Stall speed explained...
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Joined: Jan 2004
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Stall speed explained...
found this writeup today... explains the stall speed of a torque coverter. have a look...
http://www.bankspower.com/Tech_understandstallspeed.cfm
man you gotta love the web... so much info out there...
and torque converters...
http://www.bankspower.com/Tech_under...rqueconver.cfm
http://www.bankspower.com/Tech_understandstallspeed.cfm
man you gotta love the web... so much info out there...
and torque converters...
http://www.bankspower.com/Tech_under...rqueconver.cfm
Joined: May 2006
Posts: 34
Likes: 0
From: Sebastopol, California
RE: Stall speed explained...
Good info. Especially where is says "Banks' dynamometer tests show that ... the Dodge's 5.9L Cummins engine peaks at 1,400 RPM and drops off at 1,800 RPM. As RPM continues to rise, torque decreases even further."
Professional
Joined: Aug 2004
Posts: 117
Likes: 1
From: 33.43.342, 84.21.602
RE: Stall speed explained...
it doesnt decrease as much as you think. yes peak torque is made around 1600rpm. and it does decrease as RPM's go up, but the torque LINE on the cummins is pretty darn straight. the torque curves on the Isuzu and International V8's mimmic a gasser V8 more than a diesel.
Joined: May 2006
Posts: 34
Likes: 0
From: Sebastopol, California
RE: Stall speed explained...
Good point, when Banks said "decrease" they didn't say how fast exactly. I've heard of the narrow power band associated with diesels, but I haven't experienced that with my truck - which is completely stock as far as power is concerned. I take that back it does enjoy a "brew" with each fill-up. My truck seems to have power to spare for me whether I'm going 35 or 70.
Professional
Joined: Aug 2004
Posts: 117
Likes: 1
From: 33.43.342, 84.21.602
RE: Stall speed explained...
normaly with diesels the torque band is a straight line as soon as the engine gets into the torque band, the more RPM's you run the more horsepower you get since HP is a derivitave of torque. on our ISB at 2900rpm however the torque band starts going down. the decrease in torque is a bit quicker than what the RPM's can make up for. this is where the max HP occurs. Diesels and Gassers are two totaly different animals. gassers HP and TQ bands actualy cross at some point, (generaly 5200rpm) diesels never meet. unless you build it to run those RPM's
our ISBe's from 1500-2900rpm, the torque numbers at the flywheel only decrease 50-60 ft-lb. the older 12 valves decreased even less, this made them true torque monsters and better suited for pulling.
now we get to the stall speed of the torque converters which is set to where on a diesel the engine is makeing best torque. although most of this was pointed out in the link, what wasnt pointed out in the link was if you put a TC of a ford on a dodge the truck would never move and if it did you would have to run high RPM's to do so, if you put the TC of a dodge on a ford you would most likely choke the engine out since it delivers power quicker. also the torque band on the ford is more curved, especialy on the 6.0's. this curved torque band is not very friendly when you are pulling since you never have similar torque values for the horsepower needed to keep the load moveing. inline engines have a flatter torque curve, or line, that keeps torque the same at higher horsepower demands.
our ISBe's from 1500-2900rpm, the torque numbers at the flywheel only decrease 50-60 ft-lb. the older 12 valves decreased even less, this made them true torque monsters and better suited for pulling.
now we get to the stall speed of the torque converters which is set to where on a diesel the engine is makeing best torque. although most of this was pointed out in the link, what wasnt pointed out in the link was if you put a TC of a ford on a dodge the truck would never move and if it did you would have to run high RPM's to do so, if you put the TC of a dodge on a ford you would most likely choke the engine out since it delivers power quicker. also the torque band on the ford is more curved, especialy on the 6.0's. this curved torque band is not very friendly when you are pulling since you never have similar torque values for the horsepower needed to keep the load moveing. inline engines have a flatter torque curve, or line, that keeps torque the same at higher horsepower demands.
Record Breaker
Joined: Jul 2006
Posts: 1,808
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From: Upstate, SC
RE: Stall speed explained...
ORIGINAL: Drew
normaly with diesels the torque band is a straight line as soon as the engine gets into the torque band, the more RPM's you run the more horsepower you get since HP is a derivitave of torque. on our ISB at 2900rpm however the torque band starts going down. the decrease in torque is a bit quicker than what the RPM's can make up for. this is where the max HP occurs. Diesels and Gassers are two totaly different animals. gassers HP and TQ bands actualy cross at some point, (generaly 5200rpm) diesels never meet. unless you build it to run those RPM's
our ISBe's from 1500-2900rpm, the torque numbers at the flywheel only decrease 50-60 ft-lb. the older 12 valves decreased even less, this made them true torque monsters and better suited for pulling.
now we get to the stall speed of the torque converters which is set to where on a diesel the engine is makeing best torque. although most of this was pointed out in the link, what wasnt pointed out in the link was if you put a TC of a ford on a dodge the truck would never move and if it did you would have to run high RPM's to do so, if you put the TC of a dodge on a ford you would most likely choke the engine out since it delivers power quicker. also the torque band on the ford is more curved, especialy on the 6.0's. this curved torque band is not very friendly when you are pulling since you never have similar torque values for the horsepower needed to keep the load moveing. inline engines have a flatter torque curve, or line, that keeps torque the same at higher horsepower demands.
normaly with diesels the torque band is a straight line as soon as the engine gets into the torque band, the more RPM's you run the more horsepower you get since HP is a derivitave of torque. on our ISB at 2900rpm however the torque band starts going down. the decrease in torque is a bit quicker than what the RPM's can make up for. this is where the max HP occurs. Diesels and Gassers are two totaly different animals. gassers HP and TQ bands actualy cross at some point, (generaly 5200rpm) diesels never meet. unless you build it to run those RPM's
our ISBe's from 1500-2900rpm, the torque numbers at the flywheel only decrease 50-60 ft-lb. the older 12 valves decreased even less, this made them true torque monsters and better suited for pulling.
now we get to the stall speed of the torque converters which is set to where on a diesel the engine is makeing best torque. although most of this was pointed out in the link, what wasnt pointed out in the link was if you put a TC of a ford on a dodge the truck would never move and if it did you would have to run high RPM's to do so, if you put the TC of a dodge on a ford you would most likely choke the engine out since it delivers power quicker. also the torque band on the ford is more curved, especialy on the 6.0's. this curved torque band is not very friendly when you are pulling since you never have similar torque values for the horsepower needed to keep the load moveing. inline engines have a flatter torque curve, or line, that keeps torque the same at higher horsepower demands.
