exhaust temp at idle

Hey altogether

just questioning what u guys see exhaust gas temps at idle.

I am tuning at the moment a BMW m50 turbo and do see quite high exhaust temps at idle.

So I do have cylinder individual exhaust temp sensors an do see up to 480°C at idle which looks quite high to me.

Running around 0,9 lambda and in average 10-12 ° btdc in idle control...

So any coments? Appreciated :-)

When the cam timing is off, you will get high exhaust temps. I don't have much experience with turbos, so it may be that temp is more typical with a turbo blocking the exhaust.

it is a 290° turbo cam (more agressive than stock) - so timing is referred to recommendation from the cam manufacturer - not stock bmw.

I did tune other turbos and havent see those numbers

any hints or experiences from your side? I am trying to figure if I am hunting the ghost...

:-)

You are the guy who "did tune other turbos and haven't seen those numbers". Sounds like you've answered your own question. My advice is to double-check the exhaust valve timing.

well - the forum is there to help each other out and share experiences.

since the egt is also related to combustion chamber design, it would be interesting for me if anyone can share his numbers on this particular engine (m50 turbo) since I havent done this engine before...

Thanks

Have you checked the actual TDC to the TDC the ECU is registering? I would suspect the ignition needs to be advanced a lot at idle and under no load - some engines have 30, or more, at idle.

My reasoning being, other than the low advance amount, is that the later the charge is burned, the less the amount of energy used moving the piston and the greater the remaining amount in the exhaust.