Turbo or supercharge and NA gas engine
Fellow gearheads good morning, had a discussion with a coworker about turbo charging or supercharging an GM 6.0, Ford 6.2 or Ram 6.4. This is not a you need a diesel or buy a diesel question. Just you...
Forum Discussion
Turtle n Peeps wrote:transamz9 wrote:
Correct me if I'm wrong but I believe the main benefit for forcing air into an engine for towing is the fact that it will give it a significant boost in torque at a lower RPM range. All you guys are thinking about is HP. You could tune the engine to produce the same amount of peak HP but could get a significant amount more peak Torque or at least lower the peak torque in the RPM range to make the towing experience more relaxing. The Fuel mileage wouldn't really change that much. The energy used to move the load won't change much you'll just be able to do it at a lower RPM more often. If anything the fuel mileage may increase a tad.
Any time you add air to an engine (supercharging) you will have to add fuel. It doesn't matter at what RPM. Remember, gasoline engines, unlike diesels need to run in stoichiometry ratios. If you run twice the air (around 14 psi) you will need twice the fuel because you just made your engine twice as big.
Anytime you supercharge an engine you will use more fuel. It takes energy to turn the rotors or impellers and like I said above you need more fuel to go with the air you just added.
I have often hear people say that turbo chargers are free power. LOL, I wish! I've even seen this written in well know books written by people that should know better.
Another problem with supercharging is you have to over fuel to keep things cool and detonation away. This is one of the reasons the Ecoboost gets really bad mileage when towing when it's hot out. Ford over fuels to cool the whole system off...............or they try too. Sometimes it doesn't work and the engine de-rates to save itself.
As far as the big block goes. Sure you can do a CD on a big block but then you have 4 big old heavy pistons you are dragging up and down the bores causing a bunch of friction. And then you have the smog problem with the big bore. That's why Ford went to a V10. Small bore but big CI. It was a good idea and it worked.
Maybe I didn't explain my thinking right. I understand that when you add the air you also add the fuel but that's what I'm saying, if it takes 300 hp to do the work then 300 hp at 2500 rpm shouldn't use any more fuel than 300 hp at 4500 rpm. My biggest beef with towing with a gas motor has always been the constant shifting. The torque band is too high in the rpm range. You start slowing so you push the skinny pedal to get the power. When it gears down then it's making so much power you have to let up on the pedal so it dont overspeed so it gears back up. Now, its below the powerband again and starting to slow. Repeat until you make the top. If they could force feed it and tune it to peak a a reasonable hp it would in my opinion be a much better towing platform. Look at what they have with the 3.5 eco. Just under 400hp in the f150 for towing duty cycle up to I believe 600+ in the gt . They could tune it to the task.
