NOTORIOUS VR
Administrator
Hero Member
Karma: +58/-7
 Offline
Posts: 1056
|
 |
« on: February 06, 2012, 02:17:40 PM »
|
|
|
So has anyone dipped in to diesel tuning?
I'm just curious if anyone has an explanation of what changes to maps do what in a diesel ECU (VAG cars)? Like I know people talk a lot about the "smoke map" what does that do even? Control smoke only? or is there a power limiting issue with that?
I assume pump timing, fuel and boost control will be the main ones along with (apparently) the smoke map. But I'm sure there is more to it then that even for a "basic" Stage 1/2 tune.
Cheers!
|
|
|
|
« Last Edit: February 06, 2012, 02:22:17 PM by NOTORIOUS VR »
|
Logged
|
|
|
|
TheDSI
Full Member
Karma: +12/-0
Offline
Posts: 78
|
 |
« Reply #1 on: February 06, 2012, 02:40:37 PM »
|
|
|
diesel mapping is simple ....
just inject more gasoil at the right time and raise boost enought to burn all the gasoil available .
smoke limiter is just one of injeted quantity limiters .
|
|
|
|
|
Logged
|
|
|
|
NOTORIOUS VR
Administrator
Hero Member
Karma: +58/-7
Offline
Posts: 1056
|
|
« Reply #2 on: February 06, 2012, 03:02:19 PM »
|
|
|
if it is one thing I've learned when it comes to cars, nothing is simple  I understand the basics of tuning a diesel (I used to own an old 1.6L IDI that I modified the pump manually for injection quantity and timing running 20 psi). But obviously how all the maps in ME7 work together is another issue. There is tons of info to go on for petrol powered cars... but not much talk about how to even start with the basics on a diesel. |
|
|
|
|
Logged
|
|
|
|
|
TTQS
Guest
|
|
« Reply #3 on: February 07, 2012, 08:29:47 AM »
|
|
|
if it is one thing I've learned when it comes to cars, nothing is simple I understand the basics of tuning a diesel (I used to own an old 1.6L IDI that I modified the pump manually for injection quantity and timing running 20 psi). But obviously how all the maps in ME7 work together is another issue. There is tons of info to go on for petrol powered cars... but not much talk about how to even start with the basics on a diesel. I'm interested in learning this too, possibly with the longer term aim of writing up a good quality technical guide for it, illustrated with maps from a popular engine variant. Aside from the TT, I have had two 2.0 TDi cars before (Peugeot & Toyota) and would go back to a diesel without hesitation. Our next family car might well be a VAG diesel if I have my way and it would be nice to think I could remap it in a quality way myself. I agree, lots of things including tuning are simple enough to be dismissed in a few sentences by those with knowledge and experience, but very often the subtleties and practicalities are more difficult to master; for instance like raising torque output without sacrificing too much of the good fuel economy diesels are renowned for and without adversely affecting the driveability characteristic. If somebody wants to point out the key modules of the relevant funktionsrahmen, I'm happy to make a start translating them, making them available on the wiki and understanding the process. I'll run the EDC15 and EDC16 PDFs through Google Translate to get the gist and review what's worth spending time on. TTQS |
|
|
|
« Last Edit: February 07, 2012, 09:01:33 AM by TTQS »
|
Logged
|
|
|
|
|
Rick
|
|
« Reply #4 on: February 07, 2012, 12:40:05 PM »
|
|
|
Very Basically:
You have a Drivers Wish map, this is RPM vs throttle position. Units are Injected Quantity of diesel, usually in mg per stroke in EDC15, or in EDC16, in an actual unit of torque, Nm.
You then have a torque limiter map, which restricts IQ, much the same as LDRXN limits boost requested KFMIRL. The smoke map(s) usually calculate a lambda value from the current IQ and air flow reading. They limit the lambda to a certain value. Anything leaner than say 16.5:1 on a diesel will make it smoke. So, if the drivers wish and torque limiter maps are requesting 50mg of diesel, but the ECU calculates that this will result in an AFR richer than in the current smoke map cell, it will reduce the IQ to such a point as to bring the AFR into tolerance.
Rick
|
|
|
|
|
Logged
|
|
|
|
NOTORIOUS VR
Administrator
Hero Member
Karma: +58/-7
Offline
Posts: 1056
|
|
« Reply #5 on: February 07, 2012, 01:45:13 PM »
|
|
|
^^^ good info to start with, thanks Rick!
What about tuning for larger injectors? is there a type of KRKTE?
|
|
|
|
|
Logged
|
|
|
|
|
Rick
|
|
« Reply #6 on: February 07, 2012, 02:12:02 PM »
|
|
|
Depends on what kind of Diesel system, unit injector, common rail etc.
Unit injector, e.g. VAG PD there are duration maps which control how many crank degrees the injector is open for to inject a given IQ. This is because injector and pump are one unit and actuated by the cam. For Common rail you have a map of injector opening time, rail pressure with Z axis being the IQ. Ecu looks up what IQ it needs, looks at the current rail pressure and then determines an opening time.
For old VAG EDC15 VP engines, you work with pump voltage.
Rick
|
|
|
|
|
Logged
|
|
|
|
NOTORIOUS VR
Administrator
Hero Member
Karma: +58/-7
Offline
Posts: 1056
|
|
« Reply #7 on: February 07, 2012, 03:00:14 PM »
|
|
|
well a friend of mine has an AHU in a B5 A4 (swap)... with bigger injectors. So I assume that would be the pump voltage kind?
|
|
|
|
|
Logged
|
|
|
|
|
Rick
|
|
« Reply #8 on: February 07, 2012, 03:29:14 PM »
|
|
|
Yea, 90bhp EDC15 Pump voltage.
It's like calibrating a MAF, pretty much impossible out of a Lab. You can approximate/extrapolate then tune the drivers wish, torque and smoke limiter maps.
Rick
|
|
|
|
|
Logged
|
|
|
|
|
ktm733
|
|
« Reply #9 on: June 16, 2015, 07:47:19 PM »
|
|
|
The info stopped here? I feel there is something more! So I may have a million questions but lets start with fueling.
what is a good lambda reading from wot to red line?
|
|
|
|
|
Logged
|
|
|
|
AngelPowy
Full Member
Karma: +1/-0
Offline
Posts: 55
|
|
« Reply #10 on: June 16, 2015, 11:15:23 PM »
|
|
|
Lambda is not as important in diesel Tuning as in petrol tuning. Depending on what car you are working you will have to keep an afr of 16~17 if you don't want to have huge soot and high EGT .
|
|
|
|
|
Logged
|
|
|
|
|
ktm733
|
|
« Reply #11 on: June 17, 2015, 04:58:37 PM »
|
|
|
hmm good to know, how do you know your max? ex in pedtrol cars you go till you encounter knock. WHat tells us to back off in diesel tuning?
|
|
|
|
|
Logged
|
|
|
|
|
ddillenger
|
|
« Reply #12 on: June 17, 2015, 08:57:33 PM »
|
|
|
You need to pick up a book on the fundamentals of compression ignition engines.
|
|
|
|
|
Logged
|
Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your experience!
Email/Google chat:
DDillenger84(at)gmail(dot)com
Email>PM
|
|
|
Westfarmracing
Full Member
Karma: +3/-0
Offline
Posts: 110
|
|
« Reply #13 on: June 18, 2015, 12:45:27 AM »
|
|
|
hmm good to know, how do you know your max? ex in pedtrol cars you go till you encounter knock. WHat tells us to back off in diesel tuning?
As stated above, 1:17 AFR is about what you can run without smoke, that you can calculate max iq dividing your airmass. You can calculate a rough assumption what your airmass will land at by multiplying VE of the engine With boost ratio(this is theoretical). As some has said, there is differences. EDC15 is based in injection quantity, EDC16-17 is based on TQ, but you have NM-iq map that converts injection to tq. If you inject much fuel, check your end of injection, this cannot be too late or you end up With smoke and high EGT. You can change start of injection a little at high iq and see if you land in a reasonable EOI. But be careful, without a dyno/cylinder pressure sensors you can brake Things here. The basic limit maps in edc15 in iq order; Drivers wish Smoke limiter(s) Inj duration Tq limiter SOI Boost target Boost limit SVBL N75 EDC 16 is similar, but based on tq. |
|
|
|
|
Logged
|
|
|
|
|
tjwasiak
|
|
« Reply #14 on: June 18, 2015, 02:05:36 AM »
|
|
|
(...) EDC 16 is similar, but based on tq. It depends which EDC16 you are talking about. For example Mercedes-Benz EDC16 is a hybrid as main torque limiter is still in injection quantity. |
|
|
|
|
Logged
|
|
|
|
|
