Forum Discussion
158 Replies
- "waiting on a new hitch to arrive next week."
Your post is today 2/1/2020. I am curious what hitch you are getting that takes a month to get? 4x4ord wrote:
ShinerBock wrote:
I think the Ram will be slightly worse than GM's time at around 12:00 minutes. Although I would like to see this test ran in 80F because I have a feeling it would significantly change the time of the Ford while not changing the GM and Ram times too much.
So you're thinking a poor performing turbo was the reason for the Duramax's terrible performance on this run and now you think the Cummins is going to do even worse? Does the Cummins have a turbo issue as well?
It is not so much that I think the Duramax did poor or that it has a turbo issue. It preformed as I would have expected. It is more of a factor that the Ford did better than expected and I have a feeling that it was related to how cool the outside temps. I would like to see how it would perform in warmer weather. This is just a hunch and I could be wrong.
Are you calculating your times based on factory advertised power numbers? If so, then they are way too high. You will need to take off 12-15% for drivetrain lose and more for altitude. The old saying was that turbo chargers loose about 1.5% for every 1,000 ft increase in elevation(gassers loose 3%). However, turbos technology has advanced since this standard and some turbos may loose less of a percentage in power than others depending on their size, blade profile, a/r ratio, and so on. Some turbos may even be able to spin faster than others without reducing reliability like ball bearing turbos over journal bearing turbo bearing. While having a 360 degree thrust bearing does not help in spooling or performance, it does help in longevity of the turbo at high speeds allowing the manufacturer to spin the turbo much faster than they used to without decreasing life expectancy.FishOnOne wrote:
ksss wrote:
Did Ford send a ringer or perhaps a better way to say it is did Ford send a prototype 2020 that doesnt have "customer available" tuning? It will be interesting to see what Ram does, if it hits where it theoreticly should for its power spec, it would suggest that either Ford is out performing their advertised power rating or they gave these guys a "hot" pickup to test. Given that Ford has historicly underperformed it would suggest a change in philosophy by Ford if it is the former.
I wonder if in years past having the best spec was great for advertising and no way for anyone to really challenge that. Now that these internet runs up big hills are so highly viewed, you cant just throw numbers out there, you actually have to back it up or you get called out for bogus power numbers. Maybe Ford has taken the approach that outperforming in these shootouts will serve them better than showing big numbers in ads but lackluster perfomance in the internet pull offs. If their goal is to be dominate on these runs , they certainly achieved it. Ultimately the Duramax probably did as could be expected (I will leave that to others to define) given its lower numbers. However, Ford's Hero run up the hill made the Dmax look anemic by comparison.
From what I'm hearing the Power Stroke is under rated. A game I'm sure the others have played. Another nice bonus is some are reporting improved fuel economy with the new Power Stroke as well.
I haven't had mine long enough to really get a feel for it but on a couple of 100 mile plus trips that included several stop lights and a little in town driving I got 19.5 on one trip and 20.2 on the other. I'm getting about 15.5 around town. I didn't buy it for the mileage but it is a bonus compared to what I was getting with my previous Ford. My problem is keeping my foot out of it. It feels like it wants to fly. I'm anxious to get the fifth wheel hooked up but waiting on a new hitch to arrive next week.- blofgren i’m with you.
Ford makes a nice quality truck but the complex PowerStroke along with its systems make me appreciate the simplicity of my in line 6 and the 6 speed backing it up. - Now the real test will be to see the long term reliability of the new Powerstroke. I’m of an age now that I don’t give a **** about being the first to the top of the hill but I want to do it many times reliably which is why I went away from Ford to my current truck.
ksss wrote:
Did Ford send a ringer or perhaps a better way to say it is did Ford send a prototype 2020 that doesnt have "customer available" tuning? It will be interesting to see what Ram does, if it hits where it theoreticly should for its power spec, it would suggest that either Ford is out performing their advertised power rating or they gave these guys a "hot" pickup to test. Given that Ford has historicly underperformed it would suggest a change in philosophy by Ford if it is the former.
I wonder if in years past having the best spec was great for advertising and no way for anyone to really challenge that. Now that these internet runs up big hills are so highly viewed, you cant just throw numbers out there, you actually have to back it up or you get called out for bogus power numbers. Maybe Ford has taken the approach that outperforming in these shootouts will serve them better than showing big numbers in ads but lackluster perfomance in the internet pull offs. If their goal is to be dominate on these runs , they certainly achieved it. Ultimately the Duramax probably did as could be expected (I will leave that to others to define) given its lower numbers. However, Ford's Hero run up the hill made the Dmax look anemic by comparison.
From what I'm hearing the Power Stroke is under rated. A game I'm sure the others have played. Another nice bonus is some are reporting improved fuel economy with the new Power Stroke as well.- Did Ford send a ringer or perhaps a better way to say it is did Ford send a prototype 2020 that doesnt have "customer available" tuning? It will be interesting to see what Ram does, if it hits where it theoreticly should for its power spec, it would suggest that either Ford is out performing their advertised power rating or they gave these guys a "hot" pickup to test. Given that Ford has historicly underperformed it would suggest a change in philosophy by Ford if it is the former.
I wonder if in years past having the best spec was great for advertising and no way for anyone to really challenge that. Now that these internet runs up big hills are so highly viewed, you cant just throw numbers out there, you actually have to back it up or you get called out for bogus power numbers. Maybe Ford has taken the approach that outperforming in these shootouts will serve them better than showing big numbers in ads but lackluster perfomance in the internet pull offs. If their goal is to be dominate on these runs , they certainly achieved it. Ultimately the Duramax probably did as could be expected (I will leave that to others to define) given its lower numbers. However, Ford's Hero run up the hill made the Dmax look anemic by comparison. 4x4ord wrote:
I've been screwing around with the numbers and I think the Duramax time was not really that far off what should have been expected based on a 39000 lb truck and trailer and 2220 ft of elevation gain climbing the hill. Based on those same numbers the Ram should climb the hill in about 12 minutes. The thing that doesn't add up is that the Ford should not have been able to climb the hill in 6 minutes and 20 seconds running at the rpm it ran at unless it is putting out more power than Ford claims.
4x4ord, I'm curious what your calculation shows, if we pretend the L5P has a bigger turbo that does not lose hp at elevation. According to GM's graph, the engine is suppose to climb from 380 to 445hp from 2300 to 2800 rpm:
We know the high elevation dyno flattens out at 320 rwhp from 2300 - 2800 rpm. Assuming it climbs 55hp (account for drivetrain loss), so that it dynos 375 rwhp @ 2600 - 2800 rpm. What time would that turn out?ShinerBock wrote:
RoyJ wrote:
Again, watch Gale Banks explain the limit of the stock L5P turbo. To go above the stock max power at sea level, essentially you have to "choke" your turbine side by activating the variable geometry nozzles at WOT (to gain turbo rpm, and therefore CFM), which is not within OEM GM parameters.
Doing that would create a lot of drive pressure and you would likely pop a head gasket before you had turbo failure. Not to mention a restriction like that would cause extremely high EGT's. It does not make sense to do this because you will not be able to make more power for any real period of time.
I know back when I had the stock VG turbo on my 2014 Cummins, I had the VGT vane position on my monitor. Both in stock form and after being tuned, going WOT the vanes would restrict to about 50% or so for a few seconds to get the wheel turning and then go fully open.
For sure, which is exactly why OEM and a good tuner never closes the VG vanes at WTO. Banks simply showed the stock turbo couldn't produce enough airflow to exceed 445hp while keeping a safe EGT/AFR. The only way to cheat that is by closing the vanes 30%, over-driving the turbo from 110k to 130k rpm. And we both agree that creates all kinds of problems.
At 10,000' elevation, the L5P consumes the same CFM to make the 445hp. However, now the turbo has to do it at a much high pressure ratio. Given a fixed compressor design, the only way to achieve this is to spin faster, and get into a lower eff land on the map.
Since we agree GM OEM programming would never do this, I believe the turbo stays at ~110,000 rpm, and therefore the L5P runs out of CFMs past 2300 rpm. That's why we see a hp plateau.- I've been screwing around with the numbers and I think the Duramax time was not really that far off what should have been expected based on a 39000 lb truck and trailer and 2220 ft of elevation gain climbing the hill. Based on those same numbers the Ram should climb the hill in about 12 minutes. The thing that doesn't add up is that the Ford should not have been able to climb the hill in 6 minutes and 20 seconds running at the rpm it ran at unless it is putting out more power than Ford claims.
