NefMoto

Okay this post is pretty much going to be questions but I'm alittle confused.
I'm looking at just a damos runing around here I'll upload so you can see what I'm doing.
1:what is pump tension?
2:what is drivers decide? also what are the actual names for these maps?
3: last thing as I need these answers before I can ask more, what is the limit? In petrol cars you encounter knock so you back off. What tells you to back off in the diesel engines?

It won't let me upload file so here is the link, It's the last file the a4 tdi
http://nefariousmotorsports.com/forum/index.php?topic=2304.0

If u ask for the meaning of these maps.
1. Pump voltage should be the right name. Edc15 as ur alh engine has the vp37 injection pump. Over the pump voltage the fueling is regulated.
2. Drivers decide should be drivers wish map. The fueling target u wish with your throttle in mg/stroke.
Limitations u have with Diesel engine is basically fueling. You need an amount of time to inject a amount of fuel. The more your rpm is the less your window for injection left.


Basically Diesel engines don't really have knock. Lean and rich is also no harm to the engine. It's more about having smoke or don't having.
In Diesel engines power depends on how much fuel u get into the engine at the right time.
And if u keep afr at about 15.5 (if I don't lie at this point) you should see no smoke.

For a stage 1 remap there isn't a lot of stuff to change. Basically there are three maps to change.
Drivers wish (should be high enough already)
Torque map (could use some tune normally)
Smoke map (where the stage 1 remap basically happens)
You can say that out of these maps ur fueling will be decided. Smoke map is on stock almost always the limit. And the decision is made by looking on the lowest value out of these 3 maps.

But be careful the more fuel you want to inject the more time for that injection is necessary. It is mostly measured in crankshaft rotation.
The amount on time in crankshaft rotation depends on 3 values.
1.amount of fuel together with how large ur injectors are.
2.start of injection (there are about 5 maps for different conditions)
3.rpm (if u want to inject e.g. 20mg/stroke at 2000rpm ur injectors take let's say 10degree of CR . As ur rpm rises ur speed of ur crankshaft rises. At 4000rpm it will then take 20degree of CR to inject the same amount of fuel) that's just a roughly explanation.

The problem in too long injection timing based on CR is that if u go far behind of let's say 20 degree after top dead center with your end of injection (start of injection + time of injection)
Your egt will rise to unhealthy conditions.

the next problem is the boost map. Your engine runs a vtg turbo. If u inject more fuel u get mor exhaust gas to spool the turbo. This has to be compensated through n75map and  the boost map. Otherwise it will be too much.

That was alot to take in. I' going to read that about a million times!
Back to questions
1: how do you know how much fuel to put in the cylinder and how much time is needed?
2: is there an equation that can help me find out how much time is needed to push this much fuel with this cc of injector?
3: (Smoke map) what is smoke map? I understand it is literally smoke map but I don't understand the fuel meaning or description of it. Thanks for the help so far

In fact diesel engine are EGT limited.

Ad 3. Smoke map is a fueling limiter. It does limit fuel so you will not see excessive smoke - you can think of it as a AFR map (airmass divided by fuel quantity is just AFR).

Ad 1./2. You just inject as much as you can use without smoke. Do not think about time - to simplify when you are trying to inject too much you will find smoke. To some extent you can fight smoke using injection timing but too much advance is also bad.

1: where do boost come into play?
I can add fuel till it smokes then up boost to equal out afr is what I'm getting from this.
2: sesne this is diesel where is the limiting factor of these small turbos? On petrol engines you blow hot air in and that's bad. Now where is pushing the turbo to far on diesels? Is high iat temps a factor into anything, i don't know if that's even a question because obviously hot air is less dense and cold air is more dense. 
3: where do you get mg of air to calculate how much fuel you need?

You should use lowest possible boost to burn desired quantity of fuel. The problems with boost are same in petrol and diesel engines - you should use turbocharger compressor map to find maximum possible boost level.
Ad 3. You can log MAF readings to find airmass.

Ahh it's starting to make sense!
1: so i log maf reading in stock form, look up table for smoke map or drivers wish? Then that should give me an afr ratio.
2: using afr ratio up boost that up fuel to get around you said 15:1 afr?
3: the turbo is a k03 right? So peak 20psi then drop to around 12-15 by 4500-5000 and steady there?

Boost is a measure of restriction. You can't apply anything you think you know about gasoline engines here.

As i Know before u max out a stock turbo on Diesel engine u will max out our injection on stock injectors. Your afr on Diesel engines is mostly like 20:1+ so u have lot more air then fuel.


To measure ur injection timing on crankshaft rotation it was possible for me (I drove a 2.5 v6 tdi) to look at start of injection ( e.g. 15 before top dead center) and to look at time of injection (e.g. 20degree of CR ) at a specific amount of load and a specific rpm(only 100% is the load u care on Diesel engines) in vcds, to get a feeling where u at and how far u can go.

1: I should shoot for 20:1 afr?
2: explanation was a bit confusing but what I understood is your looking when fueling is being shot in=Timing=crank degrees. How do i use this information?
3: overall what i think I'm understanding is when you inject more fuel you need more time to inject that amount in so you start the injection time earlier. Injecting more fuel makes more heat= boost, now boost is controlled by n75. So with more fuel comes more boost in a way which are we using boost to keep the afr in spec with smoke map?
Yes this moght all be wrong but through failing success with derive. Stay with me guys!

It is Time to go to bed now in Germany. So tomorrow i will ask your questions. Just feel free to ask whatever ur brain wants to.

Then you don't know anything.

Easy to tell somebody doesn't know anything without having anything to say.

The 3 Diesel engines I drove had maxed out stock injection without maxing out the turbos.
In this case (alh) it is the same. First you will max out the injectors then turbo then the injection pump itself.

so BTT:
1: stock ecu is shooting very lean like 22-19:1, you should shoot for about 15:1, just go richer till you see smoke. how much smoke is oke for you u have to decide on your own.
2.there is a problem if injection timing is too long. a lot of fuel will then be burned while the piston is going down -> will generate lot of smoke and heat but very low power gain. to know how long your injection is and how much after top dead center you calculate, Start of Injection + time of injection = End of injection. e.g. -11°SOI (negative because BTDC) +20°=9°ATDC EOI.
3. At first, you can make your engine inject earlier. The problem is in going to early. A lot of the energy through burning the fuel will then work against the up going piston -> you will loose a lot of power.
More Fuel = More boost, thats correct. Boost controlled by n75 also correct.
What you will expirience if u add fuel without modding the boost map or the n75 is that you will have very high aggressive boost peaks on low rpm. this results in edc15 taking fuel out of the running engine to get the boost back under control -> less power again, or u will have the emergency modus on. Also spooling the turbo up too fast will harm the turbo.

"So with more fuel comes more boost in a way which are we using boost to keep the afr in spec with smoke map?" sry but i dont understand the question

15:1 would be too much smoke. I would use 17-17,5:1 as it should give you barely visible greyish smoke (with proper boost level and injection timing).
It is not that easy to calculate EOI this way in VP37 powered cars as you do not have access to injection duration measured in degrees - that way works in engines using PD/CR fuel systems.
In case of ALH engine you should take into consideration clutch being weak. Also here injectors are first limiter, as pump and turbocharger are exactly same as in 110HP ASV.

Yes, it's easy to say, because what you are saying is incorrect. For 99.9% of the engines.
ALH is the same, you can have black smoke on stock injectors and stock turbo. AFN too.

Lambda 1.03 on diesel = huge black smoke and molten pistons.

This only applies to CR and PD engines. There is no "duration" calibration as such in VP pumps. Only pump voltage output, which adjusts the main metering valve in the pump (which in the end adjusts duration, but this is purely mechanical) - You are not going to calculate anything on a rotary pump.

It NEVER does that. The only time you are going to have any fuel cut is when you are in limp mode from endless overboost. The ECU does not control boost by fueling period.

No, it won't unless you hit compressor surge, which you almost never do on a diesel.

Lots of misinformation in this thread.

@prj

Sure u can have black smoke with eBay tuning. Giving too much fuel before I have Boost. Also if u mess up injection timing.

15 could be too right rich, told that in my first post that Iam not sure anymore what the low smoke big power afr was.

Applys also on vp44. Worked a lot with vp44. Calculating with test drive csv will give u CR timing. Agree that there is no table with CR on fueling. Vp44/37 will calc or apply (doesn't matter how u want to call it) it itself.


Much more fuel without recalculating boost map and n75 DC will give u massive boost peak and a lot of overboost. Vp44 gave me fuel cut in that condition(bad remap).

You are able to spool  vtg turbos too fast  because of how the vtg is working.

Before u say anything against again. Engine won't cut fuel because of high boost. But engine wants to keep boost on table levels. So if u have maf readings of let's say 800mg/stroke of airmass. Then "boost control" kicks in and lowers boost(won't happen with 100mbar but with 300mbar) then what will happen to your maf readings ? Where will you go to on smoke map ? What will happen to iq then ?

No, the turbo is done before the injectors are done. Maybe you need to learn how to tune correctly.
If your only experience is VP44, then the injectors are NOT done on VP44, there is an IQ limiter in the pump. It's the only exception there is, as it's basically impossible to make a 2.5 TDI "hitlers revenge for WWII" V6 smoke due to said limiter.
No such issues on VP37.

VP44 you don't have even a pump voltage table, as it's in the pump. So does not matter what you do with it, it's not important. VP44 has an IQ limiter LONG before EOI even becomes a problem, and if you fit bigger injectors you can throw all those calculations out of the window.
VP44 does not cut anything, ECU goes to limp mode if you overboost more than a certain amount for more than a certain time. Read the FR.
Bullshit.

If you are running on WOT so that smoke limiter is limiting your IQ due to boost fluctuations you know NOTHING about diesel tuning. It should not use the smoke limiter on WOT in the area where there can be boost fluctuations. EVER. This is the first most basic rule of tuning diesel. Every single car is calibrated with this rule in mind from factory for obvious reasons.

alread after getting back to being confused can we straighten a few things out?
1: What AFR should I be shooting for on a WOT pull?
2: how do we know how to tune injectors to open earlier for more fuel? Simply guessing is something I don't like to do haha
Let's lighten the mood in this post.

hold that thought! i found this pdf that explains there is a map that already knows the calculation for a certain amount of fuel. I guess it's called duration map and there might be like 4 of them. So why modify this map s it already knows how much time it takes to inject this amount of fuel unless it doesn't reach the limits we are asking for?

Can somebody explain on page 25 when altering boost they did edit the axis to 70mg and instead did 60?