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Fuel infection....What options are best??


Mikelly

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Yes, that TYPO was on purpose.. Fuel injection is the topic of the day.

 

There are sooo many types of FI systems out there. I'd like input as to which systems work best, which work well, and which are easy and hard to do installs on. I'm personally looking at several aftermarket types and need to feed a 500HP application. Is the Holley 4Di the way to go? Accell Mini Tunnel ram? Edelbrock multipoint? Lets roll up our sleaves and chat fuel infection guys..

 

Help me out here...

Speed density Vs. Mass Air.. In the mustang world everyone wants Mass air, yet in the latest article in Hi Po Chevy, a long discussion and defenition was given that Speed Density is the best and most widely tunable... so which is the best?

 

Throttle bodies Vs individual injectors.. OK this one really has me stumped because I have personally used both... I have a throttlebody on my GMC and it has been the most reliable vehicle I have ever owned in my life, and it is pretty darned quick to boot... But what about individual injectors feeding each cylinder? Ah yes, spent many years playing with those and I built several normally asperated L6 motors with different injectors and had some good and some not so good successes with those.

 

The best of all worlds for me personally is to have a system that makes the most HP and is the most dependable and trouble free system out there... asking for the sun, the moon and the stars is my norm, so bare with me!

 

OK, what say you guys???

 

Mike

 

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"I will not be a spectator in the sport of life!"

mjk

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Guest Fast Frog

Mikelly:

 

I think you know my setup. I've got a 383 with a TPIS LT-1 type mini-ram, Edelbrock hds, roller cam, and Accel's DFI engine mgmt sys. I, like most others, could give limited "arm chair" advise based primarily upon our specific experience with our particular setups. What you might need is to brain storm some ideas and combinations with a real pro-one who has multi-facetted technical experience and has completed a variety of performance projects. I know such a guy who's been a consultant to me and who has done two major (very sucessful) projects. His name is Ron Anderson. His phone is (970) 667-4239. He does have an email address. If you call him, I know he'll give you his email address. His over the phone/email advise is free. BTW, I hear that he's got several automotive patents pending.

 

Good luck!!!

 

Rick

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Seems to me that the programmable setups (SDS, Haltech, Tech II, etc.) run about the same price new as buying new stuff to do an EFI conversion. (maybe I'm worng, just going by summit prices) I'd think that on a high hp engine like yours Mike, the programmable EFI would really let you tune it perfectly for any situation. Its not just for turbo engines! smile.gif

 

 

 

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Drax240z

1973 240z - L28TURBO transplant on the way!

http://members.xoom.com/r_lewis/datsun.html

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Dang I like all these smiley faces, it makes it fun to post . I have reasearched EFI quite a bit, and know chevy efi quite well also .

 

I would say that port injection is minimum for your setup, injector upgrades are a snap and better manifold design than a TBI conversion .

 

All things aside I think ease of tuning is probably one of the most important features . The Accel DFI is fairly easy to tune and has all the basic features you will need . It could stand an update on dataloging and a few trick but overall very good . The high performance chev guys do this again and again .

 

SDS is even simpler to tune and they have probably the best support, you will miss some fine tuning ability on the fuel maps but overall a good system, no dataloging .

 

Haltech is another worth mention kind of like the DFI for features on software is much nicer .

 

Get as much info before purchase, instructiions, opinions .

 

Mass Airflow vs Speed Density

Speed density is cheaper but as soon as you modify one thing the fuel maps must be changed . This is bad on a non programmable ECU, car runs like crap with new cam . The MAF can compensate because it knows the actual air flow .

 

Head to sdsefi.com for tons of information about efi .

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Uh boy - this is a topic I've researched for YEARS Mike :-)

 

First - MAF vs SD. MAF wins hands down IMO! The reason Chevy folks prefer the SD is because it's easier to modify those computers for their cars ECU-wise. Also, the Chevy market hasn't had decent aftermarket MAF meters until recently and the packaging issues are a bitch for them. Here's the deal - MAF actually measures the airflow (wow, what a concept) SD on the other hand INFERS the air flow using a MAP sensor (vacuumpressure) and an air temp sensor. I don't know about Chevy ECUs but the Ford ECUs are smart enough to actually know the difference if you change the distance from the throttle body to the MAF meter! Yeah, most Ford guys don't know stuff like this and half the Ford crap is a Kludge - modifying the MAF for bigger injectors is STUPID and so are FMUs for blowers. I could preach forever on this but...

 

Intakes.. Most factory style intakes were built for low RPM high torque low airflow requirements. Yes, even the ACCELL stuff! I'm not sure I like it at all to be honest. I REALLY like some of the setups that convert over SINGLE plane carb intakes. On a port injected fuelie motor suspension of the fuel isn't an issue so single plane works fine. Speaking of fuel suspension - the biggest advantage of TBI is that the fuel can cool the air through evap on the way to the valve. TBI also runs low fuel pressure so that's nice in some ways. Ever wonder why carb systems frequently beat fuelie systems in dyno tests for HP? It's the intake man - the runners are too long! Slap some injectors into a carb intake and spank that carb system into submission.

 

ECUs... Go programmable for sure. The FelPro looks very nice but I don't know much about it. If the system uses one of those handheld controllers I'd skip it - go laptop but figure in the cost of one of these puppies. Most systems don't need a beefy laptop.

 

The Electromotive system is sweet but expensive. I've got one of their latest software releases BTW. Since they're just up the road and I've got "friends", deals can be worked sometimes. Electromotive has nice intakes and throttle bodies IMO, get their catalog for that if nothing. Their datalogging kicks butt as does their data display (wow, more should do this!), I can let you see this if you'd like. Electromotive also uses MAF if you want and has direct ignition as well as knock sensing I believe. I'm pretty sure this can use a wide band O2 and with a MAF it will actually self programcorrect the fuel tables to hit your specified mixture ratio but I wouldn't advise running it like that all the time (smile).

 

SDS I've heard good things about but don't know well, I can research it if you'd like.

 

DFI? LOL! Maybe the new sequential DFI but the older one? - forget it! I've got one on my shelf from the Mustang right now. Non-sequential - couldn't lower the injector pulse enough because of that, datalogging BLOWS, no data display - have to use Excel or a text editor etc., the CPU is too slow for good granular logging, and the software is ancient. I've got the training manual on this system if you'd like to read it. Oh yeah - the injector drivers can't handle PeakHold injectors I don't think - it can fry. The O2 sensor is standard off the shelf crap too - you want wideband if at all possible. Their knock sensor falsed a good bit on my Mustang (shug).

 

Haltech - they used to do only fuel and so I didn't look hard at them. I believe that they've improved and it looks like others use them so I can't add much here.

 

Motec - squeeal! But you get massive datalogging, cylinder by cylinder mixture adjustment, racing quality hardware sealed up tight. Too expensive IMO.

 

SpeedBrain - don't know if they've got this standalone but for the Mustang this rocks. Unfortunatly I've not gotten a good feeling as to whether or not the guy in Woodbridge can tune this puppy - I bought a custom chip for my Mustang instead, it came in today..

 

Whew, that's all I can recall on various systems at the moment :-) Like I said, I've been looking into this for years due to the Mustang's needs.

 

GM ECUs until recently sucked, Ford was kicking their butts in sophistication. EEC-IV ECUs actually ran Indy cars in a config not much different than the passenger cars on the road! However they weren't "cracked" until just recently and the GMs were. Even now I doubt some of the stuff coming out for them. There are programs on the 'net that allow you to reprogram a GM ECU's PROM, some especially for GNs (oh Scottie..?). I equate the DFI with the GM ECUs - old and crude until recently. I found programming the DFI to be a bitch but then I'm no rocket scientist and had no help at all.

 

Programming is the bitch here Mike - I couldn't find anyone a couple of years ago that could help escept in NJ and it was expensive tuning.

 

Look closely at the software for whatever system you consider. I'd suggest investigating the FelPro very closely and the Electromotive. There are some horror stories about the latter out there but they're local if you have a beef :-)

 

Somewhere I've got an URL with EFI comparisons, it was on Zcar and someone here might have already posted it. This is NOT an easy decision but it's one I'll be making after my car is debugged, just as you are. After you my friend..

 

Here's some Ford info -> http://www.gothorsepower.com/eecfile.htm

 

Multi EFI makes -> http://force-efi.com/price.htm

 

SpeedBrain - read the comparison table at bottom! -> http://www.gothorsepower.com/sb.htm Depending on how my custom chip works I may go with this system on the Mustang!

 

FelProSpeedPro-> http://www.force-efi.com/felpro.htm http://www.mycar.net/sefi8lo.htm

 

Whew, I'm done at last. Sorry to ramble guys and I'm sorry if what I've said contradicts what you've been told in some cases. I've spent waay too much time looking at this stuff and waiting for things to be commercially produced for us...

 

[This message has been edited by BLKMGK (edited August 10, 2000).]

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WOW, Jim, thanks for that incredible write up! For what it's worth, Jim Biondo has told me several times that his room mate is the guy who programmed the old and new Accel? system, and then moved to Felpro to improve it. Supposedly, the Felpro rocks. Not sure about the datalogging capabilities. This guy can do lots of neat stuff to a GM ECU also.

 

Jeesh, why didn't I follow my instincts take the automotive engineering route instead of mechanical engineering and move to Detroit!

(I HATE cold weather)

There is some incredible hotrod talent up there - they get to play with the stuff at work, guys, and know the inner workings of the OE stuff! Of course, being engineers and hotrodders, they know how they'd like to change stuff to make it more hi-po and go home and do it! Can you tell I'm jealous?

 

I'll just trudge along with my Holley 750 vac sec until I see the clear choice and find an extra $3K to drop on THE EFI system... frown.gif

 

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Pete Paraska - 73 540Z - Marathon Z Project - pparaska@home.com">pparaska@home.com -

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I've got the same as Rick.

383 cid with TPIS MiniRam2. Except I'm using

the Haltech E6K. I shouldn't say using cuz

it's not running but thats what I got. Also

MSD 6AL, 2 step, and RC Engineering injectors.

 

I chose the TPI route because I figured there

would be more options over TBI in terms of

staging injectors, 2 injectors per cylinder,

individual cylinder tuning, etc.

 

My parts supplier suggested the E6K saying it

was better than SDS and had newer software than AccelDFI. I can't say yea or nay yet.

 

Note: the E6K is not fully semi-sequential EFI. More on this at: http://www.homestead.com/s30z/files/efi.htm

my page of complaints...

 

Owen

 

 

 

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http://www.homestead.com/s30z/index.html

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Guys, I'm truley impressed by the information being given on this topic. I'm feeling pretty primitive with my limited knowledge and hacked up carburetor. Where is a good place for the "need to know" novice/enthusiast to start learning about F/I? I know this is the future. I should be catching up . Now, if you'll excuse me, I going to drag my knuckles back to my cave and bang on some rocks and sticks!

JS

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....Two things that are key for me to purchase a system is the ability to Bolt it in without a lot of headaches and the ability to have it be reliable day in and day out. I drove my car to work today and while coming up the highway the carb started breaking down a bit... Which it didn't have to do last weekend.. seems I'm always having to tweek this thing and that just pisses me off. I'd like to bolt something on, and tune it and leave it.. The TBI setup in my truck is bullet proof, but I know there are limits to the ability to get maximum HP out of a TBI setup... I do like the idea of keeping my port matched intake though...

 

Mike

 

------------------

 

"I will not be a spectator in the sport of life!"

mjk

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Now I don't want to step on any toes here, but I have found when one of these systems were blamed that it ran bad usually there is another problem other than the ECU itself . I am going to stick up for the DFI a bit here having bought one . It does lack some options compared to other ECU's . I will tell you some of the limitations .

 

Datalogging is a real pain you have to be good with a spreadsheet to get any value out of it, I made an excel program to help this out .

 

If you want coilpacks the ECU has to be programmed.

 

Sequential EFI is hard to do, I think this is not nessaery in most cases .

 

John Ligenfelter has been tuning his stroker 383's with DFI for a years and run amazing, and you can't dispute the power .

 

Just about any system will be 100 times better than a carb for driveablitly than a carb "IF TUNED CORRECTLY" Excellent warmup, better gas milage, improved part throttle .

One thing that might be a problem is a high overlap cam, which give low vacuum readings which make idle suffer . In this case the system is tuned with the TPS sensor, MAP sensor is not used .

 

Mabey I will change my tune when I start my motor up in a month . Accel DFI can be bought used, I got mine for $450 with software . You can even build you own sheetmetal manifold .

 

Take your time on this one and do some reasearch . Personally I don't think you can go wrong with any of these systems . Some are just better value, others have fancy tricks .

 

Electramotive TEC II software is top notch but very confusing to learn how to tune it .

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Mikelly,

If ease of installation and tune-ablilty is what you're looking for then I would sugguest Endelrock's Performer RPM Pro-Flo EFI. At just under 2k it's a steal. Also Holly's 1000 CFM MPI Pro-Jection II is reported to be a great system at around 2k. Jeg's sells both. Mark

 

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[This message has been edited by Z-Dreamer (edited August 11, 2000).]

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Guest Fast Frog

Clint:

 

Good post!! I've got an older Accel DFI sys in my setup, but I know that Calmap has advanced greatly in the last five years. Even my old programmable sys had engine diagnostics and some useful performance feed back. Whether it's MAF or SD doesn't matter to much to me. It's an easy to install and easy to use sys. And a very reliable sys. I'll be going with an Accel DFI sys with a TBI setup on my next project.

 

[This message has been edited by Fast Frog (edited August 11, 2000).]

 

[This message has been edited by Fast Frog (edited August 11, 2000).]

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The "infection" option I elected was GM factory fuel-injection. A complete LT1 (with engine AND the injection setup) can be picked up for less than some of the aftermarket injection systems alone. With the new LT1-edit software now available you can even tune the system to your heart's content. With a decent cam and head porting 450hp on a stock bottom end isn't too difficult. With a heavy dose of forced air (and a built bottom end) there are a few 800hp LT1s running around.

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Ryalc - where can this LT1-edit software be found? I want it :-) Okay - I found it! Hey, now this is my idea of a good way to go. Use a stock ECU with it's million bux worth of research and then reprogram it! If anyone can speak to how easyhard it is to wire this up to an earlier motor please speak up. I'm betting this is LT1 only tho'

http://www.carputing.com/

 

As for the DFI - I know Duttweiler spends tons of time on it - I bought my system from him! His "base" map for my car had to be trimmed something like 40% before I could even drive it though. It was liek spraying for bugs on the way to my friend's house to get the laptop - I could hardly see out the back window it was so dense! DFI CAN work but I did NOT find it user friendly. It's initial startup routine wasn't very helful in building a map. BTW - what software version have you got? I've got what I believe is a fairly recent version here... I sort of collect this sort of software to help me decide on a system. DFI hasn't even gone Windows based for their older system and I'm not sure it's even being updated anymore.

 

As for sequential - yeah it doesn't pick up much more HP (better emissions tho') but that's not the point. When everything is batch it's firing twice per revolution, sequential fires only once I believe. Injectors have a minimum time for opening and closing. Due to mechanical hysteresis you cannot go below this time because the injector will dribble instead of spraying - it tries to close before it actually even opens! I had my car running 30lb injectors as low as I could witht he DFI and it still idled FAT. Any lower and it would stumble and hunt - ick! It was trying to take the time I'd given it (total injection time) and cut it in HALF to fire it twice! Run those SAME injectors with a sequential EEC-IV from Ford and it idled like a kitten. What can I say?

 

Datalogging with the DFI - how do you realisticly graph a .01 to say 1.0 O2 sensor reading against a range of 900 to 6000RPM powerband reading? Add to that the air temp range of say 60 degrees to maybe over 100. Don't forget ignition advance and boost level too. This is tough! I'm not a super whiz at Excel but this was just a bitch. Like I said - it was also not granular enough. If the motor revved real fast from say wheelspin you could sometimes see several hundred RPM between datalog points and O2 voltage could be all over the place. I drove nearly constantly with a laptop going next to me and datalogged entire drives home to try and work out driveability bugs. I could reprogram map values with one hand while driving after awhile. I did also have an interesting run in with a cop once while tuning but that's another thread. :-) Suffice it to say that the factory spends the big bux on part throttle driving for a reason - WOT is easy by comparison. This is why the SpeedBrain for the Ford is attractive to me - stock curves as a baseline!

 

IF you're going to use any ECU software DO make yourself a spreadsheet to show 100% duty cycle on the injectors, the DFI will let you program values higher than 100% (you don't realize it). Having a spreadsheet handy that let me see when I'd exceeded 100% sure was nice. You're not really supposed to go past 80% but... I was also not real sure on timing curves - I tried all sorts of stuff, a real shame the knock detector would go nuts from just revving the motor with no load. I didn't trust it one bit...

 

Oh yeah - I didn't mention the Holly system before. The early Holly systems I wouldn't have ever touched. They were pure analog with POTS for doing your tuning - ick! They were also TBI - yicky! I've NOT looked closely at their current offerings but I did notice that one of them can actually run close loop now - wow.... Seriously, I'm not sure just how good or bad these might be right now so at least consider them and try to find someone using them to talk to.

 

Edelbrock... Nice looking intakes! However it looks like one of those systems you program with a handheld controller. Perhaps there's one I'm not aware of but the handheld programmer thing isn't something I want. Yes, it gets rid of the "expensive" laptop but it frequently means NO datalogging! Datalogging will save your butt if it's done right. Datalogging allows you to see what's going on, the more data you get and the more granular it is the better off you are - assuming you find a way to display it...

 

Electromotive's software will show you graphs of EVERYTHING you logged on one screen with a marker displaying where you're at. As you move the marker it jumps on all of the graphs and displays real numbers on the screen for each graph as well. Very nice. Hrm, I also found that the DFI wouldn't let me log enough inputs. I don't mean to hammer that system too much but understand it's the one system I'm intimatly familier with - live with any of them and you'll find issues - I promise!

 

I've DL'ed the demo software for the SpeedProFelPro system and intend to look at it. I thought FelPro was offering intakes with their stuff - apparently not, bummer. Some of the Electromotive intakes look nice, maybe one of those with a FelPro ECU? I'd really like MAF though but it's either not available or a pricey addition to most systems (sigh). I may wind up going Electromotive myself but it'll be bux and I'll have to find a good tuner locally. Thankfully I've got a friend who used to work for Peter Farrell's RX7 shop who knows the system inside and out - he just doesn't know V8s is all. I'll ask him what he thinks of it and what the Electromotive's downsides are and report back - may be awhile tho'.

 

P.S. For those curious about the workings of an ECU - in particular the GN ECU check this FAQ link out -> http://www.thrasher-ep.com/Chips_htm/cal_hints.htm

 

Some other good links -> http://www.fl-fbody.com/members/bfranker/fbody/links.htm

 

[This message has been edited by BLKMGK (edited August 11, 2000).]

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Some very good comments, I would like to add to what you said

 

BLKMGK: As for the DFI - I know Duttweiler spends tons of time on it - I bought my system from him! His "base" map for my car had to be trimmed something like 40% before I could even drive it though. It was liek spraying for bugs on the way to my friend's house to get the laptop - I could hardly see out the back window it was so dense! DFI CAN work but I did NOT find it user friendly.

 

Clint: Well I don't really know why Duttweiler was so far off . I can't emphasize how important tuning process is . As far as userfriendliness I think it is pretty good, the only one that is easier is SDS . The 2 major tuning screens are fuel map and ignition . If you look in Electromotive it has like 4 different things just to set fuel, it is FRIGGIN CONFUSING !!

 

It's initial startup routine wasn't very helful in building a map. BTW - what software version have you got? I've got what I believe is a fairly recent version here... I sort of collect this sort of software to help me decide on a system. DFI hasn't even gone Windows based for their older system and I'm not sure it's even being updated anymore.

 

Clint:Well I have version 6.35 anc and anybody can test drive the software at www.whiteracing.com . My 386 laptop would suck with windows, so it is bitter sweet .

 

 

I had my car running 30lb injectors as low as I could witht he DFI and it still idled FAT. Any lower and it would stumble and hunt - ick! It was trying to take the time I'd given it (total injection time) and cut it in HALF to fire it twice! Run those SAME injectors with a sequential EEC-IV from Ford and it idled like a kitten. What can I say?

 

It could be a zillion different things, leaky injectors, running closed loop idle, low battery voltage . Tim78 runs 55lb injectors and has no idle problems, the car runs like a champ .

 

Datalogging with the DFI - how do you realisticly graph a .01 to say 1.0 O2 sensor reading against a range of 900 to 6000RPM powerband reading? Add to that the air temp range of say 60 degrees to maybe over 100. Don't forget ignition advance and boost level too. This is tough! I'm not a super whiz at Excel but this was just a bitch. Like I said - it was also not granular enough. If the motor revved real fast from say wheelspin you could sometimes see several hundred RPM between datalog points and O2 voltage could be all over the place.

IF you're going to use any ECU software DO make yourself a spreadsheet to show 100% duty cycle on the injectors, the DFI will let you program values higher than 100% (you don't realize it). Having a spreadsheet handy that let me see when I'd exceeded 100% sure was nice. You're not really supposed to go past 80% but... I was also not real sure on timing curves - I tried all sorts of stuff, a real shame the knock detector would go nuts from just revving the motor with no load. I didn't trust it one bit...

 

Clint: All very good comments, datalogging is very minimal and alot harder to do than other systems . The problem most people have in tuning is they try to program more than 1 thing at a time . They don't stablize a certain load point . In one afternoon a car can be tuned to give a half decent driving vehicle vehicle . Start with a flat fuel table shift it up or down, (more gas total or less gas total). Then tilt it (more gas or less gas as you load the motor down) . Next tilt the curve the other way (more or less gas as rpm increases ) . Then you can then begin smoothing the table . Most people miss these basic steps and start pulling individual points up and down . Think of tuning like sculpting, start with a block cut basic dimensions out, then begin going into more and more detail as you go along .

 

 

Electromotive's software will show you graphs of EVERYTHING you logged on one screen with a marker displaying where you're at. As you move the marker it jumps on all of the graphs and displays real numbers on the screen for each graph as well. Very nice. Hrm, I also found that the DFI wouldn't let me log enough inputs. I don't mean to hammer that system too much but understand it's the one system I'm intimatly familier with - live with any of them and you'll find issues - I promise!

 

Clint: Electramotive has awsome datalogging, I wish DFI had this, but alot of people have all this info and don't know what to do with it . DFI has little info but settings are easier to understand . For example you are

too rich at a certain point, the DFI has to change the point in the fuel table . In electramotive what do you have to change Intial Offset Time ?? Raw Fuel Curve?? VE?? One affects the other, I find this a pain and hard to get my head around . Many sucessful SDS systems were tuned with no datalogging features, and far less tunability than the DFI .

 

I've DL'ed the demo software for the SpeedProFelPro system and intend to look at it. I thought FelPro was offering intakes with their stuff - apparently not, bummer. Some of the Electromotive intakes look nice, maybe one of those with a FelPro ECU? I'd really like MAF though but it's either not available or a pricey addition to most systems (sigh). I may wind up going Electromotive myself but it'll be bux and I'll have to find a good tuner locally. Thankfully I've got a friend who used to work for Peter Farrell's RX7 shop who knows the system inside and out - he just doesn't know V8s is all. I'll ask him what he thinks of it and what the Electromotive's downsides are and report back - may be awhile tho'.

 

Clint: Yes the best way is find a shop that can install & tune your system properly . A $7000 Motec system can run like garbage if tuned incorrectly . Many people don't need all the fancy options thatcost $1000-$5000 more .

 

PS I hope I didn't scare anyone here about EFI, a good shop will tune you system so all you have to do is drive!!

 

 

 

[This message has been edited by clint78z (edited August 14, 2000).]

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Guest Fast Frog

Well:

 

My hackles are up a little bit (maybe they shouldn't be)!! I must be a genius or a savant idiot!! But I've not found Accel's DFI sys to be user UNfriendly! Granted, I don't race and I'm not looking for the last drop of HP or performance. I think a key to this is finding someone-a "guru" or technician-that has the tech savvy and experience in whatever sys-and working with him to set your sys up and expand your knowledge at the same time.

 

I got into Accel's sys in 1991 when windows was in its infancy and I didn't know the diff between a Microsoft window and an out house door. I did a little research and found a tech who lived in the region who happen to specialize in Accel products. We got together and he installed the DFI sys on my then turbo setup. What a difference!! The sys was a quantum leap above Hobb switches, 1500 ohm resisters and rising rate fuel regulators that were previously installed, ala, Ak Miller, BRE, et.al. After the DFI sys was installed, My guy gave me a floppy copy of the installation and an injector sizing/HP program for future use.

 

And I did use each shortly after the initial installation. I added a diff cam and more boost. A quick call to my guru was made and with a little consultation, he advised me where on the fuel and ignition maps to make changes. I followed his instructions and "Walla" it worked!! Now, as a help with diaing in the fuel numbers, we used a Halmeter to give us rough indication of fuel amounts-red for lean, yellow for stoich and green for rich. Fuel mapping in the "open loop" mode was easy! I could do it by myself traveling @ 100mph. However, fine tuning the sys in "closed loop" mode usually required 2 people-me and my tech guy. Still a piece of cake!!

 

In 1995, I ditched the turbo setup and installed a sbc 383. I wanted to keep the DFI sys so I called my guru who happened to be with Hewlett Packard in Oregon. I relayed some engine facts to him-type of cam, hds, etc.-and he mailed out a floppy for a sbc 400 with some instructions where to add/reduce fuel and ign numbers. With this info and an 8 lead injector harness, I got my new 383 up and running in great shape! I found out 3 months later, when he stopped in my area to do another project, that I was only 3-5% off on my numbers!!

 

8 months later, I went to roller cam, Edelbrock hi flo hds and a Paxton SC with 5+lbs of boost. A big problem? Hell no!! A call to Ron and with a little note taking I was back in business again! He's since moved back to Colorado and has been out doing other projects in my area and has stopped by to tweek up this current setup with the Paxton SC. All of this was done on "very expensive" 286 & 386 lap tops costing $2-$300. The car is track proven (see one of my previous posts a couple of months ago)-11.8 ET @ 120mph @ 4600ft. altitude!! And it will do an honest 160mph!! I'm very happy!!

 

Ahhhhh, Hmmmmmm, of course ignorance is bliss.

 

[This message has been edited by Fast Frog (edited August 14, 2000).]

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BLKMGK you email me all your calmap stuff before, it was an incredible help . I am not trying to tick any one off, I am just trying to help !! It is easy to lead down the wrong path when tuning EFI, SDS has the best information of anywhere hands down . They make it simple and don't miss any steps .

 

I have learned lots of things from people that twin turbo big blocks to GN V6's . By the way the calmap startup is table is only meant to get the engine started .

 

Here is a fuel map from Tim78zt turbo car mddified for my 37lb injectors .

tim.jpg

LOAD vs RPM vs Fuel Delivered

If you look at RPM vs Fuel you will notice that this generally follows the torque curve of an engine .

If you look at Load vs Fuel you will notice that it is generally a straight line .

This table was done on a dyno and has had lots of tuning done !!

 

Here is your fuel map that you were running current.all

mjc.jpg

As you can see the RPM vs Fuel doesn't follow torque curve . Generally this map should look simular to TIM's only shifted up or down depending on injector size . This chart just needs some more work !!

Some of the other setups for the fuel table had big dips and peaks in them, the car will not run smoothly .

 

biggrin.gif Some very good info being posted by everyone biggrin.gif

 

 

 

[This message has been edited by clint78z (edited August 14, 2000).]

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Ya, I know my tables were screwy. When I got my DFI I had th elittle manual that comes with it and... zip. Yup, nothing nadda' and no help in sight. It actually ran pretty well at WOT but I suspect that things like the spark table were WAY off. I'd graph out the fuel table and tinker with it, datalog, and just plain go nuts trying to get it to run better.

 

Frankly - the DFI software didn't make things terribly easy. Some of the Electromotive stuff LOOKS easier - set a desired AF ratio and drive - it self tunes (to a point). Without some sort of wide band O2 it's also a real bitch to know what's going on - in that car you couldn't just swap out plugs for readings either (sigh). I finally got pretty frustrated with it - it drove pretty well but I knew there was power to be had left in it. Last diddled with it about 2 years ago when the car came off the road.

 

As for the idle - brand new the injectors wouldn't idle. Same injectors with an EEC-IV - back to back - idled fine. Played with timing and most anything I could find - nope. About 6months before I gave up for a motor rebuild I DID get hold of an EEMIC (sp?) training manual - that helped some (shrug). I think a SpeedBrain may be more my speed for that car - starting with a stock baseline would be VERY nice.

 

What seems most clear here is that in order to do this well you should have someone experienced give you a good baseline. From there someone to give you advice helps. Without it you'll be lost as I was and damned frustrated with the DFI software let me tell you!

 

BTW - it runs fine on a luggable 286. Who needs Windows? :-)

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Clint: Before getting a system talk with someone who has tuned one sucessfully . I have looked into the TEC II system in a fair bit of detail . Don't be fooled by that Air Fuel Ratio (that is quite misleading.) The TEC II is not a wide band O2 system .I will warn you right now TEC II software is three times as hard to program as the DFI . There are several people on zcar.com with TEC systems and it takes a long time to learn how to program one .

 

Clint: I will give you some tips on tuning the DFI, set closed loop up to about .8 bar the DFI will show you the correction . Apply correction to lower curve . This will show you that toque curve I talked about, then extrapolate the values for the rest of the chart but multiply extrapolated values by 14.7/12.5 to give a more power up top and safer running . Now it is just fine tuning the values with O2 sensor readings . As for spark timing, start off with stock mechanical and vacuum curves, straight accelration test will show you best settings for ignition . These proceedures are used one way or another on most narrow band O2 systems .

 

Originally posted by BLKMGK:

Ya, I know my tables were screwy. When I got my DFI I had th elittle manual that comes with it and... zip. Yup, nothing nadda' and no help in sight. It actually ran pretty well at WOT but I suspect that things like the spark table were WAY off. I'd graph out the fuel table and tinker with it, datalog, and just plain go nuts trying to get it to run better.

 

Frankly - the DFI software didn't make things terribly easy. Some of the Electromotive stuff LOOKS easier - set a desired AF ratio and drive - it self tunes (to a point). Without some sort of wide band O2 it's also a real bitch to know what's going on - in that car you couldn't just swap out plugs for readings either (sigh). I finally got pretty frustrated with it - it drove pretty well but I knew there was power to be had left in it. Last diddled with it about 2 years ago when the car came off the road.

 

Clint: The software is easy, but the instructions could have way more detail on tuning . If it had instructions like the SDS, I am sure you would still be using the DFI .

 

As for the idle - brand new the injectors wouldn't idle. Same injectors with an EEC-IV - back to back - idled fine. Played with timing and most anything I could find - nope. About 6months before I gave up for a motor rebuild I DID get hold of an EEMIC (sp?) training manual - that helped some (shrug). I think a SpeedBrain may be more my speed for that car - starting with a stock baseline would be VERY nice.

 

Clint: Yes stock settings sre very helpfull,

read that EEMIC manual from Accel it will help you out tuning your new system . I will say this again go to sdsefi.com website and go to the tuning proceedures, you will need to know this for programming any EFI . If you haven't bought a new system and still have old DFI, I am sure I could tell you exactly how to tune your car with it . Would you be willing to give it another shot??

Some dyno time with a wide-band O2 sensor will get you almost dead on, and for $250 it's a bargain .

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