Strange Behaviour

[pinkgti]

Got feedback from the tuner and they've said colour is "normal" for a polished stainless exhaust - but definitely won't be pushing it and will get it checked out.

Thanks everyone. Will let you know how it goes.

[pinkgti]

Here's the "full" explanation:

"This discolouration is normal….What it shows is the Dump Pipe and Cat Converter functioning properly.

It highlights that you have good / unrestricted flow throughout the Dump Pipe. If it discolours in sections or stops after the cat converter, it would indicate that you have a restriction in the dump pipe / exhaust somewhere.

The discolouration is also highlighted due to the fully polished finish, the heat changes the colour of the stainless steel. In a painted system this is not visable.

From the images, I can say that the dump pipe is working correctly."

Though there's definitely an issue with the tune - just less concerned about the exhaust now (apart from being the wrong size for max gains that is!).

[pinkgti]

Update - car is booked in with tuner in 2 weeks for a new exhaust, tune and a few other bits.

Fingers crossed it all gets sorted. Will post some new logs once the it's complete.

[parso_rex]

Does the ECU have to come out of the car each time ?

[pinkgti]

Does the ECU have to come out of the car each time ?

In my particular case it is due to Bosch encryption. I believe this may not necessarily be the case will all Mk6 GTI's though.

It must have been that they added encryption with the pink paint option or something.

[parso_rex]

They aren't encrypted.
They may be doing it this way (via BDM) to apply their own OBDII read blocking though, some places here do this.

In my particular case it is due to Bosch encryption. I believe this may not necessarily be the case will all Mk6 GTI's though.

It must have been that they added encryption with the pink paint option or something.

[Guy_H]

Who is the tuner? as above with Parso, no MK6 GTI that is delivered in AU needs the ECU pulled out, and blocking the OBD stops VW putting any updates on the car.

[pinkgti]

Well this little pink GTI does need to get bench tuned - and understand that 99.99% of Australian delivered Mk 6 GTI's probably don't.

Bench or OBD port tuning aside I'm still trying to understand what effect having a tune file for a 3" DP being flashed into an ECU/car that only has a 2.5" DP installed.

[Guy_H]

There is some technical discussion here : Downpipe solutions, what did you get? - VW GTI MKVI Forum / VW Golf R Forum / VW Golf MKVI Forum / VW GTI Forum - Golfmk6.com - it refers to the later TSI (timing chain) motor, but you see that a lot transfers over to FSI motors as well.

You should look closely at your projected EGT's - doing this at steady state type log (easy on a dyno to hold load) you will see results quicker than single dyno power pulls or quick street blasts. It's obviously these things which are directly associated with the component protection modes (stops melting your turbo & blowing your engine) that should be looked at closely if you are unsure about your tune.

[pinkgti]

There is some technical discussion here : Downpipe solutions, what did you get? - VW GTI MKVI Forum / VW Golf R Forum / VW Golf MKVI Forum / VW GTI Forum - Golfmk6.com - it refers to the later TSI (timing chain) motor, but you see that a lot transfers over to FSI motors as well.

You should look closely at your projected EGT's - doing this at steady state type log (easy on a dyno to hold load) you will see results quicker than single dyno power pulls or quick street blasts. It's obviously these things which are directly associated with the component protection modes (stops melting your turbo & blowing your engine) that should be looked at closely if you are unsure about your tune.

Thanks Guy - interesting read on DPs. My take-out is that you really need a tune file to suit the size DP if you want to generate maximum power/torque and if you do this then the 3" is the way to go. Still not sure what having a tune file for a 3" DP is going to have when a 2.5" is installed. I think from the thread the answer would be you'd theoretically be able to work itou t but in reality you'd have to do some real world testing.

OK so next questions is how to measure EGT's. Is this data/parameters available on EA888 engine/ECU? i.e. can I log it with Vagcom or does this require an RTD/thermocouple up the tailpipe? Unfortunately I don't have access to a dyno in my driveway, so is it possible to run some meaningful tests or at very least check temps out of the turbo and make sure it's not going too high.

I want to know if the tune has done any damage to my car before things get changed and swept under the carpet.

Are there any parameters that I can log and values that you'd expect under "normal" operation plus limits that you'd recommend not to shorten engine life.

[Guy_H]

Block 112 is the main field for this - there is no individual EGT sensor, so it bases it on reading from the O2 sensor/s, block 34 shows this as well. The scale only reads to 999c & we have seen some tuned cars exceed this on warm up runs, so you can imagine the heat being generated & effects on component life. Block 34 will show the O2 sensor, but its easier to look at 112.

Certainly the size of the dump pipe will have a direct effect on that & what the tuner does with the calibration.

Hard to do full data logs on the highway, you will need to find a "closed road" or Race track to get the data you need.

Logging details (how to do it) are here: APR - High Performance Development for Audi, VW and Porsche Vehicles.

It would be worthwhile doing round 5 logging whilst you are at it.

[pinkgti]

Block 112 is the main field for this - there is no individual EGT sensor, so it bases it on reading from the O2 sensor/s, block 34 shows this as well. The scale only reads to 999c & we have seen some tuned cars exceed this on warm up runs, so you can imagine the heat being generated & effects on component life. Block 34 will show the O2 sensor, but its easier to look at 112.

Certainly the size of the dump pipe will have a direct effect on that & what the tuner does with the calibration.

Hard to do full data logs on the highway, you will need to find a "closed road" or Race track to get the data you need.

Logging details (how to do it) are here: APR - High Performance Development for Audi, VW and Porsche Vehicles.

It would be worthwhile doing round 5 logging whilst you are at it.

Thanks Guy - looks like I'll need to do a bit more logging. Can you advise what the "typical" O2 sensor reading should be. I know that once you change from "stock" everything goes out the window, however just some "ball-park" or "typical" numbers that you'd expect with a stage 1 tune and DP would be a good start.

[Guy_H]

Thanks Guy - looks like I'll need to do a bit more logging. Can you advise what the "typical" O2 sensor reading should be. I know that once you change from "stock" everything goes out the window, however just some "ball-park" or "typical" numbers that you'd expect with a stage 1 tune and DP would be a good start.

We use some higher end tools for calibration & logging in house - but this info below might help you

From an APR rep from many years ago (referring to the APR's calibration):

Here is what I can help with and please understand that ECU Upgrades and Calibration Philosophies are always evolving as new technology is introduced and new ecu mapping and coding is continually implemented by the OEM.

Meaning, what I am about to say may not be 100% accurate to all OEM and APR calibrations across 06 and 07 style FSI engines and TSI engines in Mk5's vs. Mk6's etc.

OEM EGT Logs = Accurate
APR Stage 1 EGT Logs = Accurate
APR Stage 2 or any higher level = Inaccurate

Here's why:

EGT's are collected by the oxygen sensor which is not pre-turbine and there are models or calculations inside the ecu that know that x temp at the 02 = y temp at pre-turbine and that there is a direct relationship between the 2 as long as all hardware that affects EGT's is the same as the model is designed to allow.

This means OEM EGT logs and Stage 1 EGT logs should be perfectly accurate.

When you move to a Stage 2 ecu you are getting a calibration that was made and tested with actual EGT's that differ from the modeled EGT's as reported by datalogging the ECU. This is so because when you change the downpipe, this greatly effects the EGT model accuracy in the ECU. So, you have to insert an EGT probe and measure the EGT's some other way than the ECU. Greatly btw, is relative to your perspective. Some tuners don't consider this a major change, however, APR does. Also, there is no longer a direct relationship to ecu logged EGT's and actual EGT's due to the hardware change. It simply doesn't work that way in such a dynamic system. Lot's of EGT model mapping and coding would have to be adjusted for the new downpipe. We know by simply looking at EGT models inside the ECU of say a GTi vs. an ED30 GTi or TT-S, or even a TSI vs. a FSI. The models are drastically different. True, other hardware is different than just a downpipe between those models but a change is a change and the EGT model is very complex.

We've talked about the maximum peak EGT spec and the maximum sustained EGT spec.

ECU datalogging reads up to 999c. This is below the actual EGT spec of the turbocharger and other components. That being said, I've seen some Stage 1 ECU's knock on the 999c door and maybe hit it for a couple of data points but then it comes back down quickly as hardware protection mapping kicks in.

What concerns us is when the 999c report from the ECU stays pegged for a period of time that is too long. This usually means that the EGT's are continuing to rise way above the 999c that the ecu is able to measure.

If they hit 999c for only a few data points, you can assume the EGT's are around 1010c at maximum. However, if they hit 999c for several data points, you can only imagine how high they are climbing before settling back below the 999c.

This is what we look for in customer datalogs. There is no exact recipe but we use our experience of what our calibrations reach via an actual pre-turbine EGT probe if Stage 2 or more compared to the amount of time it reaches and exceeds 999c in the ecu logs.

If the EGT's flatline at maximum reading and never come back down during the pull, its safe to assume you have an EGT problem and the hardware protection mapping isn't doing its job. This can happen if the tuner you use turns off hardware protection mapping and runs too lean or too much boost or if they calibrate the hardware protection mapping to the same requested AFR as their too lean primary fueling surface (some tuners claim they don't disable EGT protection mapping when they use this recalibration method but they are essentially doing the same thing as turning it off) or if your wastegate is not oem like its been tweaked or replaced with one that doesn't integrate into the OEM EMS (like those with different w/g tensions than OEM). This can also happen if so much hardware has been changed that the EGT model is completely and totally useless. We've only experienced this at Stage 3 calibrations and higher. With Stage 2, we can still look at the amount of time its at 999c and based on our previous actual EGT testing via a probe pre-turbine, can estimate if this is an issue for our clients or not.

Will we give the general public our exact EGT standards at all Staged ECU Upgrade levels for your own diagnosis? Sure, if that was all it would be used for. Unfortunately, since we've started talk of this EGT stuff, other tuners have paid attention as well and have improved their product.

That's good for the community so we share what we can but helping other companies is not good for business and I like my job.

I hope this helps.

[pinkgti]

Thanks Guy.

I'll check the O2 temps as you suggest, however as I have a stage 2/non-OEM DP it's going to be a bit hard to work out the temp at the entry to the turbo without installing a specific gauge.

So as a general rule of thumb offscale = bad.

Or the other way is to knock the exhaust and see if you hear where bits of molten aluminium have collected then that's probably a bad sign also.

I have been keeping an eye on my oil temps, however I'm not sure if it's because I'm watching them more or if it's normal, however they seem to be sitting around 95-105degC (higher under load).

[h100vw]

I have been keeping an eye on my oil temps, however I'm not sure if it's because I'm watching them more or if it's normal, however they seem to be sitting around 95-105degC (higher under load).

I don't consider those oil temps high. Even weedy mk1 GTIs run hotter than that, with 150 hp less.

gavin