DIY_EFI Digest Sunday, 25 February 1996 Volume 01 : Number 054 In this issue: Re: Variable intake runners Re: Injector Pulse Width Resolution 16 bit or 8 bit Re: other performance automotive maillists Re: Turbo Lag Re: Turbo Lag Re: other performance automotive maillists Re: Injector Pulse Width Resolution 16 bit or 8 bit Re: Injector driver chips? Where? Re: Turbo Lag Re: other performance automotive maillists RE: Turbo Lag ADVICE NEEDED Re: Turbo Lag Re: Turbo Lag Re: Turbo Lag Re: ADVICE NEEDED Re: Turbo Lag See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Mark Boxsell Date: Sat, 24 Feb 96 22:57:40 +1100 (EST) Subject: Re: Variable intake runners At 02:46 PM 23/02/96 CET, you wrote: >Mark, >So you have convinced me. Not that I hadn't expected this. >But _how_ do I go about it the DIY way? Anybody done this? > >Hey! Where can I buy 6 cheap used trombones for hacking? > >Seriously, I imagine lots of problems keeping such a >device from sucking false air in through the runner splices. Getting a seal with the pressure of the turbo would be difficult. > >What about using runners tuned for say 2000 RPM, to give me >some more shove before the turbos cut in at 2000-3000? >Using the web page that calculate runner lengths, I found >that they would need to be really long to do that. Would that >have any adverse effect at higher RPM? Yes it will kill it up high. + + + + + Long runner, Narrow RPM range, Stronger effect, Lower RPM. + + + + ________________________________________________ 0 1000 2000 3000 4000 5000 6000 RPM Short runner, Wider range, Lest effect, Higher RPM. + + + + + + + ________________________________________________ 0 1000 2000 3000 4000 5000 6000 RPM > >I realise I should have read the SAE paper(s), but I don't >have them. (I'm a DIY'er you see. Not working in the automobile >field at all.) Could you give some concentrated wisdom here? Sorry about that comment. It took me 20 minutes to find the bloody SAE paper in all my books and stuff. The SAE papers are such a gold mine of info it would be worth contacting the nearest SAE office and see if any Universites near your have them. The Universities in Australia allow members of the public to join their libraries maybe you can do something similar. Although some SAE papers can be "heavy going". The best (excellent) book that I have seen (probably the only book) is 'Understanding Automoblie Electronics'. It is a SAMS book written by William B. Ribbens ISBN 0-672-27358-6. As for the mechanical side of things maybe someone else can suggest a good "all round" book. > >I will swap to an injected engine this spring, and next winter >I plan on converting the current engine to injection. This >will include making a new intake manifold to take the injectors, >so I might as well make them the "optimal" length. Yes, well worth the effort. > >I'm also "brainpicking" the Weber Marelli ignition and injection >computers to gain some insight, and find what tables I can play >with. Anyone here who know these units? Both the boxes have >unused analog inputs, so it would be possible to influence them >by hanging pots on these ports. (And modify the software to look >at them of course.) Can't help you much here. >-- >einarp@xxx.no ( Maserati Biturbo Spyder ) > > regards, Mark Boxsell MRB Design. ------------------------------ From: Mark Boxsell Date: Sat, 24 Feb 96 22:57:51 +1100 (EST) Subject: Re: Injector Pulse Width Resolution 16 bit or 8 bit At 12:06 PM 23/02/96, you wrote: >Hello diy_efi'ers > >How many bits should be stored in the lookup table for a injector >pulse width map? Should I use 8 bits or 16 bits? I know 16 is >better, but is it necessary? > >Yours, >-- >Derrick Early >early@xxx.mil > If you are using big injectors (eg. turbo,etc) and/or chasing emissions then I recommend 16 bit. An easy check it have the engine idling with an exhaust gas analyser connected. Change the pulse width by your minimum increment and measure the difference. If you are idling at 2.00% CO and it changes to 3.00% CO then you know you are in trouble !! regards, Mark Boxsell MRB Design. ps. Don't laugh I have seen it happen. ------------------------------ From: Grant Beattie Date: Sat, 24 Feb 1996 08:34:26 -0700 (MST) Subject: Re: other performance automotive maillists On Fri, 23 Feb 1996, Brad Martin wrote: > Can anyone tell me of other performance related mail list servers? > Racing related? > I enjoy the diy_efi list & would like to see similiar stuff for other > related topics... There is theoretically a list called "wheel2wheel", but I can't locate the list address! I was on this list a few(?) years back and it was great (but VERY busy). GB ------------------------------ From: Bruno! Date: Sun, 25 Feb 1996 02:44:06 +1100 (EST) Subject: Re: Turbo Lag On Fri, 23 Feb 1996, ARTHUR OKUN wrote: > how about an electrically driven supercharger??? > My friends and I have thought about this one as an idea. What we came up with is that the motor driving the supercharger would have to have HEAPS of torque driving a gear arrangement to get the turbines to spin at a decent speed. Would be brilliant on a car, dial up whatever boost you'd need, and maybe going one step further and having the engine computer control boost pressure. This motor would also put quite a load on the electrical system on the car. The size I'm thinking is a small starter motor, for the torque. Would have to spin at a low speed, to stop itself from flying to bits. Bruno. ( u933234@xxx.au ) "If you've gotta go, go with a smile" ------------------------------ From: Bruno! Date: Sun, 25 Feb 1996 02:58:28 +1100 (EST) Subject: Re: Turbo Lag On Fri, 23 Feb 1996 ffmd@xxx.net wrote: > >What you are looking for is called an Anti-Lag System (ALS). It is > >used in many rally-race cars that compete in the WRC. There are a > >couple of different systems I have heard about, but the easiest to > >implement requires only a modification to the ECU on the engine. > > > >This system actually causes an intentional mis-fire by not firing one > >of the cylinders. The air/fuel mixture is still injected, and ends up > >getting pumped out the exhaust. When it hits the very hot turbine > >blades in the turbo, it ignites and works like a jet motor. Is there any reason for not using a blow-off valve in this situation? These, if you haven't heard of them before, keep the turbine spinning when the throttle is closed by bypassing the intake gases from the closed throttle when the pressure difference across the trottle increases to a certain point (eg 1 psi) and then closing when the throttle opens again. The turbine keeps spinning, maintaining the boost. I haven't driven a car with one, but from what I've heard, it makes a cool whizzing sound when changing gears, and makes a BIG difference to acceleration. I do admit it would cost a bit more than the timing system mentioned above, but i think it would not have quite the same effect on the exhaust system, and would be kinder to mufflers and cats. Bruno. ( u933234@xxx.au ) "If you've gotta go, go with a smile" ------------------------------ From: Mitsu16v@xxx.com Date: Sat, 24 Feb 1996 11:02:43 -0500 Subject: Re: other performance automotive maillists In a message dated 96-02-23 23:11:50 EST, you write: >Can anyone tell me of other performance related mail list servers? >Racing related? >I enjoy the diy_efi list & would like to see similiar stuff for other related >topics... > > I'd like a forward of any info yu get, please. Thanks! BTW... there is a Talon/Eclipse/Laser Digest put out 5 days a week if you are interested. ------------------------------ From: FIScot@xxx.com Date: Sat, 24 Feb 1996 11:52:10 -0500 Subject: Re: Injector Pulse Width Resolution 16 bit or 8 bit Subj: Injector Pulse Width Resolution 16 bit or 8 bit Date: 96-02-23 12:43:52 EST From: early@xxx.mil (Derrick Early) > How many bits should be stored in the lookup table for a injector pulse > width map? Should I use 8 bits or 16 bits? I know 16 is better, but > is it necessary? What is your expected maximum injector opening time? Divide that figure by 255, and if that is enough resolution for you, use 8 bits.... An example is a 4 stoke engine with a torque peak about 3000 RPM. If the injector is on through most of the full 720 degrees of crank rotation at 3000 RPM, that is about 40 mSec. Divide 40 mSec by 255 and you get 156 uSec. Is that enough resolution? If it is, now you have to clock your injector timer reg at that 156 uSec rate (6375 Hz)...... Scot Sealander FIScot@xxx.com ------------------------------ From: dn Date: Sat, 24 Feb 96 12:45:49 MDT Subject: Re: Injector driver chips? Where? Brad Sheridan wrote: > Does anyone have/ know where to get the Motorola MC33293T chip? > > I've tried a few places without luck, and the only place I've found that > can even get them(Newark) won't have them until April. I need 3 or so, but > if anyone can even give me a lead on one, I'd be much obliged. If you happen > to have a couple extra, email me and we can make a deal. I second this question. I need a couple of pieces of these drivers as well. I thought about calling Motorola directly to see if they'd sample me some... If I lie sufficiently well, tell them I'm Son of GM and will be ordering 10000 pieces next week, they may believe me... Meanwhile, if you find some let me know. I was working on designing my own driver, since these Motorola parts are essentially vaporware, but I can't seem to get the peak/hold circuit working. I'll keep you posted, if you're not electrically challenged, you may be able to build one up... regards dn - -- - --------------------------------------------------------------------- Darrell A. Norquay Internet: dn@xxx.ca Datalog Technology Inc. Bang: calgary!debug!dlogtech!darrell Calgary, Alberta, Canada Voice: +1 (403) 243-2220 Fax: +1 (403) 243-2872 @ + < __/ "Absolutum Obsoletum" - If it works, it's obsolete -------------------------------------------------------------------- ------------------------------ From: arthurok@xxx.com (ARTHUR OKUN ) Date: Sat, 24 Feb 1996 12:35:03 -0800 Subject: Re: Turbo Lag the idea i have is to use a 120 volt ac dc universal motor "like in an electric hand saw" and use that to drive the blower. for a small engine there are some about 1200 volt amp blower units that would work about $150 us wholesale. an a dc to dc converter and pwm to control motor speed i think you could feed it almost double voltage for acceleration bursts. ------------------------------ From: ffmd@xxx.net (Charles North @ Function First Motorsports) Date: Sat, 24 Feb 1996 16:13:09 -0500 Subject: Re: other performance automotive maillists >In a message dated 96-02-23 23:11:50 EST, you write: > >>Can anyone tell me of other performance related mail list servers? >>Racing related? >>I enjoy the diy_efi list & would like to see similiar stuff for other >related >>topics... >> >> > >I'd like a forward of any info yu get, please. Thanks! BTW... there is a >Talon/Eclipse/Laser Digest put out 5 days a week if you are interested. > >Yes there is intrest in this digest as well as for Starion/Conquests if available. Thanks, Charlie at Function First Motorsports ------------------------------ From: "Brandon L. Walters" Date: Sat, 24 Feb 1996 17:43:51 -0600 Subject: RE: Turbo Lag - ------ =_NextPart_000_01BB02DF.A9DCC100 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit It seems like I saw something a few years back, in the "what's new?" part of some "Design News" type mag., where these guys had come up with a little electric motor just for the purpose of accelerating the turbo. I wonder if you aimed a little compressed air jet at the impeller (so you wouldn't be cooling the turbine side), and just gave a little blast of air when the throttle tipped in. Even more years ago, there was a deal about variable inlet scrolls. Wouldn't that be something - variable inlet vanes under electronic DIY_EFI control? Brandon Walters - ------ =_NextPart_000_01BB02DF.A9DCC100 Content-Type: application/ms-tnef Content-Transfer-Encoding: base64 eJ8+IjUXAQaQCAAEAAAAAAABAAEAAQeQBgAIAAAA5AQAAAAAAADoAAENgAQAAgAAAAIAAgABBJAG AGQBAAABAAAADAAAAAMAADADAAAACwAPDgAAAAACAf8PAQAAAGMAAAAAAAAAgSsfpL6jEBmdbgDd AQ9UAgAAAABkaXlfZWZpQGNvdWxvbWIuZW5nLm9oaW8tc3RhdGUuZWR1AFNNVFAAZGl5X2VmaUBj b3Vsb21iLmVuZy5vaGlvLXN0YXRlLmVkdQAAHgACMAEAAAAFAAAAU01UUAAAAAAeAAMwAQAAACMA AABkaXlfZWZpQGNvdWxvbWIuZW5nLm9oaW8tc3RhdGUuZWR1AAADABUMAQAAAAMA/g8GAAAAHgAB MAEAAAAlAAAAJ2RpeV9lZmlAY291bG9tYi5lbmcub2hpby1zdGF0ZS5lZHUnAAAAAAIBCzABAAAA KAAAAFNNVFA6RElZX0VGSUBDT1VMT01CLkVORy5PSElPLVNUQVRFLkVEVQADAAA5AAAAAAsAQDoB AAAAAgH2DwEAAAAEAAAAAAAAA9xNAQiABwAYAAAASVBNLk1pY3Jvc29mdCBNYWlsLk5vdGUAMQgB BIABAA4AAABSRTogVHVyYm8gTGFnADEEAQWAAwAOAAAAzAcCABgAEQArADMABgBiAQEggAMADgAA AMwHAgAYABEAHQAcAAYAPQEBCYABACEAAAAwNjQyRDI5QkNFNkVDRjExOUEzNzAwNjA4QzY3QjRB OAAsBwEDkAYA0AMAABIAAAALACMAAAAAAAMAJgAAAAAACwApAAAAAAADADYAAAAAAEAAOQCgk4Tz EQO7AR4AcAABAAAADgAAAFJFOiBUdXJibyBMYWcAAAACAXEAAQAAABYAAAABuwMR84Sb0kIHbs4R z5o3AGCMZ7SoAAAeAB4MAQAAAAMAAABNUwAAHgAfDAEAAAAaAAAAV2luZG93cy9CUkFORE9OVy9C UkFORE9OVwAAAAMABhCqFodUAwAHEMMBAAAeAAgQAQAAAGUAAABJVFNFRU1TTElLRUlTQVdTT01F VEhJTkdBRkVXWUVBUlNCQUNLLElOVEhFIldIQVRTTkVXPyJQQVJUT0ZTT01FIkRFU0lHTk5FV1Mi VFlQRU1BRyxXSEVSRVRIRVNFR1VZU0hBAAAAAAIBCRABAAAAWQIAAFUCAABMAwAATFpGdaFhoRf/ AAoBDwIVAqgF6wKDAFAC8gkCAGNoCsBzZXQyNwYABsMCgzIDxQIAcHJCcRHic3RlbQKDM/cC5AcT AoB9CoAIzwnZAoAHCoENsQtgbmcxMDPPFFALChRRC/EgSQVAEbDDE+AEIGxpa2UZUBmAWmEH4HMD cBHAaAuAZ5AgYSBmB9F5ZRGRRCBiANBrLCALgCCTGuAaICJ3EYB0JwQgom4H0D8iIAqxdAqFLG9m GpMcwEQHkGlniwOgB8FzHZB0eXAaIPkAwGcuHEAc4ASQGiAckVERsCBndROwIBGAZKYgBaAesXVw IGBpGuCvGzAKhRnwAkBsGiBlI1CUY3QFEGMgAG90BbG8anUTwBtQBbEcknAIcFxwbyEBHmEA0GMj gXK3HQAbAhySdAhwBuAuCoV7CoUaQHcCIASBHFAecHn/CGAbMAdxIaAbQCMVIcETUPcHkBGwKYFp JFERwBswBUCXHJIHcB/gbCYxICgaoAco8gqFKGB1bGRuJ/0FQGIqEgbwJooLgBogAJA9DbApHEAA cCGgJHNnYe52GiAppwJgYSSRJcIq8H8s1hygHHQa4ANgIzMmcHDvH+AhoAuAJ11FMGADoARgdyCh G6QgIG8cQByRIKF3vzFAGzENsAdAGzAG4HUFQN52CsAHMAJgK7FuI1AZcdMFAAbwbHMnVlctVhrg 5ythLdEaqC0gN643sB1QfQQgdSiDI4QCICPgCoVE4ElZX0VGGkAFoAIw9TjBPydsQiZQKIACIDmA XwdAE9ARoAqFFTEAQbAAAAADABAQAAAAAAMAERAAAAAAQAAHMMAqO/EPA7sBQAAIMMAqO/EPA7sB HgA9AAEAAAAFAAAAUkU6IAAAAABRBA== - ------ =_NextPart_000_01BB02DF.A9DCC100-- ------------------------------ From: James Weiler Date: Sat, 24 Feb 1996 18:00:37 -0800 (PST) Subject: ADVICE NEEDED Hello: A friend is getting rid of his '79 Toyota Celica Supra (six cylinder). Is this an opportunity to obtain a bunch of sensors, injectors, air meter, etc for free? Or is this a giant waste of my time? I would eventually like to inject a 1971 Ford 351 Cleveland. I know I need a programable ECU and the injectors probably won't be big enough and I'll have to make a fuel rail, but what about the rest of it??? Fuel pump, pressure regulator, air meter, sensors, throttle body?? I know kits from Haltech, Tull, or Electromotive exist but I don't know exactly what they provide. Are these just ECU's and you have to collect the sensors anyway?? I'm thinking maybe this is an opportunity to get my feet wet...worst case is that I learn a little but none of the parts will be useful to me. Any advice would be appreciated. Thanks james wieler ------------------------------ From: Sandy Date: Sat, 24 Feb 1996 21:05:45 -0500 Subject: Re: Turbo Lag What is the point, for an engine of any size, you will be wasting more energy to get electricity from an alternator, feed it to a convertor, and then turn a motor. What is really wrong with a belt driven system? Sandy At 12:35 PM 2/24/96 -0800, you wrote: >the idea i have is to use a 120 volt ac dc universal motor "like in >an electric hand saw" and use that to drive the blower. >for a small engine there are some about 1200 volt amp blower units that >would work about $150 us wholesale. an a dc to dc converter and pwm >to control motor speed i think you could feed it almost double >voltage for acceleration bursts. > > ------------------------------ From: arthurok@xxx.com (ARTHUR OKUN ) Date: Sat, 24 Feb 1996 18:47:30 -0800 Subject: Re: Turbo Lag how about FULL BOOST AT IDLE ------------------------------ From: "George M. Dailey" Date: Sat, 24 Feb 1996 23:35:37 -0600 Subject: Re: Turbo Lag At 02:44 AM 2/25/96 +1100, Bruno wrote: >On Fri, 23 Feb 1996, ARTHUR OKUN wrote: > >> how about an electrically driven supercharger??? >> > What we >came up with is that the motor driving the supercharger would have to >have HEAPS of torque driving a gear arrangement to get the turbines to >spin at a decent speed. > ============================================================================ ======== >Check this out, an air motor connected to a centrifugal blower. Air tools frequently turn at very high speeds. A mid size air motor might be the ticket. Imagine a small air tank and an electric or engine driven pump. During low load, the pump tanks the air under high pressure. When boost is needed, high flow solenoids open up and all hell breaks lose. Almost no parasitic losses and instant gratification! This should be possible with off the shelf components. As always, EFI would be needed to make the system really work. > GMD ------------------------------ From: "George M. Dailey" Date: Sat, 24 Feb 1996 23:55:15 -0600 Subject: Re: ADVICE NEEDED At 06:00 PM 2/24/96 -0800, james wieler wrote: >Hello: > > A friend is getting rid of his '79 Toyota Celica Supra (six >cylinder). Is this an opportunity to obtain a bunch of sensors, >injectors, air meter, etc for free? Or is this a giant waste of my time? If it's free or real cheap GO FOR IT. I've still got two sets of injectors from an '76 port injected caddy (among other goodies). Never used any of them, but I learned quite a bit by gathering parts and researching. BTW, I'm in the final stages of installing my '89 350 TPI into my '58 chevy truck. I've been planning this since 1985 (go ahead and laugh, in doesn't hurt anymore :) GMD ------------------------------ From: arthurok@xxx.com (ARTHUR OKUN ) Date: Sun, 25 Feb 1996 01:26:35 -0800 Subject: Re: Turbo Lag thats what they use to start BIG jet engines ive seen pictures of those air motors in aviation books and they are quite small and turn real fast; in a big jet aircraft they use bleed air from the apu to run it or from anouther working main engine or ground service cart the apu has an electric motor starter 28vdc. The same bleed air is used for pressurisation and air conditioning. i think id rather use an electric motor for this application . ------------------------------ End of DIY_EFI Digest V1 #54 **************************** 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".