Bggrnchvy
Red Skull Member
- Joined
- May 20, 2020
- Member Number
- 663
- Messages
- 147
EGT with a stock tune/fuel/air really doesn't matter. The timing isn't aggressive enough to hurt anything. Stock motors will, even the pre dpf 325 Cummins will, run up to 1400°F+ and hang out and make rated power. Add timing and then there is more duration of burn in the cylinder and the same amount of cooling from piston squirters and coolant as before. That is when you can exceed the limits of the materials in the combustion chamber.
Bigger turbo can mean more air, but a bigger (heavier) turbine needs more engine rpm to spin. If you are undergeared or have large tires on an already fuel efficient (i.e. tall) gear set you need to drop a gear to make enough exhaust air flow to spin the charger and get the air flow in the cylinder to drop temp. The bump in mech advantage at the same time helps.
That's why compounds work, they're more efficient at scavenging the energy in the exhaust.
I'll start to back out at 1250°, and won't exceed 1350° except for a 10-30 seconds. 253k miles later it's still alive. I need compounds though, which is good because I've been waiting for a S472 since March.
I can run most anything with my 14klb trailer behind me at 72mph in 6th, but 65mph and I can only maintain RPM and slowly accel on flat ground. everything else is a downshift to direct. Not enough RPM for the sxe363 with the 5.9l. 2050+rpm seems to be about the sweet spot to make solid power with the 68mm turbine.
Bigger turbo can mean more air, but a bigger (heavier) turbine needs more engine rpm to spin. If you are undergeared or have large tires on an already fuel efficient (i.e. tall) gear set you need to drop a gear to make enough exhaust air flow to spin the charger and get the air flow in the cylinder to drop temp. The bump in mech advantage at the same time helps.
That's why compounds work, they're more efficient at scavenging the energy in the exhaust.
I'll start to back out at 1250°, and won't exceed 1350° except for a 10-30 seconds. 253k miles later it's still alive. I need compounds though, which is good because I've been waiting for a S472 since March.
I can run most anything with my 14klb trailer behind me at 72mph in 6th, but 65mph and I can only maintain RPM and slowly accel on flat ground. everything else is a downshift to direct. Not enough RPM for the sxe363 with the 5.9l. 2050+rpm seems to be about the sweet spot to make solid power with the 68mm turbine.