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+--- Thread: Small CPL big power (/showthread.php?tid=1507)
Small CPL big power - Brock - 02-25-2017
I have a family 2 500hp max cm871 cpl2733 in my prostar, cranked to 600hp. I got better fuel mileage than most of the family 3 trucks out here and usually out pull them on the hills too.
I've read on here from rawze many times that the smaller turbo and injectors will get better fuel mileage which would explain why I do.
Here's my question. I'm looking at a pete 386 with a fresh rebuild cm871 but it's a 450hp cpl 2732 so from what I can tell, it's a family 1 maybe? So would this be smaller injectors and turbo then my 2733. I know on quickserve, part numbers are different and mine don't cross up to the ones listed on cpl 2732.
So the important question, if I turned this thing to say 550 would I possibly get even better mileage out of this truck then my prostar or would I be over working this motor too much? I have super b but honestly it's pretty flat ground so they don't work overly hard.
RE: Small CPL big power - in2trux - 02-25-2017
We have a 2010 386, cpl 2732. Big turbo on Pete, he551 tuned to 525 by gearhead and it does just fine. Flat ground maybe 5 psi boost, 205 on oil temp. No complaints, love the tune!
Pete has a larger CAC and charge flow tha same in IH.
RE: Small CPL big power - Magard - 02-25-2017
I'm sure Uniliever or Gearhead could give you that answer. Uniliever has me close to 600 on a small cpl in a Volvo. I wouldn't put a driver in it. But if you keep a eye on the pyro in the upper rpm range your good. It's a cm 2250 but I'm sure it isn't the first time they did it in a 871. I think I left a little fuel mileage on the table with timing but I figured I was pushing it enough didn't want any pre detonation working on the liners also. Mileage is still better than any stock truck I ever had including pre emission Detroits.
RE: Small CPL big power - Brock - 02-26-2017
(02-25-2017 )Magard Wrote: I'm sure Uniliever or Gearhead could give you that answer. Uniliever has me close to 600 on a small cpl in a Volvo. I wouldn't put a driver in it. But if you keep a eye on the pyro in the upper rpm range your good. It's a cm 2250 but I'm sure it isn't the first time they did it in a 871. I think I left a little fuel mileage on the table with timing but I figured I was pushing it enough didn't want any pre detonation working on the liners also. Mileage is still better than any stock truck I ever had including pre emission Detroits.
I'm not so much concerned if it can be done. I can turn it up just fine but my question is would a turned up 450 hauling 140,000 be any more fuel efficienct then my turned up 500 and would I be pushing the threshold of those injectors and turbo....
RE: Small CPL big power - gearhead - 02-27-2017
It would take alot more than 500 to push that setup.
RE: Small CPL big power - Brock - 02-27-2017
(02-27-2017 )gearhead Wrote: It would take alot more than 500 to push that setup.When I say "my turned up 500" I mean it was a factory 500 but is now 605. The factory 450 I'm thinking of buying, I'd turn it to 550 probably.
RE: Small CPL big power - Nilao - 02-27-2017
I'm thinking that once upon a time I was told my cpl2732 would max out at 625 due to the limitations of the injectors. It's not the hard parts that limit the small cpl, it's the injector.
RE: Small CPL big power - Joesixpack - 03-01-2017
A small injector maxed out isn't going to be more efficient than a larger injector at the high power limit just due to poor timing. Obviously the small injector could hit better efficiency at the lower power levels.
Same with the charger.
RE: Small CPL big power - Brock - 03-01-2017
(03-01-2017 )Joesixpack Wrote: A small injector maxed out isn't going to be more efficient than a larger injector at the high power limit just due to poor timing. Obviously the small injector could hit better efficiency at the lower power levels.
Same with the charger.
Common sense would tell you that but my real world experience is the opposite. I am on a regional 140,000lbs crude oil run in Alberta and alot of the guys I run with have isx engines. I am the only one with a family 2 as everyone running trains goes for big 525+ power and has the family 3. I pull just as good on the hills as any of them and for the most part due to my lower gearing, out pull most but most importantly is the fact that my mileage is better then any of them and my truck is a autoshift.
My smaller injectors ARE doing better... but then the question is going to even smaller ones maybe they would be even better or would it be as you said.
I could possibly just overwork the piss out of that engine.