danl Posted June 12, 2015 Share Posted June 12, 2015 I'm a rookie to big trucks. Have a '04 Vision CX613 setup as a water truck and pulling a skidder rigged for forestry spraying. Just had a complete REMACK overhaul. My question relates to the power curve. This truck seems to have all the power I could ever need if I'm running upper 60's to 70+ mph, but along the way it seems kind of doggish. My mind says at any given RPM the trucks power should be about the same. Why does it have noticeably more power at the same RPM's if I'm hauling A**. I know this is supposed to be a highway truck. Is it air supply? I ask because most of my hauling is smaller roads going 40-55 mph and I'd love to have that high speed power at lower speeds. Again, down shifting at lower speeds to get similar RPMs doesn't give me the same power. This applied before and after the overhaul. I'm sure somebody out there can explain. Thanks. Quote Link to comment https://www.bigmacktrucks.com/topic/40448-can-someone-explain/ Share on other sites More sharing options...
41chevy Posted June 12, 2015 Share Posted June 12, 2015 Was the power curve the same before the ReMACK?What final gears are in it? That will cause it to be doggy.Highway and Vocational gearing is different Quote "OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK" Thomas Edison “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’” P.T.CHESHIRE Link to comment https://www.bigmacktrucks.com/topic/40448-can-someone-explain/#findComment-293104 Share on other sites More sharing options...
Dirtymilkman Posted June 13, 2015 Share Posted June 13, 2015 Sounds like at 60 to 70 you're in youre peak power. I think peak torque is at or around 1300 rpm and horsepower is 1600 1800 rpm Quote Link to comment https://www.bigmacktrucks.com/topic/40448-can-someone-explain/#findComment-293154 Share on other sites More sharing options...
Timmyb Posted June 13, 2015 Share Posted June 13, 2015 a friend of mine had a 500hp cummins with 1650ft/lb of torque, but in the top two gears it had 1850ft/lb. is it possible your truck is set up similar? I'm not sure if mack does that? Quote Link to comment https://www.bigmacktrucks.com/topic/40448-can-someone-explain/#findComment-293220 Share on other sites More sharing options...
wiserfrombud Posted June 14, 2015 Share Posted June 14, 2015 Good call TimmyB! I belive up until the newest 505 C PLUS, all Macks and Volvos had that big torque in the top two gears only. Quote Link to comment https://www.bigmacktrucks.com/topic/40448-can-someone-explain/#findComment-293307 Share on other sites More sharing options...
wiserfrombud Posted June 14, 2015 Share Posted June 14, 2015 Good call TimmyB! I belive up until the newest 505 C PLUS, all Macks and Volvos had that big torque in the top two gears only. Quote Link to comment https://www.bigmacktrucks.com/topic/40448-can-someone-explain/#findComment-293308 Share on other sites More sharing options...
wiserfrombud Posted June 14, 2015 Share Posted June 14, 2015 Good call TimmyB! I belive up until the newest 505 C PLUS, all Macks and Volvos had that big torque in the top two gears only. Quote Link to comment https://www.bigmacktrucks.com/topic/40448-can-someone-explain/#findComment-293310 Share on other sites More sharing options...
Timmyb Posted June 14, 2015 Share Posted June 14, 2015 Think it was more a stab in the dark. But I know manufacturers do a few little tricks like that. Another one I heard was giving an extra 20hp while on cruise control. Anyway, will mack plug in and give you full power in the lower gears? Quote Link to comment https://www.bigmacktrucks.com/topic/40448-can-someone-explain/#findComment-293368 Share on other sites More sharing options...
danl Posted June 18, 2015 Author Share Posted June 18, 2015 Guys, thanks for all the input. It is becoming apparent to me all the things they can do with the computer. Your comments give me some things to talk to mack about. We are hitting our busy season, so I will likely be living with it for the next few months. If I make any head way with mack, i'll post what they said. Thanks again. Quote Link to comment https://www.bigmacktrucks.com/topic/40448-can-someone-explain/#findComment-293860 Share on other sites More sharing options...
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