What's a high EGT temp?

[Sam_]

I've started taking a bit more notice of EGT temps (I usually just leave the liquid gauge on oil temp till its hot) recently and managed to get 920c yesterday on a very humid day here (we're getting closer to summer) up a steep hill with high load. I usually give the car a lot of mechanical sympathy as I know it can do wonders but just curious what a high temp is. I noticed the alarm on the liquid gauge is set to 950c.

I am going to get an AH Fabs V2 cooler shortly (friend is bringing it over from the UK I hope) which I am sure will help cooling but not sure it has much effect on EGTs, more IATs?

 

[Broken Byzan]

If you manage to hit 950 i think that's the fuel dump level for the ECU, the additional fuel cools the piston crowns and the exhaust stream, but limits power.

Airflow is important in maintaining a decent temp on EGTs, so improving the AIT with the AH IC could help.

 

[<tuffty/>]

Depends on where you are measuring it from... in the k04 the probe sits in the hotside just below the flange and egt protection kicks in at 925 degrees... an S4 for example has the probe fitted in just above where the turbo is fitted and egt protection comes in at a higher figure.. 960 ish iirc...

On an S3 then egt 's of anything much higher than 925 is potentially too high.... ideally you would want to keep them below 900 so that egt protection doesn't kick in killing performance and reduces the potential for cracking the housing....

I seem to recall reading Garrett suggesting 850 across the turbine as a ball park...

My probe is in the downpipe and see just over 700 max which is just over 800 across the turbine so for me if I saw 800 degrees or more on my gauge I would be worried...

<tuffty/>

 

[badger5]

920's it starts protection fueling kicks in..
what does your afr do under boost on liqui?

 

[Sam_]

I checked it before based on an image someone posted and it stayed in their sweet spot. I'll try and do some logging this weekend. It's only hit 920 once like I say, on that pretty steep uphill in 6th with decent throttle on a hot day. I guess it's always going to do that.

 

[badger5]

yep. its a k04 thing

 

[Westy]

I must get round to checking mine now I have the decat and 3"downpipe. My old map killed my turbo and fuel pump due to the high EGTs. Quite an expensive bill to pay

 

[Sam_]

Cheers Bill.

Westy: High EGT caused the fuel pump to fail because it dumps that extra fuel in which put it over the edge?

 

[Westy]

Cheers Bill.

Westy: High EGT caused the fuel pump to fail because it dumps that extra fuel in which put it over the edge?

Yes mate. EGTs were constantly high so the fuel pump was working its nuts off to pump the extra fuel needed to cool the engine.

 

[Sean_S3]

Yes mate. EGTs were constantly high so the fuel pump was working its nuts off to pump the extra fuel needed to cool the engine.

Was it running lean Westy ?? I'm currently having EGT issues , mainly the sensor maxing out but I also think my afr is not right.
Im having my map taken off this afternoon to be on the safe side until I can sort out the lean issue.

Cheers.

 

[Westy]

Was it running lean Westy ?? I'm currently having EGT issues , mainly the sensor maxing out but I also think my afr is not right.
Im having my map taken off this afternoon to be on the safe side until I can sort out the lean issue.

Cheers.

Yeah hugely lean. The damage was already done by the time I went to see Bill and get my car on the rollers. I now run revo stage 2 software and I know that the fueling is spot on.

 

[Sean_S3]

Not good at all then . What kind of Afr values were you seeing when running a lean mixture ?

Cheers

 

[Westy]

Not good at all then . What kind of Afr values were you seeing when running a lean mixture ?

Cheers

Have a read through my progress thread mate, all the rolling road graphs are in there with the shocking fueling.

 

[Sean_S3]

Ok will do.

Cheers .

 

[Westy]

Here you go Sean:

 

[Sean_S3]

Thanks for this.

Lambda of 11 at redline , Is that correct ?

 

[Westy]

The lower the AFR number the richer the fuelling. Ideally the fuelling should be around 12 but as you can see, my car was running lean.

Where the graph dives down on each of the 4 runs is where the EGT protection is kicking in and dumping fuel into the engine to cool.

 

[Sean_S3]

Thanks , Understanding the fueling ratio's can be a bit mind boggling !

 

[Westy]

here's a graph with the bad map compared to the new Revo with decent fuelling. This was stage 1 before I went stage 2:

 

[Sean_S3]

Fueling hold nicely at 12.5 . Im back on standard map now so I will have to do some logging of Afr and fuel trim to get to the bottom of my lean issues and high Egt. Hopefully it will be something simple to fix !

Cheers.

 

[badger5]

Thanks for this.

Lambda of 11 at redline , Is that correct ?

Its not correct as far as fueling is concerned, but a result of the 14afr under boost causing very high egt's which when protection kicks in fuel dumps, and the 11's happen. During this the timing pull is also v.high compared to cars with correct fueling under boost.

pikey map.. all the boost and no fuel adjustments.. see it often.. from some "named" tuners too *cough*

 

[Westy]

pikey map..

It was indeed. I learnt my lesson the hard and expensive way. Never again.

 

[StaceyS3]

Yes from some supposedly reputable tuners having maps requesting low fueling which could have possibly caused half my problems

And when checked said that'll be alright with egt's peaking at 1020 degrees when they drove it with me logging???

 

[Westy]

Yes from some supposedly reputable tuners having maps requesting low fueling which could have possibly caused half my problems

And when checked said that'll be alright with egt's peaking at 1020 degrees when they drove it with me logging???

Too many cowboys out there unfortunately. They want to map a car, take the money and run.

 

[Sean_S3]

Thankfully we have vagcom to help us there to double check everything is up to scratch , even when coming away from tuners with what is supposed to be tried and tested maps.

@ Westy how long did you have the dodgy map for ?

Cheers.

 

[Westy]

I had the bad map for almost 2 years. I then visited Bill and went on the rollers to find out how bad it was. When I sent my turbo away to be refurbed it turned out that it was beyond repair and has been subjected to some very very high temps:

 

[Sean_S3]

That photo should be posted whenever a new remap discussion comes up . I bet there are plenty of people driving around with bad maps who do not know the damage it is causing.

 

[Westy]

That photo should be posted whenever a new remap discussion comes up . I bet there are plenty of people driving around with bad maps who do not know the damage it is causing.

I have worse pics!

 

[Sean_S3]

That first pic is scary !!

 

[badger5]

Yes from some supposedly reputable tuners having maps requesting low fueling which could have possibly caused half my problems

And when checked said that'll be alright with egt's peaking at 1020 degrees when they drove it with me logging???

really? 1020'c measured where?