DIY_EFI Digest Wednesday, 17 March 1999 Volume 04 : Number 177 In this issue: RE: Frederic Breitwieser/turbo discussion Re: Frederic Breitwieser/turbo discussion Re: Frederic Breitwieser/turbo discussion, design Q's Re: Holley 4tbi to 7747 Re: Frederic Breitwieser/turbo discussion Re: Frederic Breitwieser/turbo discussion, design Q's Re: Dangerous injection ideas Re: Fuel tuning... Re: Frederic Breitwieser/turbo discussion Re: Frederic Breitwieser/turbo discussion Re: Frederic Breitwieser/turbo discussion, design Q's Re: How easy would it be to swap a 4L60e for a 4L80e Re: Fuel tuning... Re: Frederic Breitwieser/turbo discussion Re: Frederic Breitwieser/turbo discussion Re: Frederic Breitwieser/turbo discussion Re: Frederic Breitwieser/turbo discussion Re: Fuel tuning... Re: Frederic Breitwieser/turbo discussion Don't try this at home..... Re: Frederic Breitwieser/turbo discussion, design Q's Re: Frederic Breitwieser/turbo discussion Re: Frederic Breitwieser/turbo discussion, design Q's Re: Fuel Pump Re: Frederic Breitwieser/turbo discussion Re: Frederic Breitwieser/turbo discussion Re: Fuel Pump Re: How easy would it be to swap a 4L60e for a 4L80e Re: Fuel tuning... Re: Frederic Breitwieser/turbo discussion, design Q's Re: DIY_EFI Digest V4 #162 Re: ford efi to tbi swap See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: "Rudi Machilek" Date: Wed, 17 Mar 1999 06:11:12 -0500 Subject: RE: Frederic Breitwieser/turbo discussion Slightly out of sequence; how did you determine turbo over-speed? Rudi Machilek ------------------------------ From: "Gary Derian" Date: Wed, 17 Mar 1999 07:14:29 -0500 Subject: Re: Frederic Breitwieser/turbo discussion Yes, but each bank fired evenly. The engine as a whole fired 90-150-90-150, etc. but each bank in itself fired 240-240-240. The bank thing did not change when the engine became even fire, the phase between banks did. Gary Derian - ----- Original Message ----- >> Every V-6 I know fires bank to bank. Each bank fires 3 times, 240 deg >> apart, in a 720 deg cycle. >> >What about the old Odd-fire GM V6 - 231? cu inch? The dist cap looked >like a V8 cap with 2 towers pulled out. Idled about that way too. ------------------------------ From: ECMnut@xxx.com Date: Wed, 17 Mar 1999 08:02:43 EST Subject: Re: Frederic Breitwieser/turbo discussion, design Q's Does anyone know of a good example of reversion tubes, somewhere on the net? I'm gathering materials to build a 2.0 Ltr 4cyl turbo header. Also, if there are some good rules for volume , primary tube size/length that you are aware of, please lemme know. The engine is a 16v SOHC Neon unit. I have a spare of this particular engine, so I'll push it pretty hard.hard. The exhaust ports look weak, but the intake ports look really nice.. (see http://www.enzoco.com/mike/neon/sohchead.htm ). I will be using aToyota 3Ltr supra turbo from a 6cyl engine. I was a little hesitant at first, to put it on an engine that is 2/3 the displacement, but later found that Totota also used it on 2.0 Ltr MR2 Turbo cars with the same AR exhaust housing. I have a feeling that I'll be looking for ways to compensate for a slightly oversized exhaust housing, and was thinking there must be a particular design that accomplishes this better than others. As I said, any advice on designing the turbo header is appreciated. Mike V. ------------------------------ From: "Bruce Plecan" Date: Wed, 17 Mar 1999 08:06:25 -0500 Subject: Re: Holley 4tbi to 7747 - -----Original Message----- From: Walter Sherwin To: diy_efi@xxx.edu> Date: Tuesday, March 16, 1999 11:50 PM Subject: Re: Holley 4tbi to 7747 The 749 has two drivers in it. In the syclone (4.3L, v-6 applications) it is wired to use one in staurated mode. In the 2.0 turbo sunbird/Quad4 applications, it uses 2 Peak+Hold. There are wiring differences, from P+H to Saturated (not internal to ecm) Bruce >Thanks! Okay, can someone who has used the 749 tell me exactly how many >drivers it has, and what flavour they are? > >Walt. > ------------------------------ From: Frederic Breitwieser Date: Wed, 17 Mar 1999 13:26:15 +0000 Subject: Re: Frederic Breitwieser/turbo discussion > Yes, but each bank fired evenly. The engine as a whole fired 90-150-90-150, > etc. but each bank in itself fired 240-240-240. The bank thing did not > change when the engine became even fire, the phase between banks did. This message might sound sarcastic, its just my writing style... I'm going though this step by step so you can follow me thoughts, and in reality, so I can follow my thoughts too . Lets draw a V6 engine here, looking at the top of the engine (intake), with the fan belts to the left, and the bell housing to the right: 2 4 6 1 3 5 Good drawing, eh? . Anyway, lets connect a headers to the odd banks to a turbo, and another header to the even banks to a turbo. /---/---/---(T) 2 4 6 1 3 5 \---\---\---(T) If the firing order is 1-2-3-4-5-6 then each turbo receives and alternating pulse. If the firing order is 1-3-5-2-4-6 they don't. That was all I was saying. The buick V6 firing order is 1-6-5-4-3-2, therefore there would be no need for 180 degree headers, i.e. crossing over exhaust tubes based on these pictures. Now I'm really curious. - -- Frederic Breitwieser Bridgeport, CT 06606 http://www.xephic.dynip.com 1993 Superchaged Lincoln Continental 1989 500cid Turbocharged HWMMV 1975 Dodge D200 Club Cab (soon to be twin turbo 440) 2000 Buick GTP (twin turbo V6) ------------------------------ From: "Gary Derian" Date: Wed, 17 Mar 1999 08:46:06 -0500 Subject: Re: Frederic Breitwieser/turbo discussion, design Q's I think a good basic 4 into 2 into 1 header is the way to go. Anti-reversion tricks may help, I don't know. Look at a Porsche 944 Turbo setup. It has practically a full sized header. The turbo is on the intake side. Typical lengths are 18 inches to the first merge, 1-4 and 2-3, then 24 or more inches to the second merge, right at the turbo. A dual scroll exhaust housing separates the pulses even further. Gary Derian >Does anyone know of a good example of reversion tubes, somewhere >on the net? I'm gathering materials to build a 2.0 Ltr 4cyl turbo >header. Also, if there are some good rules for volume , >primary tube size/length that you are aware of, please >lemme know. The engine is a 16v SOHC Neon unit. >I have a spare of this particular engine, so I'll push it >pretty hard.hard. > >The exhaust ports look weak, but the intake ports look really nice.. > (see http://www.enzoco.com/mike/neon/sohchead.htm ). > >I will be using aToyota 3Ltr supra turbo from a 6cyl engine. > I was a little hesitant at first, to put it on an engine that is 2/3 the > displacement, but later found that Totota also used it on 2.0 Ltr > MR2 Turbo cars with the same AR exhaust housing. > >I have a feeling that I'll be looking for ways to compensate for a >slightly oversized exhaust housing, and was thinking there >must be a particular design that accomplishes this better than others. >As I said, any advice on designing the turbo header is appreciated. >Mike V. ------------------------------ From: Clarence Wood Date: Wed, 17 Mar 1999 07:52:38 -0600 Subject: Re: Dangerous injection ideas Could you supply a phone number, or web site, for C&H Surplus? Those prices sound great! Clarence At 08:33 PM 3/16/99 PST, you wrote: >Guys, > Received my acetylene regulator and linear stepper in the mail today >from C&H surplus. The regulator is a really solidly built unit from >Fischer Scientific, still in its original bubble wrap. Can't beat that >for $15... :) > > The linear stepper is an Airpax 4-phase motor and appears to have about >256 full steps from full retract to full extension. $10. > > It appears that this range will be sufficient to control the above >regulator. I hope it has enough force. I hay have to half step it to >both increase resolution and force. > >-Bill >Get Your Private, Free Email at http://www.hotmail.com > > ------------------------------ From: Clarence Wood Date: Wed, 17 Mar 1999 08:00:07 -0600 Subject: Re: Fuel tuning... This question may seem stupid, but please don't laugh. How do you determine degrees advance while you are driving down the road? I couldn't get anybody to hang over my fender with a timing light; well, I found one guy but he couldn't remember what he saw. Clarence At 06:43 PM 3/16/99 -0500, you wrote: >At 04:08 PM 3/14/99 -0500, you wrote: > >>>Depending on speed, at 70MPH I see between 35 and 40 degrees advance at >>>cruise... lower speeds around town, 23-30 degrees seems to be "normal" >> >>This got an AL head?. cruise might be a tad high (40), and cruise (low) of >>23 >>low.. The 23 being low is for a cruise rpm of no less than about 1400, >>if you have one of the applications that can do a low cruise of say 1100 >>then 23 might be fine, just I usually don't deal with anything that can do >>that low of cruise rpm. >>> > >Well, >not sure if the last post made it... had an attachment I had toconvert to >text... > >Yesterday, during cruise at 45 MPH in 3rd gear ~1500 RPM I see about 30 >degrees advance. >In OD at 65MPH (1700 RPM) I see between 35 and 40 degrees advance. At part >throttle accelerating up a hill at 2500 RPM I see about 30 degrees advance >and no knock counts. >I seem to pick up between 10 and 15 knock counts immediately after a shift >and timing falls to between 10 and 12 degrees then starts climbing back up >again. > > >Here's what I see at WOT immediately before the shift to 2nd gear:LeSabre >Data Scanner > >Promld 1694 >Battery Voltage 13.50 Volts >02 Voltage 910.20mV >Coolant Temp 198.95 Deg F >Knock Counts 136 >Engine RPM 5221 RPM >Speed 48 MPH >LV8 225 >Run Time 1277 Seconds >TC Slip 251.00 >N/V Ratio 105.00 >Injector PW 18.91 mSec >TPS Voltage 4.34 Volts >02 Cross Counts 0 >air Temp 47.75 Deg F >advance 20.47 Deg >Engine Torque 92 Lb/Ft >MAF 140.78 G/Sec >Weak Cylinder 0 Cyl >Gear 2 >TCC PWM DC 0.00 >Trans Temp 157.10 Deg. F > >Hopefully this helps or can give an idea of what I'm seeing or where I need >to go... >=========================================================== > David Cooley N5XMT Internet: N5XMT@xxx.net > Packet: N5XMT@xxx. Member #7068 > I am Pentium of Borg...division is futile...you will be approximated. >=========================================================== > > > > > ------------------------------ From: DC Smith Date: Wed, 17 Mar 1999 08:02:00 -0600 Subject: Re: Frederic Breitwieser/turbo discussion FWIW.. if memory serves me right, the firing order on a Buick even fire V-6 is 1-6-5-4-3-2. Drivers side is #1-3-5 and passenger side is #2-4-6. Bank to bank firing. Frederic Breitwieser wrote: > > > On a V-6, whether it be 60, 90, flat, even or odd fire, don't you get nice > > even every other pulse to a turbo when each bank has its own turbo? I don't > > see the need to cross over. > > Depends on the firing order. If the blasts of exhaust come > from alternating sides, then yes, it doesn't need a cross *********************************************************************** Dan Smith 84 Regal 12.13@112 GSCA# 1459 St.Charles, Missouri mailto:dcsmith@xxx.net http://www.tetranet.net/users/morepoweral *********************************************************************** ------------------------------ From: "Gary Derian" Date: Wed, 17 Mar 1999 09:23:00 -0500 Subject: Re: Frederic Breitwieser/turbo discussion No sarcasm taken, Fred. In theory, you are entirely correct. As a practical matter, though, all V-6's fire bank to bank. Its just the easiest way to make one. Maybe the only possible way. With a 6 the goal is 120 deg between firing. With a 60 deg V angle, the crank needs 60 deg pin offset. It is not practical to build a 60 deg V-6 with shared journals, the resultant engine would have 60-180 firing. Way odd fire. With a 90 deg V angle, the crank needs a 30 deg pin split. It is possible to build a non split crankpin odd fire 90 deg V-6, (Buick and Maserati) but even fire has much smoother torque. The Dino Ferrari engine had a 65 deg V. I don't know what the crank looked like but I suspect it had a 55 deg split. Flat 6 engines use a 180 deg split that cancels the 180 deg bank angle and acts like an in line 6. Still firing bank to bank. Gary Derian > >This message might sound sarcastic, its just my writing >style... I'm going though this step by step so you can >follow me thoughts, and in reality, so I can follow my >thoughts too . > >Lets draw a V6 engine here, looking at the top of the engine >(intake), with the fan belts to the left, and the bell >housing to the right: > > 2 4 6 > > 1 3 5 > >Good drawing, eh? . Anyway, lets connect a headers to >the odd banks to a turbo, and another header to the even >banks to a turbo. > > /---/---/---(T) > 2 4 6 > > 1 3 5 > \---\---\---(T) > >If the firing order is 1-2-3-4-5-6 then each turbo receives >and alternating pulse. If the firing order is 1-3-5-2-4-6 >they don't. That was all I was saying. > >The buick V6 firing order is 1-6-5-4-3-2, therefore there >would be no need for 180 degree headers, i.e. crossing over >exhaust tubes based on these pictures. > >Now I'm really curious. > >-- >Frederic Breitwieser >Bridgeport, CT 06606 > >http://www.xephic.dynip.com >1993 Superchaged Lincoln Continental >1989 500cid Turbocharged HWMMV >1975 Dodge D200 Club Cab (soon to be twin turbo 440) >2000 Buick GTP (twin turbo V6) ------------------------------ From: ECMnut@xxx.com Date: Wed, 17 Mar 1999 10:29:37 EST Subject: Re: Frederic Breitwieser/turbo discussion, design Q's HI Gary, Is a 4-into-2-into-1 turbo header superior to say, 4 tubes converging right at the turbine inlet? I'm trying to establish some rules as to when one design works better than another (while lag is a fairly big concern). Is there a rule of thumb, say with 4 vs 6 vs 8 cylinders? Mine is a 4cyl. The info on the Porche design is very interesting, but does anyone know why they chose that design over others? With the 4-2-1 setup, does the firing order dictate which tubes get paired together? For example, should the first merge join two cylinders that are farthest away from each other in the firing order? Thx Mike > think a good basic 4 into 2 into 1 header is the way to go. > Anti-reversion tricks may help, I don't know. Look at a Porsche 944 Turbo > setup. It has practically a full sized header. The turbo is on the intake > side. Typical lengths are 18 inches to the first merge, 1-4 and 2-3, then > 24 or more inches to the second merge, right at the turbo. A dual scroll > exhaust housing separates the pulses even further. > > Gary Derian > >Does anyone know of a good example of reversion tubes, somewhere > >on the net? I'm gathering materials to build a 2.0 Ltr 4cyl turbo > >header. Also, if there are some good rules for volume , > >primary tube size/length that you are aware of, please > >lemme know. The engine is a 16v SOHC Neon unit. > >I have a spare of this particular engine, so I'll push it > >pretty hard.hard. ------------------------------ From: Mark Stoner Date: Wed, 17 Mar 1999 08:37:38 -0700 Subject: Re: How easy would it be to swap a 4L60e for a 4L80e Nobody seems to have mentioned this yet, but the 4L60(700R4) or 4L60E have different 1st gear ratios than the TH400 based 4L80E. If I remember correctly, the 4L60 is 3.4:1 and the 4L80 is around 2.8:1 "Peter D. Hipson" wrote: > > > >So the $100 question is: How easy would it be to swap the 4l60e vs the > >4l80e. Can the stock computer talk to a 4l80e without any probs? I've > >got the mastertune software that lets me change what ever I want, so shift > >points / line pressure wouldn't be a problem, if the stock computer can do > >it. Also, are the wiring harness connectors the same? > > > >Thanks, > > > >Doug Bazarnic > > > > - -- Mark Stoner Telemetry Electronics Engineer email: mstoner@xxx.gov/ Ph: (505) 679-9745 Fax: (505) 679-9753 Research Rockets / Physical Science Laboratory / NMSU Box 30002 Las Cruces, NM 88003 / N200 LC-35 White Sands Missile Range ------------------------------ From: ECMnut@xxx.com Date: Wed, 17 Mar 1999 10:40:18 EST Subject: Re: Fuel tuning... You need a device for displaying the ALDL data stream, such as diacom, OTC or homebrew hardware/software fagelation. HTH Mike V. OR.. maybe a really little guy under the hood with a timing light and a walkie-talkie. Bruce, is Doc availabe? In a message dated 3/17/99 9:17:16 AM Eastern Standard Time, clarencewood@xxx.net writes: > This question may seem stupid, but please don't laugh. How do you determine > degrees advance while you are driving down the road? I couldn't get anybody > to hang over my fender with a timing light; well, I found one guy but he > couldn't remember what he saw. ------------------------------ From: "Clive Apps Techno-Logicals 416 510 0020" Date: Wed, 17 Mar 1999 10:50:42 -0500 (EST) Subject: Re: Frederic Breitwieser/turbo discussion > > Slightly out of sequence; how did you determine turbo over-speed? with Fred it was probably when he noticed small red hot bits of metal bouncing off the equipment live ------------------------------ From: Frederic Breitwieser Date: Wed, 17 Mar 1999 09:52:55 -0500 Subject: Re: Frederic Breitwieser/turbo discussion > Slightly out of sequence; how did you determine turbo over-speed? Unfortunately by bearing failure. We had attached discs to the turbo shaft to optically capture the RPM. Exceeded my frequency counter function on my Fluke however, so it just err'd like the turbo bearings. The easiest way, and what I should have done, is use a cheap-ass tach connected to a "divide by something" CMOS logic connected to some optoelectronics and then it could have been dash mounted. We even got clever (ha) and attempted to connect the two turbo shafts together via a simple shaft. However, the expansion of the headers and the weakness of the connecting rod resulted in a fragmentation of the shaft. DUCK! - -- Frederic Breitwieser Bridgeport CT 06606 1993 Supercharged Lincoln Continental 1989 HWMMV w/turbocharged 500cid Caddy 1975 Dodge D200 Club Cab soon to have 431 stroker + turbos 2000 (I hope) Buick GTP (Mid-Engined Sports Car) ------------------------------ From: Frederic Breitwieser Date: Wed, 17 Mar 1999 11:51:34 -0500 Subject: Re: Frederic Breitwieser/turbo discussion > Ok, I'll start! There is a certain responsibility with going first :) > I was mulling around a little idea I had about my Pontiac. It's in the > garage with no fenders, the 400 looks pretty bare, with no harness or > plumbing. I have a spare (used) turbo sitting there from my old Mustang > ('84 GT350, turbo4) and have been contemplating adding this along with efi. Its my school of thought to add the EFI first, get that running suitably, making sure your EFI configuration is upgradable to the additional boost, either by a larger MAF or a 2 or 3 bar MAP sensor depending on your configuration. > Then I thought about a setup something like the original post about the > variable exhaust system. I was thinking about a relatively small turbo > driven by one bank, to get the boost rolling, then a pretty large turbo on > the other bank that would take over at higher rpm's. I didn't get into the > pro's and con's yet. I spent a lot of time with several friends of mine trying to achieve the best bottom end combined with an awesome top end on the Buick V6 twin-turbo. For scavaging purposes, you want the exhaust restriction to be about identical on both sides of the engine, so sizing a smaller turbo on one side and a larger turbo on the other will cause ineffective scavvaging on the smaller turbo side, unless you achieve a bypass. We tried running two small 1.6L Subaru turbos off each side, but they weezed out pretty low in the RPM band (about 3600-3800 RPM on the Buick). So, we then daisychained larger turbos (TE44) in series on the exhaust lines... however the smaller turbos "got in the way" at higher RPMs exhaust flow wise. So, we got a little crazy and used four of those cast iron JC Whitney exhaust bypass thingys and put one fore and one aft on the smaller turbo, so at low RPMs the smaller turbos were working hard, flowing its waste into the larger turbos to keep them somewhat spooled. Then, at 4000 RPM, we'd cut all four bypasses so the smaller turbos were "out of the loop". This worked very well, and increased power more broadly across the RPM band. The problem now is how to control these mechanical valves. Also, this is just the exhaust side of things, we hadn't really done anything with the intake side... we just monitored RPMs of the engine and where the turbos small or large stopped making any additional boost, or started to overspeed. Plumbing was a nightmare, and certainly the weight of four turbos plus four cast iron cutouts was not exactly something we wanted hanging off the headers. So, the small turbos went, and we used the two TE44's and at 6200 RPM, we blew the crank apart and testing continued on a second engine. We also experimented with nitrious for lower RPMs, triggering it in the 1500-3000 range thus giving more punch before the turbos are at max boost, and this also worked very, very well. Using the aftermarket ECMs (Haltech in this case) you have a general purpose output which you can use for Nitrious solenoids or fangle up an injector driver circuit to drive additional injectors... solder away my friend. We ended up with three injectors per cylinder... first two were 93/94 octane gasoline, the third was an 80% alky 20% distilled water mix from a seperate tank and worked very well. This is very similar to what I will be doing on my 383 stroker (431 cid) Mopar block during the spring as the parts start to come together. Hope that helps ;) - -- Frederic Breitwieser Bridgeport CT 06606 1993 Supercharged Lincoln Continental 1989 HWMMV w/turbocharged 500cid Caddy 1975 Dodge D200 Club Cab soon to have 431 stroker + turbos 2000 (I hope) Buick GTP (Mid-Engined Sports Car) ------------------------------ From: Frederic Breitwieser Date: Wed, 17 Mar 1999 11:52:26 -0500 Subject: Re: Frederic Breitwieser/turbo discussion > Slightly out of sequence; how did you determine turbo over-speed? Unfortunately by bearing failure. We had attached discs to the turbo shaft to optically capture the RPM. Exceeded my frequency counter function on my Fluke however, so it just err'd like the turbo bearings. The easiest way, and what I should have done, is use a cheap-ass tach connected to a "divide by something" CMOS logic connected to some optoelectronics and then it could have been dash mounted. We even got clever (ha) and attempted to connect the two turbo shafts together via a simple sX-Mozilla-Status: 0009ansion of the headers and the weakness of the connecting rod resulted in a fragmentation of the shaft. DUCK! - -- Frederic Breitwieser Bridgeport CT 06606 1993 Supercharged Lincoln Continental 1989 HWMMV w/turbocharged 500cid Caddy 1975 Dodge D200 Club Cab soon to have 431 stroker + turbos 2000 (I hope) Buick GTP (Mid-Engined Sports Car) ------------------------------ From: "David A. Cooley" Date: Wed, 17 Mar 1999 12:46:09 -0500 Subject: Re: Fuel tuning... Hi Clarence, Not a stupid question at all. My PCM outputs knock counts, knock retard and advance through the ALDL. I'm using a very modified version of the GCAR software (Thanks to Mike Pitts!) and it all displays on my laptop... - -----Original Message----- From: Clarence Wood To: diy_efi@xxx.edu> Date: Wednesday, March 17, 1999 9:17 AM Subject: Re: Fuel tuning... > This question may seem stupid, but please don't laugh. How do you determine degrees advance while you are driving down the road? I couldn't get anybody to hang over my fender with a timing light; well, I found one guy but he couldn't remember what he saw. > ------------------------------ From: Frederic Breitwieser Date: Wed, 17 Mar 1999 11:42:51 -0500 Subject: Re: Frederic Breitwieser/turbo discussion > with Fred it was probably when he noticed small red hot bits of metal bouncing > off the equipment Actually it was the noise of the turbine scraping on the housing. :( - -- Frederic Breitwieser Bridgeport CT 06606 1993 Supercharged Lincoln Continental 1989 HWMMV w/turbocharged 500cid Caddy 1975 Dodge D200 Club Cab soon to have 431 stroker + turbos 2000 (I hope) Buick GTP (Mid-Engined Sports Car) ------------------------------ From: goflo@xxx.net Date: Wed, 17 Mar 1999 11:17:17 -0800 Subject: Don't try this at home..... Clarence Wood wrote: > > This question may seem stupid, but please don't laugh. How do you determine degrees advance while you are driving down the road... Used to have a shop in Hawaii. Built a lot of VW street motors. Sold one guy a long block - Few days later he shows up in his bug, with an accomplice - Asks if he can borrow a timing light. Sure... Shortly thereafter he's honking up & down the street, accomplice perched on rear bumper, holding on to the fan housing with one hand and the timing light with the other... Darwin Award stuff most places, just another day in Hawaii. Jack ------------------------------ From: "Gary Derian" Date: Wed, 17 Mar 1999 13:37:02 -0500 Subject: Re: Frederic Breitwieser/turbo discussion, design Q's Turbo engines respond to all the same tuning tricks as atmo engines. Tuned headers included. Conventional wisdom states that a 4-2-1 header gives better mid range and a 4-1 gives better top end. There is lots of racing engines that use 4-2-1 designs With largish tube diameters and appropriate lengths, I thing a 4-2-1 is better up beyond 7000 rpm. Heck, even the Ferrari F355 V-8 (peak power at 8500 rpm) uses a 4-2-1 design. Firing order definitely dictates the merging. The first merge joins opposites in the firing order. All 4s have a 1-3-4-2 order so join 1-4 and 2-3 together. I suspect that some of Porsche's reasoning is packaging the system, but it also allows enough room to fit a tuned exhaust. Back in the old days when I used to build carbureted turbo engines with draw thru carbs, putting the turbo close to the exhaust resulted in a long and tortuous intake path that results in really poor performance. With EFI your have more choices. Gary Derian >HI Gary, > Is a 4-into-2-into-1 turbo header superior to say, > 4 tubes converging right at the turbine inlet? >I'm trying to establish some rules as to when one design works >better than another (while lag is a fairly big concern). Is there a >rule of thumb, say with 4 vs 6 vs 8 cylinders? Mine is a 4cyl. >The info on the Porche design is very interesting, but >does anyone know why they chose that design over others? >With the 4-2-1 setup, does the firing order dictate which tubes >get paired together? For example, should the first merge join >two cylinders that are farthest away from each other in the firing >order? >Thx >Mike ------------------------------ From: Frederic Breitwieser Date: Wed, 17 Mar 1999 18:09:56 +0000 Subject: Re: Frederic Breitwieser/turbo discussion > No sarcasm taken, Fred. In theory, you are entirely correct. As a Good! Sometimes I worry about my writing style... > practical matter, though, all V-6's fire bank to bank. Its just the easiest > way to make one. Maybe the only possible way. I am curious why two pipes crossed over underneath on our setup, and this weekend I'll find out for sure. > deg bank angle and acts like an in line 6. Still firing bank to bank. Got it! - -- Frederic Breitwieser Bridgeport, CT 06606 http://www.xephic.dynip.com 1993 Superchaged Lincoln Continental 1989 500cid Turbocharged HWMMV 1975 Dodge D200 Club Cab (soon to be twin turbo 440) 2000 Buick GTP (twin turbo V6) ------------------------------ From: Frederic Breitwieser Date: Wed, 17 Mar 1999 14:22:10 -0500 Subject: Re: Frederic Breitwieser/turbo discussion, design Q's > Turbo engines respond to all the same tuning tricks as atmo engines. Tuned yes they do. The only thing I would append to your comments if I may is that with a turbocharged system, you want the exhaust system to have as little restriction as possible, because the turbo itself is a big spinning CORK. You want little, if any back pressure pre and post turbo, especially with the larger turbos. > headers included. Conventional wisdom states that a 4-2-1 header gives > better mid range and a 4-1 gives better top end. There is lots of racing > engines that use 4-2-1 designs With largish tube diameters and appropriate What would you recommend for low to mid end then? I am curious, for I'm building a 383 Mopar B block stroked to 431 cubes (or more if I can figure it out), using the EEC stuff to manage it. What I ended up with, since the vehicle is a truck and not a race car by any means, was either to make shorty exhaust manifolds that go forward, attach the turbos there, and blow up into the intake system I'm almost done fabricating. Also, even with turbos, and H-Pipe offers better performance. I am clueless as to why this is the case, I believe it has to do with exhaust pulse reverberation, however the H pipe does make a difference. Original testing on the Buick before we ended up with bizarre headers, the tried the H pipe before the turbos, and after the turbos. Post turbo offered slightly more power and less turbo lag from idle. We used a 3" H pipe. BTW, I had called up to the shop, and found out that I was completely mistaken. The 180 degree headers are in fact 3 to 1 headers, however underneath the dry sump oil pan there is an "X" where the left side feeds the right side, and the right side feeds the left side, in conjunction with their own side. My friend said conceptually, its the same advantage as an H pipe, however being an "X" rather than an "H" the crossover points are somewhat aligned with the airstream versus the H pipe which is a 90 degree bend of course. See, I made this and I didn't even know what it was LOL. Hope that clarifies what we did, and makes sense to some of the discussions. Hey Bruce, can I borrow your cone shaped hat for standing in the corner for 15 minutes? - -- Frederic Breitwieser Bridgeport CT 06606 1993 Supercharged Lincoln Continental 1989 HWMMV w/turbocharged 500cid Caddy 1975 Dodge D200 Club Cab soon to have 431 stroker + turbos 2000 (I hope) Buick GTP (Mid-Engined Sports Car) ------------------------------ From: rr Date: Wed, 17 Mar 1999 10:04:53 -0800 Subject: Re: Fuel Pump It is a good way to go, pricey, but good. I understand that they build the tank with baffling around the pickup. Check this, as this is the major benefit. Witout the baffling, it's not worth it, IMHO. With an inline pump, proper operation will require a fuel/air seperator. Otherwise, air pickup causes short leanouts and the corresponding problems. Unless you keep the tank over 1/2 full, can be a short term fix. BobR. >Maybe this is the wrong place to ask this, but here goes. > >I'm going to be swapping a 93 LT1 from my wrecked firebird formula into a >'66 Impala. Should I bite the bullet and buy a rock valley in tank pump, >its $300 installed. Would an inline pump be a better deal. > >- Eric ------------------------------ From: "Gregory A. Parmer" Date: Wed, 17 Mar 1999 13:51:02 -0600 (CST) Subject: Re: Frederic Breitwieser/turbo discussion >On a V-6, whether it be 60, 90, flat, even or odd fire, don't you get nice >even every other pulse to a turbo when each bank has its own turbo? I don't >see the need to cross over. I thought it was a self-equalizing measure...to insure that both sides of the engine were flowing similar amounts of air. Isn't balance a good thing? Same would hold for any twin turbo arrangement feeding specific cylinders regardless of firing order or engine layout. One good guess deserves another, - -greg (hopefully the duplicate message thing is fixed) ------------------------------ From: "Bruce Plecan" Date: Wed, 17 Mar 1999 15:28:33 -0500 Subject: Re: Frederic Breitwieser/turbo discussion - -----Original Message----- From: Gregory A. Parmer To: diy_efi@xxx.edu> Date: Wednesday, March 17, 1999 2:59 PM Subject: Re: Frederic Breitwieser/turbo discussion Equal, good. Frankenstein Monster voice off. Grumpy > >>On a V-6, whether it be 60, 90, flat, even or odd fire, don't you get nice >>even every other pulse to a turbo when each bank has its own turbo? I don't >>see the need to cross over. > >I thought it was a self-equalizing measure...to insure that both sides >of the engine were flowing similar amounts of air. Isn't balance a >good thing? Same would hold for any twin turbo arrangement feeding >specific cylinders regardless of firing order or engine layout. > >One good guess deserves another, >-greg (hopefully the duplicate message thing is fixed) > ------------------------------ From: eclark@xxx.com Date: Wed, 17 Mar 1999 15:00:12 -0600 (EST) Subject: Re: Fuel Pump On Wed, 17 Mar 1999, rr wrote: > It is a good way to go, pricey, but good. I understand that they > build the tank with baffling around the pickup. Check this, as > this is the major benefit. Witout the baffling, it's not worth > it, IMHO. > I talked to them over the phone and confimed it in thier catalog, they put baffling in the tank around the pickup, and they keep the stock fuel level sender in the tank. They also install a vent line and return line. For ~$300 with the pump included I think that I will probably go with them. - -Eric ------------------------------ From: Andrew Choset Date: Wed, 17 Mar 1999 16:21:14 -0500 Subject: Re: How easy would it be to swap a 4L60e for a 4L80e At 08:37 AM 3/17/99 -0700, you wrote: > >Nobody seems to have mentioned this yet, but the 4L60(700R4) or 4L60E >have different 1st gear ratios than the TH400 based 4L80E. >If I remember correctly, the 4L60 is 3.4:1 and the 4L80 is around 2.8:1 For what it's worth, The 700R4/4L60/4L60E ratios (all the same) are 3.06/1.63/1.0/.7 Andrew Choset 88 IROC-Z L98 T56 swap in progress ------------------------------ From: "Bruce Plecan" Date: Wed, 17 Mar 1999 16:39:25 -0500 Subject: Re: Fuel tuning... - -----Original Message----- From: ECMnut@xxx.com> To: diy_efi@xxx.edu> Date: Wednesday, March 17, 1999 11:06 AM Subject: Re: Fuel tuning... Doc no longer does the under the hood in drive timing light operations since the last timing light incident. Bruce > You need a device for displaying the ALDL data stream, >such as diacom, OTC or homebrew hardware/software >fagelation. >HTH Mike V. >OR.. maybe a really little guy under the hood with a timing >light and a walkie-talkie. Bruce, is Doc availabe? > >In a message dated 3/17/99 9:17:16 AM Eastern Standard Time, >clarencewood@xxx.net writes: >> This question may seem stupid, but please don't laugh. How do you determine >> degrees advance while you are driving down the road? I couldn't get anybody >> to hang over my fender with a timing light; well, I found one guy but he >> couldn't remember what he saw. > ------------------------------ From: "Gary Derian" Date: Wed, 17 Mar 1999 16:39:05 -0500 Subject: Re: Frederic Breitwieser/turbo discussion, design Q's Adding a turbo to an engine raises the pressure on both sides, intake and exhaust so a turbo really doesn't see much different conditions than an atmo engine. A really good setup can generate more boost than backpressure but in most practical situations, the exhaust pressure is higher. This is true even for atmo engines. Unlike a V-6, a V-8 does have uneven exhaust events in each bank, unless it has a flat crank like Ferrari V-8s. A 4-2-1 header (bi-Y or tri-Y) still works as long as you take the exhaust pattern into account. Different V-8s have different cylinder numbering and firing orders but I am pretty sure they all have the same exhaust pattern. The one I know at the top of my head is Chevy so I will use it. Its firing order is 18436572. Take it and write it like this: 1843 6572 Ideally cylinders 1-6, 8-5, 4-7, and 3-2 should be paired in the first merge but what a basket of snakes this creates! By shifting over one, you can pair 1-5, 8-6, 4-2, 3-7. This keeps each bank separate but still keeps the exhaust pulses from stepping on each other. High performance V-8s from BMW and Lexus use this type of setup with the factory exhaust. For low to mid rpm use smaller diameter tubes. Of course for a turbo setup you will want to get some nice mandrel bend 321 stainless steel ($$$)! Every installation is a series of compromises. It sound like your setup is reasonably good but a nice tri-Y each side would be better for power but not so good for cost or time. The only reason I can figure that your H pipe after the turbots helped is it balanced the flow on each exhaust pipe reducing backpressure I would not have expected it to help. H pipes work by providing a spot for the pressure waves to reflect. They don't have to actually flow gas to work. The same thing can be accomplished by building an expansion chamber in each pipe. The other h pipe benefit is higher frequency noise which is easier to muffle so a lower backpressure exhaust system can be built for the same noise level. Putting the second merge of a tri-Y at the h pipe point also gets the job done. You don't need the h pipe in that case, although it may still provide better tuning. I am interested to learn what exhaust configuration you used and maybe an explanation to go along with it. Gary Derian > >What would you recommend for low to mid end then? I am curious, for I'm >building a 383 Mopar B block stroked to 431 cubes (or more if I can figure it >out), using the EEC stuff to manage it. ------------------------------ From: "David Sagers" Date: Thu, 08 Feb 1996 05:11:58 PST Subject: Re: DIY_EFI Digest V4 #162 I have a chance to buy a new model LT1 for my truck. I'm concerned that connecting the front mounted distributor to my computer will be a major headache or rather expensive to convert the computer/harness. Is it possible to use an old style distributor on this engine instead of the front mounted LT1 style distributor? If this looks like it'll work, I plan on using my TBI intake, EFI and computer. Anything else I should know about before I dig in? Get Your Private, Free Email at http://www.hotmail.com ------------------------------ From: Mark_Duewel@xxx.gov Date: Wed, 17 Mar 1999 16:28:31 -0800 Subject: Re: ford efi to tbi swap Check out www.merkurgarage.com for links to details on a 5.0 swap and a 3.8 SC swap for the 2.3 turbo. - -Mark has anyone swaped out a ford four cyl efi turbo motor for a tbi v6 I am trying to avoid changing the entire wireing harness. I have read about maf upgrades on tbi motors and by looking at the pinouts of the computer all ford eec-4 their is only two injector wires for the four cyl if I connect these wires to the tbi and plug in the rest of the sensors it should run but my main fear is that even though the four banger was turbo'd the fuel maps might still be lean if it reads from a 2 or 3 bar map sensor (wich I haven't located in the car) so heres the topology '86 thunderbird w/v6 3.8 TBI (totaled front end) '85 thunderbird w/Turbo four and EFI (decided to get hungry and eat turbo, also has bad trany) The wires for the sensors split inside the dash half go out the drivers side and the other half go out the pasenger side. I have the computer from both but I don't have a intact MAP sensor from the '86 so I was hopeing to use the MAF since it is prefered anyway. sorry I typed so much J.O. ------------------------------ End of DIY_EFI Digest V4 #177 ***************************** 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".