Strange Behaviour

[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

[Guy_H]

yep, oil temps will be fine - that would be considered normal. If they regularly exceed 140 plus I would look into it more.

[Lucas_R]

Just as an idea, i just checked some VCDS logs i did on my car just before Christmas and my exhaust temp ranges from:
Approx 500 - 985 degrees.

The 500 degree mark at around 1,500rpm (when my logs start) and the 985 degree mark right near redline. Not sure if the fact that my dump pipe is ceramic coated has any effect on these temps?

As for the oil temp - the highest ive seen mine was 105 degrees and that was after a good 10-15 run on the Pacific Highway chasing an Evo 7. Mostly around town it rarely exceeds 80-88 degrees.

[pinkgti]

Just as an idea, i just checked some VCDS logs i did on my car just before Christmas and my exhaust temp ranges from:
Approx 500 - 985 degrees.

The 500 degree mark at around 1,500rpm (when my logs start) and the 985 degree mark right near redline. Not sure if the fact that my dump pipe is ceramic coated has any effect on these temps?

As for the oil temp - the highest ive seen mine was 105 degrees and that was after a good 10-15 run on the Pacific Highway chasing an Evo 7. Mostly around town it rarely exceeds 80-88 degrees.

What size DP are you running - obviously as soon as you change the DP the calculation for turbo inlet temps is all out of whack due to different flow rates/velocities/gas expansion etc

I did think my oil temps were running a little higher than I was used to before - thought it used to run around in the 80's pre-tune (similar to your numbers). I did notice that it was heading upwards to 110degC under load driving up a hill at constant speed (normal driving). I've also noticed that the fuel economy is really bad on cruise control going up hills. Much better to change down a gear or 2 other wise fuel economy takes a big hit.

[Lucas_R]

Its a 3inch dump pipe from 42DD.

Re fuel economy, my average is 10L per 100km, and thats on a heavier Golf R and with almost 100% city driving. On the freeway it sits on about 8.0 - 8.5L per 100km.

My friend has a Mk5 GTI thats done up a bit and he averages around 8L per 100km in the city.

[pinkgti]

Its a 3inch dump pipe from 42DD.

Re fuel economy, my average is 10L per 100km, and thats on a heavier Golf R and with almost 100% city driving. On the freeway it sits on about 8.0 - 8.5L per 100km.

My friend has a Mk5 GTI thats done up a bit and he averages around 8L per 100km in the city.

I was just meaning that I've seen the fuel consumption data in the MFD hit over 30 l/100km going uphill on cruise control but if I drop it back a gear or 2 then consumption drops considerably.