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+--- Thread: CM870 economy (/showthread.php?tid=8042)
CM870 economy - BradyHodges81 - 02-11-2022
First time post: Recently got a 2006 truck with this engine. EGR is intact and after watching your video on an 871, I cleaned as many sensors as I could get to. Before cleaning I got 4.1 hauling an overweight load 1000 miles, got 6.5 bobtail coming back. Only mod, put a 6” single stack in place of the muffler. Also... this is a 450 engine, the person I purchased from said a 550 cam had been installed. I’m not sure if tuning was performed or not. It feels a little weak to me. Question time... is that normal mpg for this engine? Is there tuning I need to have done to maximize efficiency (if so, who;how)? And finally, what do you recommend for upgrades to this engine to gain a couple more lbs of power but mostly for economy?
RE: CM870 economy - Rawze - 02-11-2022
just for reference:
the higher tier cam creates an efficiency mis-match and does not improve anything at all on the engine without all the other hard parts like the higher tier pistons, the bigger injectors, matching CPL programming, etc. to go along with it.
RE: CM870 economy - BradyHodges81 - 02-11-2022
Thank you. I’ll keep driving till it’s time for a rebuild.
RE: CM870 economy - Chamberpains - 02-18-2022
(02-11-2022 )BradyHodges81 Wrote: First time post: Recently got a 2006 truck with this engine. EGR is intact and after watching your video on an 871, I cleaned as many sensors as I could get to. Before cleaning I got 4.1 hauling an overweight load 1000 miles, got 6.5 bobtail coming back. Only mod, put a 6” single stack in place of the muffler. Also... this is a 450 engine, the person I purchased from said a 550 cam had been installed. I’m not sure if tuning was performed or not. It feels a little weak to me. Question time... is that normal mpg for this engine? Is there tuning I need to have done to maximize efficiency (if so, who;how)? And finally, what do you recommend for upgrades to this engine to gain a couple more lbs of power but mostly for economy?
1st off I'd say you need absolute proof of what cam was installed. Taking someone's word for it can go either way. But I now always assume it's a lie and get my verified proof. Then you can have the ECM programming looked at. Any mis match in parts and the ECM won't magically correct for it. But you need to absolutely know what is in there in order to have the ECM programmed right.