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Re: new engines for the GMCs [message #316345 is a reply to message #316344]

Thu, 20 April 2017 18:27

kerry pinkerton

Messages: 2565
Registered: July 2012
Location: Harvest, Al

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Senior Member

Mike S wrote on Thu, 20 April 2017 18:08

...
It takes X amount of energy to move Y mass vs drag/ mechanical load. It's why we get the same mileage no matter what gear we put in. The ls motors at best are 5-10% more mechanically efficient than the 455. ...

So the short answer is it will be fine, any gear you run. Look at your trucks, it will pull down the road that 4 ton trailer at 1800 rpm until you hit a hill and need more power. Then it adds fuel until it can't compensate, then it down shifts.

I'd tend to agree. Our diesel pusher has 330 HP and 850 ft lbs of torque. I have an aftermarket product that hooks into the coach computers and displays lots of stuff including HP and torque in real time. Even with a 26000 (empty) coach with the aerodynamics of a concrete block, it takes less than 100 HP and 250 ft lbs of torque to maintain 55 on flat ground. Hit a hill and both numbers and gallons/minute of fuel rate go up and the 6 speed Allison downshifts if the RPM gets down near the peak torque RPM (1550 RPM)...depending on which transmission mode I'm in.

My concern is how much torque the 6.0 (LS) has at 2500 RPM without a smart tranny and lots of gears and a lockout converter. While I can assure you that my 1/2 ton with the 6.0 will cruise at 60 at 1500 (or less), as SOON as I hit a hill, the RPM goes up either because the lockout converter unlocks or it downshifts. It's so smooth you can't tell unless you're watching the readouts but it does. The thing is, I don't know what it would do if there was a way to hold it at 2000 RPM and try to accelerate without downshifting. I'm suspecting not that well but probably at least as good as my 403. I also get about 18-19 on the highway. BUT, if I put any load on it due to a trailer the mileage tanks. Even an empty flatbed car hauler (weights about 2000 lbs)causes mileage to drop to 10 mpg. Put a car on the trailer and expect 5-6 mpg. It will still skoot with the weight but might go to 3rd at 60 and 5500 RPM which just ain't gonna happen with a 425 behind it.

Kerry Pinkerton - North Alabama Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L

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[Message index]

		new engines for the GMCs By: Mike S on Thu, 20 April 2017 13:49
		Re: new engines for the GMCs By: Justin Brady on Thu, 20 April 2017 13:53
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 13:55
		Re: new engines for the GMCs By: Justin Brady on Thu, 20 April 2017 13:56
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 13:59
		Re: [GMCnet] new engines for the GMCs By: James Hupy on Thu, 20 April 2017 13:54
		Re: [GMCnet] new engines for the GMCs By: USAussie on Thu, 20 April 2017 17:37
		Re: [GMCnet] new engines for the GMCs By: Botts Chuck on Sat, 22 April 2017 16:59
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 14:09
		Re: new engines for the GMCs By: Hal StClair on Thu, 20 April 2017 14:39
		Re: [GMCnet] new engines for the GMCs By: jimk on Thu, 20 April 2017 14:30
		Re: new engines for the GMCs By: JohnL455 on Thu, 20 April 2017 14:32
		Re: new engines for the GMCs By: Hal StClair on Thu, 20 April 2017 14:53
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 14:50
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 15:00
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 15:03
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 15:10
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 15:16
		Re: new engines for the GMCs By: lqqkatjon on Thu, 20 April 2017 15:50
		Re: [GMCnet] new engines for the GMCs By: k2gkk on Thu, 20 April 2017 17:16
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 15:56
		Re: new engines for the GMCs By: Hal StClair on Thu, 20 April 2017 16:46
		Re: new engines for the GMCs By: Harry on Thu, 20 April 2017 16:49
		Re: new engines for the GMCs By: Matt Colie on Thu, 20 April 2017 17:07
		Re: new engines for the GMCs By: A Hamilto on Thu, 20 April 2017 17:18
		Re: [GMCnet] new engines for the GMCs By: Ronald Pottol on Thu, 20 April 2017 16:43
		Re: [GMCnet] new engines for the GMCs By: Hal StClair on Thu, 20 April 2017 17:01
		Re: new engines for the GMCs By: kerry pinkerton on Thu, 20 April 2017 17:09
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 18:29
		Re: new engines for the GMCs By: kerry pinkerton on Thu, 20 April 2017 20:00
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 20:07
		Re: [GMCnet] new engines for the GMCs By: USAussie on Thu, 20 April 2017 17:42
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 18:08
		Re: new engines for the GMCs By: kerry pinkerton on Thu, 20 April 2017 18:27
		Re: new engines for the GMCs By: kerry pinkerton on Thu, 20 April 2017 18:31
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 18:32
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 18:37
		Re: new engines for the GMCs By: Hal StClair on Thu, 20 April 2017 18:52
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 19:08
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 19:12
		Re: new engines for the GMCs By: Mike S on Thu, 20 April 2017 19:15
		Re: new engines for the GMCs By: jhbridges on Thu, 20 April 2017 20:57
		Re: [GMCnet] new engines for the GMCs By: Mr ERFisher on Thu, 20 April 2017 21:15
		Re: new engines for the GMCs By: Francois on Fri, 21 April 2017 00:35
		Re: new engines for the GMCs By: Chris Tyler on Sat, 22 April 2017 07:08
		Re: new engines for the GMCs By: jhbridges on Sun, 23 April 2017 07:55
		Re: new engines for the GMCs By: Mike S on Sun, 23 April 2017 09:29
		Re: new engines for the GMCs By: Hal StClair on Sun, 23 April 2017 15:21
		Re: new engines for the GMCs By: TR 1 on Mon, 24 April 2017 17:40
		Re: [GMCnet] new engines for the GMCs By: Ken Henderson on Mon, 24 April 2017 18:09
		Re: [GMCnet] new engines for the GMCs By: richshoop on Thu, 27 April 2017 21:17
		Re: new engines for the GMCs By: Chris Tyler on Mon, 24 April 2017 08:14
		Re: new engines for the GMCs By: Mike S on Mon, 24 April 2017 08:42
		Re: [GMCnet] new engines for the GMCs By: James Hupy on Mon, 24 April 2017 09:13
		Re: new engines for the GMCs By: jhbridges on Mon, 24 April 2017 11:12
		Re: new engines for the GMCs By: Mike S on Mon, 24 April 2017 20:17
		Re: new engines for the GMCs By: kerry pinkerton on Mon, 24 April 2017 21:05
		Re: new engines for the GMCs By: TR 1 on Tue, 25 April 2017 09:33
		Re: [GMCnet] new engines for the GMCs By: Dolph Santorine on Tue, 25 April 2017 09:41
		Re: new engines for the GMCs By: A Hamilto on Tue, 25 April 2017 11:45
		Re: new engines for the GMCs By: Hal StClair on Sat, 29 April 2017 01:31
		Re: new engines for the GMCs By: TR 1 on Mon, 01 May 2017 06:28
		Re: new engines for the GMCs By: jhbridges on Tue, 25 April 2017 11:06
		Re: new engines for the GMCs By: kerry pinkerton on Tue, 25 April 2017 12:24
		Re: new engines for the GMCs By: jknezek on Tue, 25 April 2017 12:49
		Re: new engines for the GMCs By: A Hamilto on Tue, 25 April 2017 12:52
		Re: [GMCnet] new engines for the GMCs By: Ken Henderson on Tue, 25 April 2017 13:25
		Re: new engines for the GMCs By: TR 1 on Wed, 26 April 2017 21:14
		Re: [GMCnet] new engines for the GMCs By: Olly Schmidt on Thu, 27 April 2017 06:04
		Re: new engines for the GMCs By: rcjordan on Thu, 27 April 2017 06:34
		Re: [GMCnet] new engines for the GMCs By: James Hupy on Thu, 27 April 2017 09:08
		Re: new engines for the GMCs By: jhbridges on Thu, 27 April 2017 11:22
		Re: [GMCnet] new engines for the GMCs By: James Hupy on Thu, 27 April 2017 11:41
		Re: new engines for the GMCs By: kerry pinkerton on Thu, 27 April 2017 14:51
		Re: new engines for the GMCs By: jhbridges on Thu, 27 April 2017 13:52
		Re: new engines for the GMCs By: kerry pinkerton on Sat, 29 April 2017 07:38

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