motec map for f4i [Archive]

Ian M

11-27-2006, 07:32 AM

Yeah, this probably isn't something that someone is going to give out freely. We don't use the M800, we have the M4 so ours is in DOS and it's not that great anyhow.
What I would do is find your CRIP value, F4i injector resistance is around 12ohms, so current should be set around 1A.
Find a stock dyno map off the internet and set your timing from around 5 to 40 degrees advance and make the curve similar to the stock torque curve. Retard the timing slightly at higher loads.
I would suspect that you have a lambda sensor with a M800 so set up an air/fuel table and run closed loop and go through your table and let the Motec give you estimated values of your fuel percentage and then use these values to interpolate a table. Remember, rich is better than lean.

Does your engine run at all? Have you cut off two of the teeth on the cam sensor wheel?

Good luck

Poe

11-27-2006, 08:09 AM

Does setting the injector current to 1A work alright? We have been running the stock injectors as saturated instead of peak and hold, so we run that value at 0 and never had any problems. I thought that the current must be set on injectors with very low resistance, say in the neighborhood of 2 ohms.

Rvenom

11-27-2006, 10:30 AM

well ian,the engine is running well or used to with the stock setup,honda ECM and wiring...yes weve ground down 2 teeth on the cam trigger wheel,CRIP Is set to 70 deg...really wish i had a track to play around with values...hmmm if i go for the stock torque curve..then there really is no point running motec is there? yes,lambda a:f ratio sensor is installed and running...looking for something between 11.5 and 12... any more help would be really appreciated... oh and yes..we should be willing to pay for a good map..just to get us startedhttp://fsae.com/groupee_common/emoticons/icon_wink.gif

rjwoods77

11-27-2006, 10:46 AM

The more interesting question is why did you blow you nut for a 5000+ dollar ecu with no idea of how to tune correctly. I could see if it was a carry over but then what kind of team are you that you have a unit like that and no kind of carry over from last year.

If you are willing to pay for a map then sell that thing to someone else and get a PE unit since he has done a million of these cars and has base maps to play with. Or does the shiny gold case look bling bling and you want it just cause.

The point being above my obvious harshness is throwing money at a problem with no direction is similar to a monkey tossing shit. Its a meaningless exercise. Take time to figure stuff out and make educated purchases and design decisions. It saves you more than twice the time and money in the long run versus "just getting something done quick and wrong".

Rvenom

11-27-2006, 11:07 AM

totally get ur point....but seniors in the team wanted to take a leap in terms of data acquisition and other stuff like that,,so basically..we set aside a part of our finances for the little gold 'bling' behind the drivers seat....hopefully the whole thing is a learning process....couple of us have seen basic AEM and greddy stuff on street cars functioning, and motec is far easier to get a hang of to tune..theres always the F1 key! ..but since this is for the australian event...anything that we churn out would be brash..so was just looking for some help...so anyone out there..ready to be generous?

Ian M

11-27-2006, 01:14 PM

Poe,
Actually, I haven't ran our engine using the 1A setting. I actually had it set at 0A all last year as you have and it seemed to run fine. Our Motec quit firing one of the injectors, so we sent it to Motec to be fixed. Before I sent it back while troubleshooting I was talking to Simon at Motec and he was the one that said if the injectors are rated from 10-14.4 ohms (which is what the manual says) than it should be set at 1 due to simple V=IR equation.
I had it set at 0 because in the "HELP" section it said that for high resistance injectors set the current value to 0, so that is what I did.
Therefore, I am now confused again, so any information on the subject would be helpful.

Rvenom,
I just meant make your timing advance curve resemble the shape of the stock curve. This doesn't mean you will end up with the stock Torque curve on the dyno when fuel and other parameters are figured in, but it should get you going. Plus you will hit choked flow around 10000rpm (rough estimate depending on intake manifold, so you should level off at max advance a little above that. Also, do you have a Bosch Ignitor to boost current to the coils?

P.S. Take most of this with a grain of salt as I don't have a lot of experience, this is just what I have done in the past and what I have gained from reading books. Rvenom, pick up this book: "How to Tune and Modify Engine Management Systems" by Jeff Hartman has some good stuff

fart can

11-27-2006, 02:30 PM

Given that we run the motec M4, you need to get the four channel bosch ignitor if you plan on running the stock ignition coils and sub harness.

VXI-440 Programmable Ignition Module is the one to use from Vimx Ignition, apparently.

You guys are going to need more than just a fuel map to get your engine running. You can't just plug the stock F4i motor into motec. Listen to what Ian M posted, and that'll get you started.

Ian I'll check our injector settings and let you know what we run. One of our injectors stopped working, but since I replaced it things have been fine. We usually get some 'max duty' errors on the injectors but I haven't worried about it yet.

Poe

11-27-2006, 04:26 PM

We've run the 0A setting for the entire time we've been using the M4 to my knowledge (5 competitions and 5 years of testing), all using the stock F4i injectors. We were going off of the help file as well, but haven't experienced any problems. I'll re-read the motec documentation and see if it reads any differently than I remember.

We've never had any duty cycle errors either. Even turbocharged, we are at most just above 50% duty cycle on the stock F4i injectors.

Ian M

11-27-2006, 04:51 PM

Yeah, I sent Simon at Motec an email asking when our M4 would be back from repair and I threw in a question about the 1A vs. 0A. Sounds like 0A is fine since that is what we all seem to be doing. Poe, our injectors ran at a max duty cycle of around 60%, but I had it running pretty rich last year, not a lot of tuning time or experience. Fart can, every once in awhile I would get a max duty error but it was usually a fluke and I didn't worry about it either. Unfortunately for us it wasn't our injector that went south it was the driver for that injector inside the Motec. Motec USA had to ship it back to Australia because they can't deal with driver repair. I haven't seen the damage price wise, but I bet it isn't going to be pretty. Hopefully it was a defect but our unit is 2 years old, so I doubt it will be covered.
One more question for you guys. I made up a spreadsheet to give me some needed tuning numbers and I calculated that my injector pulse width per injector was around 5.5 ms. Motec says for naturally aspirated engines this number should be around 15 to 20, so I have ran 15 in the past and it has worked. Other material I have recently read says that from 5 to 10 ms is common. Does Motec use some weird value here or are my calculations wrong? I have not flow tested these injectors, these calculations come from an equation that uses max HP and brake specific fuel consumption and max duty cycle to give me a flow rate and then uses the amount of air and air/fuel ratio to give me this value of 5.5ms.

Andycostin

11-27-2006, 04:53 PM

What uni are you from Rvenom? I may be able to dig out an old map, but I'm all the inputs will be up the shit...

repeatoffender

11-27-2006, 04:55 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ian M:
Yeah, I sent Simon at Motec an email asking when our M4 would be back from repair and I threw in a question about the 1A vs. 0A. Sounds like 0A is fine since that is what we all seem to be doing. Poe, our injectors ran at a max duty cycle of around 60%, but I had it running pretty rich last year, not a lot of tuning time or experience. Fart can, every once in awhile I would get a max duty error but it was usually a fluke and I didn't worry about it either. Unfortunately for us it wasn't our injector that went south it was the driver for that injector inside the Motec. Motec USA had to ship it back to Australia because they can't deal with driver repair. I haven't seen the damage price wise, but I bet it isn't going to be pretty. Hopefully it was a defect but our unit is 2 years old, so I doubt it will be covered.
One more question for you guys. I made up a spreadsheet to give me some needed tuning numbers and I calculated that my injector pulse width per injector was around 5.5 ms. Motec says for naturally aspirated engines this number should be around 15 to 20, so I have ran 15 in the past and it has worked. Other material I have recently read says that from 5 to 10 ms is common. Does Motec use some weird value here or are my calculations wrong? I have not flow tested these injectors, these calculations come from an equation that uses max HP and brake specific fuel consumption and max duty cycle to give me a flow rate and then uses the amount of air and air/fuel ratio to give me this value of 5.5ms. </div></BLOCKQUOTE>

does that number of 5.5 include the time the injectors open and close?

maybe your bsfc is off slightly?

Andycostin

11-27-2006, 05:02 PM

I think you'll find that Motec is generalsing for larger engines... We use 9ms and it's worked perfectly for the past 3 years.

Poe

11-27-2006, 10:19 PM

We use an injector scaling of 7ms, turbocharged. That may increase this year though. The old N/A map was scaled at 10. The smaller you can make that number, the more resolution you'll have in the main fuel map.

Rvenom

11-28-2006, 01:15 AM

thankx for all the help ian,uv been very generous....first time we going electronic,and im in a country where i have no support from motec...so its rather difficult to learn,but were trying,if u do come across a map for m800,please let me know...right now its choking at 4500-5000,don know how to go about form there..just arbitary values?

Ian M

11-28-2006, 08:08 AM

There is a good chance that the BSFC is wrong because I just assumed it to be around .45 because that is what the book I was reading suggested for a small engine. It said V8's were around .55 or so. Poe, that is what I was thinking as far as the resolution in the fuel map goes so thanks for clarifying.
I am assuming the 5.5ms is open time only. I thought that is what the pulse width was. Do I need to figure out the total open + closed time to enter into the Motec repeatoffender?

Poe

11-28-2006, 09:37 AM

The injector scaling is the injector on-time corresponding to 100 in the fuel table and should be a little higher than the longest pulse width you expect to see. As long as you are supplying the engine with enough fuel with all the table values below 100, run with it. The injector duty cycle figure in motec shows you the percent on-time while the engine is running.

Ian M

11-28-2006, 12:42 PM

Right, that was my understanding as well. I'll just go a little bigger than I need and if the table only reaches 80% or so to reach the correct A/F ratio than I won't be too worried about it, or if I wanted really precise resolution I could drop the injector scaling number, but I don't think I have the tools to fine tune to that amount of resolution anyhow.
One more question, do you guys use a high temp thermometer to find each cylinder's exhaust gas temperature to tune each cylinder individually due to different flow characteristics? I have never worried about individual cylinder trim, but this year I would like to get it right, so I was thinking measuring the exhaust gas temperatures would give a fairly decent representation to A/F in each cylinder. Any better ideas that are cheap?

Wesley

11-28-2006, 12:47 PM

Tuning with an EGT sensor is pretty invaluable. While the numbers by themselves are fairly useless, like most things, its the comparison that can get you on the money.

The best way would be to put EGT bungs in each primary of your dyno headers, and tune so you have the same readings for each cylinder across the board. I suppose you could measure the outside header temp, but that would be less accurate.

Some of the infrared thermometers go up pretty high, but I don't think that would be accurate enough to be a useful tuning tool.

Ian M

11-28-2006, 12:58 PM

Yeah, I need to look into pricing of EGT sensors I suppose. I was planning on going the infrared thermometer route (around $50) I think and doing like you said and measuring at the header pipes.
I know this won't be extremely accurate, but if you're just going for getting them all the same as you said it should be close. It is better than nothing. I really just want to see how much of a difference there is. How much difference have other team's experienced? Is it small enough that I need more sophisticated testing apparatus or is there up to around a 20 degrees F difference, where an infrared thermometer would get the job done?

CrazyDave

11-28-2006, 01:31 PM

I would expect that by saying "high temp thermometer" your meaning thermocouples... such as J and K

Thier accuracies can be listed to be +/- 3 degF which is sufficiently accurate to be a tuning tool.

Possibly even better limited by money of course is to do individual O2 measurements in each of the cylinders, because thats really the end goal in tuning.

you can get a lamda meter for each cylinder here:
http://www.innovatemotorsports.com/products/lc1.php
http://www.innovatemotorsports.com/products/lm1.php

Poe

11-28-2006, 09:28 PM

We used thermocouples in each exhaust tube close to the head. We did a little with cylinder to cylinder balance, but mainly we just used the hottest cylinder as a monitor for not getting the engine internals too hot. We welded some bungs into the header that allowed secure attachment of the thermocouples and equal placement in the exhaust stream.

Big H

11-29-2006, 03:54 AM

Completely unrelated... Hi Eric http://images.ford-trucks.com/forums/images/smilies2/wink2.gif

Rvenom

11-29-2006, 07:55 AM

still no one who could spare me a base tuned map atleast?

bigwig

11-29-2006, 08:06 AM

Download Performance Electronics software. Open their FSAE basemap. Copy and paste it into Motec. Done and done. I'd start calling around right now trying to find someone generous to let you get some cheap dyno time.

Some other things to mention. Individual EGT probes are completely unnecessary. Yank the plugs and look at them. It will tell you if fueling per cylinders is off, if one cylinder is running hotter than the other, and all sorts of other neat stuff for the cost of $0. Checking plugs is an invaluable tool which cannot be replaced by any electronics. Also duty cycle is a non issue. People that care about duty cycle are nuts. DC means nothing. Who cares if your injectors are functioning at 40 or 80% DC? As long as they aren't at 95% DC you shouldn't give a damn. When the injectors are maxing out and won't make corrections based on ECT/IAT thats when you need bigger injectors. Also DC calcs are never super accurate because of the various multipliers that occur while driving. Again, don't worry about them.

Poe

11-29-2006, 09:14 AM

Maybe "don't worry about duty cycle unless it's above 85%" would be a better way to say it. Reading the plugs is a great way to determine how the engine is running, so thanks for bringing that up. Thermocouples are nice, but you're right again, not 100% necessary.

bigwig

11-29-2006, 09:26 AM

I don't buy into the 85% nonsense. The way I see things people have been using FMUs and dinky injectors for a long time. If that doesn't kill injectors then running high sub 100% DC won't either. I don't suggest buying small injectors and running them at high DC seeing as most injectors cost the same regardless of size, I just don't see DC has a huge thing to worry about as long as your air fuel ratios are where they should be.

KU_Racing

11-29-2006, 11:23 AM

if you think you can run injectors at 90% DC all day and not have one melt a piston for you, you are sorely mistaken....

Bill Kunst

11-29-2006, 01:59 PM

I think that 80% duty cycle is a good number for just about everything. for example: welding, engine rpms(what the equipment can actually do), drinking, girls, and other various things.

If you run equipment, engines, electronics at anything over 80% you are in definite risk of reducing the life of that object. We try not to run our rpms up until our valves float, and I guess we are somewhere around 80% for that on most motorized devices/transportation when we take it to the red.

Another example, the grandma who put-puts around is going to get more from her car then the person who beats the shit out of it, like its a racecar. Injectors are a critical link, think of anything over 80% like doing redline drops in your escort, you are guaranteeing that it will break, you just don't know when.

Ian M

11-29-2006, 02:34 PM

Good point on the 80% for everything Bill. Seems like before Thanksgiving break I was running above 80% with schoolwork and so on and Thanksgiving was the breaking point and now I can't get motivated to get over 25%. HEHE!
Good point on the spark plugs, but that is something I already do. Another question I have is what do you assume the intake air temperature to be at when it reaches the cylinders. I mean, by the time it runs past the hot valves and into the hot cylinder, by the time it is fired it is way warmer than outside air temperature, right? Yet, I know the cooler it is outside the cooler the air in the chamber (starts off cooler so doesn't heat up as much) which produces more power and has the capability to burn more fuel, correct? So what do you assume your intake air temp. to be? Outside temp. or heated by engine temp.?

pengulns2001

11-29-2006, 03:13 PM

someone sending you a basemap is not even going to save you any time... by the time you typed your post you could have made one

Poe

11-29-2006, 03:47 PM

Ian, are you asking about air temp for calculation purposes or for compensation of the engine fueling in the engine tables?

Don't FMU's increase fuel pressure? Higher fuel pressure equates to more fuel flow for the same injector pulse width, within reason of course.

Ian M

11-29-2006, 05:54 PM

Well, I was wondering about the temp. for calculations for air density, but I haven't even messed with the air temp. compensation in the Motec software. That is something I need to set up this year as well, so any info. on that would be beneficial. How do you test your compensation table? Just test running the car on different temperature days because typically your dyno area is going to be relatively the same temp. Wish I could go tune outside today (70 degrees) and then Friday when the low is (21). That should be a suffecient change! I am just being sarcastic about the crazy weather lately.
I am not sure what you are talking about with "FMU's". I know a higher fuel pressure will allow more fuel through the injector for a given amount of open time. I assume this had to do with the over 80% duty cycle and instead of getting new injectors just boost the fuel pressure to them to keep them from having to stay open so long.
I have learned a lot from this post, even though it is pretty off topic by now.

Poe

11-29-2006, 08:35 PM

FMU = fuel management unit and appears to be an aftermarket add-on for people who add some sort of forced induction to their street car that will make sure fuel keeps up with boost without having to do major reprogramming of the engine computer or something like that.

Our air temp comps started out as guesses really, but just tweaked until the engine ran close enough to what we wanted. From what I understand from the Motec people, get the main fuel map set accurately on the dyno at constant temperature, without any compensations. Then work on the cold start, warm up, and other compensations afterwards. I don't think that it is entirely necessary, but it is nice for the wide changes in the weather in Michigan. Our car didn't use any air temp compensations at all until last year.

Kirk Feldkamp

11-29-2006, 08:39 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by bigwig:
I don't buy into the 85% nonsense. The way I see things people have been using FMUs and dinky injectors for a long time. If that doesn't kill injectors then running high sub 100% DC won't either. I don't suggest buying small injectors and running them at high DC seeing as most injectors cost the same regardless of size, I just don't see DC has a huge thing to worry about as long as your air fuel ratios are where they should be. </div></BLOCKQUOTE>

That's all well and good you're seen it done before... but having seen lots of 'things' done, I can't say I agree with most things that happen in the aftermarket. The whole idea behind keeping below a certain % duty cycle is that above a certain value there is no discernable difference between say 75% and 100%. This is a common characteristic of certain types of valves (think butterfly throttle body). The problem isn't getting enough flow, it's controlling the flow you've got. If you haven't melted a piston yet, you're only cheating fate. It's really not difficult to set your maximum pulsewidth (or even base fuel pressure) to a value that you can get a more reasonable, and controllable, duty cycle % that will allow you to better control the fuel flow at higher loads.

-Kirk

Bill Kunst

11-30-2006, 07:03 AM

FMU= bullshit

FPR 1:1 ratio, while FMU can have up to a 10:1 ratio of air pressure to fuel pressure increase. It is used when people don't take the time to tune and just run up fuel pressure to substitute. I think we all should know that thisis not a correct sub for proper tuning, but it is done pretty commonly. Problems exist where the fuel pump has neither the volume nor the pressure rating to keep up with the boost, and when the mapping is way off because the computer wasn't designed for boost.

bigwig

11-30-2006, 07:28 AM

You guys aren't reading what I'm saying. I'm pointing out a common, specific instance, where injector duty cycle is well above 100% for extended period of time yet I've never heard of injector failure as a result. I was actually so curious about it, I spent the one night on google trying to find a case of injector failure due to high DC, I couldn't find a case(not saying they don't exist, but I couldn't find it). If you read what I said, I don't suggest running 90% DC, but fuel injectors have been proven to be able to run at such a DC for long periods of time without a problem. Meaning as long as your duty cycle is low enough to deliver enough fuel at all times then its fine. Worrying if your DC is 55% vs 65% is a waste.

Poe

11-30-2006, 09:33 AM

How the hell can a duty cycle be more than 100%?? The injector is on for 1.5 seconds in a 1 second time frame? I don't think the problem is injector failure from high duty cycles, it is engine failure due to inaccurate fueling. I don't think anyone here is worried about a difference of 10% duty cycle as long as it is below the ~80% area. You listed FMU's as an argument, but they have no effect at all on the duty cycles of injectors. They are a bandaid as Bill said so that people can get by with no tuning and without increasing injector size because more fuel is injected for the same pulse width/duty cycle.

Ian M

11-30-2006, 01:03 PM

Well, apparently our Motec is still in Australia, not cool! It is supposed to be back in a couple of weeks. Just wanted to let everyone know that Simon said (HEHE) to continue running at 0A due to the high injector resistances. (a.k.a saturated) Sorry to lead you guys astray for a bit. Have a good one.

fart can

11-30-2006, 08:37 PM

Most importantly, I think we should all reflect for a moment at the number of times we've said

'duty'

And then not worry about it.

Ian, I haven't had the dyno up this week because we just assembled our new car, but I want to say that we run a pulse width of 5.5 ms 'ish'. The 0 A number is useful, so thanks for that.

Regarding EGT, we have a 'Land and Sea' dyno that has EGT sensors attached via hoseclamps to each header, and we typically get around 1200 F as readings, but the electrical connections to the sensors are shitty and I haven't fixed them yet, so I'm not sure what the differences are going to be. I'll be sure to get back to you when I have something useful, but it will probably be after winter break.

Also, what brand of injectors are you running, and where do you get them? We have some MSC (I think) and I'm curious what other teams are running. Does anyone know a good source for buying fuel injector o-rings, also?

Will

Ian M

11-30-2006, 10:28 PM

We use the stock F4i injectors. We are using them this year on an RR. They are probably a little oversized due to the restrictor, but they are small enough to allow it to idle, so they work fine.
If you aren't using the same injectors than you need to figure out the injector resistance because I would assume if it isn't up around 16 ohms than you should probably be using something different than 0A.
The F4i injectors are either Bosch or Denso. The RR should use Denso and I think the F4i is as well, but I don't have the manual with me right now.
A roundabout exhaust temp. would be helpful, but I mainly want to use exhaust temps. just to use them as a ratio between cylinders and match them all up therefore knowing that I don't have one running rich and one running lean and not knowing it because by the time it hits the lambda sensor it has all mixed. According to CFX our intake doesn't quite flow as well into the first cylinder so I think it should be leaned out a little compared to the rest.

fart can

11-30-2006, 11:52 PM

yah i ll post something as soon as i get data, but don't hold your breath.

and what is CFX? we are going to be using solidworks flow works to test the plenum design to make sure air is getting where it should. i ve heard other teams have benefitted a lot from using flow works.

Benjlv

12-01-2006, 08:39 AM

i am fairly certain the F4i injectors are made by the same company that does the ECU and throttle bodies for the F4i. I forget the name but it starts with a K.

B Lewis @ PE Engine Management

12-01-2006, 09:35 AM

Benjlv,

I think you are thinking of keihin for the throttle bodies. Also, I am 90% sure the Honda fuel injectors are Denso as are the coils.

Ian M

12-01-2006, 03:13 PM

CFD (computational fluid dynamics), is what our intake design guy is using. It is a program exactly like Solidworks Floworks for the most part. Input a mass flow rate and it disperses the air as it would flow through that shape. Shows flow like FEA shows stresses.
Yeah, I'm thinking Denso as well.
Using the CFD should help me a little with how much to lean out the weak cylinder, but I was thinking exhaust gas temps. would be a good way to test our theoretical calculations. I am a big fan of experimental evidence myself.

MSD

12-04-2006, 07:51 AM

I'm pretty sure that the stock F4i injectors are Keihin. Is that right Poe?

Poe

12-04-2006, 08:11 AM

I'll check tonight and see, but I'm pretty sure they are made by Keihin along with the throttles and ECU.

fart can

12-05-2006, 07:59 AM

hey guys, while we re on the topic of injectors, what BSFC values do you typically use or get on the dyno?

we re troubleshooting our dyno right now but i m curious as i m about to start design for next years car and am working on the injectors right now.

i think we have some stock injectors laying around, and they're either kehin or denso.

Ian M

12-05-2006, 05:38 PM

The BSFC info would benefit me as well as the dyno I use has no way of reading this information. I took a stab in the dark and guessed .45 for my calculations, but if someone could throw out a roundabout number they have seen that would be very helpful!

Tim.Wright

12-07-2006, 11:43 PM

Our Autronic dealer advised us that the F4i injectors are Keihin.

Tim

Ian M

12-08-2006, 07:38 AM

Agreed. The new RR ones with 12 laser cut holes as opposed to 4 for the F4i are Denso. The RR also has a new in-tank regulator system, so Honda must have switched companies on the new redesign.

Bacon117

12-22-2006, 02:45 PM

Whoever was the origional poster, contact me if you still want assistance with the motec. There is some SERIOUSLY "iffy" info here. We run the motec successfuly and I would be willing to give you an NA map, and give you some pointers. My email is RS89899@hotmail.com

Poe

12-23-2006, 08:28 AM

What is so "iffy" may I ask?

Frank

12-25-2006, 09:12 PM

you don't want a "map" and certainly not a "fuel - map"

you want to see a "lambda - map" (and know where the lambda sensor was placed) and an "ignition - map"

Poe

12-26-2006, 08:42 AM

I don't know about you, but I tune the fuel map using a reading from a lambda sensor. There is also a lambda aim table in Motec, but that is set beforehand to desired values used to tune each efficiency site in the fuel table (is table a better word than 'map'?).

Bacon117

12-27-2006, 01:21 PM

not all of it is iffy. I was pretty shocked when somone said EGT's are useless. Those are perhaps the MOST valuable thing when tuning for max power (hotter is meaner http://fsae.com/groupee_common/emoticons/icon_wink.gif ). EGT's are, however, useless if you don't know the max temp your head / valves can withstand. once you know the materials and melting temps involved you can get your egt's close to that temp for max power (remember your factor of saftey!). Also keep in mind certain things can cause your EGT's to spike above the desired point, ruining your day.

As far as duty cycle, I'd be very surprised if you maxed out a stock injector's duty cycle, given that we have less air to work with than a stock bike.

I run a base injector pulse width of 5ms. My fuel map (table) is then a percentage of the 5ms. I use MAP and RPM for my load sites and TP for accel enrichment Keep in mind that the lower the fuel pressure in the fuel rail, the longer the injector pulse width will be and therefore the higher the duty cycle. (I'm running 45psi with about 35 lb/hr injectors)

There are so many little things to learn when tuning all night on an engine dyno. I have found the engine likes to run best at 13% rich, or richer. If I try to run it leaner, the lambda values become very erratic. Startup and initial run tables are important, so the car starts easy, and you don't look like an @ss!

As far as FMU, you don't need it. If you are using the motec, as you tune the engine, it will take into account any delta in fuel pressure. if you want to be accureate, use a regulator that you can run intake pressure/vacuum to , so that the fuel pressure to intake pressure delta is always the same.

Lambda table is useful for running closed loop with the motec, and for a visual while doing live tuning, AND necessary for using motec's "lambda was" feature. Like poe has said, its somthing set before hand. After much trial and error, i have settled on a lambda map and looks fairly flat, with .87 lambda at low loads low RPM and .85 lambda at high loads high rpm. Remember that even if you want to use closed loop, you still need a solid base map incase the motec goes open loop (lambda sensor failure, or during warmup.)