Pre vs Post turbo temp data log
Posted: Fri Oct 29, 2021 4:00 pm
As a follow-on to my DPF temp post here, I often see people trying to use pre and/or post turbo temps to make [some sort of] a point. So I thought I'd share some data I have that directly compares the 2 turbo temps on my PX3 3.2TD. The bit of graph I've grabbed shows cruising along and then about 1/2 way into the graph is a DPF regen cycle.
Some things I note:
- the temp between the two varies based on engine load. More load = bigger difference.
- For this bit of logging the max difference was ~150C both colder and hotter for pre-turbo. It will likely be bigger under heavy constant load.
- Normal cruising has the pre-turbo temp sitting just under 400C. Post-turbo is under 300C.
- Pre-turbo got up to 700C during the DPF regen (5 second-a-side steaks)
- While the engine torque looks like it gets close to 550Nm (versus advertised 470Nm), it's a stock tune. (I think it's a scale issue)
(The values on the left of the graph reflect where the vertical white line is. The scale is on the right hand side. EGRT=PreTurbo, EGT11=PostTurbo)
Some things I note:
- the temp between the two varies based on engine load. More load = bigger difference.
- For this bit of logging the max difference was ~150C both colder and hotter for pre-turbo. It will likely be bigger under heavy constant load.
- Normal cruising has the pre-turbo temp sitting just under 400C. Post-turbo is under 300C.
- Pre-turbo got up to 700C during the DPF regen (5 second-a-side steaks)
- While the engine torque looks like it gets close to 550Nm (versus advertised 470Nm), it's a stock tune. (I think it's a scale issue)
(The values on the left of the graph reflect where the vertical white line is. The scale is on the right hand side. EGRT=PreTurbo, EGT11=PostTurbo)
- EGRTvsEGT11.jpg (311.5 KiB) Viewed 83 times
- EGRTvsEGT11.jpg (311.5 KiB) Viewed 83 times