Thread: Madman 2 high EGT alarm setting?

A point people need to remember is peak temps seen and safe operating limits are 2 totally different things. An engine which regularly or consistently sees higher temps will have a shorter life. So if we assume a typical Td5 will last 500,000km, then if everything else is equal an engine regularly run above 700 degC EGT will have a shorter life than an engine that never goes above 600 degC.

The more times you run at high temps, the more damage you do and the damage is cumulative. Eventually it catches up with you.

I used to alarm at 700deg but since reading up on this topic I now alarm at 650. I don't tow and don't have to deal with long uphill runs so the only time I see 650+ is when I do full throttle full revs in 3rd and 4th gear - this see peaks at 700deg about when I change gears.

So the trade off is - yes you can exceed 700 or 800 or 900 but each time you do you shorten the life of the engine. The higher the temp the more cumulative damage done.

I completely agree, as i'm regularly towing a 1500Kg boat and often uphill there are moments when i must force it cos there are sections with steep climbs where if i'm not pushing the throttle i stop, then it goes up to 900... what i do to prolonge the engine's life even in these harsh conditions is that i change the oil and filters twice a year and always using fully synth oil...and went back to stage 1 from atage 2 as well

The issue is the thermal stress will be damaging the pistons, the turbo etc. I would still be selecting a lower gear and not using all the extra power from your remap - but it is all a compromise. Truck drivers who want reliability will drive to the EGT and not to a speed limit.

Before I fitted an EGT gauge I did a run up to the Northern Territory when they had unlimited top speeds and sat on 150kph for several hours in summer with the air con running. I have no doubt now that my EGT would have been sky high and I hate to think what damage I was doing but yes the motor can do it. At one point I was following a Nissan Patrol which did blow up its motor. After stopping to see if they needed help I then carried on a bit slower.

If I was building a Td5 for sustained high EGT operation, I would be investigating ceramic coatings on the piston tops.