fight detonation (pump gas of course). Aluminum heads are little more forgiving to fight of detonation. Regardless 11.9 - 12 is optimum under boost. Total boost cautiously to 7lbs. Fuel pressure should remain constant per the injectors particular recommendation. Changing fuel pressure other than for boost reference is not a wise idea. Programming changes A/F by adjusting time injector fires compared to MAP.
Unless you have a system that has boost reference variable corrections you can find yourself in a detonation situation. As boost climbs, your A/F should drop to fight detonation (pump gas of course). Aluminum heads are little more forgiving to fight of detonation. Regardless 11.9 - 12 is optimum under boost. Total boost cautiously to 7lbs. Fuel pressure should remain constant per the injectors particular recommendation. Changing fuel pressure other than for boost reference is not a wise idea. Programming changes A/F by adjusting time injector fires compared to MAP.
#33
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Fogducker don't even worry about the a/f numbers from the dyno. Check it out in the boat when it warms up and see where you're at. An engine running in a cold dyno cell with headers is worlds apart from an engine enclosed in a small hot humid engine compartment with wet exhaust. Also a dyno sweep test doesn't load your engine the same as the boat. You'll be in completely different parts of your fuel map on the water. It'll be all good
I have to come over and at least check out your shop in the very near future......
#34
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Dyno numbers are just for a starting baseline. Load water testing is really the only way to get your A/F close. On an EFI blower engine with no boost 13-13.8 is optimum for cruising. Caution should observed if you load the engine and climb quickly in boost.
Unless you have a system that has boost reference variable corrections you can find yourself in a detonation situation. As boost climbs, your A/F should drop to fight detonation (pump gas of course). Aluminum heads are little more forgiving to fight of detonation. Regardless 11.9 - 12 is optimum under boost. Total boost cautiously to 7lbs. Fuel pressure should remain constant per the injectors particular recommendation. Changing fuel pressure other than for boost reference is not a wise idea. Programming changes A/F by adjusting time injector fires compared to MAP.
Unless you have a system that has boost reference variable corrections you can find yourself in a detonation situation. As boost climbs, your A/F should drop to fight detonation (pump gas of course). Aluminum heads are little more forgiving to fight of detonation. Regardless 11.9 - 12 is optimum under boost. Total boost cautiously to 7lbs. Fuel pressure should remain constant per the injectors particular recommendation. Changing fuel pressure other than for boost reference is not a wise idea. Programming changes A/F by adjusting time injector fires compared to MAP.
PS. Fix, is the ex tired of you yet?
#35
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Fixx
Awesome info, thank you. As well as yourself, others are telling me to wait and see the numbers I get IN the boat. I have ordered the LM-2 Innovate unit and even if it just gives me a real world base line, I am ahead of the game, thank you again gentlemen.
((((PS. Fix, is the ex tired of you yet?
((((PS. Fix, is the ex tired of you yet?
Nope,,still pumping her full of fluids
#36
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There is no way to change fuel curve in the box without someone flashing it.
The link you put up is for the tool to "measure" what's going on.
You can use the fuel pressure regulator to change it up or down as long as there are no trouble areas. The meter will tell you if there are.
Otherwise, if you have spots in the rpm range that are rich or too lean in the curve you will have to reprogram it.
You really ought to have this done for you by a professional based on what you're saying. If you built a nice engine with someone and they are leaving it up to you to finish it... I don't know... And you are playing with one aspect that will kill your motor if you are not sure of what you're doing.
Having "car guys" build boat engines never seems to smell right.
Just be careful and don't lean it out for very long.
If the reprogram is necessary and if you send it out, you'll need to keep testing until you know what you have.
The link you put up is for the tool to "measure" what's going on.
You can use the fuel pressure regulator to change it up or down as long as there are no trouble areas. The meter will tell you if there are.
Otherwise, if you have spots in the rpm range that are rich or too lean in the curve you will have to reprogram it.
You really ought to have this done for you by a professional based on what you're saying. If you built a nice engine with someone and they are leaving it up to you to finish it... I don't know... And you are playing with one aspect that will kill your motor if you are not sure of what you're doing.
Having "car guys" build boat engines never seems to smell right.
Just be careful and don't lean it out for very long.
If the reprogram is necessary and if you send it out, you'll need to keep testing until you know what you have.
Amen to that brotha!!!! car guy here just fried his fresh 7.4 rebuild that was "upgraded" with more cam, ported heads and bigger valves.... motor ran lean (suspected detonation)and now I have rod knock! I wish this thread would have been here about a month ago! I have an innovate LM-1 that I have used very successfully to tune carbs and make jetting changes in cars. I am not sure how to tap into the exhaust stream on my OSCO manifolds but I see that tuning the engine in the boat with water manifolds is the best and most accurate way to tune your engine............. I guess learning things the hard way is better than not learning at all????? TBF
#37
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I blew mine up 3 times before I figured everything out. If you want to do your own programing you will have to go aftermarket. There are very few dealers that can program the factory comp.
Last edited by jeffswav; 02-26-2011 at 02:27 PM.
#38
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Originally Posted by jeffswav
I blew mine up 3 times before I figured everything out. If you want to do your own programing you will have to go aftermarket. There are very few dealers that can program the factory comp.
#39
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I have been using the Innovate LM-1 for a few years now with very good results. The best way to tune carb or efi is with a wide band O2 sensor. As far as a solution to getting a sensor in the cast manifolds, check the classifieds.
http://www.offshoreonly.com/classifi...o38189-en.html
Jeff
http://www.offshoreonly.com/classifi...o38189-en.html
Jeff
Last edited by WAGS382; 02-26-2011 at 06:16 PM.
#40
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I have been using the Innovate LM-1 for a few years now with very good results. The best way to tune carb or efi is with a wide band O2 sensor. As far as a solution to getting a sensor in the cast manifolds, check the classifieds.
http://www.offshoreonly.com/classifi...o38189-en.html
Jeff
http://www.offshoreonly.com/classifi...o38189-en.html
Jeff