From owner-fsj-digest@digest.net Mon Sep 24 08:11:00 2012 From: fsj-digest To: fsj-digest@digest.net Date: Mon, 24 Sep 2012 15:11:17 +0000 Subject: fsj-digest V1 #3974 fsj-digest Monday, September 24 2012 Volume 01 : Number 3974 Forum for Discussion of Full Sized SJ Series Jeeps Brian Colucci Digest Coordinator Contents: fsj: Fwd: Latest harbor freight ads (fwd) fsj: axle ratios RE: fsj: axle ratios fsj: RE: [db] Fwd: Latest harbor freight ads (fwd) Re: fsj: axle ratios RE: fsj: axle ratios Re: fsj: axle ratios FSJ Digest Home Page: http://www.digest.net/jeeps/fsj/ Send submissions to fsj-digest@digest.net Send administrative requests to fsj-digest-request@digest.net To unsubscribe, include the word unsubscribe by itself in the body of the message, unless you are sending the request from a different address than the one that appears on the list. Include the word help in a message to fsj-digest-request to get a list of other majordomo commands. ---------------------------------------------------------------------- Date: Sun, 23 Sep 2012 17:32:28 -0700 (PDT) From: john Subject: fsj: Fwd: Latest harbor freight ads (fwd) ok, now for a little humor... http://www.vintagemotoring.net/forum/viewtopic.php?f=2&t=2109 Vintage Motoring b" View topic - Latest harbor freight ads ----- - ---------------------------------------------------------------------------- -o|||||o- Linux: the choice of a GNU generation http://WAGONEERS.COM Snohomish, WA- where Jeeps don't rust, they mold ...shop AMSOIL directly at: http://AMSOIL.com/redirect.cgi?zo=283461 - ---------------------------------------------------------------------------- "A thorough knowledge of the Bible is worth more than a college education" Theodore Roosevelt (26th President (1901-09), 1858-1919) RTM: TRSTGZS - ---------------------------------------------------------------------------- - ---------- Forwarded message ---------- From: Jimmyjeeper Date: Sun, 23 Sep 2012 13:55:37 -0400 (EDT) Subject: Fwd: Latest harbor freight ads This was too good not to share. Vintage Motoring b" View topic - Latest harbor freight ads http://www.vintagemotoring.net/forum/viewtopic.php?f=2&t=2109 ------------------------------ Date: Sun, 23 Sep 2012 22:42:38 -0400 From: JeepNut Subject: fsj: axle ratios Can someone help me get my mind around axle ratios? I'm losing it in my old age. Do I have it right that racers like low gears like 4:10 over say 3:31 because that gets them off the line quicker and to redline faster / shorter times / better. Lousy mileage on the highway. Right? So why would Off roaders also like the same gears racers do? A 4:10-5:XX ratio allows the engine to rev higher, but the wheels turn slow:slower. I grasp that... I think... but how does that equate to the faster times on the track? My thoughts are that if the pinion turns 4x for every 1 rotation of the axle...it seem like the rush to speed must end at some point... I guess that's redline... are race cars setup to run to redline at a certain distance or speed? I mean given the rear doesn't change, but maybe you increase your engine's horsepower, so now to use that horsepower efficiently you'd have to change the transmission gearing... Maybe the light bulb is flickering in my mind.... redline...so... i guess the difference is that in a drag car, the engine is going to redline in a very short time in each gear, and that will be accomplished over very short distances. So the gearing isn't "impractical" like it would be for a street car. The street car would be running at much higher than normal RPMS on the highway burning tons of fuel....it would get to 90 in a hurry and then burn fuel like a Spruance class destroyer if you maintained that speed over time...lol...(never mind the DFM vs. gasoline argument) For the offroader that runs REAL low gears I suppose they don't really run those on the street too much... I'm guessing that 4:10 gets to be about as much gas as anyone really wants to spend on a street ride, whereas running something like 5:2x in a rockcrawler would require a continuous unrep evolution to be maintained for freeway driving....or something like that. Question stems from a 2wd Jeep project I'm working on...so far just in my mind...and I need performance vs. mileage ratios to joust in my mind...so if I have it right in my mind, for a "performance" street truck I'm thinking: 4:10 or lower improves performance at the cost of mileage... 3:73ish better mileage... ?by how much?... maybe the best compromise? 3:55ish might be acceptable. 3:31 would help it be cheaper to drive... gonna run on ethyl.... 2:78 best for mileage but would be lame in the performance characteristics compared to 3:73/4:10... right? Thanks! - -- - --------------------------------------------------------------------------- "We either make ourselves happy or miserable. The amount of work is the same." -Carlos Castaneda- - --------------------------------------------------------------------------- Registered Linux user #287453 ------------------------------ Date: Sun, 23 Sep 2012 19:41:39 -0700 From: Jim Blair Subject: RE: fsj: axle ratios Tire size has a lot to do with it. How often do racers run 40" tires? Jim Blair, Lynnwood, WA '87 Comanche, '83 Jeep J10, '84 Jeep J10 > Date: Sun, 23 Sep 2012 22:42:38 -0400 > From: JeepNut@zoho.com > To: fsj@digest.net > Subject: fsj: axle ratios > > Can someone help me get my mind around axle ratios? I'm losing it in > my old age. > > Do I have it right that racers like low gears like 4:10 over say 3:31 > because that gets them off the line quicker and to redline faster / > shorter times / better. Lousy mileage on the highway. Right? > > So why would Off roaders also like the same gears racers do? > A 4:10-5:XX ratio allows the engine to rev higher, but the wheels turn > slow:slower. I grasp that... I think... but how does that equate to > the faster times on the track? > > My thoughts are that if the pinion turns 4x for every 1 rotation of the > axle...it seem like the rush to speed must end at some point... I guess > that's redline... are race cars setup to run to redline at a certain > distance or speed? I mean given the rear doesn't change, but maybe you > increase your engine's horsepower, so now to use that horsepower > efficiently you'd have to change the transmission gearing... Maybe the > light bulb is flickering in my mind.... redline...so... i guess the > difference is that in a drag car, the engine is going to redline in a > very short time in each gear, and that will be accomplished over very > short distances. So the gearing isn't "impractical" like it would be > for a street car. The street car would be running at much higher than > normal RPMS on the highway burning tons of fuel....it would get to 90 in > a hurry and then burn fuel like a Spruance class destroyer if you > maintained that speed over time...lol...(never mind the DFM vs. gasoline > argument) > > For the offroader that runs REAL low gears I suppose they don't really > run those on the street too much... I'm guessing that 4:10 gets to be > about as much gas as anyone really wants to spend on a street ride, > whereas running something like 5:2x in a rockcrawler would require a > continuous unrep evolution to be maintained for freeway driving....or > something like that. > > Question stems from a 2wd Jeep project I'm working on...so far just in > my mind...and I need performance vs. mileage ratios to joust in my > mind...so if I have it right in my mind, for a "performance" street > truck I'm thinking: > 4:10 or lower improves performance > at the cost of mileage... > 3:73ish better mileage... ?by how > much?... maybe the best compromise? > 3:55ish might be acceptable. > 3:31 would help it be cheaper to > drive... gonna run on ethyl.... > 2:78 best for mileage but would be > lame in the performance characteristics compared to 3:73/4:10... right? > > Thanks! > > -- > --------------------------------------------------------------------------- > "We either make ourselves happy or miserable. > The amount of work is the same." -Carlos Castaneda- > > --------------------------------------------------------------------------- > Registered Linux user #287453 ------------------------------ Date: Sun, 23 Sep 2012 19:46:05 -0700 (PDT) From: john Subject: fsj: RE: [db] Fwd: Latest harbor freight ads (fwd) for me if they work twice I feel like I've doubled my investment... saved money over renting, and if you're careful with them you can get many uses out of them. :) I bought some tools from JC Whitney almost 30 years ago, they were the harbor freight of the '60's/70's... I'm still using it... it's not sturdy, but using it carefully has lasted me through 128 cars... :) I am considering returning my electric impact wrench for money this time... have had it replaced three times... needed it the first time to get the flywheel off of an engine... then it wouldn't work on lug nuts... the 2nd time I returned it, it wouldn't take the nut off of a pulley for an alternator... 3rd time it wouldn't undo my lug nuts... I'm getting ready to do an axle swap on my J10... I may have to find another place to buy an electric impact wrench. :) john ----- - ---------------------------------------------------------------------------- -o|||||o- Linux: the choice of a GNU generation http://WAGONEERS.COM Snohomish, WA- where Jeeps don't rust, they mold ...shop AMSOIL directly at: http://AMSOIL.com/redirect.cgi?zo=283461 - ---------------------------------------------------------------------------- "A thorough knowledge of the Bible is worth more than a college education" Theodore Roosevelt (26th President (1901-09), 1858-1919) RTM: TRSTGZS - ---------------------------------------------------------------------------- On Sun, 23 Sep 2012, FParker wrote: # # Sadly, it's pretty accurate. Most of their tools are one-and-done. # They get you out of a bind or through the project, but that's about it. # # # -----Original Message----- # From: owner-diesel-benz@digest.net [mailto:owner-diesel-benz@digest.net] # On Behalf Of john # Sent: Sunday, September 23, 2012 8:32 PM # To: undisclosed-recipients: # Subject: [db] Fwd: Latest harbor freight ads (fwd) # # # ok, now for a little humor... # # http://www.vintagemotoring.net/forum/viewtopic.php?f=2&t=2109 # ------------------------------ Date: Sun, 23 Sep 2012 19:58:41 -0700 (PDT) From: john Subject: Re: fsj: axle ratios it depends on a lot of things... but you've got the basic idea right... lower gears (higher numerical) allow for easier acceleration, makes for better rock crawling, lots of available torque for towing... so 4.10's or even 4.88's get you more torque earlier on, faster off the line, slower speeds for rock crawling... of course with overdrives you can have it all... freeway and in town. on my '91 GW with the 6.2 Diesel and stock 3.54's my 6.2 did so so for economy... I found that 4.10's actually improved it... to 24mpg on the freeway... because with the OD it put me in the sweet spot for that engine... ideally you want your cruising speed to match your peak torque. that's what the AMC engineers were thinking when they put 2.72 gears in my J10 so that at 55mph it would be around 1700 rpm or so and at peak torque... problem is getting to 55 mph is a workout for the truck and hurts in town mileage, makes the beast a slug and consumes more fuel... going to 3.31's on my J10 should bring my mileage up to 10-12 from 8. If I take it out on the freeway I'll still be ok... haven't done the math, but the mid-80's and later used them with the 727 and did "ok". john ----- - ---------------------------------------------------------------------------- -o|||||o- Linux: the choice of a GNU generation http://WAGONEERS.COM Snohomish, WA- where Jeeps don't rust, they mold ...shop AMSOIL directly at: http://AMSOIL.com/redirect.cgi?zo=283461 - ---------------------------------------------------------------------------- "A thorough knowledge of the Bible is worth more than a college education" Theodore Roosevelt (26th President (1901-09), 1858-1919) RTM: TRSTGZS - ---------------------------------------------------------------------------- On Sun, 23 Sep 2012, JeepNut wrote: # Can someone help me get my mind around axle ratios? I'm losing it in my old # age. # # Do I have it right that racers like low gears like 4:10 over say 3:31 because # that gets them off the line quicker and to redline faster / shorter times / # better. Lousy mileage on the highway. Right? # # So why would Off roaders also like the same gears racers do? # A 4:10-5:XX ratio allows the engine to rev higher, but the wheels turn # slow:slower. I grasp that... I think... but how does that equate to the # faster times on the track? # # My thoughts are that if the pinion turns 4x for every 1 rotation of the # axle...it seem like the rush to speed must end at some point... I guess # that's redline... are race cars setup to run to redline at a certain distance # or speed? I mean given the rear doesn't change, but maybe you increase your # engine's horsepower, so now to use that horsepower efficiently you'd have to # change the transmission gearing... Maybe the light bulb is flickering in my # mind.... redline...so... i guess the difference is that in a drag car, the # engine is going to redline in a very short time in each gear, and that will # be accomplished over very short distances. So the gearing isn't # "impractical" like it would be for a street car. The street car would be # running at much higher than normal RPMS on the highway burning tons of # fuel....it would get to 90 in a hurry and then burn fuel like a Spruance # class destroyer if you maintained that speed over time...lol...(never mind # the DFM vs. gasoline argument) # # For the offroader that runs REAL low gears I suppose they don't really run # those on the street too much... I'm guessing that 4:10 gets to be about as # much gas as anyone really wants to spend on a street ride, whereas running # something like 5:2x in a rockcrawler would require a continuous unrep # evolution to be maintained for freeway driving....or something like that. # # Question stems from a 2wd Jeep project I'm working on...so far just in my # mind...and I need performance vs. mileage ratios to joust in my mind...so if # I have it right in my mind, for a "performance" street truck I'm thinking: # 4:10 or lower improves performance at the # cost of mileage... # 3:73ish better mileage... ?by how # much?... maybe the best compromise? # 3:55ish might be acceptable. # 3:31 would help it be cheaper to drive... # gonna run on ethyl.... # 2:78 best for mileage but would be lame # in the performance characteristics compared to 3:73/4:10... right? # # Thanks! # # ------------------------------ Date: Mon, 24 Sep 2012 07:50:12 -0700 From: Jim Blair Subject: RE: fsj: axle ratios AMC set them to be optimum for "economy" with stock size tires. As soon as you go over that, economy and the "feel" of power drops. Jim Blair, Lynnwood, WA '87 Comanche, '83 Jeep J10, '84 Jeep J10 > Date: Sun, 23 Sep 2012 19:58:41 -0700 > From: john@wagoneers.com > To: JeepNut@zoho.com > CC: fsj@digest.net > Subject: Re: fsj: axle ratios > > it depends on a lot of things... > > but you've got the basic idea right... lower gears (higher numerical) allow for easier acceleration, > makes for better rock crawling, lots of available torque for towing... so 4.10's or even 4.88's get > you more torque earlier on, faster off the line, slower speeds for rock crawling... > > of course with overdrives you can have it all... freeway and in town. > > on my '91 GW with the 6.2 Diesel and stock 3.54's my 6.2 did so so for economy... I found > that 4.10's actually improved it... to 24mpg on the freeway... because with the OD it put > me in the sweet spot for that engine... > > ideally you want your cruising speed to match your peak torque. > > that's what the AMC engineers were thinking when they put 2.72 gears in my J10 so that at 55mph > it would be around 1700 rpm or so and at peak torque... problem is getting to 55 mph is a workout > for the truck and hurts in town mileage, makes the beast a slug and consumes more fuel... > > going to 3.31's on my J10 should bring my mileage up to 10-12 from 8. If I take it out on the > freeway I'll still be ok... haven't done the math, but the mid-80's and later used them with the 727 > and did "ok". > > john > > > > ----- > - ---------------------------------------------------------------------------- > -o|||||o- Linux: the choice of a GNU generation > http://WAGONEERS.COM Snohomish, WA- where Jeeps don't rust, they mold > ...shop AMSOIL directly at: http://AMSOIL.com/redirect.cgi?zo=283461 > - ---------------------------------------------------------------------------- > "A thorough knowledge of the Bible is worth more than a college education" > Theodore Roosevelt (26th President (1901-09), 1858-1919) RTM: TRSTGZS > - ---------------------------------------------------------------------------- > > On Sun, 23 Sep 2012, JeepNut wrote: > > # Can someone help me get my mind around axle ratios? I'm losing it in my old > # age. > # > # Do I have it right that racers like low gears like 4:10 over say 3:31 because > # that gets them off the line quicker and to redline faster / shorter times / > # better. Lousy mileage on the highway. Right? > # > # So why would Off roaders also like the same gears racers do? > # A 4:10-5:XX ratio allows the engine to rev higher, but the wheels turn > # slow:slower. I grasp that... I think... but how does that equate to the > # faster times on the track? > # > # My thoughts are that if the pinion turns 4x for every 1 rotation of the > # axle...it seem like the rush to speed must end at some point... I guess > # that's redline... are race cars setup to run to redline at a certain distance > # or speed? I mean given the rear doesn't change, but maybe you increase your > # engine's horsepower, so now to use that horsepower efficiently you'd have to > # change the transmission gearing... Maybe the light bulb is flickering in my > # mind.... redline...so... i guess the difference is that in a drag car, the > # engine is going to redline in a very short time in each gear, and that will > # be accomplished over very short distances. So the gearing isn't > # "impractical" like it would be for a street car. The street car would be > # running at much higher than normal RPMS on the highway burning tons of > # fuel....it would get to 90 in a hurry and then burn fuel like a Spruance > # class destroyer if you maintained that speed over time...lol...(never mind > # the DFM vs. gasoline argument) > # > # For the offroader that runs REAL low gears I suppose they don't really run > # those on the street too much... I'm guessing that 4:10 gets to be about as > # much gas as anyone really wants to spend on a street ride, whereas running > # something like 5:2x in a rockcrawler would require a continuous unrep > # evolution to be maintained for freeway driving....or something like that. > # > # Question stems from a 2wd Jeep project I'm working on...so far just in my > # mind...and I need performance vs. mileage ratios to joust in my mind...so if > # I have it right in my mind, for a "performance" street truck I'm thinking: > # 4:10 or lower improves performance at the > # cost of mileage... > # 3:73ish better mileage... ?by how > # much?... maybe the best compromise? > # 3:55ish might be acceptable. > # 3:31 would help it be cheaper to drive... > # gonna run on ethyl.... > # 2:78 best for mileage but would be lame > # in the performance characteristics compared to 3:73/4:10... right? > # > # Thanks! > # > # ------------------------------ Date: Mon, 24 Sep 2012 15:11:10 +0000 From: john@wagoneers.com Subject: Re: fsj: axle ratios I've generally run my jeeps at stock size. And those economy gears are not. ;) __john_at_http://wagoneers.com__ - -----Original Message----- From: Jim Blair Date: Mon, 24 Sep 2012 07:50:12 To: john Meister; Cc: local Jeep list Subject: RE: fsj: axle ratios AMC set them to be optimum for "economy" with stock size tires. As soon as you go over that, economy and the "feel" of power drops. Jim Blair, Lynnwood, WA '87 Comanche, '83 Jeep J10, '84 Jeep J10 > Date: Sun, 23 Sep 2012 19:58:41 -0700 > From: john@wagoneers.com > To: JeepNut@zoho.com > CC: fsj@digest.net > Subject: Re: fsj: axle ratios > > it depends on a lot of things... > > but you've got the basic idea right... lower gears (higher numerical) allow for easier acceleration, > makes for better rock crawling, lots of available torque for towing... so 4.10's or even 4.88's get > you more torque earlier on, faster off the line, slower speeds for rock crawling... > > of course with overdrives you can have it all... freeway and in town. > > on my '91 GW with the 6.2 Diesel and stock 3.54's my 6.2 did so so for economy... I found > that 4.10's actually improved it... to 24mpg on the freeway... because with the OD it put > me in the sweet spot for that engine... > > ideally you want your cruising speed to match your peak torque. > > that's what the AMC engineers were thinking when they put 2.72 gears in my J10 so that at 55mph > it would be around 1700 rpm or so and at peak torque... problem is getting to 55 mph is a workout > for the truck and hurts in town mileage, makes the beast a slug and consumes more fuel... > > going to 3.31's on my J10 should bring my mileage up to 10-12 from 8. If I take it out on the > freeway I'll still be ok... haven't done the math, but the mid-80's and later used them with the 727 > and did "ok". > > john > > > > ----- > ---------------------------------------------------------------------------- > -o|||||o- Linux: the choice of a GNU generation > http://WAGONEERS.COM Snohomish, WA- where Jeeps don't rust, they mold > ...shop AMSOIL directly at: http://AMSOIL.com/redirect.cgi?zo=283461 > ---------------------------------------------------------------------------- > "A thorough knowledge of the Bible is worth more than a college education" > Theodore Roosevelt (26th President (1901-09), 1858-1919) RTM: TRSTGZS > ---------------------------------------------------------------------------- > > On Sun, 23 Sep 2012, JeepNut wrote: > > # Can someone help me get my mind around axle ratios? I'm losing it in my old > # age. > # > # Do I have it right that racers like low gears like 4:10 over say 3:31 because > # that gets them off the line quicker and to redline faster / shorter times / > # better. Lousy mileage on the highway. Right? > # > # So why would Off roaders also like the same gears racers do? > # A 4:10-5:XX ratio allows the engine to rev higher, but the wheels turn > # slow:slower. I grasp that... I think... but how does that equate to the > # faster times on the track? > # > # My thoughts are that if the pinion turns 4x for every 1 rotation of the > # axle...it seem like the rush to speed must end at some point... I guess > # that's redline... are race cars setup to run to redline at a certain distance > # or speed? I mean given the rear doesn't change, but maybe you increase your > # engine's horsepower, so now to use that horsepower efficiently you'd have to > # change the transmission gearing... Maybe the light bulb is flickering in my > # mind.... redline...so... i guess the difference is that in a drag car, the > # engine is going to redline in a very short time in each gear, and that will > # be accomplished over very short distances. So the gearing isn't > # "impractical" like it would be for a street car. The street car would be > # running at much higher than normal RPMS on the highway burning tons of > # fuel....it would get to 90 in a hurry and then burn fuel like a Spruance > # class destroyer if you maintained that speed over time...lol...(never mind > # the DFM vs. gasoline argument) > # > # For the offroader that runs REAL low gears I suppose they don't really run > # those on the street too much... I'm guessing that 4:10 gets to be about as > # much gas as anyone really wants to spend on a street ride, whereas running > # something like 5:2x in a rockcrawler would require a continuous unrep > # evolution to be maintained for freeway driving....or something like that. > # > # Question stems from a 2wd Jeep project I'm working on...so far just in my > # mind...and I need performance vs. mileage ratios to joust in my mind...so if > # I have it right in my mind, for a "performance" street truck I'm thinking: > # 4:10 or lower improves performance at the > # cost of mileage... > # 3:73ish better mileage... ?by how > # much?... maybe the best compromise? > # 3:55ish might be acceptable. > # 3:31 would help it be cheaper to drive... > # gonna run on ethyl.... > # 2:78 best for mileage but would be lame > # in the performance characteristics compared to 3:73/4:10... right? > # > # Thanks! > # > # ------------------------------ End of fsj-digest V1 #3974 **************************