Help me understand my engine map (1.9L ALH) (Or I intend to do stupid things)

robnitro said:

If I got my launch control smooth at 2600, the same can be done for 1200. See page 3 for my example.
It wont work for running a generator load though.

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see but the launch control is limiting fuel, not applying fuel up to a certain rpm.. Like I said, give it a try and see how it idles.. You won't be happy..

Jason,
Yeah plus the idle speed would change based on load, like alternator, a/c.


Sbeghan,
Yeah, launch control will lose revs as load goes up. Lets say you have IQ 50 at 1750 and 10 at 1850. In the middle is 30 at 1800. When load goes down it will shift to 1850 rpm. When load goes up it will shift down to 1750 rpm.

What kind of generator are you using?
At 1800 rpm with vnt15 you can do 12 psi max (at the surge line). With that, you can get 800mg/s air, which at 16.5 afr gives you 48mg/s max.
So it's probably can only do about 50 HP or so. Thats around 40kw. I'm estimating based on the vagsuite graph figures.

EDIT: the 40kw is a direct conversion, like Jason said, there's less that can get out of it. And of course, with a TDI, best generator would be 3600rpm for max power!

Haha you'll need a little more hp than that to twist a 40kw generator.. A good rule of thumb for generator sizing is to take your engine hp rating and get a generator about 60-65% of the hp.. For instance if you have a 10hp engine, get a 6.5kw generator unless you have something against your engine or you never intend on making the generator run at more than 75% output..

TDIJetta99 said:

Give it a try and let me know how rough it idles LOL.. Look at all the maps like that, they start a 0 and something dumb like 21rpm..

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These ECU's are 8-bit. That means values from 0 to 255. Since we're scaling singnals to within these values, there is a finite resolution as to how accurate one can be dependingo on units. The max reported value in VCDS for RPM is 5355. Divide that by 255 and you get 21. Since 0 is 0 RPM, 1 would be 21 RPM, 2 would be 42 RPM, and so on and so forth.

Digital Corpus said:

These ECU's are 8-bit. That means values from 0 to 255. Since we're scaling singnals to within these values, there is a finite resolution as to how accurate one can be dependingo on units. The max reported value in VCDS for RPM is 5355. Divide that by 255 and you get 21. Since 0 is 0 RPM, 1 would be 21 RPM, 2 would be 42 RPM, and so on and so forth.

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ok I understand the 8-bit thing, but the editing software translates everything to real world values in most cases.. .. like the torque limiter map.. the rpm increments start at 21, then 550, 551, 1008, 1239, 1491 etc.. The stock map goes in arbitrary increments (19 steps) up to 5355. the first one in line doesn't represent 5355rpm just because it says 21..

No generator in mind yet actually. Walking around the scrap yard I realize that I should really just get a 2.0 and use that instead of using an expensive TDI engine.
If I got a TDI I would probably do it sans turbo since you can leave off soooo much extra stuff if you don't use a turbo.
a SDI ALH would still put out more than enough power to run my whole house in the event of a power outage (I only have 100 amp service)

TDIJetta99 said:

ok I understand the 8-bit thing, but the editing software translates everything to real world values in most cases.. .. like the torque limiter map.. the rpm increments start at 21, then 550, 551, 1008, 1239, 1491 etc.. The stock map goes in arbitrary increments (19 steps) up to 5355. the first one in line doesn't represent 5355rpm just because it says 21..

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Yeah, the maps are not even square, let alone confine to 7 or 15 bit dimensions. I don't understand the logic, but from what I've seen here, and as expected, there is a whole lot of information in the ECU for controling it. Taken together, they operate a well performing engine so their details are restricted or expanded to a limit of engineering significance, I'd assume.

Does the pump voltage map translate directly to duration of injection and if so, how long is the injection event and what is the optimal window? How many degrees btdc do I want to start at and how many degrees atdc do I want to end at?

If I understand the system well enough from my questions to the community earlier, the duration is a function of the amount of fuel being sent to the injector, the pressure of said fuel, and the nozzle's hole size. The optimal window is dependant on the amount of fuel going into the cylinder as well as boost pressure. As you increase the pressure from the turbo and thusly the fuel, you'll want to start retarding the timing to avoid engine damage, but also to increase power.

Sorry for a vauge answer, but it depends on your hardware setup.

From a stock vehicle, it's fine to inject as easrly at 5 degrees BTDC as several members have done this for many years. Now, with Race 520 nozzles, I'm told and have the timing set to be at the bottom line on teh VCDS graph for the optimal and the upper safety range being half way between the bottom and middle lines. I've never quite heard a concrete answer or what, or how to determine, the range in degrees that the timing graph represents, but I digress...

The timing graph represents the default timing if the start of injection solenoid is not functioning (can't move the timing forward or back). So that's the timing that the engine starts at. If it is retarded then the SOI can only be moved between very retarded and not too retarded. If its advanced then it can only be moved between very advanced and not so advanced. The effect it has is to put upper and lower limits to where the SOI can actually be moved to by the injection pump. Some times you want the injection to be retarded or advanced, so you should set the timing to the middle of the graph on the blue line so that the pump can get what it wants. If you need to retard the SOI so that its not too advanced with larger nozzles then you should go ahead and change the SOI map in the ECU across the board (now that you know how to do it!).

Retarding the static timing is retarded, LOL.
But really, the top line is good.... so what if you can't inject ADTC in part load.
It's only the very start of injection, so why would anyone want injection to start AFTER TDC? Not even the stock map does this at high IQ.

BTW, see the stock SOI map where timing is ATDC? It is where the EGR map is used. No need for any ATDC, except for noise/NOx concerns.
I always thought that EGR retards combustion, but found out that in low loads it actually speeds it up (I guess the heat added?). So that makes sense now why they went ATDC.
Some stock SOI maps have bumps to 3-4 deg BTDC in the big ATDC area, right where fuel economy testing speeds are (or so they say on ecuconnections).

Change nozzles, and you see the static timing changes (so its not going to inject sooner if you readjust the timing to the top line). That's not going to make you have bad timing up high where it's dangerous. It just makes the range from example 3ATDC to 18 btdc, to be able to be 3 to 24 . Still the tune is what calls for the timing, which sets the timing solenoid. The thing is, if that timing solenoid can't keep up - you lose timing, even though your range can go to 18 lets say, you may not get it when its requested. Like anything mechanical, there's "slack"

Following ecu connections, with some input by someone who did dyno testing (brum?). See where it used to be negative (ADTC) now it is slightly BTDC, don't need much timing because such little fuel is going in. As rpm climbs, timing goes up because of delay of combustion. As fueling goes up, timing goes up because of injection window being bigger.

rob, that's a good point, there's no reason to have timing start ATDC unless you have an almost imperceptable ignition delay.
I've read that you want ignition to start around 5-10* ATDC and depending on the conditions ignition can start 1-5ms after start of injection which, at 2000 rpm, 1ms is 10.8* delay. So why not start injection across the board at say, 2000 rpm at 6-7* BTDC? I could see actually retarding injection as fuel quantity goes up because increased boost means decreased ignition delay.
So instead of having the SOI start at -2 BTDC and going up to 7* BTDC why not start at 7* BTDC and lower to 3* BTDC?

To stop the brake pedal from killing throttle (for left foot braking or trail braking). I got this from the winOLS audi a4 damos and adapted it to my alh ecu. It works!

Update: Don't do the second line,
if you did, go search for
00 00 B0 04 00 00 50 00 88 01 and change that first 00 to 01!
I found out it disabled the brake lights, DOH!

Very nice.. I have never run into a situation where it affects my car while driving, but it would be useful for ALH swaps where the VW brake switch isn't used..

rob, awesome info! I'll add that to my next update. Its hilly around here and I like revving the engine up while I'm holding the brakes.

I've never once had an issue rev-matching or anything like that.. The only place I can see it being a problem is trail-braking out on a track..

when braking around a corner I can't also downshift right now. Doesn't cause a problem obviously, but I'm more interested in it for holding starting from a stop on a hill (too lazy to grab the e brake).

I can downshift "right now" while on the brakes.. It will let you do a quick blip to get the rpm up..

I don't know of any other way to say it, and I'm not trying to be condescending or trying to insult, but if you have to hold the brakes (e-brake or foot brake) to start off going uphill without a huge trailer, you might need a lesson in driving with a manual transmission LOL..

disabled the brake lights?? How is that possible? mk4 brake lights will work without an ECU installed..

I have no idea, I just fixed that line and now the brakes cut the throttle.. im confused. LOL

Now I have another issue... even though I am pushing 1275 maf, and made my last column 1250 on smoke map, it's not using that value according to group 08...
Example: 3100 rpm, 1275maf- group 08 says 51 51 41.6
In my smoke map, for around that rpm, I have
800 950 1100 1250
33.5 39.7 45.9 52
So, why the heck is it picking 41.6?!?! Looks like it's doing right after 950.
I wonder why the stock tune has last 4 columns like this (which might be a clue):
850 851 852 853
38 38 38 38
Why so close values? Is it maybe because the ecu ignores the last 2 columns, like happens in my logs?
time rpm req MAF % time rpm 1 2 3
73.3 2877 850 1275 4.8 73.64 2940 51 51 41.6
73.96 2982 850 1275 4.8 74.3 3045 51 51 41.6
74.64 3108 850 1275 4.8 74.96 3171 51 51 41.6

Did you modify both smoke maps or just the larger one? I haven't screwed around with mine since you sent me the one modified pump voltage map since I popped an injector seal.. I'll get that sorted out this weekend and play around with it some more..

EDCsuite doesn't recognize the pump voltage map in any of my files so I have to find it again.. Too bad you can't name any of the unknown maps to make them easier to find later..

I only have 1 map for each (manual, auto, auto 4). Maybe vagsuite didn't detect a map?

dose any one know the alh block casting numbers. going to look at a short block today and whant to make sure im geting the right short block. it needs to be a alh!

it will say 1.9 and DI on the back.. Not sure what else is there.. The BEW and ALH short blocks can be interchanged if you swap the crank sensor wheel and the crank gear that drives the timing belt..

robnitro said:

I only have 1 map for each (manual, auto, auto 4). Maybe vagsuite didn't detect a map?

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I have 4 for each but it's just manual and Auto, the 03 doesn't have 4wd maps.. 2 of the smoke maps are flat so they might not be actual smoke maps..

The one you're seeing on yours, is it a 13X16 or a 10X16?

shoot me the file you're working with and I'll look for the other one..

TDIJetta99 said:

I have 4 for each but it's just manual and Auto, the 03 doesn't have 4wd maps.. 2 of the smoke maps are flat so they might not be actual smoke maps..

The one you're seeing on yours, is it a 13X16 or a 10X16?

shoot me the file you're working with and I'll look for the other one..

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It's 10x16, ecu bosch # 0281010385
Where is the other map usually located?

the 10X16 map is seemingly useless.. no matter what I do with that, it never seems to affect anything.. On my 03's map, it says 04D61C for the 13X16 smoke limiter address

Ok, the smoke map is listened to. BUT the ecu only does values up to 1000 mg/s lol.
Need to find out if this can by bypassed...

Even this latest map I did 4 last values,
900--1050--1150--1151,
40.6--47.2---51----52
In testing I always maxed out at 45, even when maf was reading 1275!
45 turns out to be where 1000mg/s is..

Same thing happened before, but the values were different.
From memory the last 3 values were:
850--950--1150
37----40----52
And I was getting around 42 max, which surprise, is what 1000mg/s calcs to on that map.

So 1000mg/s limit to the smoke map- doh!

I would just use 1000mg, and use the torque limiter to moderate fueling in the range where your airflow is between 1000 and 1275.. Might be easier to do it like that..