โOct-04-2012 05:21 PM
โOct-07-2012 08:47 PM
No, that is IMPOSSIBLE. A turbine simply CANNOT have those power numbers, it just is not possible! Turbines spin an incredibly high RPM's (they often idle over 15,000RPM!)...the horsepower will ALWAYS be much higher than the torque! Again: this is basic physics!
โOct-07-2012 06:18 PM
jmtandem wrote:This discussion always reminds me of the specifications for the M1A1 Abrams tank. 135,000 lbs, top speed of 60 mph, able to climb 45% slopes! And all with 270 ft lbs of torque!
Granted there have been some varants of the Abrams tank but here are the numbers. It has a Honeywell 1500 shaft horsepower multi fuel turbine engine that equates to 24.5 hp per ton, develops 2750 foot pounds of torque, mated to an Allison six speed trans. It has a governor that will not let it go faster than 45 mph on pavement and the tank is not driven much faster than 35 on pavement and 25 on dirt. It gets 1.67 gallons per mile. Engine start up burns 10 gallons. Cost new is just over eight million per copy. It has a crew of four. What does this have to do with a diesel or gas motorhome?
โOct-07-2012 06:10 PM
โOct-07-2012 05:17 PM
Again, no one has explained how a high reving gas turbine (with torque levels under 300 ft-lbs) can move heavy tanks up steep inclines if it is only engine torque that does it.
โOct-07-2012 05:10 PM
This discussion always reminds me of the specifications for the M1A1 Abrams tank. 135,000 lbs, top speed of 60 mph, able to climb 45% slopes! And all with 270 ft lbs of torque!
โOct-07-2012 04:27 PM
Lots of
diesel lovers on this forum[
/b] and the diesels have their points-----------------both good and bad. For the way we use ours (we pull a 5000 lb toad), a diesel made no sense, and we have been very pleased with the "lowly" 310 hp V10.
โOct-07-2012 02:05 PM
โOct-07-2012 01:45 PM
uncleluap wrote:427435 wrote:uncleluap wrote:
argue till the cows come home but a known fact is this.
A 400Hp 500Lb torque gas engine will not propel a 34-38K lb MH up 7% grade at the same speed and ease as a ISL cummns 400HP 1250 lb torque engine
nor will it be as fuel efficient nor will it run as cool nor will it even last 1/10 what a cummins diesel will and thats why u do not see this happening in this day and age.
Sorry, but you are wrong as far as how fast. Speed will be determined by hp. If the gas engine has enough transmission speeds to keep the engine at or near it's peak hp, it will keep up with a diesel of the same hp. The only caveat to that would be at higher altitudes where the turbo'd diesel would gain an advantage as its hp would not drop off as fast. Of course, many gas car engines (and gas PU engines) are gaining turbos these days, so that caveat could disappear in the future.
I disagree.MH Too heavy and not enough torgue to keep up to the load faction to be equal to the diesel. it would take way too low of a gear ratio to attain what U claim.I suppose in some obscure land of theory(what your in) it may succeed but in my world(reality) there is no way no how and thats why U will not see such a situation as I aluded to in previous posts.SO in theory U may have a valid idea(point) But in REALITY there is no such situation
โOct-07-2012 01:18 PM
427435 wrote:uncleluap wrote:
argue till the cows come home but a known fact is this.
A 400Hp 500Lb torque gas engine will not propel a 34-38K lb MH up 7% grade at the same speed and ease as a ISL cummns 400HP 1250 lb torque engine
nor will it be as fuel efficient nor will it run as cool nor will it even last 1/10 what a cummins diesel will and thats why u do not see this happening in this day and age.
Sorry, but you are wrong as far as how fast. Speed will be determined by hp. If the gas engine has enough transmission speeds to keep the engine at or near it's peak hp, it will keep up with a diesel of the same hp. The only caveat to that would be at higher altitudes where the turbo'd diesel would gain an advantage as its hp would not drop off as fast. Of course, many gas car engines (and gas PU engines) are gaining turbos these days, so that caveat could disappear in the future.
โOct-07-2012 12:40 PM
โOct-07-2012 12:32 PM
Cloud Dancer wrote:427435 wrote:jmtandem wrote:I am a retired Engineer also and designed engines. You can not argue with the equations above. they work for both gas and diesel,in fact any engine.
Let's keep it simple!! Go to any NASCAR race or drag strip. See that they are talking about weight/HP not torque to make there machines do something faster.
It also works for Motoehomes!!!
The purpose of a race car is to go fast. Horsepower is more important than torque as the car is relatively light and needs to possess violent acceleration and high top speeds. The discussion of this thread is to get a heavy motorhome up a mountain; horsepower is less important than torque. It is not the same desired results as what is needed in a race car. 40,000 pounds of MH towing a 3800 pound car behind up six percent grades that are miles and miles long. It is not the same thing. And what does the Holiday Inn reference mean?
In either case, speed on a race track or speed of a heavy MH up an incline----------the more hp, the faster you go. What a high torque rated engine may give you is less need to shift gears frequently.
Again, no one has explained how a high reving gas turbine (with torque levels under 300 ft-lbs) can move heavy tanks up steep inclines if it is only engine torque that does it.
It's THRUST that propels that tank. And, if you give me the total gear ratio and the rolling radius of the track drive, I'll calculate the amount of thrust.
โOct-07-2012 12:28 PM
uncleluap wrote:
argue till the cows come home but a known fact is this.
A 400Hp 500Lb torque gas engine will not propel a 34-38K lb MH up 7% grade at the same speed and ease as a ISL cummns 400HP 1250 lb torque engine
nor will it be as fuel efficient nor will it run as cool nor will it even last 1/10 what a cummins diesel will and thats why u do not see this happening in this day and age.
โOct-07-2012 12:27 PM
โOct-07-2012 12:17 PM
daveshan wrote:
I have one question for the HP is all that matters folks.
In the situation I posted back a while where you have a very slow turn right before a steep grade isn't it the torque that accelerates you up that grade? HP=HP is all fine and dandy when you're pulling grades on I-70 but I do mostly 2 lane (with the occasional passing area) mountain roads. Never had a gasser pass or tailgate me yet and I've passed more than a few.
โOct-07-2012 12:12 PM
topflite51 wrote:
It seems that the consensus opinion is and will always be -
Which ever I own is the best.๐
So be happy with whatever you own as you bought the best in your opinion that there is.:b