PDA

View Full Version : More Boost = Higher EGT?



gmenor
02-22-2005, 18:06
I ordered SS Diesel's air intake and installed last weekend. I normally run 70 mph with boost at average 5-6 and EGT average at 400 (2250 rpm). I ran it for a 70 mile run and noticed a average 6-7 boost and and EGT average at 420 (same rpm). This was posted on the best air filter posting. Just basic understanding of turbochargers, more boost means more exhaust output (higher heat) to the turbo. I guess JohnC reply has got me thinking that my understanding of the turbo application is wrong? More boost will have to create more heated exhaust temperature to turbo to run. Thanks in advance for getting me straight on this.

Scooby
02-23-2005, 03:19
When I put the SSDiesel air filter on, I saw noticibly quicker boost pressure, and slightly less egt, due to higher boost for same load. If you are seeing higher egt with same load and higher boost, I wonder if you had a headwind (more load), or higher ambient temps. I may be wrong, but with the load being the same, more boost will bring egt down, up to a point, and Im sure you are not at that point running empty.

gmenor
02-23-2005, 03:42
I drove around town and noticed quicker boost (and 1-2 pounds higher) but at the same time higher EGT temperature.

Billman
02-23-2005, 05:01
The Air-Intake you guys have is not the best choice...

rjschoolcraft
02-23-2005, 06:07
Originally posted by Billman:
The Air-Intake you guys have is not the best choice... I would agree with that.

Increased boost, especially with intercooling, brings egt down. Without intercooling, it will lower egt until your intake air temperature gets too high, then it will increase egt. When I first installed the middle Kennedy chip running about 12-13 psi boost without intercooler, I saw about a 200F drop in egt...until climbing mountains in Colorado and California, where boost had to stay high for extended periods. Then the egt would climb.

My bet is that breathing the warm underhood air is what is causing you to see higher egt.

Scooby
02-23-2005, 11:43
There is much debate about the effect of drawing air from under hood & from under fender. How much cooler is the air when drawing from fender-- especially with the holes in the fender into the engine compartment?? I dont know. SSDiesel said they tested both ways on a loaded vehicle, and saw no increase in IAT. Of course, they are the ones selling the air cleaner. I am planning on getting the AutoEnginuity software in the future, and I will be doing a test on IAT as soon as possible. I kept my old airbox, and it takes 10 minutes to put it back on. I'll check both ways. It'll be a few months though. Had to buy laptop first !!
smile.gif