Ecoboost vs. V8 - Can you explain?
I'm nowhere near being a gearhead, and I can't seem to wrap my mind around how the Ecoboost outperforms the V8 in towing. I understand the fuel economy issue, but how is it that the V6 can actually h...
Forum Discussion
mich800 wrote:ShinerBock wrote:Groover wrote:
"Most modern diesels with VG turbos have very little lag. I would compare the turbo lag of my stock turbo on and stock tune my Cummins to the turbos on my old Ecoboost. With a tune, the turbo lag on my Cummins wasn't even noticeable."
The diesel that I drive the most is a 6.7 Cummins but it is in a motorhome on a 2013 Freightliner chassis and is detuned to only produce 300hp and 660lb-ft. Maybe it doesn't represent what is sold in pickup trucks. But, the 2019 F250 that I rented a few months ago had very noticeable turbo lag that even showed up in the acceleration charts that I shared. If traction wasn't an issue the Ecoboost handily beat the Powerstroke off the line.
On the Kubota tractor it is kind of hard to tell what the turbo is doing.
Ford changed the turbo on the Powerstroke in 2015 to a larger one than the previous 2011-2014 turbo. This was needed to create the 440 hp numbers, but at the expense of low end response which many who traded up from the smaller turbo version complained about.
There is no doubt that Cummins can slap a larger turbo on the Cummins with its new CP4 and make huge power, but it will loose low end response of the turbo which and will have more of an effect on lag at altitude. As I said before, it is all a give and take with turbos and it depends what the manufacturer(or owner if you are going aftermarket) wants out of their engine. For some, big horsepower is their goal, while others go for better driveability.
As far as the lower power rated Cummins in the Freightliner, that is probably due to vehicles weight as well as tuning. Generally, with the same turbo, a lower power tune with less fueling will spool slower than a higher power tune. The weight probably exacerbates the issue.
That is true. But I would bet if you really dug into it. You would find much of the turbo lag found on today's vg turbos is built in intentionally via tuning for emissions.
Yes, you are correct. Another reason is to keep drive pressure down at low rpms to keep from popping head gaskets which was an issue for all three when they switch to VG turbos. You can't add too much timing and boost at low rpm or bye bye head gasket. It took a few years for each of them to figure it out.
