The Big Three's New Diesels put on a Dyno

Huntindog wrote:


There is really only one realistic possible explanation for the Ike 30K results being inconsistent with the other test result.
But you cannot consider it, let alone accept it.

You "KNOW" too much

And what that might be?


In all actuality my EGT and high intake temp theory still fits with the 30K run.

For one, when the Ford pulled the 30K lb trailer it was at night when intake temps are much cooler not allowing the intercooler to get heat soaked. The lower temps would also make the air more dense which gives the truck more power.

Second, from the few views I got in the video, the Ford ran that test in 3rd and 2nd at higher rpms. This coincides with not having high EGT's since running at a higher rpm will generally decrease EGT's since you are utilizing more of your gear torque multiplication, more rpms to power you through, enough air to burn the fuel, and the engine is exhausting the heat fast enough to keep the EGT's from getting too high. Running in a higher gear at a lower rpm (like the Ford and Ram did in the most recent Ike) with high load increases EGT's because you are dumping a lot of fuel and not enough air at low engine speeds, and the engine cannot exhaust them quick enough(hence the reason why also having a free flowing exhaust lowers EGT's).

So yes, the defueling due to high EGT theory is still very realistic whether you agree with it or not. I have no doubts that if the TFL guys would have manually downshifted the Ford and Ram then the Ford probably wouldn't have defueled due to high EGT's and both would have had quicker times. It is like Fish said earlier about how the GM was in its towing sweet spot and the Ram and Ford having much higher tow ratings were geared to run much heavier loads. But, it is what it is just like the dyno results.


Here is some good reading material on EGT's from the same company who helped test the L5P for GM, Banks Power, on what makes them increase/decrease. WHY EGT IS IMPORTANT