NefMoto

Firstly my name is Martin and my eyes have really been opened with this site and the ME7 ECU !

I am used to older Japanese turbo cars and aftermarket ECU's and a miriad of options etc. ... so this whole new tuning approach (yeh OK not so new as its's beenn around for donkeys years LOL) removes the smoke and mirrors but unfortunately, for an inquisitive IT geek like me with an Audi S3 GTRS which isn't running quite right, it also means my brain is in overload ...

I am like a kid in a candy shop with my laptop full of software, ideas coming out of my ears I but wanted to just put some things down and basically ask some advice on where I am at the moment cause I need a bit of a steer ... I have done quite a bit of logging, research and downloads of all the bits of software to try and see what I have and what is going on so didn't want to just come on here in the first instance with no information to provide ...

So please bear with me for those that can help out and are prepared to read my post and who might be able to throw some light or ideas or validate some of my findings ...

MY SITUATION ...

A few weeks ago I bought a 2003 BAM engined Audi S3 with a GTRS ATP eliminator kit, Forge FMIC, Forge Unos MBC, Forge F007P, 3inch Induction pipes and Large filter, sports cats and Milltek exhaust. The work was originally done in 2006 by Jim at Star Performance and included a directport tune (assuming it was APR) and I have a dyno sheet showing a 330 hp. The car was detuned shortly after by Jim due to it being too quick for the lady owner. The details of the tuning history are now a little sketchy as Jim doesn't know the current state of tune. I do know that in 2011 the car was dyno'd and was pretty much running at stock 225 power and, with turning upt the boost of the Unos MBC, a stable 265 hp is now on tap - again I have a dyno chart for this. It was originally tuned with 440 injectors but now has stock ones and did in 2011.

So in summary the car seems to have all the right parts, which is why I bought it, but is currently running at 265 hp. This isn't the end of the story as I 'should' be happy ... I am not quite ...

MY ISSUES ...

The car seemed sluggish/laggy below 4k rpm when I bought it but it shows no codes and actually runs very well above 4k rpm - on part throttle it is, for the most part, VERY fast. On WOT it seems a bit hit and miss and I have experienced the odd limp mode and occassional overboost etc. which seem to manifest in either boost dumping via the N249 or sudden power drop.

Firstly I did loads of research into the turbo kit, the 1.8T characteristics, the ECU and what I could do to diagnose any problems as a drive in another S3 with a remap and stock K04 made me realise my car maybe wasn't running at its low-down potential. This is partly why I am on this site. I have added a boost gauge, I have the VAGCOM 409-1 software and plenty of other stuff and have been merrily logging away and doing varying experiments and decided it was time to ask for some help/advice.

MY EXPERIMENTS (I can provide some logs but these are my summary observations) ...

Firstly to get a baseline, I tried the car on actuator boost, which seems to be around 13psi and the car feels OK-ish. I hit a max of 13psi at around 4k rpm - low down power delivery is less than impressive but the car pulls strong again above 4k rpm. MAF readings show around 186 g/s and 100% throttle which equates to 220 hp at the 1.2 ratio so this seems about right for maximum power on the BAM engine. I assume the power delivery is not great because the actuator is opening due to no boost control.

With the N75 connected (which I really want to retain), the car is much faster, the boost hits 1.5 bar again around 4k rpm but boost is below requested at low revs and often above requested once boost comes in - this variance can also exceed 300mbar and so I assume the limp mode is cutting in. On occassion the MAF g/s and boost exceed maximum values which suggest the maps are still in place for the 330 hp tune. Obviously driveability is not ideal at WOT but the car performs very well on part throttle with the lag below 4krpm. Without the 440 injectors A/F is also causing pull on the throttle which can be as low as 40% open at WOT.

Finally, with the Unos connected (which is how I got the car) the car is still laggy below 4krpm, not as much as with actuator boost control only. Not a great difference over the N75 and certainly the boost doesn't come on any quicker than with the N75. The N75 delivers better part throttle control which is why I want to leave it. Boost, from the setting it was at when it was dynod at 265 last year, is still around the 1.5 bar mark. This is not going over limits as before with the N75 but is on the borderline of limp and sometimes on WOT I can feel the boost being dumped. I think the boost has been set on the borderline of what the car will perform. Even if I reduce boost on the Unos power doesn't drop off greatly but eventually the spring pressure becomes so low it feels like actuator boost. I guess this is because there isn't a great margin between the 13psi actuator boost and maximum requested boost which is in the map.

MY SUMMARY AND HYPOTHESIS

I make an assumption, from what I have read, that the GTRS (which I believe is the GTR2871 RS) is inherently laggy ? ... and that I cannot expect the kind of low down response of a K04 for example - that is a big boo for me ... I can't seem to spool it up currently using either of the main 3 means of boost control that I have.

I think there must still be some residue of the 330 tune map in place as requested boost figures are around 2200 mb (I need to check my logs again) and I can exceed the MAP sensor with actual boost - with the N75 setup. The N75 duties also suggest that it is trying to deliver and control these figures but is maybe unable too due to actuator spring pressure. I assume the limp is due to overboost (300 mbar conditio) and also maxing out MAF/MAP sensor values - all in all the potential is there. Add to this the fact the injectors on NOT 440 and this all adds upto maybe the detuning being done by dropping boost and installing OEM injectors.

Does the above make sense ?

MY QUESTIONS AND CURRENT SITUATION

Clearly I could have the car remapped - but you guys and I don't see that simply all the time do we ? ... How do you learn if you take the easy option - right ?

Can I determine what tune is in the ECU as a basis for doing further diagnostics and perhaps contacting the vendor in case I need a remap ? I have used the NefMoto software and WinOLS but don't know if there are any 'signatures' which tell me the tune ? I have tried to see if the APR tune is in place by using V-Tune to access the boost adaption and also the cruise control sequence to try and access the different maps but to no avail. This makes me think the APR tune is no longer there or maybe it never was APR tuned.

If I can't determine the current tune, can I risk reflashing the ECU with a new tune - like an OEM one for example ? I am able to read the ECU with Nefmoto OK and realise there are checksums for ECU bin files to prevent/reduce corruption risk.

Has anyone got a tune that I could try for a similar spec engine ?

Has anyone got any thoughts as to what expectation of low end driveability I should have with this turbo kit. I hear loads of positive things about power and torque delivery with various tunes on K04 and hybrids but wonder if this kit is just too 'top end' and maybe I am chasing a dream with unrealistic expectations ? The car pulls VERY VERY well above 4krpm on part throttle so I know there is massive potential there for high end power.

Would I run a high risk of damage to cat or otherwise if I was to fit the 440 injectors to experiment ? I understand my ECU has wideband functionality and would expect the ECU to be able to manage A/F to some degree with trimming/adaption ? Or am I talking rubbish on this ?

Are there any things I can do to diagnose or change things further ? I have had a brief look at Unisettings and wonder if there is anything I can do with this based on the injector question above ?

I think that is enough for now and, for those that got this far, many thanks for reading ... I would really appreciate any advice or help and hope to learn a lot from this site and the great work which is done here.

Thanks

Martin

Hi Martin,

First of, I'm not an GT owner, but I can throw you some bones to help ya. I'm not a pro either, so I'm dumping knowledge that I get here from the forum. But probably GT28 will not give you the torque spike that k04 has, but you'll get more top end boost/power. Like you said, after 4k rpm you get full boost, and I guess it'll not drop pressure until redline.

1 - Do a little study in http://s4wiki.com/wiki/Tuning;
2 - Read your ECU with nefmoto and make a backup of it. Double check it;
3 - Instead of vag-com learn how to use me7logger and ecuxplot; Then do a few runs/logging and came back to computer to analyze how is your car BEFORE change anything by yourself;
4 - Post these logs here, so more people can have insights on it and help you out;

But for sure I can say to you that first mod you need to do is installing the 440cc injectors and tune KRKTE/TVUB. Fueling is needed for sure to get you high boost levels/power.

Do the steps I listed and then came back with your logs :)

Thanks I really appreciate the advice :-)

Since posting I have ...

1. Been looking at Nefmoto, TunerPro, WinOLS and other software - it's all really great stuff :-)
2. I have successfully read the ECU bin file and posted it in another thread http://nefariousmotorsports.com/forum/index.php?topic=2098.0title= (http://nefariousmotorsports.com/forum/index.php?topic=2098.0title=) and had some good feedback and direction from Dan (littco) so that's a good start ... Do you have any comments on this bin file ?
3. Been doing background research on the ECU definitions compatible with my ECU (8N0906018BP 0002) and trying to understand some of the 'functions' and maps a little more.
4. Researching whether my 440 Bosch Green top injectors are actually suitable (I believe the spray pattern is wrong and that spacers would be needed) or whether I really need the Audi specific ones.

From there I think your advice really comes into its own as I would like to ...

1. As you say, do more logging to understand what is going on. And post on here then :-)
2. Compare my tune with an OEM one to try and understand any changes now I know more about the definition and maps.
3. Maybe also flash an OEM tune and log again. This is my biggest nervousness so I am looking at how to 'unbrick' an ECU should this happen with 'boot mode' etc.
4. Come up with a strategy of whether to replace the injectors (as you have suggested) or try and make some tuning adjustments, maybe to an OEM tune, in small increments. I would do this within the boundaries of what the OEM injectors can cope with. Modest improvements rather than massive gains are what I'm after and this is a learning exercise for me not a 'mad power' exercise.

Martin

back your e2...
rig up a boot mode harness for yourself.. just in case ;)

in terms of spool... simply mechanical test with your mbc is open it up, and it will spool as soon as it can... it wont be quick like a k04 however.. its an eliminator. they are slow

stock injectors on 3bar are at their limit at ~285bhp region on 12:1 AFR's as a guide
440s would be ok, 1/2" spacers will be needed for the rail but thats all. but looking at fuel trims will guide their suitability... low trims, they will likely be ok...  changing your injector scaling etc to suit of course