Elwood2020 Posted July 24, 2020 Share Posted July 24, 2020 I have a 2003 ch613 with a e7-427 engine. Heavy haul ( double frame ) 4.42 gears, lift axle, 13 speed Eaton. I recently bought the truck and overhauled it. It runs good , smooth , but it’s a slug with 80k on my lowboy. Has anyone done the rochester diesel upgrades? they suggest stage 2 injectors, manifold and turbo. Claiming 550hp range. ??? Before I spend the coin I was looking for some more feedback from other driver. 2 tuners and rochester diesel said to leave the ecm alone. Any other options or suggestions would be greatly appreciated! thanks. Quote Link to comment https://www.bigmacktrucks.com/topic/63443-my-427-needs-more-power/ Share on other sites More sharing options...
Mack Technician Posted July 24, 2020 Share Posted July 24, 2020 (edited) Truck looks nice and fresh for its age. Your asking a lot of a 12 liter. Thing’s squatting a big load. I’d check boost system for leaks under pressure, make sure I have fuel psi and then ECM flash it up to 460HP. I’d have to check, pretty certain turbo should be the same....427 to 460. EUP’s will be the same. Injectors, i’d have to check. @550 HP the heads will crack and stuff may come apart. That’s 14-15 liter country. Edited July 24, 2020 by Mack Technician 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63443-my-427-needs-more-power/#findComment-456558 Share on other sites More sharing options...
fjh Posted July 24, 2020 Share Posted July 24, 2020 Yup I agree with Tech ! Also Its unfortunate but in that era is the year prior to Egr They were struggling to meet emissions Targets And to do so they were being stingy with fuel ! We had a lot of power complains back then, we even dynoed 460s that were putting barely 360 to the ground And they would NOT Fix it! We live in steep country here and need the ponys to get things up and down mountain sides anything less than 500 hp is inadequate!The V8 or Mp ten was the answer for this However they saw fit to remove these from the line up! Quote Link to comment https://www.bigmacktrucks.com/topic/63443-my-427-needs-more-power/#findComment-456570 Share on other sites More sharing options...
Elwood2020 Posted July 25, 2020 Author Share Posted July 25, 2020 Thanks Mack technician. This is why I’m asking before I blow this thing up. I’ll check the pressures and verify I don’t have leaks and flash the ecm to 460. If you could let me know about the injectors and turbo that would be much appreciated! Quote Link to comment https://www.bigmacktrucks.com/topic/63443-my-427-needs-more-power/#findComment-456624 Share on other sites More sharing options...
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