NefMoto

Hello,

The victim is a A4 1.8t -03, wideband. Trying at the moment to get some of the potential power out of the engine, but the success is limited.

Attached is a log over a 1500 - 6800 rpm pull in 3rd gear. As you can se the requested load peaks at 168 at around 5500 rpm, after that it starts to decrease.

Also the WG duty cycle is not at all doing what I would like it to do, makes for really slow spool when it starts at ~50 %. Attached is also my LDRXN and the KFLDIMX table, am I doing something wrong with the boost PID?

Grateful for any input.

BR. Kenneth

Please post original csv.

also consider using ecuxplot

1) 95% I max everywhere is not good.
2) what is KFLDRL?
3) when tuning the PID you should be paying attention to lde, not load

Hello,

Thank you for the fast reply!

Attached is the KFLDRL. Plese dont be afraid to hurt my feelings with input, could be that these maps are WAY off. And needs lots of correction.

The TC hardware is twinentry Borg Warner S200 with Tial 38 mm wastegate on tubular manifold, as you see it spools at ~3500 rpm, before that...dead.

Regarding the log, it is quite long, but attached. Sorry for the length.

This KFLDRL looks like a complete reverse of what it should be... At high RPMs you translate anything below 50% duty into ZERO WGDC. 70% outputs 26%... no wonder you never get up to the proper boost level.

Agreed. Also, when tuning the PID you need to be logging a few more things


Your wgdc should be 95% until just before boost meets req. then it should drop, then come back up a bit and stabilize.

Thank you for the input, I will add those symbols to the log.

I fully agree regarding how the DC should behave, It´s getting it to do that causes some problems. The ME7.5 boost PID is quite different from other brand ECUs I have looked at. But maybe it´s good and logical, I just havent gotten a grip of it yet =)

BR. Kenneth

If you aren't going to calibrate KFLDLR, recommend setting it to 1:1 everywhere for now.

0 0 0 0 0
10 10 10 10
20 20 20 20

etc.

Hello,

Made a new log with the values added, modified the KFLDLR according to the suggestion with and took the KFLDIMX from a 225 hp TT bin, thought it could be better than the one i had at the moment?

Took a log of a 3rd gear pull, it is attached if someone has a interest in looking at it.

Also should be mentioned that the MAP sensor is exhanged for a 3.5 bar one, this could of course affect a thing or two...

BR. Kenneth

Err, you did change the transfer function maps in the ECU for that, right?

Something very very wrong here

Did you log lditv_w, ldptv, ldrdtv?

Also, i don't know what base boost is in that file, but you might want put KFLDIMX axis back to stock.

Hehe, I dont know if there is a good way of saying this so I´ll just say it. No, I dont think the transfer function has been changed...

Is there any point with a larger map? Can ME internally handle higher values than 2550 mbar absolute?

ME7.1.x can't

I assume 7.5 can't either without the 5120 hack.

Hello,

Ok, I found the Gradient für Drucksensor Ladedruck - DSLGRAD at 15A16 and maybe also the offset should be modified? Offset Drucksensor Ladedruck - DSLOFS was at 15A18 right after...hopefully...

I´ll scale DSLGRAD by 3500/2500 and hope that it improves, the 5120 hack seems like a awful amount of work I must say. I would rather just rely on the MAF if this is the case? Quite a limitation this 1.55 bar max boost for a small engine like 1.8t =(

BR. Kenneth

Edit: Sorry for the many questions, but the bin and car i have are made for returnless system, this system does not take manifold pressure in to account? This has now been changed so that the fuel pressure is 3.5 bar above manifold, should i put FRLFSDP to 1?

You cannot just scale the values by a set factor. You need to use the values for your specific sensor. In any even, you still have the 1.55 bar limitation, so you might as well use the stock MAP.

Hello,

Yes I understand that there is no gain with modifying the MAP sensor, but it was on the car when I bought it and I do not have the stock replacement at hand. So I will attempt to make it work with this one. Atleast attempt.

BR. Kenneth

Hello,

Well, at least now the Boost PID works as it should. at least almost. Scaling the MAP better and using standard values from a TT 225 hp file helped.

But the problem is still the load request, I request high values in LDRXN and have taken KFMIOP and FKMIRL from a 225 TT file. The last row in KFMIRL is increased to 260 and the last row in KFMIOP is 99.99. but still the load requested is very limited.

KFLDHBN

Hello,

Thank you for the reply, the map in question looked like this when I took the log, now all values are max. I dont think this was limiting, but maybe? I will test with the new maxed map.

Italian tuning KFLDHBN isn't a great idea (outside of debugging a problem you can't explain, short term)... you should really consider using proper values..

Consider fixing that huge overshoot before turning the boost up.

Well, I plan on exceeding the map limit anyhow, or past 2550 mbar so this map is maybe not so important. Better for now that it is not interfering with the load reached.

Must say that the car is quite booring to drive with 170 in load =( WG-DC is available, it would only be to get it in use. Well ME7.5 has limiters so I guess this is quite a normal problem.

Hello, yes I was considering if I dare show that log here or not. Quite bad overshoot to say the least. But still the tuning for that is also a bit different dependent of the pressure desired, now the requested pressure is very low and close to base boost.

Hello,

That seems to be the answer yes, now requested load is LDRXN. So that is good.

But now I started to get fault code 16683/P0299/000665 - Boost Pressure Regulation: Control Range Not Reached with reduced power as result. What is the reason behind that? Any suggestions?

LOG YOUR CAR WITH ME7L.

POST THE .CSV

Hello,

Yes it´s attached. After that run i tried to press the trottle again but then the power was already limited. So I guess that 3rd gear pull triggered the fault code.

1) reduce KFLDIMX
2) bring in LDRXN a bit faster
3) possibly shift Q2 upwards in rpm, maybe increase
4) possibly raise NDLDRAPU

You have massive overboost.

I wonder if Italians are offended by statements like this. lol

Hello,

Thanks for all the help. I modified the KFLDIMX a couple of times so that helped. It´s not very god yet but better.

Another issue, quite many already listed in this post but I would like to make the car smoother to drive. I understood that the x-axis in KFVPDKSD and KFVPDKSE should be scaled:

(new base boost [bar a])/(old base boost [bar a]) * old value. My question is, can I interprit from the old values what the original cars base boost was?

The 3rd to last axis value is usually your original pressure ratio. In your case, 1.4 (6psi).

note to self (or you): that needs to be added to the wiki :)

Thanks, I used 1.4 to scale the axis. The current base boost is 1.7 absolute so a slight increase.

But still, this did not make the engine silky smooth. The problem is still the 16683 code. Is the boost pressure so bad that I should get this fault code and it should go away with fixed tuning or is this code a result maybe from the 3.5 bar MAP?

As you see from the plot something is stopping the throttle plate from opening at lower RPM even though the accelerator is pressed fully. And yes, I have modified the max allowed throttle plate angle map. It allows larger values than that. Could be that i got the 16683 code at ready at engine start and it was on during that log.

Suggestions what to do?

In that log, your throttle plate looks wide open.

Something else is going on there preventing you from spooling properly, which is causing the code.

Boost leak? Bad wastegate?

Do you get proper spool with the wastegate line disconnected?

I am assuming you fixed the transfer function to properly represent your MAP.

If not, return your MAP sensor to stock.

Maybe it´s better visible in this log, the throttle plate angle does some funny stuff up to maybe 1800 rpm, after that it goes like normal. I guess that is the fault code doing that, I checked the WG yesterday and it was ok, I will pressure test but I did not get it done today.

The spool is slow with this turbo, but hopefully it will produce some sort of power. Should I lower LDRNX in the lower rev range? I tried that earlier and it did not help so I raised it back up.

Did you fix the MAP tables?

Low rpm throttle plate stuff isn't an issue. With your laggy setup, it simply doesn't matter.

I'd be wary of shifting LDRXN too far up, but if you can make sure your WG stays 100% before peak boost while spooling, you're ok.

I'd maybe look at NDLDRAPI and SDLDRA instead. In particular, if you have a really laggy turbo, NDLDRAPU probably has to be shifted pretty high RPM wise (for the 2.7t anyway).

Yep, the scaling and offset of the MAP is now what it should be. So shown boost equals to true boost, about 1.5 bar on gauge.

Something strange is going on with the throttle during driving, it's really noticeable and was not there before.  I'll look a bit at the mechanical side tomorrow but if I guess it is control related.

It sounds like your axis scaling is bad. If you do that wrong it makes for some wonky behavior. Post your new values.

I´ll look at these maps, regarding the throttle. You can really feel that the engine is much weaker before the throttle goes open, up to 1800 rpm in the log I was wondering what had happened, after that it started pulling normally. It will maybe not help spool much but power is ridiculously low with throttle plate at ~20 even though pedal is to the floor.

Yes, THAT is possible. Even likely =)

The values I now use are

DSLGRAD: 700 hPa/V

DSLOFS: 172 hPa

As said 3.5 bar MAP, without any data what so ever delivered with it.

Not for the MAP, the axis for KFVPDKSD.

Of course, sorry

Old values   New values
0.949465   1.152921786
0.999424   1.213586286
1.049383   1.274250786
1.099342   1.334915286
1.149362   1.395653857
1.199321   1.456318357
1.24928   1.516982857
1.299239   1.577647357
1.349198   1.638311857
1.399218   1.699050429
1.449177   1.759714929
1.499136   1.820379429

Does it log near 1 bar (i.e. ambient) with motor not running?

This axis is desired manifold pressure ratio (post throttle).

If the map value is greater than 0.95, then the throttle is forced that percentage towards 100%. A value of 1.0 forces the throttle wide open.

Yes, very close to that. I tried to get it so show the same value as the barometric pressure with engine off. It may have changed since then so it´s a couple of mbar +/- but close.

Ok, so if I understand that correctly then with these larger axis values the throttle will stay closed longer and only open fully if more than 1.7 bar absolute is requested? At least I think that is the way it should be.

Hello,

I´m having some issues findind NDLDRAPU in the bin I use, in a TT file I have looked at it´s just after KFVPDKLD but that does not seem to be the case in by bin.

KFVPDKLD I have at 27E7B but the NDLDRAPU seems to be somewhere else. The bin is in this post: http://nefariousmotorsports.com/forum/index.php?topic=6021.msg56390#msg56390 if someone has time/interest to take a look.

I pressure tested the system and found some small leak at the hose from compressor to N75 valve, but nothing major. WG seems OK also but I dont know how it behaves when it´s hot and under driving.

BR. Kenneth

Unfortunately, I don't know much about avoiding 16683 in ME7.5 :(

I'm assuming it is equivalent to positive deviation in ME7.1 (P1557), but more than that... no idea

Request reasonable boost, have a properly calibrated PID.

His req didn't seem that crazy... and for lazy turbos, NDLDRAPU has to be shifted rpm wise no matter what...

Hello,

In this log you can really see what the throttle plate is doing. Still NDLDRAPU is stock.

I wasn't speaking to his case specifically, but rather the avoiding the charge pressure deviation code.

Oh wow. No amount of NDLDRAPU hacking is going to fix that. No wonder you are seeing that code.

I think your TB is toast, or you need to do a TB adaptation.

Please revert the pressure axis for KFVPDKSD and relog.

Changing the axis back on KFVPDKSD helped and also finetuning the KFWDKMSN and KFMSNWDK for the larger throttle housing made it better.

So with this fixed and a new walbro 450 lph fuel pump installed I tried to raise the output a little bit. But this did not go so well, with LDRXN somewhat raised requested boost goes to 2550 mbar and then I get wastegate DC at 95 % all the time. Resulting in 2+ bar boost, not really the desired result.

The 12_6 log shows the problem I´m having and 27acc3 how it was before with load request resulting in less than 2550 mbar requested boost.

I guess my question is how to do to handle boost over 2550 mbar. Option 1 is to scale my 3.5 bar MAP so I measure for example 2450 mbar when true boost is 2700 mbar (underscale mbar/volt) and change the request in LDRXN so that stays below 2550 mbar boost or is there a better way? PID controlled boost would be nice to have.

BR. Kenneth

All of this is covered in the tuning wiki.

It is not a proper way to tune! Proper solution is described here on the board so do not take any shortcuts...