For Sale - 2006 Dodge Ram 2500- Flatbed for long box bed Winch bumper Flat Bed for Long Box 3rd generation Cummins Tootlbox are included with key I have a flatbed for 3rd Generation dodge Cummins. This flatbed comes with a gooseneck hitch already in the bed. The winch bumper is part of the set. Tootlbox have a key to lock and unlock all box a single key. There is rust starting and electrical will have to be sorted out on your own.
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Price: $1,000.00
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Location: New Meadows, Idaho
I have been digging and digging and everything I read contradicts itself so I want to get a discussion going on this. There is a formula for efficiency that states that a higher compression ratio equates to a higher efficiency percentage. However, we all know the truck pull guys are running no compression and enough boost to top your air compressor at home. Then we have nascar guys running 14:1 gassers. Now the main point of discussion is 4 core things. Effective pressure and density/temperature/pressure at TDC compression. Effective pressure is the theoretical compression ratio you would have when running a turbo. Meaning an engine with 18:1---0psi boost has the same TDC compression pressure as an engine with 15:1----4.3psi boost, so the latter engine has an effective CR of 18:1. So using those 2 engines, here is what I get with everything being equal other than boost and CR. These are all figures at TDC Compression before any fuel or anything comes into play (I haven't got that complex with formulas, yet). [TABLE=width: 500][TR][TD]Parameter[/TD][TD]Engine A[/TD][TD]Engine B[/TD][/TR][TR][TD]Compression Ratio[/TD][TD]18[/TD][TD]15[/TD][/TR][TR][TD]Boost[/TD][TD]0[/TD][TD]4.3[/TD][/TR][TR][TD]Pressure (psi)[/TD][TD]841[/TD][TD]841[/TD][/TR][TR][TD]Temperature (F)[/TD][TD]1318[/TD][TD]1193[/TD][/TR][TR][TD]Moles of air (Density)[/TD][TD]0.0406[/TD][TD]0.0531[/TD][/TR][/TABLE]As you can see there is a 10.5% temperature difference and a 23.4% density difference. Now all the gasser forums I go to say these 2 engines would have the same power as they go by pressure for some reason and diesel guys go by density. I have no idea why but ok. So to me, because there is more density in engine B, you could throw more fuel in it so you could get more power. However, the counterattack of engine A is that the higher compression gives it a big edge on efficiency which I think is what the gasser guys are going by. Now I did run across one guy who said CR wins at low RPM but as you increase RPM, you need flow, so a low CR high boost engine would start to take the lead on power. There is also the difference in temperature which would make the fuel ignite faster. My books say igniting the fuel and having it burn as fast as possible is another trick to efficiency, which is why common rails are in production because they inject all of the fuel in an instant. The preinjection seems to just be there to make it marketable (quiet). I have searched for a long time, posted to forums about the actual physics of it so they could possibly enlighten me, but they told me they dont seem to know either. So does anyone have anything to add to this that I haven't already said concerning engine A vs engine B or just more info on the principles behind each scenario?