DIY_EFI Digest Tuesday, 27 February 1996 Volume 01 : Number 057 In this issue: Re: Turbo Lag & superchargers.. RE: ADVICE NEEDED Re: Injector driver chips? Where? RE: Real world TPI hp gains Re: Turbo Lag Re: Turbo Lag & superchargers.. Re: Turbo Lag & superchargers.. Re: Injector driver chips? Where? Re: Injector drivers (L9335/L9336) Re: Blow off valve Re: Injector driver chips? Where? RE: B&S fuel-pump Re: Blow off valve Re: ADVICE NEEDED Re: Injector driver chips? Where? spark and MAP See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Craig Pugsley Date: Tue, 27 Feb 1996 10:33:11 +1100 (EST) Subject: Re: Turbo Lag & superchargers.. Hi, > 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. I wondered about this too, like have an air tank in the trunk filled by a small 12V compressor, and a 1/2 inch air line to the turbo with a solenoid valve to dump all the tank into the turbo (like pointing a water hose at a bicycle pedal). > 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? Err, another innovation from the rotary world- 13B turbos have had 'twin scroll' exhaust profiles, selected by a vacuum controlled flap since 1986 (or was it 1987??) Re the electric motor powered supercharger, on RX7 club a 'CVT drive' was suggested (ie power the supercharger from the crankshaft). I thought you could use a '2-speed drive' similar to the following: A B A _____________ |\#/| / _______/. .\ |\#/|| # | |. O_______. O .| | # || # | | ... \.../ | # || # |=== To s/c input | / | # || # | | / |/#\|| # | | / # |/#\| | / # # | / |\#/||\#/| | / ]| # || # | | / ]| # || # | | ... / a/c clutch]| # || # |=== Idler wheel |. ./ ]| # || # | \___/ C ]| # || # | |/#\||/#\| 'overspeed' 'Normal' pulley pulley The idea is that 'A' has a pawl arrangement for both belts and when the a/c magnetic clutch is engaged this 'overspeeds' the normal pulley. (However, I can get a complete 13B turbo engine for less than a 2nd hand toyota supercharger so I canned this idea). Cheers, Craig. ------------------------------ From: "Zublin, Bryan (SD-MS)" Date: Mon, 26 Feb 1996 16:35:00 -0800 (PST) Subject: RE: ADVICE NEEDED The EFI computer in the 79-81 Toyota Supra might be the analog type, so it may (or may not be) useful. Depends on how you look at it. Simply tweaking resistors might be enough to make it work. The fuel pump, air flow meter, injectors, and throttle body are probably way too small for a 351. But if it's free, take it. Bryan Zublin bzublin@xxx.com ------------------------------ From: "Zublin, Bryan (SD-MS)" Date: Mon, 26 Feb 1996 16:49:00 -0800 (PST) Subject: Re: Injector driver chips? Where? SGS Thomson sells the L9335 and L9336 Injector Drivers. The former is a 2.4 amp / 0.6 amp peak/hold, and the latter is a 4 amp / 1 amp peak/hold. The pinout looks the same as the Motorola MC3484S2-2 and MC3484S4-2. Cherry Semiconductor also sells the part (CS-452 and CS-453). Bryan Zublin bzublin@xxx.com ------------------------------ From: Jim Pearl Date: Mon, 26 Feb 1996 18:07:07 -0600 Subject: RE: Real world TPI hp gains One of the reasons why this is\was done on Late Model Mustangs was to richen the mixture. As was stated below going too cold would never allow the computer to get out of warm-up mode and didn't help much. Other than simply trying to richen the mixture I've not heard of any other benefit except possibly cooler intake temps (ha!). All in all on the Mustang at least it's not worth much and is a Band-Aid... - ---------- >From: John T Stein[SMTP:JSTEIN@xxx.com] Sent: Monday, February 26, 1996 5:33 AM To: diy_efi@xxx.edu Subject: Re: Real world TPI hp gains > Date: Wed, 21 Feb 1996 07:39:47 -0800 > From: jzalesny@xxx.com (JimZ -92' AWD Tsi ) > Subject: Re: Real world TPI hp gains > To: diy_efi@xxx.edu > Reply-to: diy_efi@xxx.edu > You wrote: > > > >Decreasing inlet air temp(and intake manifold temp) will increase horsepower > >with no other changes, assuming the ECM is allowed to adjust accordingly. > >Has any one dyno tested a '89 350 TPI engine and then changed only the > >thermostat (195 to 150) and removed the hot coolant going to the throttle > >body to see the net 'real world' torque increase? > >GMD > > On a a large number of EFI vehicles (if equipped)the ECU will never switch over > to closed loop mode due to the low coolant temp. The bypassing of the throttle > body will work and give more power. > > JimZ > Jim (or anyone else for that matter), Has anyone done any QUANTITATIVE testing of this effect?? I've been hearing of the benefits of going to a colder thermostat, or NO thermostat for that matter, since the '60s -- but nobody has ever mentioned controlled testing. Does one see gains of 10% HP, 1%, 1e-6 ??? John begin 600 WINMAIL.DAT M>)\^(B<"`0:0" `$```````!``$``0>0!@`(````Y 0```````#H``$-@ 0` M`@````(``@`!!) &`&0!```!````# ````,``# #````"P`/#@`````"`?\/ M`0```&,`````````@2L?I+ZC$!F=;@#=`0]4`@````!D:7E?969I0&-O=6QO M;6(N96YG+F]H:6\M``,P`0`` M`",```!D:7E?969I0&-O=6QO;6(N96YG+F]H:6\M5]E9FE 8V]U;&]M8BYE;FHBG!+L!'@!P``$````<````4D4Z(%)E86P@=V]R;&0@5%!) 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M\'-!L #0+B;Q7?\[SSS=!F ",#X//QL@P"E "&%Y+#VP96)R=1,*P!\`,C9' M$#$Y.; V(#4Z'! 4L$U"GSD\W51O1-\_&REP>5^=+W% !: EL -P8BX)\,1G M+C_P:6\M(]--L(QD=4C/0ZYU8FHZX?-*[S\;4F514%,P!T U(ELE84#022G0 M*,!G"W%S\S01Q Y'H!S=2+0)-(>,45#'DTV$R9B)!$L(6%D:OLA M,29 8P6A*7 ;T"N -Q:=:Z%('\$NHQW!9'ER(0\3T!/!)" V4"(=\#H'*T+E%M,!\"96LX*J*O!& CTC'P2 `U+!(Q>/#_;Y I M,AC0!& F$'GS<($%0'\PP@xxx. ;@=\ L$A&P?_(M ML?TGP2<>86$%7F L(!-@"E#%;_<_:RE'341:YUKG[QVP-D$V4 M@P)>!S M<.0JP M,%$DT;\=]8 6:>B!,V^S-3%K*2/_>8 MH01@+5%PXW986N==XO^3GEWA,? % ML2ZA( (@\'!A/P(0*M,%0 # `D $D"DL'U3L=P5W@R "+J)154$@3E1)5$&: MH%9%WW@xxx.N$_A# M=/\D0")A"H4N$H^9+T4$(!WQ?W]'-E E0BK# M?"9'$ 6Q3OY/-X9\"9<]1Q!LT2_@'A/^)U90!" [("0P* $MT($S?Q& G!$F M$@> `C!HP!W 9/\*A06@`C #8"9@=-*;1([!_$1O!Y$@`H&R5),=XAOP:B69 M$%!'X25'$$?P9?8M2#"`#T``0````4` ,``!213H@`````)18 ` end ------------------------------ From: Brad Martin Date: Mon, 26 Feb 1996 20:30:33 -0500 Subject: Re: Turbo Lag At 02:20 PM 2/26/96 -0800, you wrote: >You wrote: >> >>How about just pressing the gas peddal? >> >This is fine at +3500 rpm, but at a cruising 2500 rpm you will just >have to wait. Of course a downshift will bring you into the correct rpm >range, but sometimes that is not a possability. The simple solution here is called "left foot braking". Keep your right foot buried, use your left foot to modulate your speed. Peace- The Hacker '92 Subaru SVX '84 VW Rabbit GTI ex-PRO Rally car, now all 'round racer/beater '83 VW Rabbit GTI PRO Rally Car wannabe - hillclimbs too '81 VW Scirocco S street car TBD '79 VW Scirocco ice racer ==== Also, you may want to check out: http://www.win.net/bmicad/welcome.html (bmi CAD's homepage) http://www.win.net/bmicad/strahome.html (Stealth Racing's homepage) http://www.win.net/bmicad/nehahome.html (New England Hillclimb Association's homepage) http://www.win.net/bmicad/icetrial.html (Mo-HUD SCCA ice time trials info) ------------------------------ From: arthurok@xxx.com (ARTHUR OKUN ) Date: Mon, 26 Feb 1996 17:38:46 -0800 Subject: Re: Turbo Lag & superchargers.. i like the two speed idea how about some sort of an electricaly controled variable ratio transmission like they use in snowmobiles or some sort of viscose coupling ie fluid coupling "like a torque converter i once heard of an electronicaly controled "magnetic" transmission that might work very well in this application you see i am shying away from electric drive "diesel locomotives are electric drive how come no one calls them stupid or inefficient" ------------------------------ From: Johnny Date: Mon, 26 Feb 1996 17:57:48 -0800 Subject: Re: Turbo Lag & superchargers.. Craig Pugsley wrote: > > Hi, > > > 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. > > I wondered about this too, like have an air tank in the trunk filled by > a small 12V compressor, and a 1/2 inch air line to the turbo with a > solenoid valve to dump all the tank into the turbo (like pointing a > water hose at a bicycle pedal). > > > 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? > > Err, another innovation from the rotary world- 13B turbos have had 'twin > scroll' exhaust profiles, selected by a vacuum controlled flap since 1986 > (or was it 1987??) > > Re the electric motor powered supercharger, on RX7 club a 'CVT drive' > was suggested (ie power the supercharger from the crankshaft). I thought > you could use a '2-speed drive' similar to the following: > > A B A > _____________ |\#/| > / _______/. .\ |\#/|| # | > |. O_______. O .| | # || # | > | ... \.../ | # || # |=== To s/c input > | / | # || # | > | / |/#\|| # | > | / # |/#\| > | / # # > | / |\#/||\#/| > | / ]| # || # | > | / ]| # || # | > | ... / a/c clutch]| # || # |=== Idler wheel > |. ./ ]| # || # | > \___/ C ]| # || # | > |/#\||/#\| > 'overspeed' 'Normal' > pulley pulley > > The idea is that 'A' has a pawl arrangement for both belts and when the > a/c magnetic clutch is engaged this 'overspeeds' the normal pulley. > > (However, I can get a complete 13B turbo engine for less than a 2nd hand > toyota supercharger so I canned this idea). > > Cheers, > Craig. That is drawing is really impressive for acsii! Nice Job! - -j- ------------------------------ From: Sandy Date: Mon, 26 Feb 1996 21:35:27 -0500 Subject: Re: Injector driver chips? Where? Look at national's LM1949, it is a single piece part, but is very flexible. It is being tested to also see if it will work as an ignition driver. Very flexible, and not to expensive. Sandy At 10:20 PM 2/26/96 +0100, you wrote: >> >> > >> > Brad Sheridan wrote: >> > >> > > Does anyone have/ know where to get the Motorola MC33293T chip? >> > > >> > >> > 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... >> >> I just got off the phone with Newark. They said that due to some sort of >> die problem, Motorola won't have them available until July. This is way past >> when I need them. I may try to build a circuit, but I'd rather buy one. Does >> anyone have any reccomendations for decent peak&hold injector driver >> circuits? In a quad package would be a real plus. >> >Have you checked out the L584 from SGS-Thomson? >You can build a complete driver circuit with one L584 (DIP16), two darlingtons >and a few resitors and capacitors. The L584 can be set up to use one of four >diffrent load current waveshapes, including peak-hold-drop and peak-drop. >I don't know if the IC is easy to get hold of, or if it's still in production. > >If you want more details then let me know. > > >Sincerely, >Daniel Henriksson > >damoto@xxx.se > ------------------------------ From: Craig Pugsley Date: Tue, 27 Feb 1996 13:31:42 +1100 (EST) Subject: Re: Injector drivers (L9335/L9336) > SGS Thomson sells the L9335 and L9336 Injector Drivers. The former is a 2.4 FWIW, I have heard the L9335 is used in a certain local EFI computer as an injector driver. Haven't heard of any problems and they must be readily available. Very few external components required (only a Zener clamp I think). Looks easier to use than a MC3334 / MJ10012 combination. Craig. ------------------------------ From: jengel@xxx.NET Date: Mon, 26 Feb 1996 22:09:59 +600 Subject: Re: Blow off valve > From: einarp@xxx.no (einarp) > Subject: Blow off valve > >From what I read, the blowoff valve is there primarily to > relieve the compressor impeller from the shockwaves it generates > when it does not "move air" because the throttle is suddenly shut. > It "stalls out" as you would say if it was an airplane wing. > In other words it will give the turbo a longer life. > My source in fact showed a curve where the turbo speed decreased > _faster_ with a blowoff valve (on a Porsche). Probably because it > pumps more efficiently when not stalled, and the backpressure is > still there. > > Blowoff to atmosphere is better than recirculation because the > heat rise is lower. But a problem if there is an airflow sensor > before it. > > If the blowoff valve were controlled by the engine management unit, > the blowoff valve could be opened _fully_ when going off throttle. > (The EFI unit already have the data to detect this condition.) > Then the turbo should have less resistance and keep the speeed. > Right or wrong? > > > -- > einarp@xxx.no ( Maserati Biturbo Spyder ) > > A variation I've seen on the Porsche 924 Turbo had the blowoff valve feeding back into the turbo inlet in order to keep the air flow through the metering plate correct (the 924 had mechanical injection). When I bought my SVO intercooler from Spearco (plug) they offered a device similar to the 924's. It uses vacuum from the other side of the throttle plate to operate the valve. Can't say how well it works right now because other problems have kept me from putting it on. je ------------------------------ From: dn Date: Mon, 26 Feb 96 20:05:05 MDT Subject: Re: Injector driver chips? Where? > Brad Sheridan wrote: > > > Does anyone have/ know where to get the Motorola MC33293T chip? Brad: Where did you get this part number? I really didn't look too close on the original post, I assumed you were referring to the MC3484 chips... I looked in my data book and couldn't find a MC33293 (mind you, my data book's a bit dated). Is this a newer version of the 3484? I talked to my local suppliers and it appears that the 3484 is discontinued in all flavors, no one has had stock for some time. Mind you, I haven't talked to Motorola directly, so who knows. From a couple of the other posts on this subject, it looks like SGS Thompson is now second sourcing them, though... The problem with these chips is that they are not your average consumer chip, so hardly anyone has them in stock. Keep me posted if you find some. 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: dn Date: Mon, 26 Feb 96 20:22:47 MDT Subject: RE: B&S fuel-pump Hans wrote: > > My problem is to DRIVE the pump! > A Bosch-car-fuel-pump consumes around 12 V 58W, > my alternator brings 6V 60W. Aren't there any belt- or vacuum driven > fuel-pumps? I have a small fuel pump that I used for a 2 cyl Onan generator that is a solenoid type unit with a built in transistor oscillator to drive the plunger. Only uses an amp or so at full flow... it even has a pressure regulator of sorts in that as the pressure builds up, the frequency increases until it eventually stops at 5 or 6 PSI, until demand causes it to start again. I still have this thing kicking around, if you want I'll see if there's a manufacturers name / part number on it. I just picked it up at a local industrial supplier for around $30. Another suggestion: I believe that Volkswagen Beetles used a small electric pump to run the gas powered heater, this may be suitable for a small 2 cyl engine, although I have no idea what kind of pressure it puts out... 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: Bill Sarkozy Date: Mon, 26 Feb 1996 22:53:04 -0800 Subject: Re: Blow off valve At 01:02 PM 2/26/96, you wrote: > > >>If the blowoff valve were controlled by the engine management unit, >>the blowoff valve could be opened _fully_ when going off throttle. >>(The EFI unit already have the data to detect this condition.) >>Then the turbo should have less resistance and keep the speeed. >>Right or wrong? > >That makes sense to me, but I have also been wondering about the turbine >side. Wouldn't the turbine be trying to pull a vacuum through the engine >during throttle-lift and cause the turbo to spin down? If so, the same >concept could be applied to the exhaust side by using an electronicly >actuated wastegate. What do you think? > >I have been thinking about this because I was considering implementing some >sort of electronic wastegate to allow the boost limit to adjust from 12-15 >pounds at low rpm to 7-10 pounds at red-line. Why? Well the way I see it >there are all sorts of restrictions to power at the top end (air-flow, >exhaust-flow, fuel-flow) that disappear at say half red-line why not take >advantage of them? Any comments? > >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >Jeff Hansen >Anaheim, California, USA >JHansen777@xxx.com >http://members.gnn.com/JHansen777/car/index.htm >Seven pounds of boost is a 'Good-Thing' >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > If you had some sort of RPM-activated switch, the solution is easy......bleed off some of your boost via a solenoid valve to "fool" the wastegate at low RPM. When you hit your arbitrary limit, close the bleed solenoid and the wastegate will see full boost and react normally. Most T-Bird Turbo-Coupe owners know of this trick, but simply use a manual bleed valve to keep the boost high all the time........hang on!!!!!! ------------------------------ From: "George M. Dailey" Date: Mon, 26 Feb 1996 22:06:04 -0600 Subject: Re: ADVICE NEEDED At 05:17 PM 2/25/96 -0600, you wrote: > >On Sat, 24 Feb 1996, George M. Dailey wrote: > [ munch ] >> 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 > >greetings: > so, did you start planning in 85 to use an 89 motor, or ... :) > >later, >kc >--------------------------------------------------------------------------- - ---------- >No KC, I actually fell in love with the '85 TPI when it was introduced. I'm glad I got the '89, it's much more 'young and fresh' GMD ------------------------------ From: "Andrew Dennison" Date: Tue, 27 Feb 1996 16:29:00 +1000 Subject: Re: Injector driver chips? Where? On 26 Feb 96 at 10:38, Brad Sheridan wrote: > > Brad Sheridan wrote: > > > > > Does anyone have/ know where to get the Motorola MC33293T chip? > > > > Does anyone have any reccomendations for decent > peak&hold injector driver circuits? In a quad package would be a > real plus. > Note that the 33293 is NOT peak and hold. It's a quad driver intended for high impedence injectors. The Harris HIP0081is functionally equivalent, ie. quad current limiting driver with serial diagnostics interface. Information on all these devices (and heaps more) is on the motorola and harris web pages: http://motserv.indirect.com/ http://www.semi.harris.com/ ------------------------------ From: Krister Wikstrom Date: Tue, 27 Feb 1996 11:16:13 +-200 Subject: spark and MAP I was inspired to design my own ignition controller by Tim Drury's DDIS project article (thanks). I'm thinking of later adding also a separate EFI system, but that will require some more study and reading of this list... I have one open question: Is there a real benefit in adding a MAP input to an ignition system, or do the timing just by rpm curve? I'm thinking of having inputs from a crank sensor, possibly a MAP, and then two optional inputs RETARD and INHIBIT for future expansion. I understand, that all this depends on the target engine, but any advice here is highly appreciated. Have anyone had any problems on using commercial (0-70 deg. c) components for automotive applications? Krister Wikstrom krister.wikstrom@xxx.fi ------------------------------ End of DIY_EFI Digest V1 #57 **************************** 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".