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| Supernatural 3.7L 9,000RPM Project (Page 14/20) |
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pmbrunelle
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FEB 17, 07:08 PM
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| quote | Originally posted by ericjon262:
it has the availability to do staged injection, I'm just not sure it can do it in the manner I described. because my engine isn't anywhere near a power level that could possibly require it, I haven't really explored. it. it could be very interesting to explore, and I might on one of my next builds. but I suspect that won't exactly need the fuel flow either.
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Have you been getting accurate AFR control lately?
A set of 15 lb/hr injectors near the ports could have your AFR pretty accurate for idle/calm driving... basically making dead-time issues with big injectors go away.
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La fiera
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FEB 17, 10:04 PM
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| quote | Originally posted by Joseph Upson:
Understood, I'm just gently pointing out that your performance knowledge base coupled with the generalized statements can discourage with the assumption by others that they must be correct coming from an experienced motorhead, considering there are 3.6L swaps going on here. I'm sure some of what you've stated is true, I just haven't observed it with the GM platform, imports however, are a different story, particularly with BMW and VW at the advent of DI. I've made similar statements to yours in the past as a reason to keep it simple on projects, but have come to appreciate the benefit of the added tech & accept the additional labor in working with it. Making a project/plan work is part of the DIY experience. The cost is relative, it's a 4 cam motor, with 4 cam cost and benefits. I'm following your progress, not questioning your plan. |
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Point taken Joseph, what's coming next won't disappoint you!
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ericjon262
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FEB 17, 10:14 PM
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| quote | Originally posted by pmbrunelle:
Have you been getting accurate AFR control lately?
A set of 15 lb/hr injectors near the ports could have your AFR pretty accurate for idle/calm driving... basically making dead-time issues with big injectors go away. |
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Honestly, I haven't been driving the car enough to know for sure, but the injectors in the car came with a datasheet for MS3, so they should be very close. once I get the new tank in, I'll drive it more and hopefully get a better idea of how things are working. I'm not super interested in doing staged injection on this car, it would require a ton of custom work, if it happens, it will be with a different engine, and a one off intake manifold. ------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
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La fiera
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FEB 18, 09:14 PM
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| quote | Originally posted by sanderson231:
Compared to a standard liquid to air intercooler freon chilling should be able to decrease the charge air temperature by over 60 'F which will increase the density by over 10%. Mass air flow gain is probably something less say 7%.
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That is why I have the injectors high up in the runners. To give it enough time for the alcohol in E85 to evaporate and do its thing. There is no intercooler that will do a better job than that. And you may wonder about transient throttle response. Well, the Megasquirt has an algorithm to compensate for that. So now due to software technology I can have injectors farther away and be able to program them to make up for the difference of transient throttle response.
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ericjon262
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FEB 19, 12:51 PM
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| quote | Originally posted by La fiera:
That is why I have the injectors high up in the runners. To give it enough time for the alcohol in E85 to evaporate and do its thing. There is no intercooler that will do a better job than that. And you may wonder about transient throttle response. Well, the Megasquirt has an algorithm to compensate for that. So now due to software technology I can have injectors farther away and be able to program them to make up for the difference of transient throttle response. |
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to a point, I'll agree that technology can make transient fueling acceptable even with the injectors further away, but only to a point, eventually, time and distance will become a factor and the fueling needs can start to change as the fuel is traveling down the ports to the cylinder when the injectors are far away. This is part of the reason I like the idea of direct injection, the engine could be provided with the exact amount of fuel required for that combustion cycle, AFTER, the valves are shut(ting)
a blended injection system could be awesome, port injectors spray a minimal amount of fuel for cooling and cleaning, direct, or near port injectors provide trimming for AFR, and getting the exact amount of fuel for maximum power. By spraying the minimum amount of fuel to provide cooling, you maximize the available air to enter the cylinder, because the fuel will displace some air, and therefore some available oxygen to support combustion. I'd love to implement a system like this, but I think it's probably outside the scope of what I'll ever do with one of my cars, definitely outside the scope of what I'll do to my Fiero. ------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
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La fiera
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FEB 19, 05:57 PM
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| quote | Originally posted by ericjon262:
By spraying the minimum amount of fuel to provide cooling, you maximize the available air to enter the cylinder, because the fuel will displace some air, and therefore some available oxygen to support combustion.
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Well said Eric! For pure gasoline that statement is absolutely true but if an oxygenated fuel like E85 is used more oxygen can be introduced in the combustion chamber compared by the air displaced by the fuel itself, in this case E85. By weight E85 is about 30% oxygen and the air we and our engines breathe is only about 23% by weight.
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La fiera
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FEB 20, 09:59 PM
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| quote | Originally posted by Notorio:
And folks like me appreciate being exposed to the thinking going on in the Forum. It's encouraging to see what can be done with the lowly 3.4 PR block, with 1 cam and valve train, and NA. 
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Notorio, we have a great thing here in this Fiero forum. There are forums like ThirdGen, S10, 60*V6 and some Pontiacs forums that share the 60* V6 engine platform but you'll never see any of those forums with the same amount of talented individuals as our Fiero community. I'm a nobody compared to the scientific minds of this Fiero group and I'm saying this without mentioning any names to keep them anonymous. I personally consider it an honor to be part of this Fiero family. Yes, we fight and fuzz but don't all families also do so? I have learned a lot over the years here and I can honestly say that I would never achieve my goals without the help and critics from the members of this forum. I think the common denominator we have is the Fiero, which now a days is a Unicorn and that makes us unique individuals![This message has been edited by La fiera (edited 02-25-2023).]
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La fiera
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MAR 01, 10:21 PM
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Finished gaping the rings now I can assemble it and start working on the bracket for the dry sump, the oil pan and the lines.
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Blacktree
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MAR 04, 05:17 PM
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| quote | | Originally posted by ericjon262: a blended injection system could be awesome, port injectors spray a minimal amount of fuel for cooling and cleaning, direct, or near port injectors provide trimming for AFR, and getting the exact amount of fuel for maximum power. |
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For a hybrid DI / MPFI system, I'd want to use the DI injectors for normal operation, and the MPFI injectors for WOT enrichment... like the pump shot in a 4-barrel carb.
Edit to add: That dry sump is gonna be a game changer! You can probably get a few ponies via crankcase vacuum, as well.[This message has been edited by Blacktree (edited 03-04-2023).]
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sanderson231
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MAR 04, 05:57 PM
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Since the goal seems to be to get as much atomization as possible in the big plenum, I was wondering if it would make sense to use single stage high pressure drop (direct injection) injectors . ------------------
formerly known as sanderson
1984 Quad 4
1886 SE 2.8L
1988 4.9L Cadillac
1988 3800 Supercharged
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