Forum Discussion
151 Replies
demiles wrote:
The maximum torque limit on today's emissions controlled diesels is dynamic depending on many variables. The two different tests by TFL with the Ford proves this.
These are general limitations and each manufacture may use variations and set points to suit they're needs.
1)Maximum engine torque is limited by DPF soot load,atmospheric pressure, and intake pressure / temperature.
2)Transmission torque limit
3)Torque reduction for heating protection
4)Torque reduction for smoke limitation
5)Fail safe mode ECU failure
So these tests are really only valid under the very specific conditions they were performed. Change the weather conditions, temps ect and the results will probably change as well. The rated peak torque figures will only occur under proper conditions and obviously Ford is reducing it's max torque number under the TFL test conditions that day. So what is learned from this test? Ford guys don't challenge a LP5 or a RAM 6.7 during the heat of the day,wait till night time.
Exactly! With computer controlled injection and turbocharging, the manufacturers can program an array of fuel maps for many different variables. They can set the engine to reduce power if certain temps are getting to high or even program the engine to not get all the fuel(power) available in the first few gears like the Cummins has had for a while and now the new Ford from what I have read. I know from my time at Cummins that the 6.7L is definitely programmed to de-fuel if EGT's get to high.
I also know from my experience in the diesel aftermarket world, that if a 450 whp(@ 520 hp crank) tuned diesel with an intake and a free flowing deleted exhaust can get it's EGT's high enough when towing heavy to need to be turned down(de-fuel) to it's 400 whp (@ 460 hp crank) tune to keep then in check. Then there is no way a 450 hp truck with a stock intake and all of its emissions equipment will not have high EGTs pulling heavy loads. There is a reason why the aftermarket diesel tuners recommend their customers to tow heavy with their lowest power(fuel and timing) setting and high EGTs with the higher power tunes under sustained load is the main reason.
So it is not a shocker that while these new trucks will put out the advertised power numbers if all the temps are good like in normal driving or towing light to medium loads, but will reduce power output(de-fuel) to lower power numbers if the temps get too high. Although, if the Ford would have downshifted to a lower gear then it would have lowered the EGTs a little or at least kept them in check for the whole run. The Cummins was probably fine in fourth due to the 6.7L "play it safe" lower power numbers along with the Ram Active Air intake it probably had enough air to burn the fuel to keep the EGT's from getting to high. Just to be clear, these are just my theories.- The maximum torque limit on today's emissions controlled diesels is dynamic depending on many variables. The two different tests by TFL with the Ford proves this.
These are general limitations and each manufacture may use variations and set points to suit they're needs.
1)Maximum engine torque is limited by DPF soot load,atmospheric pressure, and intake pressure / temperature.
2)Transmission torque limit
3)Torque reduction for heating protection
4)Torque reduction for smoke limitation
5)Fail safe mode ECU failure
So these tests are really only valid under the very specific conditions they were performed. Change the weather conditions, temps ect and the results will probably change as well. The rated peak torque figures will only occur under proper conditions and obviously Ford is reducing it's max torque number under the TFL test conditions that day. So what is learned from this test? Ford guys don't challenge a LP5 or a RAM 6.7 during the heat of the day,wait till night time. Dadoffourgirls wrote:
I encourage everybody involved in this thread go buy a one-ton crew cab with 8 ft box and diesel engine. We will then pick a specific trailer to purchase as well. We will then pick multiple places around the country to perform testing ourselves! Who is in?
Sounds like a plan. I can be there with my 2500 CTD, but it is not exactly stock though.Dadoffourgirls wrote:
I encourage everybody involved in this thread go buy a one-ton crew cab with 8 ft box and diesel engine. We will then pick a specific trailer to purchase as well. We will then pick multiple places around the country to perform testing ourselves! Who is in?
I'll be there with my ole 2500.:B- I encourage everybody involved in this thread go buy a one-ton crew cab with 8 ft box and diesel engine. We will then pick a specific trailer to purchase as well. We will then pick multiple places around the country to perform testing ourselves! Who is in?
Huntindog wrote:
ShinerBock wrote:
Not really much point in that. You present some things as fact.... When you have no way to KNOW if it is or not.Huntindog wrote:
https://www.vocabulary.com/dictionary/theory
When you have a theory, you have a set of beliefs or principles that might not be proven yet.
I do believe I said it was my theory and what I think happened multiple times in this thread so....
I would love to hear your theory or educated guess and debate it.
If you are not willing to open your eyes to ALL possibilities, then your theory becomes stronger in your mind to the point that you believe it to be fact.
A closed mind cannot learn anything.
Have a nice day
No, it seems you are a bit confused and should reread my statements without the bias hatred you are having right now. I stated that this is what I think happened and that it is my theory multiple times and backed it up with facts on why my theory is very plausible. That is how rational and logical theories work. They are based on knowledge, experience, and facts which I presented to support my theory. We use these theories to explain things that we cannot prove until they are either proven or a better theory presents itself.
If you have another possibility that is more plausible then I willing to debate it as I said earlier, but you have yet to to state one while complaining that I won't listen to it. How can I "open my mind" if another theory has not been presented?
I just think that you are biased due to who is stating the theory rather that the theory itself.ShinerBock wrote:
Not really much point in that. You present some things as fact.... When you have no way to KNOW if it is or not.Huntindog wrote:
https://www.vocabulary.com/dictionary/theory
When you have a theory, you have a set of beliefs or principles that might not be proven yet.
I do believe I said it was my theory and what I think happened multiple times in this thread so....
I would love to hear your theory or educated guess and debate it.
If you are not willing to open your eyes to ALL possibilities, then your theory becomes stronger in your mind to the point that you believe it to be fact.
A closed mind cannot learn anything.
Have a nice dayHuntindog wrote:
https://www.vocabulary.com/dictionary/theory
When you have a theory, you have a set of beliefs or principles that might not be proven yet.
I do believe I said it was my theory and what I think happened multiple times in this thread so....
I would love to hear your theory or educated guess and debate it.- https://www.vocabulary.com/dictionary/theory
When you have a theory, you have a set of beliefs or principles that might not be proven yet. 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
