Dyno tuning technic
#51
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Location: Olmsted Falls,Ohio Marblehead,Oh
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As joe did, we did mine slow rate also in marine trim, that was as accurate as we could get, still changed a lot putting them in the boat mid summer I see low 11 air fuels sonetines a high 10, I am rejetting This week glad I have widebands to keep eye on that, I recommend that on any HP boat.
http://youtu.be/F5sQmgFHOf4
http://youtu.be/F5sQmgFHOf4
#53
Registered
Most dyno shops dont simulate part throttle loads. They simply do a full throttle pull, and call it a day. That does nothing for part throttle fuel tuning.
Ryan Retter allowed us to bring the engine up to certain rpms, and partially load the engine and monitor the air fuel ratios, etc. For example, 3000rpm and 0" , 3500rpm, and 2psi boost, etc
From what Ive been learning over the past couple years, is that , a dyno tune on your engine, is only as good as the operator,tuner, and equipment they have. Slapping an enginr on a dyno for unrealistic sweep rates, questionable data acquisition, and 30 year old tuning techniques, is pretty much a waste of time. And in the wrong hands, can do more damage to the engine than its worth.
Ryan Retter allowed us to bring the engine up to certain rpms, and partially load the engine and monitor the air fuel ratios, etc. For example, 3000rpm and 0" , 3500rpm, and 2psi boost, etc
From what Ive been learning over the past couple years, is that , a dyno tune on your engine, is only as good as the operator,tuner, and equipment they have. Slapping an enginr on a dyno for unrealistic sweep rates, questionable data acquisition, and 30 year old tuning techniques, is pretty much a waste of time. And in the wrong hands, can do more damage to the engine than its worth.
#54
Registered
Yup. Was that 200rpm/sec ? Appears pretty slow.
Just so people know, 600rpm/sec seems to be the standard rate as 95+% of sheets you see show 600rpm/sec. I'm just proposing here, and others agree, closer to actual engine accelration rates will of course be better. That's why OEM's and big $$$$ race outfits will dyno (huge $$$ dyno) for actual conditions. Example: road race engines will be dyno'd as it's at a certain track. Acceleration, deceleration, shifts, and etc will be done as close to exact on dyno as it's 'being driven' . Obviously not just for power/hp, but for tuning and alos component durability, and etc.
https://www.youtube.com/watch?v=J-62SiWKJzM
Just so people know, 600rpm/sec seems to be the standard rate as 95+% of sheets you see show 600rpm/sec. I'm just proposing here, and others agree, closer to actual engine accelration rates will of course be better. That's why OEM's and big $$$$ race outfits will dyno (huge $$$ dyno) for actual conditions. Example: road race engines will be dyno'd as it's at a certain track. Acceleration, deceleration, shifts, and etc will be done as close to exact on dyno as it's 'being driven' . Obviously not just for power/hp, but for tuning and alos component durability, and etc.
https://www.youtube.com/watch?v=J-62SiWKJzM
That was 150 per second starting around 2800rpm to 6500rpm. . We ended up going to 300 rpm per second i wanna say on the next engine. I felt the 150 per second was a bit extreme. My boat would never accelerate THAT slow.
#55
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We held mine at peak TQ for how long to monitor A/F? Like 3 minutes just held it there.. That was good to see stable A/F throughout.
Most dyno shops dont simulate part throttle loads. They simply do a full throttle pull, and call it a day. That does nothing for part throttle fuel tuning.
Ryan Retter allowed us to bring the engine up to certain rpms, and partially load the engine and monitor the air fuel ratios, etc. For example, 3000rpm and 0" , 3500rpm, and 2psi boost, etc
From what Ive been learning over the past couple years, is that , a dyno tune on your engine, is only as good as the operator,tuner, and equipment they have. Slapping an enginr on a dyno for unrealistic sweep rates, questionable data acquisition, and 30 year old tuning techniques, is pretty much a waste of time. And in the wrong hands, can do more damage to the engine than its worth.
Ryan Retter allowed us to bring the engine up to certain rpms, and partially load the engine and monitor the air fuel ratios, etc. For example, 3000rpm and 0" , 3500rpm, and 2psi boost, etc
From what Ive been learning over the past couple years, is that , a dyno tune on your engine, is only as good as the operator,tuner, and equipment they have. Slapping an enginr on a dyno for unrealistic sweep rates, questionable data acquisition, and 30 year old tuning techniques, is pretty much a waste of time. And in the wrong hands, can do more damage to the engine than its worth.
#56
Platinum Member
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Most dyno shops dont simulate part throttle loads. They simply do a full throttle pull, and call it a day. That does nothing for part throttle fuel tuning.
Ryan Retter allowed us to bring the engine up to certain rpms, and partially load the engine and monitor the air fuel ratios, etc. For example, 3000rpm and 0" , 3500rpm, and 2psi boost, etc
From what Ive been learning over the past couple years, is that , a dyno tune on your engine, is only as good as the operator,tuner, and equipment they have. Slapping an enginr on a dyno for unrealistic sweep rates, questionable data acquisition, and 30 year old tuning techniques, is pretty much a waste of time. And in the wrong hands, can do more damage to the engine than its worth.
Ryan Retter allowed us to bring the engine up to certain rpms, and partially load the engine and monitor the air fuel ratios, etc. For example, 3000rpm and 0" , 3500rpm, and 2psi boost, etc
From what Ive been learning over the past couple years, is that , a dyno tune on your engine, is only as good as the operator,tuner, and equipment they have. Slapping an enginr on a dyno for unrealistic sweep rates, questionable data acquisition, and 30 year old tuning techniques, is pretty much a waste of time. And in the wrong hands, can do more damage to the engine than its worth.
#57
Registered
Where do you start getting uncomfortable with exhaust temps? Depending on where you look in the powerband it's down sometimes as much as 10hp and ft lbs after richening it up. Further, how much fatter should it be because we ran it on a 90 degree day to keep it safe on a 72 degree day?
I mentioned earlier regarding seeing extremely high EGT's while jetting was overkill. It was one of my learning days many years ago on BBC with a 420 mb. In a nutshell the the EGT's were so high from way to much fuel/jetting. Fire was blowing out of the hole (exh port) so to speak. Had to bring jetting way down to get numbers where they needed to be. Initially it was a real head scratcher with seeing such outrageous EGT's yet the plugs showed extremely rich. Would have been caught much quicker if the wideband would have not malfunctioned via day one.
What did your engine builder say about your AFR's currently vs when in the boat?
#58
Platinum Member
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I may have missed it somewhere in your other post however are do you have wideband o2 installed in your boat? With where your currently running AFR's I believe your engine will like the cooler temps without a concern. I'm probably old school but along with wideband I still like to do plug checks from time to time on hottest cylinder due to equipment failure or possibly inaccurate?
I mentioned earlier regarding seeing extremely high EGT's while jetting was overkill. It was one of my learning days many years ago on BBC with a 420 mb. In a nutshell the the EGT's were so high from way to much fuel/jetting. Fire was blowing out of the hole (exh port) so to speak. Had to bring jetting way down to get numbers where they needed to be. Initially it was a real head scratcher with seeing such outrageous EGT's yet the plugs showed extremely rich. Would have been caught much quicker if the wideband would have not malfunctioned via day one.
What did your engine builder say about your AFR's currently vs when in the boat?
I mentioned earlier regarding seeing extremely high EGT's while jetting was overkill. It was one of my learning days many years ago on BBC with a 420 mb. In a nutshell the the EGT's were so high from way to much fuel/jetting. Fire was blowing out of the hole (exh port) so to speak. Had to bring jetting way down to get numbers where they needed to be. Initially it was a real head scratcher with seeing such outrageous EGT's yet the plugs showed extremely rich. Would have been caught much quicker if the wideband would have not malfunctioned via day one.
What did your engine builder say about your AFR's currently vs when in the boat?
#59
Charter Member#568
Charter Member
Thread Starter
I do have O2 in the boat so I will be able to check/ compare. We haven't discussed changes to be made after installation. I'll probably have to start another thread...
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Straight bottoms and flat decks
Straight bottoms and flat decks
#60
Registered
If EGT`s are too high with a rich mixture I`d say it doesn`t need less fuel but may need more timing to burn the fuel off.
I saw lower egts with more fuel. Pulled 4 jet sizes EGTs went up.
I saw lower egts with more fuel. Pulled 4 jet sizes EGTs went up.