DIY_EFI Digest Thursday, 4 April 1996 Volume 01 : Number 098 In this issue: Re: Vortech on 4.3 SCPI ATI Supercharging RE: TEC MAF sensor types (was re: Re: Sensor Questions?) Re: Re[2]: Commercial systems (regulator) Re: ATI Supercharging Re: Switching from carb to FI on a Ford (fwd) Re: TEC Metal Matrix Catalysts... Re: ATI Supercharging Re: Re[2]: Commercial systems (regulator) RE: TEC re:dig.#97/ Syclone 4.3L Re: MAF sensor types (was re: Re: Sensor Questions?) RE: TEC Re: TEC RE: Metal Matrix Catalysts... RE: TEC RE: TEC karman vortex maf RE: Metal Matrix Catalysts... Re: Question regarding possible car purchase. Karman Vortex MAF Re: ATI Supercharging Re: ATI Supercharging Re: Vortex flow meter Syclone Injection Burnt Miata cat. See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Matt Sale Date: Wed, 3 Apr 1996 07:54:26 -0500 (EST) Subject: Re: Vortech on 4.3 SCPI > Uhrrr? A V8 Syclone? Weren't they the 3800/231 Buick V6, of the > late,lamented Buick Grand National/GNX? That's my understanding. GMC decided > to tweak the suspension on an S-15, drop the GNX turbo-intercooled V6 into > it, and voila', a pickup that outhandled and out-accelerated the base Vette, > but not the ZR-1. > > Terry > > Close, but not quite. They turbocharged & intercooled the 4.3 liter V6 for the short-lived Syclone and Typhoon. Now, if they would drop the LT-4 into a Blazer, THAT would be interesting! - -- Matt Sale '69 Mustang 351W 5-spd (13.870/101MPH using cave-man technology). Creeping slowly into the 90's. ------------------------------ From: Brad_Miller@xxx.com (Miller,Brad) Date: Wed, 3 Apr 1996 05:07:07 PST Subject: ATI Supercharging ATI's secret is also the intercooling that they use - - a fact ignored by most other blower manufacturers. The pressure drop across their intercooler is only about 3 psi - but the cooling effect makes up for it. I think (from memory) that you can run up to the 12 psi system without ignition retard - - past that I think it becomes a lot more critical. Then again - - past 12 psi and I wouldn't want to even think about 93 octane fuel. I've got a Daytona coming in May with a Turbo II setup (intercooler/the works and only 135 ci) and I think it's getting by on about 14 psi (I think) and making 275 horsepower. I can't wait to get this puppy to the dragstrip to see what it'll do. The head and intake manifold was ported by Chrysler engineers - - this should be fun! Bradley Miller, President Midwest Shelby Dodge Automobile Club, Inc. email for club info at SDACMW@xxx.COM or WWW at http://users.aol.com/shelby2run/shelby.htm ------------------------------ From: Frank Parker Date: Wed, 3 Apr 1996 09:07:22 -0500 (EST) Subject: RE: TEC > > ---------- > You would be shocked to know the price I paid for the system. I won't > get into how or exactly how much but it was legal. The software cost me > about half what you would expect and the system was > discounted also. > > Muhammed > Ok, that does not do much good. Did you buy direct as dealer?? Did you buy more than 1 to qualify?? What was price???Or did you buy from a distributor??? frank ------------------------------ From: Tommy.Palm@xxx.se Date: Wed, 3 Apr 1996 11:27:43 -0500 Subject: MAF sensor types (was re: Re: Sensor Questions?) >Type #4 ??? - Karman Vortex (is this really a MAF?) > > >Bryan Zublin >bzublin@xxx.com > I made an home made Karman-Vortex after an lesson in aorodynamics, i did not know that any carmakers had done it before me, so this was a nice surprise to me. I used ultrasonics to detect the massincrease inside the wirls. In theory the Karman-Vortex-(its around 100 years old name,as i remember) wirls are induced linear to MASS-flow in an area of Reinholds number (assume you know what that is) that covers air density. The interesting part with this was that i could map the engine at all powers almost perfect w/o even starting it using only mathematics. Anyone interested?? I can supply formulas and Reinhold diagrams. I never finshed the job ( lack of reasons) but had a working MAF ready. Tommy Palm SWEDEN tommy.palm@xxx.se ------------------------------ From: Tommy.Palm@xxx.se Date: Wed, 3 Apr 1996 11:32:30 -0500 Subject: Re: Re[2]: Commercial systems (regulator) > >Will > >The part number for the Bosch fuel regulator is [0 280 160 001]. Its = >from a 1968 VW type 3. = >"Pressure Regulator Screw" that fits these regulators and makes then = >sensitive to the intake manifold pressure. = = >Muhammed Hadzic > Just a question: = I have a bunch of these regulators w/o the magic screw. Isn't it just a = screw with a hole in to apply pressure and underpress to the back of the diafr= agm? Should be easy to do yourself. = Thats how it works on other airpress controlled regulators. Thanks for the information! Tommy Palm tommy.palm@xxx.se ------------------------------ From: doug@xxx.com (Doug Gubbins) Date: Wed, 3 Apr 1996 11:41:51 -0500 Subject: Re: ATI Supercharging Help!! Seeking engineering expertise: I'm running an aftermarket intercooled supercharger on a 1.6L Mazda Miata. Max boost 12psi, using 93 octane fuel, higher when I can find it. The system uses a boost-controlled variable fuel pressure regulator and an MSD spark retarder. This past weekend I clogged up, fused, or melted the honeycomb in my catalytic converter. I haven't yet inspected the cat, but I believe it's heat damage. I'm told this could have been caused by one or more of the following: 1) running too rich most of the time, allowing unburnt fuel to reach the cat, where it ignites, 2) running too lean at boost, causing excessive combustion temperature, 3) too much spark retard (the MSD unit's over-compensating), 4) too much spark advance (the MSD unit's not working at all--but I haven't heard any knock). Should I be able to glean any clues from the appearance of the cat? For example, if the face of the honeycomb is fused, would that indicate condition 2, rather than 1? The exhaust system does have an oxygen sensor, which I am told outputs a voltage between 0 and 1v--lower is leaner and higher is richer. Should I be able to monitor this to diagnose the condition? I am considering replacing the MSD spark retarder with a knock sensor package that also contains an LED oxygen-sensor monitor. But it isn't cheap. Can one of you engineers enlighten me a bit and maybe prevent my throwing money away on a solution that might not be fixing the basic problem? Or how to tell conclusively what's going on here? ------------------------------ From: gtk110@xxx.edu Date: Wed, 3 Apr 1996 17:29:21 GMT Subject: Re: Switching from carb to FI on a Ford (fwd) > >Not to start a flame war, but the V-8 to get for towing is the 351...I >believe that the I-6 has a higher torque rating (at a lower RPM even) >than the 302. The I-6 is a real stump puller. If I wanted to, I could >drive around town all day with only 3rd through 5th. The problem with >the 302 is that it has such a short stroke compared to the 300 (4+ inches >for the 6 compared to 3 inches for the 8) That's my $.02. > > If you're going to pull the engine from the yunkyard anyway, I have 2 words: REPLACE CAM The 351 does have a longer rod enabling better torque but you'd bet screwed if you ever wanted more BOLT ON power from the 351....There is just soooo much more bolt-on's available for the 5.0L EFI--intakes (about 7 the last time I counted) for example) that would allow further customizing of the torque curve....cams, underdrive pullies, you name it...just my $0.03... I can drive around all day with 2nd and 5th and like you say... "Knowledge is power, but cubic inches help"....try to live by it if you say it! "Gripping the wheel, his knuckles went white with desire...the wheels of his Mustang exploding on the highway like a slug from a .45... True death... 400 horsepower, maximum performance piercing the night... This is BLACK SUNSHINE!" ------------------------------ From: LotusM50@xxx.com Date: Wed, 3 Apr 1996 12:49:42 -0500 Subject: Re: TEC In a message dated 96-04-02 20:45:11 EST, you write: >You would be shocked to know the price I paid for the system. I won't >get into how or exactly how much but it was legal. The software cost me >about half what you would expect and the system was >discounted also. > >Muhammed Hi, I'm looking for another system for another car. Any recommendations as to where I can get one discounted? I already have software. Thanks, Bonn ------------------------------ From: Land Shark Date: Wed, 03 Apr 1996 12:41:34 -0700 Subject: Metal Matrix Catalysts... Does anyone have a source for Metal (not ceramic) matrix catalysts??? Jim Conforti ------------------------------ From: Frank Parker Date: Wed, 3 Apr 1996 15:15:07 -0500 (EST) Subject: Re: ATI Supercharging > > I'm running an aftermarket intercooled supercharger on a 1.6L Mazda Miata. > Max boost 12psi, using 93 octane fuel, higher when I can find it. The system > uses a boost-controlled variable fuel pressure regulator and an MSD spark > retarder. > > > I am considering replacing the MSD spark retarder with a knock sensor > package that also contains an LED oxygen-sensor monitor. But it isn't cheap. > I have a lot of experience using those fpr and msd boost retard. The first thing you need to do is find out if you are rich which I suspect. The O2 sensor does put out a voltage when changes very little from rich to very rich unless you buy expensive $2500 UEGO sensor/electronics package. You need to dial in the a/f ratio better and it is hard to do with fpr. Can adjust to be ok @xxx. There are some new electronic controllers to chg fuel press with boost but much more controllable. Hook digital voltmeter up to o2 sensor and monitor while driving. Will jump around but average about .5 during cruise. If lift throttle will drop to 0 as cpu shuts off fuel and @xxx. I have lots of other things you can do. email mail back if interested. PS. The msd retard is a dumb system that depends on you to hear knock and it is hard to do. You need feedback knock retard like factory systems available from J&S in the aftermarket. Frank Parker > ------------------------------ From: Hadzic Muhammed <3mh31@xxx.ca> Date: Wed, 3 Apr 1996 15:18:25 -0500 (EST) Subject: Re: Re[2]: Commercial systems (regulator) > Just a question: = > > I have a bunch of these regulators w/o the magic screw. Isn't it just a = > screw > with a hole in to apply pressure and underpress to the back of the diafr= > agm? > Should be easy to do yourself. = > > Thats how it works on other airpress controlled regulators. > Thanks for the information! > > Tommy Palm > tommy.palm@xxx.se > > Yes it is just a screw with a hole in it. Nothing special, buying it just saves you the trouble of making one.. Muhammed ------------------------------ From: Hadzic Muhammed <3mh31@xxx.ca> Date: Wed, 3 Apr 1996 15:21:50 -0500 (EST) Subject: RE: TEC > > > Ok, that does not do much good. Did you buy direct as dealer?? Did you > buy more than 1 to qualify?? What was price???Or did you buy from a > distributor??? > > frank > > Sorry Frank I don't want to get into details (as I said before). There is always some way to get a deal. You just have to find a way that works for your situation. Muhammed ------------------------------ From: john spears Date: Wed, 3 Apr 96 16:48 EST Subject: re:dig.#97/ Syclone 4.3L Terry Faugno, there must have been a little misunderstanding on the various subjects I was talking about in reference to the various truck engines! I was talking only about the 96 trucks in reference to the V8 Vortec engine; not the Syclone. My point there was that I feel they could have made a big hit had they used the already existing LT1 instead of the money spent on the redesigned SCPI Vortec V8's. The LT1 has more power and is more impressive than the SCPI engines. I guess if you're selling every one you can make they must be doing something right! The Syclone/Typhoon trucks used a true port fuel injected version of the 4.3L engine; it was NEVER a 3.8L intercooled/turbo Buick engine. The only other production vehicle to use that engine was the 1989 Turbo Trans Am Indy Pace Car. If a guy could get ahold of the intake manifold from a Syclone/Typhoon it would be a great building block for a nice 4.3L; it even used the same throttle body assembly as the TPI/LT1 engines. John Spears Speartech Fuel Injection Systems ------------------------------ From: ehernan3@xxx.com (Edward Hernandez (R)) Date: Wed, 3 Apr 1996 16:45:42 +0500 Subject: Re: MAF sensor types (was re: Re: Sensor Questions?) Tommy Palm, please post formulas and diagrams for your homemade Karman-Vortex meter. ------------------------------ From: Jim Pearl Date: Wed, 3 Apr 1996 18:49:30 -0600 Subject: RE: TEC Not telling us HOW it was done is just about useless - why tell us at all? A friend of mine is building a sponsored race car (ATI blowers among others) and when he contacted Electromotive he spoke to a guy and things sounded really good. Next time he called he got hold of another guy and the price tripled. Needless to say they lost out and he'll be running a DFI just like mine, too bad. I myself would've bought a TEC system and was already talking to a couple of people about installation etc. - then I found out what they wanted for their software - NOT! there's no sense in having the best system around if it costs too much for people to afford, they don't seem real interested in doing much volume (IMO)... Also - I was told that their prices include no wiring. They'll make you a harness (reseller telling me this) but again it's $$. Be prepared to make your won - this was about 2 years ago. Sad thing is they're local and that was one of the big reasons I wanted to buy from them, oh well - maybe next time... - ---------- >From: Frank Parker[SMTP:fparker@xxx.edu] Sent: Wednesday, April 03, 1996 3:07 AM To: diy_efi@xxx.edu Subject: RE: TEC > > ---------- > You would be shocked to know the price I paid for the system. I won't > get into how or exactly how much but it was legal. The software cost me > about half what you would expect and the system was > discounted also. > > Muhammed > Ok, that does not do much good. Did you buy direct as dealer?? Did you buy more than 1 to qualify?? What was price???Or did you buy from a distributor??? frank ------------------------------ From: jwharris@xxx. Harris) Date: Wed, 3 Apr 96 19:05 EST Subject: Re: TEC > >The lawsuit involves a "technology" whereby the spark timing is controlled >nearly independently to the CPU using a digital PLL circuit quite simlar to >the Silicon Systems 68Fxxx(?) chip. Since I am convinced that the man who >runs Electromotive didn't invent PLL's (or even digital PLL's), I personally >think the suit is hogwash. Just a personal opinion. If you can't compete, sue. > Back when I was at Virginia Tech I remember seeing some tech infor on how the TEC used the PLL. I can assure them that There aren't any PLLs associated with ignition control in my PCM (1996 V6 engine). We had a lot of problems with Electromotive. They have a really good product, but are a bear to deal with. - ---------------------------------------------------------------------------- J.W. Harris Delco Electronics Corp. Project Engineer One Corporate Center Powertrain Electronics M.S. CT40C Kokomo, IN 46904-9005 jwharris@xxx.com jwharris@xxx.com Of course, all responses are my own and should not be mistaken for those of Delco Electronics or General Motors. ------------------------------ From: Billy-Bob Doughnut OBE Date: Thu, 4 Apr 1996 01:31:29 +-100 Subject: RE: Metal Matrix Catalysts... - ------ =_NextPart_000_01BB21C6.7533F080 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Does anyone have a source for Metal (not ceramic) matrix catalysts??? Jim Conforti Shouldn't that be a metal monolith catalyst, metal matrix being a metal = or alloy reinforced with ceramic fibres, particle etc? Anyway, some = production cars use this technology now, try your local BMW dealer. The = M3 uses it, as do the newer V8 and V12 E38 models. - ------ =_NextPart_000_01BB21C6.7533F080 Content-Type: application/ms-tnef Content-Transfer-Encoding: base64 eJ8+IiEAAQaQCAAEAAAAAAABAAEAAQeQBgAIAAAA5AQAAAAAAADoAAENgAQAAgAAAAIAAgABBJAG AGQBAAABAAAADAAAAAMAADADAAAACwAPDgAAAAACAf8PAQAAAGMAAAAAAAAAgSsfpL6jEBmdbgDd AQ9UAgAAAABkaXlfZWZpQGNvdWxvbWIuZW5nLm9oaW8tc3RhdGUuZWR1AFNNVFAAZGl5X2VmaUBj b3Vsb21iLmVuZy5vaGlvLXN0YXRlLmVkdQAAHgACMAEAAAAFAAAAU01UUAAAAAAeAAMwAQAAACMA AABkaXlfZWZpQGNvdWxvbWIuZW5nLm9oaW8tc3RhdGUuZWR1AAADABUMAQAAAAMA/g8GAAAAHgAB MAEAAAAlAAAAJ2RpeV9lZmlAY291bG9tYi5lbmcub2hpby1zdGF0ZS5lZHUnAAAAAAIBCzABAAAA KAAAAFNNVFA6RElZX0VGSUBDT1VMT01CLkVORy5PSElPLVNUQVRFLkVEVQADAAA5AAAAAAsAQDoB AAAAAgH2DwEAAAAEAAAAAAAAA9xNAQiABwAYAAAASVBNLk1pY3Jvc29mdCBNYWlsLk5vdGUAMQgB BIABAB4AAABSRTogTWV0YWwgTWF0cml4IENhdGFseXN0cy4uLgDbCQEFgAMADgAAAMwHBAAEAAEA HwAdAAQAHAEBIIADAA4AAADMBwQABAABABQADAAEAAABAQmAAQAhAAAAOTg4MzhBNkI3QThEQ0Yx MUFCRTM0NDQ1NTM1NDAwMDAACQcBA5AGAHADAAASAAAACwAjAAAAAAADACYAAAAAAAsAKQAAAAAA AwA2AAAAAABAADkAgLu3EL4huwEeAHAAAQAAAB4AAABSRTogTWV0YWwgTWF0cml4IENhdGFseXN0 cy4uLgAAAAIBcQABAAAAFgAAAAG7Ib4Qt2uKg5mNehHPq+NERVNUAAAAAB4AHgwBAAAABQAAAFNN VFAAAAAAHgAfDAEAAAAVAAAAYmlzb25AZW50ZXJwcmlzZS5uZXQAAAAAAwAGEK8YxQQDAAcQHAEA AB4ACBABAAAAZQAAAERPRVNBTllPTkVIQVZFQVNPVVJDRUZPUk1FVEFMKE5PVENFUkFNSUMpTUFU UklYQ0FUQUxZU1RTPz8/SklNQ09ORk9SVElTSE9VTEROVFRIQVRCRUFNRVRBTE1PTk9MSVRIQ0EA AAAAAgEJEAEAAADqAQAA5gEAABgDAABMWkZ1Yd0GA/8ACgEPAhUCqAXrAoMAUALyCQIAY2gKwHNl dDI3BgAGwwKDMgPFAgBwckJxEeJzdGVtAoMzdwLkBxMCgH0KgAjPCdk78RYPMjU1AoAKgQ2xC2Dk bmcB0DU3CvsUUQvylRNQbxPQYwVARG8HkaUAcHkCIGUgEYB2G9BoYSBzCGFjG9ACEHLhCotsaTM2 GpEZ7xryRk0RwAdAIChuGtAgARygcmFtaWMpIPUAwHQFEHggMCDgB0ATsVxzPyHQCoUKhUoHcCDl CFBuHNF0aQqHHkoiZlsZfwwBYwBABgBoCGBsaGRuJwVAdBGABUBi/xwiB4AfsgRgIAAd0CeQITfe LCgmIOQn4AuAZygHBbHzB0AVoHkgFhALgBzRHKA8ZCAD8CjyIFQcwGlinRYQcymgJTEjgGNsG9AZ EcBjPxSwG5B3YXmfKaAcYAeALfADYGR1GwDOaQIgITERoCB1EbAngZcEACeABZBoKLFvZyvgfSAA dymgIPAr4BugCHAghxWgIUADIEJNVyANsEMHQASQLiBUaBvQTV4zMKIEICjgKaBhBCBkLm8ngRvQ G8B3BJAgViY4G3EskFYxEeBFM+M2AARibHMuIgwdDx4fvxrFN8843znvJTIVMQA+cAAAAwAQEAAA AAADABEQAQAAAEAABzDgV3N9vCG7AUAACDDgV3N9vCG7AR4APQABAAAABQAAAFJFOiAAAAAAIOg= - ------ =_NextPart_000_01BB21C6.7533F080-- ------------------------------ From: Fred Miranda Date: Wed, 3 Apr 1996 17:17:28 GMT Subject: RE: TEC At 03:21 PM 4/3/96 -0500, you wrote: >> > >> Ok, that does not do much good. Did you buy direct as dealer?? Did you >> buy more than 1 to qualify?? What was price???Or did you buy from a >> distributor??? >> >> frank >> >> >Sorry Frank I don't want to get into details (as I said before). There >is always some way to get a deal. You just have to find a way that works >for your situation. > >Muhammed > Why make the post in the first place then? I don't see how anyone has gained from this. Fred ------------------------------ From: Fred Miranda Date: Wed, 3 Apr 1996 17:39:04 GMT Subject: RE: TEC >Also - I was told that their prices include no wiring. They'll make you a >harness (reseller telling me this) but again it's $$. Be prepared to make >your won - this was about 2 years ago. Sad thing is they're local and that >was one of the big reasons I wanted to buy from them, oh well - maybe next >time... Jim I like doing the harness myself. I run the wires where and how I want. Neat or sloppy. Also it's much easier to troubleshoot and change things with the green connectors they use. Hope you weren't refering to the TEC when you refered to the best system that nobody can afford. The TEC isn't in the same league as some of the other systems out there. Fred ------------------------------ From: Mike Klopfer Date: Wed, 3 Apr 1996 19:39:45 -0600 (CST) Subject: karman vortex maf I'd love to hear nitty gritty details of the construction, operation and calibration of such a device. mike ------------------------------ From: Land Shark Date: Wed, 03 Apr 1996 18:52:27 -0700 Subject: RE: Metal Matrix Catalysts... At 01:31 4/4/96 +-100, you wrote: >Shouldn't that be a metal monolith catalyst, metal matrix being a metal >or alloy reinforced with ceramic fibres, particle etc? Anyway, some production >cars use this technology now, try your local BMW dealer. The M3 uses it, >as do the newer V8 and V12 E38 models. Yes, metal monolith ... But the US M3 does not use metal monoliths ... it has the SAME ceramic setup as the E36 325i :( Are you SURE about the V8's?? BMW's are my game and I had never heard that .. Jim PS: Has anyone ever heard of "Emitech"?? ------------------------------ From: pjwales@xxx.net (Peter Wales) Date: Wed, 03 Apr 1996 22:17:57 -0500 Subject: Re: Question regarding possible car purchase. > I may be switching cars soon. Going from a Dodge Neon to a Dodge >Stealth R/T TT. Are there mods out there for this car to increase the >effeciency of the FI system, or is it pretty much as good as it's going to >get?? > > Thanx, > Terry Nice change. Tuning the TT is difficult as there is no chip in the computer to allow the boost limit to be overcome. Check out our web page on the boost graphic as the best solution. Sorry about the ad guys, but there was no return address for direct mailing. Peter Wales pjwales@xxx.net President Superchips Inc Chairman Superchips Ltd "Timing is everything" Superchips home page with all the answers http://www.superchips.com ------------------------------ From: Darrell Norquay Date: Wed, 3 Apr 96 21:02:17 MDT Subject: Karman Vortex MAF Tommy Palm wrote: > I made an home made Karman-Vortex after an lesson in aorodynamics, i did not > Anyone interested?? I can supply formulas and Reinhold diagrams. I never > finshed the job ( lack of reasons) but had a working MAF ready. Damn right I'm interested. Sounds like there are a couple of other people on the list who'd like the info as well. BTW what's a Reinhold diagram? regards dn - -- - ----------------------------------------------------------------- Darrell A. Norquay Internet: dn@xxx.ca Datalog Technology Inc. Voice: (403) 243-2220 Calgary, Alberta, Canada Fax: (403) 243-2872 "Absolutum Obsoletum" - If it works, it's obsolete - ----------------------------------------------------------------- ------------------------------ From: Darrell Norquay Date: Wed, 3 Apr 96 21:13:35 MDT Subject: Re: ATI Supercharging Doug Gubbins wrote: > I am considering replacing the MSD spark retarder with a knock sensor > package that also contains an LED oxygen-sensor monitor. But it isn't cheap. Sure it is... At least the oxygen sensor monitor part. If you're at all capable with electronics, you can build a monitor for about 20$ and a couple of hours. Use a National Semiconductor LM3914 and a handful of LED's. Gives you a 10 dot readout and requires only a handful of readily available parts. The graphic readout is much more readable than squinting at a voltmeter while you're trying to drive, and you can add a little filtering to smooth out the fluctuations. I don't know too much about the spark retarder, but I've heard the MSD unit isn't that great. > Can one of you engineers enlighten me a bit and maybe prevent my throwing > money away on a solution that might not be fixing the basic problem? Or how > to tell conclusively what's going on here? Sorry, can't help you much with your catcon problem, but it seems to me that running too rich would burn the thing up in short order. I don't think that running lean would cause it to burn out, since there wouldn't be enough fuel to combust inside the converter, which after all is it's purpose. You didn't mention how many miles were on the converter, if it was a few years old it's possible it just died a natural death... Regards dn - -- - ----------------------------------------------------------------- Darrell A. Norquay Internet: dn@xxx.ca Datalog Technology Inc. Voice: (403) 243-2220 Calgary, Alberta, Canada Fax: (403) 243-2872 "Absolutum Obsoletum" - If it works, it's obsolete - ----------------------------------------------------------------- ------------------------------ From: Seth Allen Date: Wed, 3 Apr 1996 20:34:14 -0800 (PST) Subject: Re: ATI Supercharging On Wed, 3 Apr 1996, Frank Parker wrote: > Date: Wed, 3 Apr 1996 15:15:07 -0500 (EST) > From: Frank Parker > To: Doug Gubbins > Cc: diy_efi@xxx.edu > Subject: Re: ATI Supercharging > > > > > I'm running an aftermarket intercooled supercharger on a 1.6L Mazda Miata. > > Max boost 12psi, using 93 octane fuel, higher when I can find it. The system > > uses a boost-controlled variable fuel pressure regulator and an MSD spark > > retarder. > > > > > > I am considering replacing the MSD spark retarder with a knock sensor > > package that also contains an LED oxygen-sensor monitor. But it isn't cheap. > > > I have a lot of experience using those fpr and msd boost retard. The first > thing you need to do is find out if you are rich which I suspect. The O2 > sensor does put out a voltage when changes very little from rich to very > rich unless you buy expensive $2500 UEGO sensor/electronics package. You > need to dial in the a/f ratio better and it is hard to do with fpr. Can > adjust to be ok @xxx. There are some new > electronic controllers to chg fuel press with boost but much more > controllable. > Hook digital voltmeter up to o2 sensor and monitor while driving. Will > jump around but average about .5 during cruise. If lift throttle will drop > to 0 as cpu shuts off fuel and @xxx. > I have lots of other things you can do. email mail back if interested. > Frank Parker> - --I mostly agree with Frank-- IMHO, it is running rich, which results in the highest exhaust temp. Lean has excess oxygen, but the temp is cooler, the excess oxygen burns valves and seats that way. A lean misfire with unburned fuel and oxygen would really heat up the catalyst as it burned in the matrix. You could detect a lean misfire as it stumbled under boost. Leaning it back to stoichiometric would cool it off a bit, but if it got lean, the exhaust valves could have a hard time. I think you might need a bigger catalyst to reduce the catalyst loading. The stock catalyst cannot put up with the extra exhaust gasses. The stock catalysts on my VW golf will eventually die an early life when exposed to continuous full throttle and stightly rich mix. (My friend had this problem with his Golf gti, I had slight clogging with my rabbit gti). So, IMHO get a larger catalyst, maybe V8 sized. Good luck, Seth Allen WWU Vehicle Research Institute These opinions are just my own, and no warranty is expressed or implied. ------------------------------ From: Steve Baldwin Date: Thu, 4 Apr 1996 17:26:00 +1200 (NZST) Subject: Re: Vortex flow meter I'm interested too. Either directly or to the list. It certainly fits the charter. Steve. ------------------------------ From: Ryan Harrell Date: Thu, 04 Apr 1996 00:32:18 -0600 Subject: Syclone Injection Mr. Spears, if the 4.3L V6 in the Syclone is so great, why is it not available on the aftermarket? Does GM not allow aftermarket reproductions of the Syclone port-injection? To me this makes no sense. I mean GM has the best injection system available and both the aftermarket and GM just ignore and let it DIE?!!??!? Confused and Bewildered Ryan Harrell cyborne@xxx.com ------------------------------ From: Haas@xxx.nl Date: Thu, 4 Apr 96 09:44:25 +0200 Subject: Burnt Miata cat. Hi Guys, About the burnt cat I would like to advise you to check for leaks in the exhaust system. If you are running rich (which is to be expected under high loads) the catalyst is not damaged so easily (as far as burning is concerned) because there is not much oxygen left in the exhaust gas. If, however, you are running say 10 % rich and combine this with a leaking exhaust allowing oxygen to come in you will develop a lot of heat in the catalyst. This can be as much as (10% of engine power)/(engine efficiency) or something near to that kW of power being released in the catalyst. Also lean running can cause this sort of a problem. A lean running engine produces more hydrocarbons (specially under mis-fires) which will easily burn in the catalyst with the excess air available. As far as ignition timing is concerned I would say that I see the largest problem in a retarded timing for this will increase exhaust gas temperatures (combustion starts later, expansion is less complete etc.). Just some basics to keep in mind. Joeri de Haas ------------------------------ End of DIY_EFI Digest V1 #98 **************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. 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