DIY_EFI Digest Wednesday, 13 August 1997 Volume 02 : Number 271 In this issue: What is Ockham's Razor? Re: Apology Re: additional injector Re: Adjusting Boost Re: What is Ockham's Razor? Re: What is Ockham's Razor? Re: Reality of Fuel Consumption RE: fuel filter location Re: Adjusting Boost RE: TPI Questions RE: Treatise on intake systems Re: additional injector Re: Adjusting Boost Re: Reality of Fuel Consumption Remove RE: What is Ockham's Razor? Re: fuel filter location Re: Motorola FI driver? Re: Adjusting Boost Re: Too good to let go by - Miller Cycle Adjusting Boost Re: additional injector Anti-turbo lag systems Re: Adjusting Boost Re: Not strickly efi........more turbo stuff Re: Treatise on intake systems See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Terry Martin Date: Tue, 12 Aug 1997 14:23:30 -0700 Subject: What is Ockham's Razor? Tom Cloud wrote: > > >> Terry Martin wrote: > >> > > >> > Fuel injection is one of those concepts that make you go DOUGH! However,... > > >Michael McBroom wrote: > >> > >> Thank you for that, Terry. Now go away. And start practicing what you > >> preach from now on. Pedal your blinkety-blink bicycle to work. > > and Terry retorted: > >Hmmm. Methinks you didn't. I also posted this. > > > >Yeah, I would be impressed if the carburetor by itself could do 100mpg. > >According to my weed eater, you can carry it and it gets about 4mpg. > > [ snip ] > > >doesn't cover himself in the entrapments of heat engines. With a gallon > >of gas, he probably wouldn't make it back to the car without a Coke. > > > >Terry > > Terry, you appear to be a very smart man .... perhaps you > don't belong here ;-) .... one very redeeming item though, > you did mention Coke and not Pepsi 8^) > > I would like to interject a couple of things > > 1 - I'm not a very smart man (thought I'd clear that up > right away 8^) Define "smart" > > 2 - I have a major in Philosophy and Greek ... don't > remember nothin' 'bout nobody's razor See below > > 3 - following your logic, walking must be the least > efficient form of energy, since it was "accidental" (well, > I guess crawling is mebbe even less efficient) Walking is probably one of the least efficient modes of movement, particularly if you try to emulate the efficiency of an organism with a machine. Hence we have wheels. > > 4 - I sincerely respect your thoughts on the energy thing > but, when will we get that the global warming crisis is > a bunch of crap (a 1 degree rise during the short time we've > measured temps is nothing to a planet that has experienced > some pretty serious warming/cooling trends long before > anyone ever heard of R12 -- in fact long before there > WAS anyone !! ). I look forward to the development > of something not nearly so crude as a reciprocating > engine or the burning of petroleum products to power it, > and I concur that it will happen some time, but .... Oh, I'm not so worried about global warming as I am nuclear war over control of the resources, air pollution, and other bothersome irritants. > > I remember when I was in elementary and junior > high looking at the Popular Science mags (this > was back in the 50's) .... there was lotsa > articles on anti-gravity devices and nuclear > power and much discussion about how we were > going to have problems controlling the airways > since EVERYBODY was going to have a personal > flying saucer (or something like that) -- sorta > a George Jetson kinda world. And this was pre- > dicted to happen in less than 20 years .... it's > been over 40 years and I haven't seen any movement. > My 1949 Ford and my '52 Studebaker Champion are > not far removed from the technology of today, > as also the aeroplanes (well, there has been > some major movement in turboprops and jets) You haven't looked under the hood of a late model GM for instance. They have a neural network. Vehicles are "smarter" than humans in given instances. > > I guess what I'm saying is that (a) I (honestly) recognize > the intelligence of our list members -- and of yourself > but (b) I don't see us moving away from the reciprocating > engine and fossil fuels in the near future (no, not even > during the lifetimes of our children) unless forced to do > so by an international nanny (read UN) run by people who > know oh-so-much-better than the rest of us low-life slugs. > > Tom Cloud If we don't, with the near future now being much nearer than anyone had anticipated with the invention of the piston engine, we collectively are stupid, forget smart. The doom & gloom crowd tend to detract from the immediacy of the problem, simply because they are extremest. The nirvana is here bunch tend to detract from the immediacy of the problem, by simply saying there isn't one. Do the read below, and apply Ockham's Razor to the middle position, and fiqure out for yourself what's most likely to be true. Ockham's Razor (Occam) is a bit of logic that was apparently first made mainstream about 1300AD. In folk talk it means the less assumptions you make in a statement the more likely you are to be right, or, for those like lawyers, that don't get that, the more times you flip a coin, the less likely you are to keep coming up with the same side. It sounds stupidly simple, however, that is just an appearance as a result of the characteristics of simplicity and elegance, basic properties of the truest scientific principles. Here's a snippet from Encarta '95, (who said WIN95 was dumb?) Ockham or Occam, William of (circa 1285-1349?), known as Doctor Invincibilis (Latin, “unconquerable doctor”) and Venerabilis Inceptor (Latin, “worthy initiator”), English philosopher and Scholastic theologian, who is considered the greatest exponent of the nominalist school, the leading rival of the Thomist and Scotist schools. See NOMINALISM; SCHOLASTICISM. Ockham was born in Surrey, England. He entered the Franciscan order and studied and taught at the University of Oxford from 1309 to 1319. Denounced by Pope John XXII for dangerous teachings, he was held in house detention for four years (1324-28) at the papal palace in Avignon, France, while the orthodoxy of his writings was examined. Siding with the Franciscan general against the pope in a dispute over Franciscan poverty, Ockham fled to Munich in 1328 to seek the protection of Louis IV, Holy Roman emperor, who had rejected papal authority over political matters. Excommunicated by the pope, Ockham wrote against the papacy and defended the emperor until the latter's death in 1347. The philosopher died in Munich, apparently of the plague, while seeking reconciliation with Pope Clement VI. Ockham won fame as a rigorous logician who used logic to show that many beliefs of Christian philosophers (for example, that God is one, omnipotent, creator of all things; and that the human soul is immortal) could not be proved by philosophical or natural reason but only by divine revelation. His name is applied to the principle of economy in formal logic, known as Ockham's razor, which states that entities are not to be multiplied without necessity. Contributed by: Rev. W. Norris Clarke "Ockham," Microsoft (R) Encarta. Copyright (c) 1994 Microsoft Corporation. Copyright (c) 1994 Funk & Wagnall's Corporation. (You really have to stretch to fit this into the subject matter of this group. :-) ------------------------------ From: "Mark A. Hetzel" Date: Tue, 12 Aug 1997 17:26:51 -0500 Subject: Re: Apology I'm not receiving double... > Is everyone getting my mail twice?? I dont know why my mailing system would > be doing this. I am sorry if this is happening. I hate to litter mail boxes. > Everyone's input will be appreciated. ------------------------------ From: Todd King Date: Tue, 12 Aug 97 16:11:00 PDT Subject: Re: additional injector <<< > >If you want more power and the engine can handle it you can use the > >cold start injector as a water injector this then allows you to run > >more boost without worring about detonation..... > > I was thingking of an additional injector that activates on specific > rpm. What do you think? The big problem in doing this with EFI is that in general the O2 sensor will "see" the fuel mix go richer then the ecu will lean off the other injectors to compensate and try to keep the mix at 14.7 to 1....thats why you need to either re tune the ecu or get a replacement that you can tune. The good thing about an aftermarket ecu is that you can tune it how you want not how the factory set it. >>> Well actually the car will not be under closed loop control (at least the current ones that I know of) at wot so this correction you refer to won't happen at wot. The enrichment should work fine; we (v6) refer to these devices as "seventh injectors" and see them alot. And most cars go to (or try to) around 12.5:1 or so at wot too. Todd tking@xxx.com ------------------------------ From: bibie@xxx.com (Bibiana Lim) Date: Wed, 13 Aug 1997 07:31:53 +0800 Subject: Re: Adjusting Boost Hi Simon, You wrote: >The big problem in doing this with EFI is that in general the O2 >sensor will "see" the fuel mix go richer then the ecu will lean off >the other injectors to compensate and try to keep the mix at 14.7 to How about disabling the o2? Bad idea..huh! >1....thats why you need to either re tune the ecu or get a >replacement that you can tune. The good thing about an aftermarket >ecu is that you can tune it how you want not how the factory set it. Yeah...this is better! > >Too true !!! I'm glad you agree! >you said it.... woman ! ;-) >Most girls I know prefer back seat entertainment over screamin' tyres >and purring engines >:-) There's time for many things but screamin' tyres and being on the wheels is a whole kind of climax...Agree? Now...steady on the wheels, man! Bibie. ------------------------------ From: "barry coleman" Date: Tue, 12 Aug 1997 16:46:26 PDT Subject: Re: What is Ockham's Razor? List members, *snip* >(You really have to stretch to fit this into the subject matter of >this group. :-) Enough said! Barry Coleman a 351C w/SEFI...why didn't Ford think of that? p.s. ...I'm still trying to figure out how to inject that "boiling gas" vapor... ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com ------------------------------ From: Jason Walters Date: Tue, 12 Aug 1997 17:55:11 -0700 Subject: Re: What is Ockham's Razor? Ockham's Razor: It's strange how when you 'register' something, it starts popping up in everything you see. A few days ago, I saw the movie "Contact", and Ockham's Razor was tossed around with respect to the existence of a creator. Today, I see it applied to the existence of a 100 mpg carburetor. Wow. I never thought about the institutional nature of this discussion group's technology set. Hooray for the heretic! I'm also sorry for being caustic on the topic after you posted the 100 mpg link. I think subject is cool, I just couldn't resist jabbing you on some of the site's quotations. It's amazing how a concept can be totally obscured by its support literature. But can you blame me (or others) for being skeptical? If you can email me with a straight face and tell me that you didn't chuckle when you read the lines . . . "We believe these answers are found in the inventive resourcefulness of the Americium people." "Then we show evidence that gas cars have been invented. These vechiles don't even require gasoline as a fuel!" "This is not designed to be a book of make-believe." . . . then I'll eat a carburetor. Sorry to jab again. It's just too much fun. At least I know you have a sense of humor. Damn! There I go again! I think I'll go now before I embarrass myself further. Jason Walters jasonw@xxx.com ------------------------------ From: Clint Corbin Date: Tue, 12 Aug 1997 19:03:37 -0600 Subject: Re: Reality of Fuel Consumption At 02:16 AM 8/12/97 -0400, you wrote: >1. Until Columbus, the world was flat, not round. Actually, there where a whole lot of people who thought the world was round way before Columbus! Heck, in the bible Christ says "In the day in which I come........ In the night in which I come....." That was just a bit before Columbus, don't you think? >4. Certain purpose-built automobiles have broken the 300MPH bracket. Actually, certain purpose-built automobiles have gotten right up to the speed of sound! >5. Stealth fighers exist. (we think). They are not fighters, but light bombers. Unless you count the F-22. >6. Helicopters can fly straight up, with the rotor assembly held on by a >single grade 5 aircraft nut. (okay, a big one) >And while we don't have 100MPG cars, the technology is right around the >corner. Advanced materials are constantly being developed, new ideas form, >people think. The Wankel engine was a fantastic example of a new idea. No >pistons. Piston engines have been around since 1903. Its 1997. Its time >for a new idea folks. Uh, the Wankel DOES have pistons. They just aren't round! But they are pistons by any measure. As for 100MPG cars, they are going to be itty bitty tiny things unless someone figures out a good way around the laws of thermodynamics. I'm definitely not going to hold my breath waiting on that on! Now me, I personally would like to see a vehicle that ran on the background cosmic energy! That would be interesting! Clint PS: Sorry folks, just couldn't help but add my $0.01 worth. ------------------------------ From: John Hess Date: Tue, 12 Aug 1997 20:32:11 -0500 Subject: RE: fuel filter location Most pumps would rather push than pull (suck), even your well pumps at home (for those who have wells). It all has to do with gravity and it being easier to push a fluid up a pipe than suck it from the top. Some of the problem has to do with efficiency in that when you suck, the pipe is initially filled with low density air. You have to create a low enough air pressure to pull the liquid up the pipe before the pump can act directly on the much higher density liquid. I know, I know. Everyone is going to tell me that there is not much rise in a car situation; but, with the forward momentum (acceleration) of the car, there is still a deep gravity well to overcome. >---------- >From: James Weiler[SMTP:james@xxx.ca] >Sent: Monday, August 11, 1997 9:38 PM >To: diy_efi@xxx.edu >Cc: diy_efi@xxx.edu >Subject: Re: fuel filter location > > > >On Tue, 12 Aug 1997, Simon Quested wrote: > >> This is what I have found out about installing your own efi..... >> >> 1) the fuel pump needs to be as clost to the tank as possible. >Why? > >I'm not saying you're wrong. Just asking. Is there something about the >way a pump is designed such that it would prefer to push rather than pull? > >I was going to put mine there as well. Now I'd like to know why I made >that decision. > >thanks >jw > ------------------------------ From: Simon Quested Date: Wed, 13 Aug 1997 13:47:10 +1200 Subject: Re: Adjusting Boost Hi Bibie & All I wrote: > >The big problem in doing this with EFI is that in general the O2 > >sensor will "see" the fuel mix go richer then the ecu will lean off > >the other injectors to compensate and try to keep the mix at 14.7 to Todd replied: > Well actually the car will not be under closed loop control (at > least the current ones that I know of) at wot so this correction > you refer to won't happen at wot. The enrichment should work > fine; we (v6) refer to these devices as "seventh injectors" and > see them alot. And most cars go to (or try to) around 12.5:1 or > so at wot too. Sorry Bibie looks like I'm putting you wrong..... I was under the impression that once a system went to closed loop mode it stayed there to optimise fuel economy not usually power? Hence the reason for getting an aftermarket chip or complete system.....as well as the ignition mapping & boost control. > There's time for many things but screamin' tyres and being on the wheels > is a whole kind of climax...Agree? Gotta luv that adrenlanin rush ;-) > Now...steady on the wheels, man! Now why would I want to do that, woman ;-) Cheers Simon +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Simon Quested (E-mail questeds@xxx.nz) Computer Technician, Silicon Graphics & Windows NT Support Centre for Computing and Biometrics LINCOLN UNIVERSITY OF NEW ZEALAND Phone (64)(03) 3252811 Ext. 8087 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ http://www.lincoln.ac.nz/ccb/techs/simon/default.htm +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ f u cn rd ths, u cn gt a gd jb n cmptr prgmmng +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------ From: James Boughton Date: Tue, 12 Aug 1997 22:12:51 -0400 Subject: RE: TPI Questions EGR is used to decrease NOx emissions, as well as to dilute the incoming mixture to improve fuel economy. Because EGR causes the burn rate of the mixture to decrease the spark advance must be increased. So for an engine calibrated with EGR there is a spark advance increase any time the engine controller thinks the engine is breathing in EGR. The problem with removing the EGR valve is that some people don't let the engine controller know that EGR is not functional (to keep the check engine light from coming on). This means that the engine controller thinks you have EGR when you really don't and therefore the spark advance is far more than what it should be. This can cause very high peak pressures and possibly knock. I know when I did this I holed a piston:-P I wish somebody had told me what I am telling you. Since EGR is only operational under part throttle conditions it is really arguable that it should be used even on streetable performance applications. I will say that I wouldn't put it on my car, but if faced with using an engine controller that expected it to be there I wouldn't hesitate to install it. Jim Boughton boughton@xxx.net - ---------- From: Jeffrey R Muehl[SMTP:JRMUEHL@xxx.com] Sent: Tuesday, August 12, 1997 10:03 AM To: diy_efi@xxx.edu Subject: Re: TPI Questions I was hoping someone would jump in here. Do you have any evidence of the engine knocking without EGR? I have the same question - do I want it or not? I'm also not concern with economy, only power. >I'm lost, for a performance engine, do you want egr or not ? When I built my tpi 350, I pulled the egr valve and stuck >a blanking plate over the hole instead, oh, I also put the little metal plates in the manifold gaskets where the egr is >meant to breathe through. Was this a mistake (I don't care about economy, only power)?>> > > >Dan dzorde@xxx.com > > >The EGR valve is still present and connected, but doesn't actually do >anything since there isn't a supply of exhaust gas to the valve. > >Grounding the EGR feedback wire will set off the SES light (it simulates >the EGR being stuck in the open position) > >Leaving it disconnected will also occasionally set off the SES light (there >are a few cases where the ECM will command the EGR to actuate, then look to >see what happened.) Fortunately, temps down here are high enough that this >doesn't happen often. (been about 4 months since the last time the code >went off) It will also clear itself within a few minutes of driving. > >Someday I'll have an EGR flange welded to one of the exhaust headers to >supply external EGR.. but it's a low priority. ------------------------------ From: James Boughton Date: Tue, 12 Aug 1997 22:24:34 -0400 Subject: RE: Treatise on intake systems I'm sorry about using g for gamma, but I don't have a gamma on my keyboard and g looked like the closest thing:-) I guess I should have explained myself, sorry! According to table D.1 of Heywood's "Internal Combustion Engine Fundamentals" gamma does change with temperature, however, you are correct regarding the gas constant which does not. I guess that is why they call it a constant:-) I was noting that the specific heats change with temperature and wasn't thinking. Again, sorry! Thank you for the corrections. Jim Boughton boughton@xxx.net - ---------- From: wstrass@xxx.com] Sent: Tuesday, August 12, 1997 11:48 AM To: diy_efi@xxx.edu Subject: Treatise on intake systems To: DIY --INTERNET DIY From: Wayne Strasser (CED Polymer Development) *** Resending note of 08/12/97 11:24 _______________________________________________________________________ Subject: Treatise on intake systems ========================================================================= (The speed of sound is simply (gRT)^0.5 where g and R are considered constant. If you wanted to be rigorous you could actually vary g and R for temperature, but probably not worth it.) Jim: I have a question....how can g (is this gravitational constant?) and R (the universal gas constant) vary with temperature? ------------------------------ From: DemonTSi@xxx.com Date: Tue, 12 Aug 1997 22:31:18 -0400 (EDT) Subject: Re: additional injector In a message dated 97-08-12 21:31:26 EDT, you write: << The big problem in doing this with EFI is that in general the O2 sensor will "see" the fuel mix go richer then the ecu will lean off the other injectors to compensate and try to keep the mix at 14.7 to 1....thats why you need to either re tune the ecu or get a replacement that you can tune. The good thing about an aftermarket ecu is that you can tune it how you want not how the factory set it. >>> Well actually the car will not be under closed loop control (at least the current ones that I know of) at wot so this correction you refer to won't happen at wot. The enrichment should work fine; we (v6) refer to these devices as "seventh injectors" and see them alot. And most cars go to (or try to) around 12.5:1 or so at wot too. >> The o2 sensor would not see a rich condition if you set the additional injector to come on when needed...i.e. when the car is starting to run lean. In turbocharged applications, this is usually at high boost and high rpms...when the existing fuel injectors can't supply enough fuel for the increased air flow. That's when the additiona inj comes in and saves the day....! :) Van ------------------------------ From: James Weiler Date: Tue, 12 Aug 1997 19:43:12 -0700 (PDT) Subject: Re: Adjusting Boost On Wed, 13 Aug 1997, Simon Quested wrote: > Hi Bibie & All > > > There's time for many things but screamin' tyres and being on the wheels > > is a whole kind of climax...Agree? > > Gotta luv that adrenlanin rush ;-) > > > Now...steady on the wheels, man! > > Now why would I want to do that, woman ;-) > > Cheers > > Simon We're going to have to hose you two down soon. :) jw ------------------------------ From: JRECPA@xxx.com Date: Tue, 12 Aug 1997 23:01:34 -0400 (EDT) Subject: Re: Reality of Fuel Consumption In a message dated 97-08-12 21:38:37 EDT, you write: << And while we don't have 100MPG cars, the technology is right around the corner. Advanced materials are constantly being developed, new ideas form, people think. The Wankel engine was a fantastic example of a new idea. No pistons. Piston engines have been around since 1903. Its 1997. Its time for a new idea folks. Cheers :) Frederic Breitwieser Homebrew Automotive Mailing List Bridgeport, CT 06606 http://www.geocities.com/MotorCity/Downs/4605/index.html 1989 AG Hummer 4-Door 1993 Supercharged Lincoln Continental 2000 Mid-Engine Sports Car >> You all might want to take a look at this engine under developement at http://www.getnet.com/charity/aha/engine.html American Hydrogen Ass ociation: Larsen Engine. interesting 8 cylinder engine. James ------------------------------ From: "Juha Saarinen" Date: Wed, 13 Aug 97 03:00:15 UT Subject: Remove Remove ------------------------------ From: "Juha Saarinen" Date: Wed, 13 Aug 97 02:59:53 UT Subject: RE: What is Ockham's Razor? >Ockham's Razor: Occam's Razor, surely? After William of Occam. Now could someone please tell me how to get off this list? Unsubscribe doesn't work. - -- Juha ------------------------------ From: "Stuart Baly" Date: Wed, 13 Aug 1997 13:34:26 +1000 Subject: Re: fuel filter location >A petrol head working for and Air Pollution Station ?? ;-) Got to give ourselves something to measure... >Over here you aren't allowed to have the surge tank in the engine bay. Silly regs. I don't know why not. Maybe they're nervous about having a pressurised container of fuel in the engine bay. >What happens once the surge tank is full ? >I don't know if it is good to a pressurise a surge tank ? >can anyone on the list enlighten us..... Hopefully what will happen will be the same as what happens when the float bowl is full on a carbed vehicle, as far as the mechanical pump is concerned. The EFI pump will pump the fuel in a loop, so it won't pressurise the tank. The regulator should still work OK, since the fuel rail pressure should always be higher than the tank/return line pressure. >This is what I'm doing....... >Low pressure pump feeding the surge tank (in the boot), efi pump >feeding fuel rail (from ST), out from regulator going back to surge >tank, surge tank over flow going back to tank, Fuel tank vented to >atmosphere. This should give good pressure regulation and no pressure >build up in the ST. It's a better setup than my plan, but I'm too cheap (and more importantly, too lazy) to do it. Cheers, Stuart "environmentally hostile" Baly. ======================================================== Stuart Baly (s.baly@xxx.au) Technical Officer Cape Grim Baseline Air Pollution Station '71 Datsun 510, '81 Yamaha RD350LC, '89 Kawasaki GPz900R ======================================================== ------------------------------ From: Seth Date: Tue, 12 Aug 1997 20:42:03 -0700 (PDT) Subject: Re: Motorola FI driver? On Tue, 12 Aug 1997, Stuart Baly wrote: > Seth wrote: > > >Call allied electronics 800-433-5700. > > >$25 minimum orderUS currency. Add a few trnsistors to the price for > >the=20 MPX 4250AP at ~ $22 US and you have a $25 order.=20 > > Good luck. In May this year I emailed Allied for a quote on three > MPX4250's, and the reply came back - 6 week wait, $20 each, minimum > order qty 20 units. Seemed like a bit of a brush-off to me. Anyway I found an > Australian supplier and ordered seven. That was eight weeks ago and > I'm still waiting... I'm convinced there's a conspiracy to keep > these things out of the hands of Joe Public. > > Stuart > ======================================================== > Stuart Baly (s.baly@xxx.au) > Technical Officer > Cape Grim Baseline Air Pollution Station > '71 Datsun 510, '81 Yamaha RD350LC, '89 Kawasaki GPz900R > ======================================================== > Perhaps DIY-EFI should sponsor a big group buy with MXP4250AP's, LM1949's and 5w 33v zeners. Not to mention heatsinks. Oh yeah, and through hole plated PC boards, then send them out in kits for 4, 6 and 8 cyl setups? Just an idea, I haven't had a big problem getting parts... yet Seth ------------------------------ From: bibie@xxx.com (Bibiana Lim) Date: Wed, 13 Aug 1997 11:44:42 +0800 Subject: Re: Adjusting Boost Simon, You wrote: >Sorry Bibie looks like I'm putting you wrong..... I was under the NO harm done...I'm still trying to siphon as much info from you guys! >impression that once a system went to closed loop mode it stayed >there to optimise fuel economy not usually power? >Hence the reason for getting an aftermarket chip or complete >system.....as well as the ignition mapping & boost control. >Gotta luv that adrenlanin rush ;-) Rev man ! >> Now...steady on the wheels, man! > >Now why would I want to do that, woman ;-) 'COZ maybe the Men in Black has momentarily taken off his earphone attached to his walkman and woken up to hear that deep roar of straight thru exhaust fury..! Later Bibie ------------------------------ From: Seth Date: Tue, 12 Aug 1997 20:49:38 -0700 (PDT) Subject: Re: Too good to let go by - Miller Cycle On Mon, 11 Aug 1997, Robert Harris wrote: > Most Miller Cycle engines ASSUME adequate power is available and > there fore trade POWER for FUEL Efficiency. The specific mechanism > is that raising the compression ratio raise's the efficiency of an engine > quite startlingly. Research suggests that POWER and EFFICIENCY > increase with compression ratio up to about 17 to one. The problem > is detonation. A Miller Cycle conversion made by Crane or Crower > after the 79 Crude Control Crisis ran a small block Chevy at a 15 to > one compression on unleaded low octane pump gas. They had to > stroke the crap out of it to both get the compression and regain the > power. By limiting intake charge, you can safely compress the > reduced charge back to the original low compression chamber pressure > of say 9:1 and have an EXPANSION ratio of 15 or 16 to one and all > the bennies of really good forced exhaust extraction. > > Running a higher octane fuel reduces the advantages of extreme compression > and by the time you are running methane - there is no advantage. > > Increasing the charge density by mechanical means simply means the > Miller Cycle becomes detonation limited at ridiculously LOW manifold > pressures. Just drop the compression and put a power cam in. > > One thing tho - every one of you has watched Miller Cycle engines in > triple digit competion - pret near every weekend. NASCAR. Yup. The > restrictor plate effectively turns the engine into a Miller Cycle at RPM > and thats why they are limited to 14 to one. Some smart ass's figured > out that with restricted intake, you could go to 18 to one or more and > get back most of the lost power without detonation. Cam's aren't the > only way to limit the charge to less than 100% VE > > "When some one gets something for nothing - > some one else gets nothing for something " > > If the first ingredient ain't Habanero, then the rest don't matter. > Robert Harris > > Mr. Harris, That's quite an intriguing insight into the NASCAR CR limit. With a lot of overlap, you get miller cycle at low RPM, then as the VE climbs with RPM, the intake chokes. An interesting idea. Seth ------------------------------ From: bibie@xxx.com (Bibiana Lim) Date: Wed, 13 Aug 1997 12:00:46 +0800 Subject: Adjusting Boost Hi Guys, Latest News: OK..this is what I've round up and before I get my hands dirty I thought I let you guys know:- One variable boost controller (HKS - Norgen made) Some silicon tubes and T-joints plus clips Is an after market boost meter necessary? I will be hooking them as follows: Turbo housing -----| | | | | |V| boost meter------= B =----------PCV |C| | | | | Actuator-----------| I hope the above comes out ok Over to you all, guys! Bibie ------------------------------ From: Seth Date: Tue, 12 Aug 1997 21:01:41 -0700 (PDT) Subject: Re: additional injector On Tue, 12 Aug 1997, Todd King wrote: > <<< > > >If you want more power and the engine can handle it you can use the > > >cold start injector as a water injector this then allows you to run > > >more boost without worring about detonation..... > > > > I was thingking of an additional injector that activates on specific > > rpm. What do you think? > > The big problem in doing this with EFI is that in general the O2 > sensor will "see" the fuel mix go richer then the ecu will lean off > the other injectors to compensate and try to keep the mix at 14.7 to > 1....thats why you need to either re tune the ecu or get a > replacement that you can tune. The good thing about an aftermarket > ecu is that you can tune it how you want not how the factory set it. > >>> > - -------------------------------------- Just a reminder. I posted an active circuit to vary the output of an o2 sensor a while back. It was relatively simple and cheap and is probably worth a try. Even if it doesn't work at WOT, it should help with throttle response during transients. And if you are running CNG, it will work even better:) Seth ------------------------------ From: MaxBoost@xxx.com Date: Wed, 13 Aug 1997 00:13:28 -0400 (EDT) Subject: Anti-turbo lag systems Not strictly DIY_EFI but sorta related. This thread on the Saab APC system has got me thinking. I have seen several references in Racecar Engineering to anti-lag systems used on current FIA rally cars like the ford, subaru and mitsubishi. In particular I was wondering how the system worked? I know that early eighties ferrari F1 cars used a system that bypassed air from the turbo compressor straight into the exhaust system when the throttle was closed and ran a rich mixture to create combustion in the exhaust. I also read somewhere that peugeot used to inject propane into the exhaust to acheive the same effect before it was banned in the group B rally cars. Depending on how these current systems work, I would like to adapt it to my current project. Any info would be appreciated. Max ------------------------------ From: DemonTSi@xxx.com Date: Wed, 13 Aug 1997 00:28:21 -0400 (EDT) Subject: Re: Adjusting Boost In a message dated 97-08-13 00:22:38 EDT, you write: << Latest News: OK..this is what I've round up and before I get my hands dirty I thought I let you guys know:- One variable boost controller (HKS - Norgen made) Some silicon tubes and T-joints plus clips Is an after market boost meter necessary? I will be hooking them as follows: Turbo housing -----| | | | | |V| boost meter------= B =----------PCV |C| | | | | Actuator-----------| I hope the above comes out ok Over to you all, guys! >> Basically...you should find the vacuum line that leads from somewhere along the intake piping or intake manifold to the turbo's wastegate. This one's easy to find as it should be the only vacuum line going to the turbo. Now you can cut and tee your manual boost controller into that vaccum line...or you can remove the line completely and run new vacuum line so that you can place the boost controller wherever you want to. I would recommend getting an aftermarket boost gauge just so that you won't make the mistake of turning the boost up to high... Van ------------------------------ From: MaxBoost@xxx.com Date: Wed, 13 Aug 1997 00:29:28 -0400 (EDT) Subject: Re: Not strickly efi........more turbo stuff >It has some good turbo info and some handy java scripts for >calulatiing turbos size C/R's etc.... >Does anyone know if there is a turbo mailing list??? >I have looked for one but no joy :-( We need to get one started. I think that there are probably enough people interested, unfortuneatly I know nothing about starting something like this. Just would want to participate. Max ------------------------------ From: James Weiler Date: Tue, 12 Aug 1997 23:54:08 -0700 (PDT) Subject: Re: Treatise on intake systems On Tue, 12 Aug 1997 wstrass@xxx.com wrote: > (The speed of sound is simply (gRT)^0.5 where g and R are considered > constant. If you wanted to be rigorous you could actually vary g and R > for temperature, but probably not worth it.) > > Jim: I have a question....how can g (is this gravitational constant?) and > R (the universal gas constant) vary with temperature? n is the number of moles of gas. Part of this formula comes from the ideal gas law PV=nRT except he's using g instead of n. R is a constant and so there is no variation. later jw ------------------------------ End of DIY_EFI Digest V2 #271 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".