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RE: Diesel vs gas......................
You know Bert,
You should learn to keep them pharts to yourself!:B then you could use them to power your dmax instead of Ace powering his V10!
Sometimes I think that if I could plumb a line from the cab of the truck to the engine intake, I would get 70mpg pulling my 5er!! :) Plus, sometimes I get gas as well :E
Bert
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BertP
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04/13/09 11:45am |
Tow Vehicles
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Savana TV
Does anyone have any experience with using a GMC Savana 3500 as a TV? A neighbor just bought a 35' TT (7600 empty, 11,000 gvw he says) and has a Savana with a 6.0l gasser. I have never pulled anything with a full sized van so I don't have any advice for him.
Thanks
Bert
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BertP
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04/13/09 11:34am |
Tow Vehicles
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RE: Diesel vs gas......................
You forget, thought, Marty, that many diesel truck drivers still have more "gas" to add to a fire than diesel :)
Bert
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BertP
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04/12/09 06:14pm |
Tow Vehicles
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RE: Dodge cummins vs everyone else
But they are consistent. They compare the trucks that you and I would buy when we walk onto the dealers' lot. If the dealer offers V10's, then we would buy a V10. We wouldn't try to find a vehicle with the same layout as another manufacturer.
Bert
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BertP
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04/11/09 12:53pm |
Tow Vehicles
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RE: Dodge cummins vs everyone else
Marty & Jarlaxle - Tire size can account for some of it but the difference in tire size is only 4% (incidentally, Marty, the diesels in the test were all 3500 DRW trucks - see page 4 of the shootout) while the difference in gear ratios is almost 15%. That still gives the Dodge better than a 10% advantage. It would be interesting to see the results of a chassis dyno run of both trucks just to see how much power is actually getting to the rear wheels.
Bert
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BertP
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04/10/09 08:30pm |
Tow Vehicles
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RE: Dodge cummins vs everyone else
Unless you have a link to this info, I believe you are incorrect as far as the diesels are concerned. The GM was fastest, followed closely by the Dodge, and the Ford was third.
Now in the gassers, the smallest Dodge Hemi was indeed third against the larger GM 6.0L and Ford V10, but we are talking about the Cummins in this thread, not the Hemi.
And the times between the three were pretty close in that the third place truck was usually only a second or two behind first place up the hill. Not enough to make much difference really.
I found a link to the article from 2007.
http://www.pickuptrucks.com/html/2007/shootout/hdshootout1.html
That's the one. Sorry, I thought that the Ford beat the Dodge. Having looked at it again, though, it seems odd that the Dodge didn't do better. It had slightly less power then the GM (350 HP vs 365 HP) but it had a deeper RE (4.10 vs 3.73) and first gear (3.23 vs 3.10). With that gearing advantage, it should have beaten the GM.
Bert
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BertP
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04/10/09 11:14am |
Tow Vehicles
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RE: Dodge cummins vs everyone else
Wasn't there a link to an article in pickup.com (I think) in which there was a pull off amongst all three - gasser and diesel? If I remember correctly, it was GM then Ford then Dodge in quarter mile pulls up hill with a 12K lb trailer.
Bert
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BertP
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04/10/09 09:03am |
Tow Vehicles
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RE: Diesel vs gas......................
What facts, Tarantula? I seem to be the only one in this conversation providing facts. All I have seen from you so far is innuendo and hearsay. No facts, unfortunately.
Bert
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BertP
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04/06/09 12:55pm |
Tow Vehicles
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RE: Diesel vs gas......................
And???? All I have ever said is that you need HP to do anything. If the engine is at low rpm, then you need high torque to get the power. If the engine is at high rpm, then you need low torque to get the same power. How does the JD quote above contradict that?????? Notice that they did not say the it is "torque alone" just that there is high torque at low rpm - and therefore, high HP at low rpm.
Bert
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BertP
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04/05/09 02:18pm |
Tow Vehicles
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RE: Diesel vs gas......................
No one questioned what it is called. But, in order to lift the front wheels of any vehicle requires power. Regardless of what rpm the engine is turning, it requires power to lift the front end.
Bert
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BertP
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04/05/09 12:02pm |
Tow Vehicles
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RE: Diesel vs gas......................
At the risk of being picky, that tractor was not at idle. An engine produces no more power at idle than is required to run its accessories. It can - as is apparent in this video - develop power at idle rpm but not at idle. By definition, an engine at idle is producing no power.
So, how much power is that engine developing in the video? I don't know for sure but it is enough to raise the front wheels slightly. But to say that it is "all torque" is incorrect. If it was all torque and no HP, then nothing would be turning, including the engine. Since we know that that is not possible in this case, then there must be HP being developed. Not much, I suspect, but enough to raise the front wheels.
Bert
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BertP
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04/05/09 11:17am |
Tow Vehicles
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RE: Diesel vs gas......................
Tarantula, here is a post I made a long time ago. It may help you to understand where I and others are coming from:
This is getting down right silly. How about if I provide a few engine examples using 500 HP and axle rpm of 550 as a starting point? We can then figure out what happens with engines of different torque ratings (all engines will be 500 HP).
To start, if we have 500 HP available at the drive axle, we then have 500 * 5252 / 550 = 4775 lb-ft of torque.
Engine type: Diesel
Power: 500 HP@550 rpm
Torque: 500 * 5252 / 550 = 4775 lb-ft
Gear ratio required to obtain 550 rpm: 1:1
Torque output of gear reduction unit: 4775 * 1 = 4775 lb-ft
Engine type: Diesel
Power: 500 HP@1100 rpm
Torque: 500 * 5252 / 1100 = 2387 lb-ft
Gear ratio required to obtain 550 rpm: 2:1
Torque output of gear reduction unit:2387 * 2 = 4774 lb-ft
Engine type: Diesel
Power: 500 HP@2200 rpm
Torque: 500 * 5252 / 2200 = 1193 lb-ft
Gear ratio required to obtain 550 rpm: 4:1
Torque output of gear reduction unit: 1193 * 4 = 4772 lb-ft
Engine type: Gas
Power: 500 HP@4400 rpm
Torque: 500 * 5252 / 4400 = 597 lb-ft
Gear ratio required to obtain 550 rpm: 8:1
Torque output of gear reduction unit: 597 * 8 = 4776 lb-ft
Engine type: Gas
Power: 500 HP@ 5500 rpm
Torque: 500 * 5252 / 5500 = 477.5 lb-ft
Gear ratio required to obtain 550 rpm: 10:1
Torque output of gear reduction unit: 477.5 * 10 = 4775
Engine type: Turbine
Power: 500 HP@30250 rpm
Torque: 500 * 5252 / 30250 = 86.8 lb-ft
Gear ratio required to obtain 550 rpm: 55:1
Torque output of gear reduction unit: 86.8 * 55 = 4774 lb-ft
Is it my imagination or is there a pattern here?
Bert
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BertP
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04/05/09 09:19am |
Tow Vehicles
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RE: Diesel vs gas......................
The thing you seem to keep missing is that it makes absolutely no difference if the engine is turning 200 rpm or 200,000 rpm. If it is producing enough HP to life the front wheels, they will come off the ground. If there isn't enough HP, the front end will stay on the ground. Obviously, the engine turning 200 rpm will produce a lot more torque than the engine turning at 200,000 rpm but if the gearing turns the wheels at the same speed, there will be exactly the same amount of torque at the drive axle if both engines are producing the same HP.
Bert
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BertP
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04/05/09 09:08am |
Tow Vehicles
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RE: Tow Haul Questions
You don't have to use it at all if you don't want to but it does have some advantages. As mentioned earlier, it cahnges the shift points of the tranny which helps cut down on tranny hunting. It also (in the case of GM at least) changes the speed tolerances of the cruise control. If my truck is not in T/H, it will command a downshift if my speed drops 2 or 3 mph below set value. In T/H, it will allow the speed to drop 7 or 8 mph before commanding a downshift. It also downshift on decelleration differently. Mine (D/A) sounds like it is double clutching - even though it is an automatic :)
Bert
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BertP
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04/03/09 09:27am |
Tow Vehicles
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RE: Dodge CTD RPM's when climbing
The size of the breaker bar, if any, is irrelevant in measuring the torque (or HP) output of the "engine". It will change the amount of torque (but not HP) deliverd through the wrench to the nut but it will in no way alter the torque supplied by the source. Therefore, I stand by my original statement: your step-son is torque because he can supply more force than you can and you are HP because you can supply your lower force more rapidly.
Bert
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BertP
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04/02/09 02:18pm |
Tow Vehicles
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RE: Dodge CTD RPM's when climbing
I think you have these two backwards. Your step-son is bigger than you and, therefore, can presumably apply a lot more force than you can. He would be torque. You, on the other hand, are smaller and squirrelier than your step-son and can do things faster than he can. You would be horsepower. It'll be a toss up to see who gets done quicker. If torque hid an impact wrench on his side of the truck, he'll beat you, though.
Bert
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BertP
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04/02/09 01:52pm |
Tow Vehicles
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RE: Dodge CTD RPM's when climbing
Yes, much of it is wrong but a lot of it is accurate as well. There is a lot of very useful information in that thread that explains the whole HP vs torque business and why it is quite often misunderstood. Even the author in that "How it works" article got it whrong when s/he mentioned that people discuss HP when talking about cars but they talk about torque when talking about trucks. That is only true when people talk about pickups. When talking about OTR rigs, manufacturers specify the amount of HP produced by the engine and only provide torque details when you ask for them.
Bert
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BertP
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04/02/09 09:25am |
Tow Vehicles
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RE: Dodge CTD RPM's when climbing
Which site? The one you provided a link to? If so, I agree with you. That's why I said that the author was wrong in how s/he presented the information. Some of it is correct but his/her extrapolation from the given data is absolutely wrong.
Bert
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BertP
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04/02/09 09:04am |
Tow Vehicles
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RE: Dodge CTD RPM's when climbing
You should try reading the diesel vs gas thread, Tarantula. The author in the article you provided the link to is wrong and it has been proven wrong many, many times. If you check the engineering documents outlining how much power is required to get a particular load up a hill at a particular speed, it will always tell you how much HP you need not how much torque. Plus, if you look at the power ratings of virtually all engines from OTR rigs to marine engines to aircraft engines to train engines, you will always find HP ratings, never torque ratings. Some engines produce high torque and some produce low torque but in the end, it is HP that tells you what an engine is capable of.
Bert
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BertP
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04/02/09 08:10am |
Tow Vehicles
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RE: Dodge CTD RPM's when climbing
:C One can argue "torque vs horsepower" ad nauseum, as witness this site, but what it come down to is: All the horsepower in the world won't help if you don't have enough torque to nove it off the line. :B
Close. That should read: All the torque in the world won't help if you don't have enough horsepower to nove it off the line. :B If there's no HP at the drive wheels, you ain't going anywhere.....
Bert
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BertP
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04/02/09 05:25am |
Tow Vehicles
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