NefMoto

Hi folks, I'm running a 1.8t with a k04 hybrid. I'm sure most of us are aware that one of their biggest issues is super high egt's.

My question is though, what's acceptable and what are the methods people use to check egt's.

I've done plenty of looking around and the majority of people say around 900-920 Celsius is about as high as we want to see on the k04-023 housing (so it's actually turbine inlet temp).

From looking at other peoples logs I see some hitting 900c or so at top end of a 3rd gear run! What about a 4th gear run? Or sustained 3rd/4th/5th abuse around a track or mountain roads? Is it acceptable to see 900c in 3rd gear?

I currently see ~880c at the top of a 4th gear run, but if I do a couple of runs through the gears or back to back 4th gear runs I get up to protection fairly easily (920c).

How do you more experienced guys measure real world use egt's?

This was a 16 second 4th gear run, boost has been smoothed since but didn't affect egt.

real world EGT's=thermocouple in the exhaust manifold or hot side housing. everything else at this point is speculation based on wrong models.

Thanks for your reply, however (as I mentioned), this is real measured egt, not modelled.

ETA - Upon re-reading my post maybe I wasn't so clear. To confirm, the thermocouple is in the hotside housing.

Any opinions folks?

Reduce boost, increase ignition angle.

Thanks Dd' if you had these numbers on your dyno, would they be unacceptable to you?

900C pre-turbo EGT is within design limits usually.
Your objective is to not let it keep climbing until meltdown, but rather stabilize it at some value by dumping lots of fuel and reducing boost.

Thanks prj, well it's in the turbo hotside, which I'm led to believe it's slightly hotter there also (as all the gases converge into the bottleneck and isn't a measurement of a single cylinder) so from my assumption (be it a good or bad one!) is the egt's would be right around 900c pre-turbo.

As soon as it gets to 920c it hits protection and as you say dumps fuel, then it will cycle up and down +/- 10c's as it cycles between dumping fuel and returning to normal.

I seldom see this mind, usually it's at the top of 4th after a few mins of giving it stick or deep into 5th gear but I just get close to the protection during 4th gear logs. Seeing other logs hitting >900's (measured) in a 3rd gear pull just doesn't sound ideal to me.

Think I'm worrying too much :) Cheers guys

I'd try to get them to be sustained around 850. 900 pre-turbo is not an issue, but it's also not ideal.

Ok great! Thanks, I'm still yet to port the hotside so that will alleviate the temps a little, think it's certainly time for wmi by the looks.

Cant agree with the pros here.

Friends of me working at BW/3K/KKK and the material is capable for 950°C.
On a turbo the temperature is energy and energy is what we want :)

My BTS is set to 950 and i have no problems with the wardware on my K04-064 with D5S material.
On a Garrett in combination with cheap material manifold i would set it lower.

I think the problem is not just the turbo, but mainly engine internals.

Besides fitting EGT sensor, what is the variable that needs to be logged in Me7?

tats_w is what I log for the factory fitted EGT sensor

EGT is always lower the further you go away from the port.
EGT should be limited to design limit. On VAG using the factory sensor it tends to be around 950-980C.
With these EGT's components usually last through the warranty mileage of the car, however factory calibration is emission/consumption-first.

On OEM quality parts I would not worry at all about 900C EGT in turbine housing.

Sure, with hotter EGT's things wear quicker, but components have temperature design specifications for a reason.

I dont have tats_w in my file

Any way of edding it in ecu. file?

You have a narrowband EGT sensor...It's only going to tell you if temp is over 945C unless you have fitted RS6 units.

I know that. It is still usefull information.

Thanks for your opinions guys! Really helps.


I've seen some claims that turbo inlet temperatures is generally slightly higher than egt temps measured in a single runner. Albeit it's further away from the exhaust port, they all converge at the collector so there's more backpressure and the sensor sees continuous gas pulses from each firing event across all 4 (baby 4 cylinder here :) ), rather than the sensor in a single runner which would see the pulses less often.

Seems to make sense in theory, but theory never always reflects what actually happens.

950-980c is quite high! I think I'll leave it as is for now then, head for more boost/leaner afr when the hotside is ported and wmi is installed.

With a really really good exhaust wrapping on the runners you might get closer to same temp and for sure better use of the heat and better keep the speed of exhaustgases all the way to the turbine. But exceed temp close to head, hardly. :-)

Correct me if im wrong..  Internals like valves and stuff are protected by dumping alot of fuel.. But the down side with that is that the turbo and the manifold will be set on fire instead. You kinda pushes the problem further down the line. To balance this up you need to add ignition to also burn the fuel but then you are playing a danger game with the knocking.  I think i have read a post with Fotis saying that you need to add fuel and give mor ignition and lower boost to get it balanced.

Yep. At some point this is the only sane fix.

You are wrong.

Please share your thoughts..

There is no combustion taking place in the manifolds in that scenario.

ATR