Gotta love the ECM AFR Guage, shame about the price :cry: :cry: it's on my wish list lol

Been on mine for a long time too mate... ;)

Im trying to think how to attack chapter 6 now.. im busy with other stuff too im afraid. Chapter 5 took me an hour of spare 5mins here n there to compile :oops: :wall:

is the answer to the 255 complicated stu?

What did you use before? surely theres something as capable but slightly more errrr economical lol?

cracking thread, with a nice write up!
nice one stu :top:

Hey Stu,
Good info and well explained... :clap: :clap:

Here is a future chapter for you (after the basics have been done) :cry2:
(as if this is not enough already)

:wall: Transient fuelling
:wall: 3 dimensional Interplolation
:wall: Checksums and encryption

I suppose some subjects are best left alone!! :DD:

Stu, if its ok with you can I copy and paste this into a word file?

Had a Horiba first (Most unreliable pile of crap ive ever bought :mad: ) and a Lumenition unit that was pretty decent and small too :DD:



Yes and no.. :cry:
The 255 is simply a decimal number and happens to correspond to FF in hex. Large numbers are used to enhance resolution.
Later more sophisticated ecu's run from zero to 255000 :? :wall:


Essentially, only the programing can decide what 255, 100 or even 0 means. That is also a pain for us to figure out. In the terms of that fuel map, lets just say that 1=0.06ms because thats what the programmers wanted it to be.

Other maps will add or subtract to this value by multiplication.

EG:
The cold start map may say at 5deg C add 15% to the fuel table value. ;)

1 DEC would then equal 0.069ms. :cool:

Does that make sense? :?

If you wanna get together one evening with some beers and help me write it mate, lets go for it. :cool:

The only subject il have trouble explaining in laymans terms of the above 3 is Delta negative and positive gain cos ive tried before and everyone just got lost... :? :oops:

:wall: :wall: :wall: :wall: :wall: :wall:
i still dont understand all the functions :wall: :wall: :wall:

https://img4.photobucket.com/albums/...s/22c50d38.jpg
https://img4.photobucket.com/albums/...s/b6034b26.jpg

:beers: :beers: :beers: :beers: :beers: :beers: :beers:
Look forward to it.
:top:

this thread is REALLY interesting!!!!
thanks for doing this stu!! :cool: :top:
that new chip is teeny!!!! wouldent fancy soldering in an ERST socket never mind one of them! :eek:
:clap: :top: :)

yeah makes sense now stu!! :top:

right, simple question for you stu, or SECS or anyone else in the know:

the fueling map is load vs. rpm. the load is, i believe, the MAP sensor output in V form 0 - 5 V which is scaled to -1 bar to +1.5 bar. correct?

now why is there a fuel requirement for the very low engine speeds with positive pressure? unless you got anti-lag, surely you can never operate in this area?

Not all sections in the map are used because a turbo cannot produce boost
at low rpms but the map is usually filled in at these points anyway just in case of fault conditions !!!

Gareth - Nice pic :) Kinda answered my question on the other thread :cool:

Stu - This kind of topic is properly interesting :clap: Its this kind of thread that makes PF better than the 'other' bbs's out there.

I'd love to see a list of the axes in all the tables - exactly what parameters are used by the ECU.

Thank you for taking the time to write this up!

Neil.

EDIT:

U just raised and answered my other question all in one sentence there! ;)

assuming it's right mate ;)

I had previously assumed it to be a function of boost and rpm over throttle angle, rather than pure boost.


Neil.

if you have a 3d graph though, isn't is useful to show you some errors in the mapping?

if you look at the fuel map that stu posted earlier of a std P8, it looks like this

https://img4.photobucket.com/albums/...ap_mistake.jpg

you can see that there seems to be 2 points where something is wrong. that is because i deliberately made a typing error, but it just go to show you how a 3d chart is instantly useful. the real map should of course look like this:

https://img4.photobucket.com/albums/...d_fuel_map.jpg

so, i think that the 3d charts can be useful, both to check your input, and their main use is to see that the surfaces are more or less smooth as otherwise may indicate a bad site (unless it's where you've had to take a pulse wave into account or something).

Yes but when you have decent software, you can check it line by line on both axis for smoothness ;) As the pic below shows.

https://img4.photobucket.com/albums/...onfinished.jpg

I inderstand what your saying though, and yes, it can be very usefull indeed, so i take back what i said earlier as it only applies to the way i do things :top:

Whats your name by the way, as i really dont like caling you foreigneRS :oops:

I will get round to another chapter guys, but its time consuming and ive other work on too.. but i havent forgotten ya ;)

my name is Nick, but if i was bothered about that, then i would've had it as a username. whatever stu, call me nick as it's easier to write if you want.

a few more questions if i may stu (and to karl if he's reading)

i'm in the process of installing EGT thermocouples into my exhaust manifold. i've got 4 inconel probes, is it worth using all 4 (one for each cylinder), or just one?

obviously 4 is better, and if i get an ecu that allows individual injector trimming i will be able to get the best out of the engine. but the question is, as an inexperienced tuner should i be approaching these limits?

and at what temperature should i start to get worried?

if i'm using a WB lambda sensor to setup the fuelling, and set it up to, say, 12:1, what will cause the EGT to rise to dangerous levels?

Actually, you will get the highest EGT at right around 14.7 to 1 since there is no 'extra' fuel or air to cool the mixture. Obviously fuel has a greater effect since it requires 'latent heat' to change state from liquid to vapor. Air provides SOME cooling, but not nearly as much as fuel.

Last weekend we were mapping a 2.2L turbo Impreza with an Electromotive setup in it. We were seeing about 1600 degrees (F obviously) of EGT and the AFR was around 14.5 or so (about. 0.98 lambda) and I added fuel until lambda was about 0.84 and EGT was around 1500 max.

When I was playing with the dyno just about every day, we found that max power was almost always around 12.7:1 AFR and that anything beyond that (richer) was just additional cooling.

Chapter 6: Running the car from a laptop.

Ok,
You’ve got a very basic grasp now of what goes into getting the car to a mappable scenario. All we gotta do now is hook our emulator into the setup and fire her up.

Heres the emulator, note how we have fitted a socket where the chip used to be, and then that socket is cabled across to the emulator.
https://img4.photobucket.com/albums/...mulconnect.jpg

And here you can see it connected to a Marelli Ecu:
https://img4.photobucket.com/albums/...kieemulate.jpg

So that brings us to “What the fook does an Emulator do Stu?”
Well,
Basically, as the ecu requires info, it access a lookup table in the control maps and then, based on various parameters, draws a result from the software and applies that result to the engine.

What we want to do, is change that result whilst its happening. That’s where the emulator comes in. It loads the software required into its very fast flash memory and addresses it correctly so that the Ecu thinks it is still a chip. Now whilst the Ecu needs info, its taking it from the same control maps, only its being taken from its storage area within my Emulator, and not from an Eprom as normal :DD:

“so why is this good?”

Ok,
This is good because now I have the ecu on one side of my Emulator, but I have my Laptop on the otherside doing two VERY usefull things:
1) Showing me what data the ecu is asking for and at what time.
2) Allowing me to change it :DD: :DD:

Remember at 6000rpm, the Ecu will access for the same data 50 times per second so its not like I will miss anything if that’s what you think ;)

So:
Were hooked up now, the engines running, we will now get a screen something like these:
http://www.motorsport-developments.c.../mapping_1.JPG

http://www.motorsport-developments.c.../mapping_2.JPG

Note the difference between these and previous screenshots is the addition of a red box, covering 4 separate values? That is the live “trace” and its position, is the exact data the ecu is using to run the engine at that time.. so we can now alter the data in these boxes, whilst the engine is running.. at 200mph if we like. :top:


To lighten the load a little, whilst I nip out and get all your mail order onb its way to you, someone asked earlier:
“Who drives whilst your mapping?”
Well, this varies: 90% Of the time, either Kenny or Myself will drive and the other will map.
In rare cases, we will allow you to drive us around.
In even rarer cases, this little beauty may drive for me. :top:
https://img4.photobucket.com/albums/...ping/steph.jpg

What do you want as chapter 7? Have i missed any questions?

so you've shown us what you are changing, and the equipment that you are using to change it, but not what to change it to. that should be the next chapter - how to optimise the fuel and ignition maps

Chapter 7 must be acheiving base settings to get an unmapped engine running OR why the settings need changing and limits/targets that are attempted to acheive, off out will check in later for some more technical info, have know most of what goes on so far but it's good to know that i'm on the right tracks :top:

1600 F = 871 C, so is this approaching danger levels for a yb running std pistons?

obviously the down side to this is that fuel economy is worsened, but do you also start to lose power significantly or cause any other dangerous situations (e.g bore wash)?

How about Chapter 7: SAFE LIMITS ???

Modern ignition systems can light off VERY rich charges, but if you get TOO silly you can still get bore washing.

I've seen AFR maps in some rally cars over here that had them set at 10.8 and even richer, so I'm not too concerned about anything at 12.7

You can't use the words 'fuel economy' and 'max power' in the same sentence anyway, so it is a moot point.

I set my stuff up for about 14.6 at 'cruising' speeds and loads (low TPS and MAP) and then go richer at full chat.

kind of, but you still want to get the most power using the least fuel possible. what i'm trying to say is that there is no point bunging fuel in if it isn't acheiving anything (either cylinder cooling or more power).

Hey Stu, If you give too much away, you will be out of a job !!!! :eek:

Not in all cases......

If it is a HOT day at an event and your cooling system is not keeping up, you *can* add fuel to help. Not the BEST solution, but it does work.

Top post :top: Thanks Stu :DD:

I have'nt commented on this thread so far as I choose not to educate everyone about certain issues, mapping being one of them. :DD:

I dont think that the point of the excersise is to tell poeple what their ignition curves should or shouldnt be Karl...

Seems to be a tutorial on what the steps are involved in a live map session :?

Unless I am missing the point!

Neil.

Dont worry guys,
IMO ive taught people only how interesting the job can be, and given them an insight into whats involved in "Live mapping", a job i know for a fact that many people think is really easy and in no way worth £500, which is what i personally charge. I al;so think this is too cheap TBH. But there you go.. the market dictates the price, and i believe im expensive in the cossie market. :oops: However, in various other Uk markets we are in the unique position of being the ONLY people who can live map certain systems! :cool:

Anyway, lets face it, if you print off this post, then sit everyone on passionford in an escort cossie armed with this printout and my entire entourage of mapping hardware software.. how many do you think could proceed to map a car?

Better still, if a couple had grasped the knowledge, how many would have the balls to risk a £5K explosion and a long walk home? :cool:

Ive told people only what i want to tell em, you know what they say.. those who can, teach ;) :cool:

Even so Stu, a little knowledge is a dangerous thing to some people. :DD:

agreed karl thats 50% of pf m8 :cry: :cry: :cry:

I disagree.

This post has been and hopefully will continue to be very informative.

I do not see any real danger for anyone with this thread at all. Stu is Very commendable for going to the trouble to explain it in the detail it has.

But after reading, that post i am not going to be have gained the skills to accurately solder in the carrier for the emulator, I do not own the equipment for doing, and ive got fook chance of exactly adjusting things to make an impact on the running of my car.

it just gives a very useful and informative insight into what goes on and where the money goes.

decent cylinder heads are £500 - thats with about £100 worth of valves and the rest in labour and machining time. £500 for mapping seems a reasonable rate now considering the experise required.

there was a documentary on TV the other week about brunel, after watching that I feel I now have the knowledge to build my own tunnels, so tomorrow im going to be digging myself from home to work so I can beat the morning traffic!! :clap:

good work stu, much respect for going to the trouble!!

supposing you wanted to increase the fuel at 6000rpm, and retard the ignition, would you have to alter the lookup values in the tables to do that then? or can you like drag/adjust something on the graph to do that? would you say make the 255 to 256 if it was in that particular region?

Stu, want to explain what effect timing changes have on EGT ???

Its definitely counter-intuitive.....