Trog,

I think the idea in the book is to have the VE-Table be a true representation of VE (How the engine breaths) so for this reason they want the AFR set to one fixed value. Then they recommend using the fuel trim to achieve different AFRs for different loads. But they do point out that tuning for different AFRs at different loads is also often done via just the VE-Table, they only suggest that you not do it this way because then the VE-table will not truly represent the VE of the engine.

So, are you only tuning via VE-table? what about a fuel trim map? do you have one? if so what do you do in the Fuel trim map? And finally can you apply auto-tune feature to the Fuel Trim Map also? Meaning after you Auto-tune the VE-table can you then also further Auto-tune the Fuel Trim Map?

Trog; Glad to see you are having some success with the tuning. I also tried the VE approach and it will work. The correct number are the correct numbers no matter which table they wind up coming from. I did however back off of this approach. Not sure why other than being told the VE table should be mostly zeros if the base fuel curve is set up properly. I didn't think it was going to be possible to achieve this but I am happy to say that I did finally get it done. I was all over the place trying to find the right combination of setting and finally went back to an older setting that I had originally labled runs OK. After turning off all automatic adjustment I was dealing with the raw fuel curve. I knew what was needed down low and what was needed WOT. I then sent several logs to Richard Clewett and he was able calculate pretty closely what was needed. It gets pretty particular when you start getting close.
In my case the car has a hesitation if I run it too lean. It really likes to be in the 12.5 to 13.5 range. In the end I now have the timing adjusting the idle speed, the acceleration enrichment takes out a slight leaning condition just after shifting and the wide band stays within 5% or so. The V/E table is pretty much all zeros. Tomorrow I will try to post some pictures of the tables and setting. Again it sound like there is no problem using the V/E table in the end only the total pulse width matters.
I do plan to install a dash gage and utilize the inputs for on dash adjustment of the AFM and timing.

Getting back to this thread.
I have gotten my -84 euro engine professionally mapped. This engine is stock except for ITB intake, headers and an aftermarket EFI.
I thought I'd post this as a reference. There is plenty of ignition advance, but its mapped on good fuel, 99 RON, which would translate to ~95 PON.

http://forums.pelicanparts.com/uploa...1240599440.jpg

http://forums.pelicanparts.com/uploa...1240599476.jpg

http://forums.pelicanparts.com/uploa...1240599501.jpg

Magnus,

The ignition advance is conservative and I bet you could get more power by pushing it further. I have my Full Throttle (WOT load) advance set at 30 BTDC and no detonation at all but I run USA 93 octane fuel.

I also push timing to 50 BTDC at moderate load (25%) for the 3500-4000RPM range, really helps with throttle response.

Your current maps are slightly more aggressive than stock and I'm sure they work well, just letting you know that my 3.2L Euro goes even more aggressive and runs great.

Sal
Good to know, I like to have some safety margin!
It's making pretty good HP anyway, all the way to 6800 :)
I don't think it can make more power than it does. If a few more degrees would have made more power he would have dialed it in.

Safe, How much HP you getting with the ITBs? My car turns about 230HP at the wheels with stock injection, Euro Motor, SSIs M$K 2in2out exhaust, Web Cams 20/21 grind, ported intake.

Not sure at the wheels, but 265@6800 at the crank (calculated). Actually it made 270 but I convinced the engine mapper that pulling to 7000 was a bad idea.... Makes good even torque above 300 Nm from 2000-6000 rpm.

So I have a problem, it makes power way to high for my stock internals.

I'm a bit sceptical, I think 265 is slightly high.

270HP is very impressive, I pull about 265 at the crank with WebCams (not very aggressive cams) Euro Engine. So for reference it is possible, to be certain you could try another dyno, mine was run on a dynopack that bolts directly to the wheel hubs.
see here: http://www.eurotechracecars.com/dyno.html

One thing hit me today. We never checked if 0 degrees really was 0 degrees, I just counted tooths on the trigger wheel and eyeballed the alignment. Shouldn't matter much, but the numbers in my map might be of from the actual value by a degree or two.

I double check this by setting the idle ignition to 0deg and then check with timing light.

I was about to do that but realized with timing light in hand; "Hmm, I use coil-on-plug ignition, how do I do this...."
So I forgot to do it later :)

I wish to resurrect this thread.

I now have my Motronic DME fully modified with a chip emulator, this means I now have a fully real-time tunable motronic DME! The Emulator lets me emulate the EPROM Chip and I can download and alter any part of the chip including any map in real-time with car running. The setup also lets me see what cell within a map is currently being selected!

This has been my project for the last 2+ years and it's all come together.

Now I'm ready to go to the dyno, I'm going to use a load dyno for tuning Part Throttle Ignition and it's this area I'm looking for help with. I've done a bit of reading on how to tune the PT Ignition Map and I think the best idea is to put the car on the load dyno and hit every cell in the PT Ignition Map and tune each and every cell for Max Torque. Does anyone else have tips on tuning PT Ignition?

Thanks.

Very impressive. Do you have access to all the MAPS including WOT?

Trog, I have access to all the maps

Idle Fuel
Idle Ign

PT Fuel
PT Ign

WOT Fuel
WOT Ign

I also have many more maps I tune like:
Cold Start Maps
Fuel cutoff on decel
Base Idle Speed
RPM Rev Limit
...

You name it.

There's another fella on RenList doing the same on the 944 cars
DIY Tuning walk-through (TunerPro) - Page 12 - Rennlist Discussion Forums

Tuning the Bosch Motronic system real-time is now a done deal. Others are also doing this now on the BMW cars.

This means you can now tune the Motronic DME just like any of the other tunable systems ie: Motec, Megasquirt, ...

Goto TunerPro and TunerPro RT - Professional Automobile Tuning Software and start reading!

Sal, This is fantastic! Impressive work.

I see it's been a while since the last post in this thread. But I hope I can wake it up again.

The last few days I have been tuning my Carrera 3.0 engine. The engine is stock inside, with the only upgrades beeing Megasquirt 1 for fueling and Electromotive HPV-3b for ignition control. Also I have installed headers and a free flowing 2 in 2 out muffler. The CR is 8.5:1, and the original output from the engine is 200 bhp.

When tuning, I have taken into consideration that the CR on my engine is much lower than the 3.2, and also I have single plugs compared to many of you here running twin plugs. Therefore I can go quite a bit higher in ignition advance. I have been told by a reputable source that I could start with the Carrera 3.2 ignition map, and then add at least 5-8 degrees advance overall.

This is my current setup:
AFR table (I used jpnovak's table as reference):
http://i396.photobucket.com/albums/p.../TargetAFR.jpg

Ignition map:

100kpa__ 10_ 11__ 15__ 22__ 36__ 33__ 34__ 38
90 kpa__ 11_ 12__ 16__ 23__ 37__ 33__ 34__ 38
80 kpa__ 15_ 17__ 21__ 29__ 42__ 36__ 37__ 39
72 kpa__ 19_ 20__ 24__ 32__ 44__ 38__ 40__ 42
64 kpa__ _9_ 10__ 27__ 35__ 46__ 40__ 42__ 45
56 kpa__ _5__ 5__ 10__ 20__ 52__ 44__ 46__ 50
50 kpa__ _5__ 3__ 0___ 0___ 46__ 40__ 44__ 48
40 kpa__ _4__ 2__ 0___ 0___ 40__ 36__ 38__ 40
Rpm____ 900 950 1000 1300 3000 4200 5000 6000


By plotting the table in excel I get this:

http://i396.photobucket.com/albums/p...gnitionmap.jpg

I had a long drive today, where I autotuned against the above AFR-table until I was there.

But, running with the above fuel and ignition didn't give the result I had hoped for. The car felt pretty much as last year when running the stock CIS. It pulled strongest between 3500 and 5500 rpm, above that it felt a bit dead. And below, I didn't get the transformation I had hoped for by increasing the ignition advance.
The only place I noticed detonation occuring was when I tried accelerating in fith gear below 2500 rpm. Note that I didn't use any device, I heard detonation/knocking with my ears while driving.

Any ideas as to where I am off?

I'm in the process of doing mine now. I went with a generic Megasquirt. Ant pics or diagrams on how you wired for the fuel pump, mine is not running when I crank.

Hi
Don't you have this all wrong, isn't 20kpa WOT?
I would say you are very lean.

If you hear knocking, back off the ignition.

If you have a good tuner with a rolling road dyno in the neighborhood he would get you 90-95% on the way in 2 hours, money well spent.

No, it's correct. Just look at the first page in this thread, and you'll see others have it the same way around. 100kpa is atmospheric pressure. And this is what you get when the throttle is wide open. When the throttle is closed air from outside can't as easily enter the manifold. Still the engine is sucking in air from the manifold. And this creates a vacuum in the manifold, thus a pressure lower than atmospheric. As the throttle opens more and more, the pressure inside the manifold rises more and more towards atmospheric pressure.

The only problem with going to a tuner is that I have two separate systems for fuel and spark. The ignition map can't be adjusted on the fly. It has to be uploaded to the controller when the engine isn't running. So I guess that makes it much more time consuming and expensive on a dyno. I had hoped to tune in a good ignition map myself, and then go to a dyno to get the afr's where they are optimal. But I'll have a look at which tuners are available in the area and contact them for price estimates.

The 20 kpa row isn't used by the engine, as the pressure never gets that low. I noticed that while driving yesterday. So I can remove that row and add better solution to the map further up on the pressure-scale. The lean AFR's on the 30 kpa row is because the engine will only be there when the throttle is fully closed and so detonation isn't an issue. So it provides a bit better fuel economy. Or at least that is what I have been thinking when making the table.


EPorsche: Sent you a PM. :)

First let's start with Fuel Table: I assume you plan to run in closed loop? no matter I think your low load (first 3 rows) are a tad on the lean side for initial tuning. I suggest you set the first 3 or rows (20-50kpa rows) to 14.2 across all cells. Then start to enrich so that at 100kpa you have about 12.8 across that row, something like this:
20kpa=14.2
30kpa=14.2
50kpa=14.2
60kpa=14.0
70kpa=13.8
80kpa=13.5
90kpa=13.0
100kpa=12.8

I suggest these fuel values initially till you dial in ignition. Then you can come back and fine tune fuel later if you wish.

You will find very little gain in messing with AFR! Simply use the above suggested values then go and tune ign.

The real power and throttle response is in the ignition not the fuel.

I assume your setup has a WOT fuel and Ign map? or do you only have a single PT map that simply assumes WOT conditions at 100KPA? I'm not familiar with your setup but I have been live tuning the stock 84-89 Motronic system for sometime now.

Tuning ignition on the street is not the way to tune these cars, you need a real good load dyno that can allow you to stay put in a cell within the ign table. For example, you set the dyno to hold you at 3000RPMs this should hold you in the 2500RPM row then you MUST be able to know exactly what cell you are in within that row, my setup has 'hit trace' feature that highlights the cell currently selected. Then you simply apply throttle till you are in the first lo-load cell and record the given torque produced then start increasing ign advance 2 degrees at a time and you'll notice torque will increase as it does it may move you to the next cell if this happens back off on throttle till your back in the cells your tuning. Torque will increase as ign adv increases then it just flattens off, meaning more advance does not give you more torque, this is the sweet spot for that given cell. This is known as max torque for the given condition.

The other variable I find very useful to watch is intake air, my car still uses the stock AirFlowMeter and I monitor that signal on my laptop during tuning. I use this signal as the metric to tune the cell. The idea is to setup dyno at given RPM then apply throttle till you reach the desired cell you wish to tune, then record and watch the amount of intake air (How many liters/sec of intake air are flowing). Then I start to adv ign, torque goes up but the the increase in torque sometimes increases intake air if this happens back off on throttle till your back to original intake air. Then repeat process till you find the max torque for the given amount of intake air. The idea is simply to generate the highest torque possible from a given unit of air, if you keep this in mind it's simple.

OK, so that's howto tune the PT tables and I suggest you start with the low load section of the ign table first as this will start to give you an idea of what the engine ign curve looks like and then you have a decent chance of getting the higher load section of the table right. You will also find that the engine needs more ign adv as RPMs go up within the same row, this is normal because as engine speed increases ign adv must also increase so that the max cyl pressure can be achieved at about 10-15 degrees past TDC.

So what about street tuning? can anything be done on the street? The answer is yes, you can get the low load ign in the ballpark on the street but you'll need a buddy to drive while you tune on a level stretch of road. Here's how: select a gear and a speed to get you into the desired RPM column. For example 3rd gear 50MPH then monitor intake air and record how much intake air is required to achieve this speed. Have driver target the 50MPH speed then increase ignition by 2 deg and speed will most likely increase slightly if it does not increase ign again by 2 deg. When speed increases above the target have driver back off on throttle till 50mpg is achieved again. Then record new air flow and repeat till you find sweet spot. The idea here is a little different than on the dyno, here you are finding the least amount of intake air required to achieve a given speed. Once you understand this process simply select different speeds and different gears to target different columns in the PT IGN table. You won't be able to tune the PT hi-load section of the table this way but you can certainly tune most if not all of the lo-load sections of the table. Don't try to force tune a section of the table using this procedure, simply target a speed and a gear to achieve an RPM then let the chips fall as they may. Meaning just tune whatever cell the car wishes to be in for the given condition, then you can simply interpolate the cells you may not have hit.

Little secret to fuel economy, a lot of folks tend to lean the AFR at lo-load thinking this will help save fuel. This approach usually does NOT WORK! It is far better to target a AFR=14.2 at cruise then monitor intake air and tune ign, think about it: if you can achieve the target cruise speed with least amount of intake air then you just improved MPG! It's that simple. But if ign is not set properly for target cruise speed messing with AFR will really not help muchI know first hand that the factory for some reason (most likely drive-ability) decided to de-tune the ign at lo-load! Meaning that as set from the factory these cars are NOT setup for best MPG.
Tuning the PT ign table correctly leads to best throttle response.

The other reason to first tune the 20-60kpa part of the ign table is that at these lo-load conditions detonation really is not a factor and you'll be able to start to see what the ignition values are.

Then what I do is tune the WOT ignition but here you need to be very careful as these engines can and do detonate very easily if you push ign to far at hi-loads. I can tell you that for a street car running on pump fuel I would not push ign past 30deg at WOT if you have not checked and tuned these values on a dyno with knock detector! You already told us you heard knock, this is very bad! You really need to back off those ign values in the 100KPA row or you'll be hating life real quick! Also without going nto great detail I'll tell you that intake air temps pay a huge role in how much ign advance you need. As IAT goes up flame front speed increases and thus you need less ign adv, so if you dyno tune on a cold day and set best WOT ign advance then you run with this setup on very hot day with IAT>40c you'll most likely detonate! If this is a street car I suggest not pushing past 30deg at WOT unless the tuner really knows what they are doing and can properly build IAT ign compensation maps, most tuners can't do this even if they know howto because it requires multiple times on the dyno, like a Winter run (cold IATs) then another Summer run.

I suggest you only tune and mess with the 20-70kpa part of the ign tables till you really get the hang of this. Plus most experienced tuners always start by doing lo-load ign tuning first then moving up through the load slowly. Any tuner that tries to tune WOT ign without first understanding PT lo-load ign you should simply walk away from.

UPDATE: I just re-read your prior post. You said you can not live tune the ign values, this is very very bad! You really invested a lot of money in a setup that simply can never be properly tuned. Trying to tune ign by trial and error (change values upload then test) will be very time consuming and most likely will never achieve the best ign setup. I suggest you re-visit your ign setup. Sorry for the bad news.