|
prj
|
 |
« Reply #45 on: June 06, 2012, 12:04:45 PM »
|
|
|
IMO just find your own method of tuning me7 which works and is safe. Btw, I fully agree with this. In the end, as long as the car is fast, good on fuel, has good performance, and things do not overheat on prolonged WOT usage, you have been successful. |
|
|
|
|
Logged
|
|
|
|
ibizacupra
Full Member
Karma: +4/-10
 Offline
Posts: 111
|
|
« Reply #46 on: June 07, 2012, 12:51:39 AM »
|
|
|
This is where understanding the hardware plays a huge part, If you know the turbo setup is going to be prone to raised EGTs and you want BTS to play a big part to keep the engine safe, then you will need to recalibrate the simulated egt maps buy using and external EGT system and lots of logging and graphing data.
Or you can just offset TABGBTS to a temp you know and have recorded that works. This is the way I work, its handy when you have a braked dyno and you can load the turbo upto the max and monitor the elevated egts under the most extream conditions.
With Me7.5 tuning you can try to go too much into detail thinking you have to do it right or a way eveyone says. IMO just find your own method of tuning me7 which works and is safe.
cheers nik. I am happy with how I choose to tune, lamfa, bts etc... It works.. and as you say, loaded eddy brake dyno and logging shows whats required. This thread direction and prj's approach did make me ask the question.. re another approach/methodology etc.. For alchy burning cars, drag cars, mega power, I believe they tune to egt's....... Interesting thread tho.. thx |
|
|
|
|
Logged
|
|
|
|
ibizacupra
Full Member
Karma: +4/-10
Offline
Posts: 111
|
|
« Reply #47 on: June 07, 2012, 12:54:11 AM »
|
|
|
If you want a accurate EGT model you have to calibrate it for you specific hardware. Backpressure, ignition calibration s.o. all have a big influence.
yep, Bingo.. thats my point I was eluding to. thx for confirming. who actually does this, and does it make for a "better" job? I am sceptical. |
|
|
|
|
Logged
|
|
|
|
silentbob
Full Member
Karma: +30/-1
Offline
Posts: 141
|
|
« Reply #48 on: June 07, 2012, 10:07:58 AM »
|
|
|
No, it does not result in what you have said.
I quote:I don't know where you are reading this out from, but it's not the case at all. You assume I want to reach a certain EGT with LAMBTS, which I don't. Also, there is ATR. I don’t get it. If you don’t want to limit the EGTs to a certain threshold why do you enrich by EGTs then? On one hand you said that using LAMFA on low RPMs is not good because it hurt’s fuel economy and on the other hand you enrich by EGTs when it is not needed  And why exactly? I've logged different gears on the local airfield with this approach, and it behaves exactly the way I want to. That was under the assumption that you want to limit the EGTs with it. So tell us how exactly you are going to use LAMFAW to run main fueling on a performance oriented car.
And I mean tuning an existing software when you can't compile what is needed from source.
What exactly is a performance orientated car? In your opinion a stock RS4 falls not into this classification then? Stock cars are calibrated to meet their specified power goal most efficiently (use more load and leaner mixture instead of running richer and use less load). That’s why all modern Audi/VW turbo engines only enrich from lambda 1 based on component protection (and where it’s needed for other safety reasons or to stabilize combustion). Other concepts like the supercharged B8 S4 for example have to use full load enrichment by a functionality similar to LAMFA additionally to component protection, because otherwise they will not reach the aimed power on lower RPMs. Now we want most power possible out of the engines. Strategy is still the same. Use the protection maps for protection (LAMBTS, LAMKR) and use LAMFA for best power enrichment when high load is demanded. Simple as that. I also don’t understand why you are against using LAMFA on low RPMs. What do you want to achieve when you smash the pedal on low RPMs? Win the fuel economy award or accelerate as fast as possible? |
|
|
|
|
Logged
|
|
|
|
|
prj
|
|
« Reply #49 on: June 07, 2012, 04:05:42 PM »
|
|
|
I don’t get it. If you don’t want to limit the EGTs to a certain threshold why do you enrich by EGTs then? On one hand you said that using LAMFA on low RPMs is not good because it hurt’s fuel economy and on the other hand you enrich by EGTs when it is not needed That was under the assumption that you want to limit the EGTs with it. ATR can limit EGT's to an exact number. LAMBTS mixture output will be similar regardless if EGT is 700C or 900C (unless timing retard significantly goes up). If I enrich enough via LAMFAW to be at the mixture that is giving me best torque, then enriching too much too early with LAMBTS will cost me performance, where it might not be needed yet for component protection. Plus, unless I have a dyno and can load the turbo very high at each RPM, then filling it out KFLBTS based on 3rd gear logs is pretty meaningless. What exactly is a performance orientated car? In your opinion a stock RS4 falls not into this classification then? Stock RS4 is detuned quite a bit. My point is that when you don't leave a huge margin, you can't stabilize EGT's with LAMBTS, as eventually they will still get too high and ATR will kick in. I perfectly know that remapping my RS4 to run 22 taper 20 psi means I am going to have to reduce boost to meet my EGT goals by the time I'm in 6th gear. Whereas if I had more margin, I would not have to do this. Now we want most power possible out of the engines. Strategy is still the same. Use the protection maps for protection (LAMBTS, LAMKR) and use LAMFA for best power enrichment when high load is demanded. Simple as that.
I also don’t understand why you are against using LAMFA on low RPMs. What do you want to achieve when you smash the pedal on low RPMs? Win the fuel economy award or accelerate as fast as possible? I don't like fueling based on requested load. I am not saying it doesn't work, but until the turbos have spooled up, and at lower RPM's in lower gears even if the driver is mashing the pedal, the richer mixture is not going to do much besides reduce fuel efficiency. Maybe I am too used to the other ECU's, but usually fueling is done based on actual load. And transient enrichment is a different thing. For load based fueling I use KFLAMKR, KFLAMKRL. I use LAMFA to enrich at higher RPM's at WOT, so that I get better fueling during gear changes, but the requested lambda I have in LAMFA is higher than the combination of KFLAMKR and KFLAMKRL. I use LAMBTS from 700 with FBSTABGM as additional enrichment. I don't enrich via EGT's when "it's not needed". I only reach in excess of 700 calculated EGT at 6000+ RPM in a 3rd gear pull from low revs. When logging, everything works as expected. |
|
|
|
« Last Edit: June 08, 2012, 01:18:15 AM by prj »
|
Logged
|
|
|
|
silentbob
Full Member
Karma: +30/-1
Offline
Posts: 141
|
|
« Reply #50 on: June 08, 2012, 01:19:50 AM »
|
|
|
ATR can limit EGT's to an exact number. LAMBTS mixture output will be similar regardless if EGT is 700C or 900C (unless timing retard significantly goes up). Like I said, you haven’t fully understood what LAMBTS is about. Have you ever looked up what comes out of KFLAMBTS with stock rlmax values? Almost nothing. That’s why TABGBTS is so low on S4/RS4. It’s only a small precontrol to help ATR not to overshoot too much. The massive EGT sensors are shit for dynamic situations so you need some sort of precontrol. That’s one of the reasons (beside being expensive and prone to failure) they have disappeared. On vehicles with no EGT sensor TABGBTS is significantly higher. If I enrich enough via LAMFAW to be at the mixture that is giving me best torque, then enriching too much too early with LAMBTS will cost me performance, where it might not be needed yet for component protection. See above Plus, unless I have a dyno and can load the turbo very high at each RPM in LAMBTS, then filling it out based on 3rd gear logs is pretty meaningless. What’s your thing with third gear logs? If someone uses max 3rd or 4th gear in the critical region what’s the problem then? It simply has to be calibrated with the intended use in mind. I live in Germany and my LAMBTS is calibrated till top of 6th. Stock RS4 is detuned quite a bit. Stock RS4 is calibrated to meet the specified power goal. That is not only under norm conditions but also up to a certain altitude at a certain temperature. At high altitude with high temperatures the turbos are very near to be maxed out with stock power level. My point is that when you don't leave a huge margin, you can't stabilize EGT's with LAMBTS, as eventually they will still get too high and ATR will kick in. Not if calibrated accordingly. I perfectly know that remapping my RS4 to run 22 taper 20 psi means I am going to have to reduce boost to meet my EGT goals by the time I'm in 6th gear.
Whereas if I had more margin, I would not have to do this. Mmh what fuel do you use and what’s your EGT goal? That behavior seems strange. I don't like fueling based on requested load. I am not saying it doesn't work, but until the turbos have spooled up, and at lower RPM's in lower gears even if the driver is mashing the pedal, the richer mixture is not going to do much besides reduce fuel efficiency.
Maybe I am too used to the other ECU's, but usually fueling is done based on actual load. And transient enrichment is a different thing. When I step on the pedal I want to go all in because otherwise I would not have to. That has nothing to do with transient enrichment which is ESUK. I use LAMBTS from 700 with FBSTABGM as additional enrichment. I don't enrich via EGT's when "it's not needed". I only reach in excess of 700 calculated EGT at 6000+ RPM in a 3rd gear pull from low revs. Beginning enrichment based on ETGs from 700°C on is dumping fuel for me, because it’s absolutely not necessary. When logging, everything works as expected.
When you are happy with your outcome for your needs then perfect. |
|
|
|
|
Logged
|
|
|
|
|
prj
|
|
« Reply #51 on: June 08, 2012, 01:41:47 AM »
|
|
|
What’s your thing with third gear logs? If someone uses max 3rd or 4th gear in the critical region what’s the problem then? It simply has to be calibrated with the intended use in mind. I live in Germany and my LAMBTS is calibrated till top of 6th. So you say that the fueling need in 3rd and 6th gear is equal for a given RPM? Because if you just map KFLBTS based on RPM, it's output will be the same any time the threshold is reached. Whether you are 1 degree or 200 degrees over the threshold. Also, it is pretty damn hard to get to ATR (950+) in a properly calibrated RS4. Even in stock form you have to try hard to reach that high EGT. I also don't think going that high is healthy for components. Stock RS4 is calibrated to meet the specified power goal. That is not only under norm conditions but also up to a certain altitude at a certain temperature. At high altitude with high temperatures the turbos are very near to be maxed out with stock power level. Yes, exactly, because stock the car is calibrated to always make the same power, and not make the best power possible at a given moment. When I step on the pedal I want to go all in because otherwise I would not have to.
That has nothing to do with transient enrichment which is ESUK. There is a difference between going "all-in" and pure waste. In a higher gear at lower RPM you may want as much as 0.85 and below, whereas in a lower gear, there is a high chance nothing is spooled up yet at all. Yet for the driver it is instinctive to give more throttle. I guess this is more a personal difference of how people modulate throttle input. Beginning enrichment based on ETGs from 700°C on is dumping fuel for me, because it’s absolutely not necessary. It does not dump fuel at 700C. It starts very slightly enriching to be able to maintain ignition angle. It starts dumping fuel at 900, due to my FBSTABGM curve. And after that ATR takes over... My point is basically, that if you run the same lambda, then ignition timing at the same RPM is dependant on EGT, so you would get more correction in higher gears at the same RPM. You can either reduce timing based on knock which has already occurred or you can pre-emptively enrich the mixture to not get to knock. In both cases you lose some torque. |
|
|
|
« Last Edit: June 08, 2012, 01:46:46 AM by prj »
|
Logged
|
|
|
|
silentbob
Full Member
Karma: +30/-1
Offline
Posts: 141
|
|
« Reply #52 on: June 08, 2012, 07:53:32 AM »
|
|
|
So you say that the fueling need in 3rd and 6th gear is equal for a given RPM?
Because if you just map KFLBTS based on RPM, it's output will be the same any time the threshold is reached. Whether you are 1 degree or 200 degrees over the threshold. Take the FR and read the application hints for LAMBTS again. Also, it is pretty damn hard to get to ATR (950+) in a properly calibrated RS4. Even in stock form you have to try hard to reach that high EGT. I also don't think going that high is healthy for components. No problem to do that here. S4/RS4 are 980°C concepts, but I agree that running cooler is better. Yes, exactly, because stock the car is calibrated to always make the same power, and not make the best power possible at a given moment. But what does that have to do with downtuning? There is a difference between going "all-in" and pure waste. In a higher gear at lower RPM you may want as much as 0.85 and below, whereas in a lower gear, there is a high chance nothing is spooled up yet at all. Yet for the driver it is instinctive to give more throttle. I guess this is more a personal difference of how people modulate throttle input.
If I request full load I want all the engine can give on the current operation point. That has nothing to do with gear or turbo spool. It does not dump fuel at 700C. It starts very slightly enriching to be able to maintain ignition angle. It starts dumping fuel at 900, due to my FBSTABGM curve.
And after that ATR takes over...
My point is basically, that if you run the same lambda, then ignition timing at the same RPM is dependant on EGT, so you would get more correction in higher gears at the same RPM.
You can either reduce timing based on knock which has already occurred or you can pre-emptively enrich the mixture to not get to knock.
In both cases you lose some torque.
With the basically not existing valve overlap on S4/RS4 engines you more likely see an IAT influence going through the gears than EGTs. At least I have never seen anything like this. |
|
|
|
|
Logged
|
|
|
|
|
prj
|
|
« Reply #53 on: June 08, 2012, 09:15:47 AM »
|
|
|
Take the FR and read the application hints for LAMBTS again.
No problem to do that here.
S4/RS4 are 980°C concepts, but I agree that running cooler is better. So here, you get my point. Running cooler is better. I don't want to reach the measuring point of the narrow range EGT sensors, I want to enrich more earlier, to run cooler, to run more timing, etc. And that is why I use KFLBTS not as intended. If you have a better idea how to accomplish my goal, do let me know. I understand that KFLBTS is meant for steady state to pre-control the temperatures, but unless you have a steady-state dyno to dial this in, you will not get it perfectly accurate. Of course living in a world, where you do this for living, a such thing might not occur to you. Last I checked this site was still aimed at both the professional and the enthusiast  But what does that have to do with down tuning? The fact that most cars will not reach those conditions. The fact that there is more to extract in 90% of conditions. If I request full load I want all the engine can give on the current operation point.
That has nothing to do with gear or turbo spool. Interesting. So you think going richer than 12.5 afr is always a bad idea? Do you think 12.5 afr is always needed at 100% pedal? My RS4's engine makes the most torque around 0.8 lambda on 98 RON, when the turbos are fully spooled up. However, going that rich at start of spoolup is dumping too much fuel. Also, mapping the engine based on pedal, creates an on-off type behavior, where at 70% pedal you are running stoich, and then at 100% pedal suddenly quite rich. This also creates a problem with the timing maps. Because timing is done based on actual load. If you dial in the timing advance based on WOT spoolup with the richer mixture, then when you are running 70% pedal, you will be well into knock at stoich mixture. With the basically not existing valve overlap on S4/RS4 engines you more likely see an IAT influence going through the gears than EGTs.
At least I have never seen anything like this. Granted, I have not tuned many S4/RS4 engines. But from my experience with other engines (and you could say I have tuned a few...), this statement is incorrect. What I find is given the same ignition advance and the same lambda, 100-150C differences in EGT can affect the spark advance 1.5-2 degrees. In some cases more. Even when the IAT's do not have a significant rise. And this has been true so far for many different engines. Different cam setups. etc. How a RS4/S4 engine would magically break this observation is really weird. And from my point of view - increased EGT means that everything in the cylinder gets hotter, and it's pretty normal that this has a detrimental effect on spark advance. So I would say there is a pretty significant difference between for example 800 and 950C EGT. |
|
|
|
« Last Edit: June 09, 2012, 03:52:45 AM by prj »
|
Logged
|
|
|
|
|
Rick
|
|
« Reply #54 on: June 09, 2012, 11:11:20 AM »
|
|
|
prj, the biggest problem you have is you are trying to tune based on an EGT model. This model is developed primarily for cat heating purposes. The steady state, wot is simply taken from a map. This map isn't particularly accurate, even if recalibrated, in all states. Fuelling on req load is actually a god send. The inrush of fuel cools and prevents knock as actual load builds. The main thing is you are happy with how your car drives Rick |
|
|
|
|
Logged
|
|
|
|
|
prj
|
|
« Reply #55 on: June 09, 2012, 11:26:16 AM »
|
|
|
Fuelling on req load is actually a god send. The inrush of fuel cools and prevents knock as actual load builds. And how do you correctly calibrate timing then? I already said that my main fueling is not coming from LAMBTS, multiple times. I just use it for additional enrichment, to drift between about 0.83 and 0.77 lambda. You seem to ignore this though. I use LAMFA, KFLAMKR, KFLAMKRL for main fueling. I am talking mostly about the "slow-spool" zone here when I say that fueling based on requested load is not a good idea. Not about fueling over the RPM threshold where your turbos basically insta-spool on WOT, for which LAMFA is perfect. |
|
|
|
« Last Edit: June 09, 2012, 12:02:19 PM by prj »
|
Logged
|
|
|
|
ibizacupra
Full Member
Karma: +4/-10
Offline
Posts: 111
|
|
« Reply #56 on: June 13, 2012, 07:56:26 AM »
|
|
|
A question for you knowledgable folks... Sample below, wideband 1.8t, polo. Log from 4th gear pull on dyno  Sample ols screen of its settings which those logged numbers came from....  From the logs you can see it fuel dump severely (its so much as to cause a misfire), but lamfa, kflbts are not asking for this intervention... FBSTABGM is shown, although axis name looks wrong.. clearly not km/h... but I think the data's correct(?) TABGBTS is set to its factory setting 399'c... no egt sensor on this car, but I am assuming ecu is getting a temp measurement from lambda which I logged to see if it correlated to anything. Wideband lambda is std on this car. My question is whats intervening to drop the lambda request so low...? When logging 001 lambda adjust (in vagcom) the % adjust drops to zero when this intervention kicks in (much like it does when hard limit 920'c on 225 cars do when egt protection kicks in) Set TABGBTS higher perhaps? I am not convinced FBSTABGM is showing correctly.... another 150/180bhp 1.8t shown below and different numbers again.  Why is this additional lambda request coming in... |
|
|
|
|
Logged
|
|
|
|
|
prj
|
|
« Reply #57 on: June 13, 2012, 12:55:47 PM »
|
|
|
Make proper logs with setzi's tool and you will /know/ instead of guessing.
FBSTABGM looks just wrong to me, KFLBTS in this setup looks almost useless. The 0.5 will do nothing in most conditions because LAMFA is richer.
Why disable LAMBTSZW completely? It is very effective when tuned right.
LAMFA at 2000-4000 RPM is pretty useless, it will not really do anything. Depending on the turbo size, go all out on LAMFA after the spool is instant. in 2nd gear WOT.
If you want to enrich at lower RPM's, enrich based on actual load via KFLAMKR and KFLAMKRL. So that you have adequate enrichment without dumping fuel in the slow spool zone, and use LAMFA in instant spool zone...
Use KFLBTS properly for component protection, don't make it always active...
Before I get flamed to high hell again - this is just how I would do things, it's not the only way to do things, it might not be the same others do, etc.
|
|
|
|
« Last Edit: June 13, 2012, 12:57:45 PM by prj »
|
Logged
|
|
|
|
|
littco
|
|
« Reply #58 on: June 13, 2012, 03:10:11 PM »
|
|
|
FBSTAGM should be degrees c not rpm
I see your rpm goes upto to 7600 but the axis are still 6520. Would rescaling the axis not help and if it doesn't would give a better spread, I assume if these aren't done then the axis for timing etc aren't done?
I've just checked an HN and HJ and they both have tabgtbs set to 400 as well. I know on non EGT it's all simulated EGTs.
|
|
|
|
|
Logged
|
|
|
|
|
professor
|
|
« Reply #59 on: June 14, 2012, 03:07:30 AM »
|
|
|
So on ME7.5 where axles are different from ME7 should rescale and do equal changes or it works different way?
|
|
|
|
|
Logged
|
Seat Ibiza MK4 Cupra 1.8t 20V, stg3.
"Those 1.8T 20V machines are really tough" ©
|
|
|
|
