Audi S3 weird boost issue in higher gears

Actua

Registered User
Greetings from Norway!

No luck getting any help here in Norway, so figured out trying here :). Been lurking here for a couple of months, so much good information. But haven't found a solution for the problem I have.

First of all, I have an chipped 1999 S3 APY with some mods and uprated parts:
- TFSI Coils
- N249 Delete
- SAI Delete
- DeatschWerks DW65v fuel pump
- Forge 008p Diverter Valve
- Silicone TIP

and some parts recently changed: MAF, N75, Sparkplugs (NGK PFR6Q), fuel filter, lots of vacum lines.

The problem I have is boost in the higher gears 4-6. First, second and third gear is boosting as they should, 1.5 bar/21 psi. Getting around 200g/s at the maf. Here's a graph I made after some logging in 3rd gear, everything looks good.
23.05.16-3GEAR-RPM-BOOST.png


But as fast as I shift into 4th gear, things start to look weird.
23.05.16-4GEAR-RPM-BOOST.png

When I reach 3000 rpm, I lose boost, 1.5 bar falls down to 0.9/1.0 bar. And then the funny part is, when I reach 5000 rpm the boost comes back. As the graph shows, the ECU starts to request 2500 mbar. Same thing in 5th and 6th gear. Hope these graphs helps to visualize my problem.

I have tried to change a lot of parts as mentioned above, done a boost leak test with no leaks, no fault codes.

So the only thing that I can think of is bad map. The turbo is a bit old/worn, but I don't think it is an issue since it boosts fine after 5000k? Any suggestions? I am really close to go get a new map :p Just scared it is not the issue :(

I have cvs files for most runs in different gears if anyone wants to take a look. My graphs are based on them.

Thanks
Victor
 

IPG

Registered User
download a program called ecux plot
this is the most simple method and you set the RPM to be the X axis then set the other's at either the left or right with Y axis. it's kind of confusing with the RPM in the wrong place as your graphs show

but yes something is strange there for sure!
 

<tuffty/>

Badger 5 Edition...Its all about the flow...
Staff member
Moderator
1.5bar is quite a lot of boost... its at MAP sensor limit pretty much and the limit of what the map will know how to deal with

What map is on it? what mods? I assume you haven't got anything silly like a manual boost controller?

<tuffty/>
 

Actua

Registered User
1.5bar is quite a lot of boost... its at MAP sensor limit pretty much and the limit of what the map will know how to deal with

What map is on it? what mods? I assume you haven't got anything silly like a manual boost controller?

<tuffty/>

The car's map is unknown, I think it might be from BSR since the car has air filter from them. Was one of the prev owner who chipped it, not been able to reach him the mods I was talking about was the SAI delete etc. No mbc or anything like that.

Will do after work IanPG!

Thanks for replies

Edit: Car is mostly stock, should be stage 1 map
 
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<tuffty/>

Badger 5 Edition...Its all about the flow...
Staff member
Moderator
I meant what supporting mods on the car for the map you have... FMIC? TIP? 3" downpipe?

1.5bar is a high boost figure and based on the graphs posted it looks like its a pikey lets turn the boost up map as its seemingly flat out asking for 1.5bar from as soon as it can...

This is a concern for several reasons... there is no AFR plot so cannot see if the map has had fuelling done (factory AFR is lambda 1 and is too lean for a mapped engine), the boost request is too much for a non rodded engine... that much boost requested that soon can lead to rod failure... 1.8t's don't like all that boost from early on as it makes them hot and they pull loads of timing as a result top end...

The issues you describe seem to point to the fact the ECU is not happy under the extra load that the higher gears will give you... I suspect if you are banging through the gears changing at near redline then you don't get the problem... you most likely get this from being in a higher gear from low rpm and driving through spool... this will put more load on the engine and show up the problems that pikey maps give... looks like the ECU is trying to hold back as its not happy

Needs logging using VCDS or similar to see whats going on really but I would be concerned about your map and the effect its having on your engine

<tuffty/>
 

Actua

Registered User
Sad to say, stock exhaust, intercoolers. I just changed to a silicone TIP because the old one was leaking. I haven't had the car for so long, these are things I was going to do, just trying to figure out what the problem is before starting to spend on these upgrades. I bought TFSI coils in hopes to fix the problem, N249 bypass and SAI Delete fixed some other issues. Fuel pump died a couple of months ago so got a new DW65v. I have always thought these were required mods for stage2+. Not a chip for around 250-265 hp. I have ordered a XSPower Pro v4 manifold, coming soon. Aswell as a new orginial K04 turbo, as there is some slack in the turbo. Car has 207 000 km or around 130 000 miles on clock. Don't want it to die on the road :(

The issues you describe seem to point to the fact the ECU is not happy under the extra load that the higher gears will give you... I suspect if you are banging through the gears changing at near redline then you don't get the problem... you most likely get this from being in a higher gear from low rpm and driving through spool... this will put more load on the engine and show up the problems that pikey maps give... looks like the ECU is trying to hold back as its not happy
<tuffty/>

Well yepp, you just descibed everything better than I could hah. Really annoying, have to gear down to third when entering an highway or overtaking a car. I don't know if the car has any forged rods or not, car was imported from Germany in 2008. Been driving in Norway since, very sure the car was chipped after it was imported. So the rods have been holding, but that might not be forever. I have access to VCDS, I know how to log, just not what to log. I also have FIS-Control installed in the car. well yeh looks like I have spent some money on the car..

IanPG, did not have access to my home computer so I remade the graphs I already have in Excel with how you wanted. is this better?
23.05.16-4GEAR-RPM-BOOST-Bedre.png
 

<tuffty/>

Badger 5 Edition...Its all about the flow...
Staff member
Moderator
running all that boost is not a stage 1 tune... you don't have the hardware for stage 2 either... for your hardware you would be looking at 18psi tops not the 22 you have...

Too much boost and still not said what AFR you run under boost... you should be able to see this in block 31 on FIS control... should be running around 0.82 lambda ideally under boost...

I'd be seriously considering rods or at least detune the car so boost delivery is not so hard... any mods you do now is likely to make matters worse tbh...

Seen this kind of map before and they are just nasty... fitting stuff that flows better and produces even more boost will probably not end well...

Have seen std rods bend as the result of just fitting a FMIC especially on aggressive maps...

You should also fit a boost gauge... maps that are set to ask 2550mbar are inherently spiky and you won't ever see that spike as MAP sensor can only read 2550 max... looking at your first graph there is every chance there is an overshoot of boost at spool and have seen 26psi (and more) on the dyno with these maps on spool which chances are whats getting the ECU upset... the ECU is blind above 1.5bar so won't know what to do with the spike... your rods will though...

<tuffty/>
 

Actua

Registered User
Couldn't say anything about AFR because I have never checked it. I will check it next time I am out driving.

As I stated in first post, my thoughts is that it is a bad map so I want to get a new one but less aggressive. I asked here to try eliminate other causes, before spending money on a new map. Didn't know the ECU was blind above 2550mbar, thanks for the information. I used a cheap boost gauge earlier, it maxed at 1.6, thought it was less since the FIS showed lower and the gauge was cheap. I should stop with the excuses, I'll book an remap for the car. I am going on vacation for a week, next week. So much will happen when I get home.

My plan for the car: I want a solid daily car, with a basic tune while I am still getting an education and working part time. In two or three years, I want to do a full engine rebuild, rods, pistions, etc and grab a hybrid of some sort. Untill that time, I'll do exhaust, IC, etc. Not the ideal car for my life.. but gotta have some fun too.

Reason for getting manifold first is because got it cheap from a friend of me, and because I'm getting a new turbo so changing them at the both time.

Really appreciate all the help, a lot more than what people could help me with here in Norway. But man, your avatar makes me feel your angry haha
 

<tuffty/>

Badger 5 Edition...Its all about the flow...
Staff member
Moderator
Ah... hold the phone :/...

Just re-read your first post, didn't realise it was an APY... you won't be able to check AFR on WOT as its a narrow band ECU...

1.6bar spike is a biggy dude!... its just as well you are booking in for a map... :D

If you can get a 3" DP and fit that too then that will be the best time to do it as they are fiddly at best and you will gain benefits even if not chasing power etc...

1.8t's run hot especially when tuned... adding 'stage 2' hardware serves to keep the engine happier by letting it run cooler... you can still tune to stage 1 (18psi or so) but it will retain consistency

<tuffty/>
 

Actua

Registered User
Not much on block 32 hehe :p

Thinking about getting the zinram 3" dp and catback from milltek, just so pricey :D

Kinda looking for a intercooler kit of some quality that does not require to sacrifice fog lights, wagner has one but it is so expensive. Any recommendations? Will probably find if I search the forums, just lazy :D

The same guy with the manifold also has some spare injectors (550cc) because hes going larger, I could get them real cheap if I wanted. Will the ECU be able to regulate the extra flow without having a custom map for it? I will probably need these in the future when going bigger, so why not get them now for a good price.

Edit: Yeah I know my priorities are all over the place.
Edit 2: Picture of my sweetheart
20160514_200530.jpg
 
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<tuffty/>

Badger 5 Edition...Its all about the flow...
Staff member
Moderator
You will need the map customised for larger injectors... especially on an APY as it will have no idea what the AFR is on WOT and will be pulling loads of fuel out on cruise/idle...

No real need to go bigger injectors at your current level of tune... this is the realm of hybrids and people that have every conceivable mod on the planet while still running std K04's... if you plan to go for more later though and they are cheap enough then probably worth getting them to stick on the shelf but if you have no real plans beyond your std K04 then I wouldn't worry too much... std injectors tend to get maxed at around 280hp of airflow... on a healthy engine you can make 280-290hp with the right mods with a std K04... its at this level that the 550's make sense but they will need custom mapping...

There is a huge FMIC thread in the FAQ's so don't be lazy! ;)

<tuffty/>
 
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