Author Topic: Quickchange horse power drain  (Read 25338 times)

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Offline ronnieroadster

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Quickchange horse power drain
« on: December 06, 2016, 04:18:21 PM »
Would anyone have an idea about how much horse power it takes to turn a quick change rear axle? My rear axle choice has been a good old Halibrand six spline quick change its small size works well in my application. At speed week I ran a 28 inch tall rear tire and a 270 final drive ratio. I've heard the quick change gives up some MPH the added advantage of the easy gear change seems to blend that out at least for me. But I would like to get an idea on what it take's to make it work not looking for exact numbers just some general knowledge from you fellows in the know.
Working in the shop I use the 'F' word a lot. No not that word these words Focus and Finish go Fast and Flathead Ford!
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 LTA    XF/BGRMR  Record 200.921 First  Ever Ford Flathead Roadster to hit 200 MPH burning gasoline July 2018
 SCTA  XF/BGRMR Record 205.744  First gas burning Ford flathead powered roadster to top 200 MPH at Bonneville August 7, 2021 top speed 219.717
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Offline jdincau

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Re: Quickchange horse power drain
« Reply #1 on: December 06, 2016, 05:05:38 PM »
According to these sources a Hypoid (most popular third members) gear set is 92 to 96 percent efficient at power transmission. A spiral bevel (V-8 quick change) gear set and a single spur gear set are both 99 percent efficient. That makes a V-8 quick change 98.01 percent efficient . Tell me again why I should dump my quick change.
http://www.zakgear.com/Hypoid_worm.html
http://www.roymech.co.uk/Useful_Tables/Drive/Gear_Efficiency.html
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Offline ronnieroadster

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Re: Quickchange horse power drain
« Reply #2 on: December 06, 2016, 05:51:50 PM »
According to these sources a Hypoid (most popular third members) gear set is 92 to 96 percent efficient at power transmission. A spiral bevel (V-8 quick change) gear set and a single spur gear set are both 99 percent efficient. That makes a V-8 quick change 98.01 percent efficient . Tell me again why I should dump my quick change.
http://www.zakgear.com/Hypoid_worm.html
http://www.roymech.co.uk/Useful_Tables/Drive/Gear_Efficiency.html




 Very interesting I knew hypoid pinion location in the 9 inch Ford was not as efficient as the Chevy 12 bolt due to the pinion location my thought has been the Chevy was closer to the centerline. I always wondered if the centered pinion location of the quick change spiral bevel would be a better choice.
 I'm thinking its a pretty good choice.

Working in the shop I use the 'F' word a lot. No not that word these words Focus and Finish go Fast and Flathead Ford!
 ECTA  XF/BGRMR Record 179.8561
 LTA    XF/BGRMR  Record 200.921 First  Ever Ford Flathead Roadster to hit 200 MPH burning gasoline July 2018
 SCTA  XF/BGRMR Record 205.744  First gas burning Ford flathead powered roadster to top 200 MPH at Bonneville August 7, 2021 top speed 219.717
 SCTA  XXF/BGRMR Record 216.131 plus a Red Hat
"Life Member of the Bonneville 200 MPH Club"

Offline Dynoroom

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Re: Quickchange horse power drain
« Reply #3 on: December 06, 2016, 06:53:12 PM »
I have run my setup on an engine dyno & a chassis dyno. We have a Winters Extreamliner quick change and my calculations show a 25% loss through the drive line.
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Kugel and LeFevers Pontiac Firebird

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Offline kiwi belly tank

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Re: Quickchange horse power drain
« Reply #4 on: December 06, 2016, 08:22:59 PM »
Ron, your 2.70 ratio is a calculated number I presume & you have arrived at that with an over driven set of spur gears with a 4.11 ring & pinion, that's a whole different animal & a lot more junk to go through than actually having a 2.70 ring & pinion.
How about one of the numerical whizzbangers on the forum show us some real numbers on what the difference is here because it defies logic to suggest a quick change could be more efficient in this situation?
  Sid.

Offline ronnieroadster

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Re: Quickchange horse power drain
« Reply #5 on: December 06, 2016, 09:42:33 PM »
Ron, your 2.70 ratio is a calculated number I presume & you have arrived at that with an over driven set of spur gears with a 4.11 ring & pinion, that's a whole different animal & a lot more junk to go through than actually having a 2.70 ring & pinion.
How about one of the numerical whizzbangers on the forum show us some real numbers on what the difference is here because it defies logic to suggest a quick change could be more efficient in this situation?
  Sid.

   Sid the 270 is the change gear final drive the ring and pinion ratio is 378.  I would expect more HP loss from turning the lower shaft to the spur gears and then turning the pinion certainly more stuff to move and more bearings to turn compared to just a ring and pinion.
Working in the shop I use the 'F' word a lot. No not that word these words Focus and Finish go Fast and Flathead Ford!
 ECTA  XF/BGRMR Record 179.8561
 LTA    XF/BGRMR  Record 200.921 First  Ever Ford Flathead Roadster to hit 200 MPH burning gasoline July 2018
 SCTA  XF/BGRMR Record 205.744  First gas burning Ford flathead powered roadster to top 200 MPH at Bonneville August 7, 2021 top speed 219.717
 SCTA  XXF/BGRMR Record 216.131 plus a Red Hat
"Life Member of the Bonneville 200 MPH Club"

Offline Jack Gifford

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Re: Quickchange horse power drain
« Reply #6 on: December 07, 2016, 12:24:26 AM »
Were there ever any bevel-gear ring-and-pinion QC's made (not spiral-bevel)? If so, that would be the most efficient QC design.
Efficiency of any gearset can be significantly improved by a well-designed lube system. Dragging gear teeth through a bath of viscous gearlube is NOT efficient.
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Offline floydjer

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Re: Quickchange horse power drain
« Reply #7 on: December 07, 2016, 10:37:22 AM »
I suspect that no matter how efficient the gear sets are..The power loss comes from gear multiplication through the change gears.  I have a Benson q/c in my 3 window and rotating the input by hand is a challenge with the change gears swapped around for long trips. In their "normal" position I have a 4:86 final drive and the input spins easily.  JB
I`d never advocate drugs,alcohol,violence or insanity to anyone...But they work for me.

Offline kiwi belly tank

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Re: Quickchange horse power drain
« Reply #8 on: December 07, 2016, 12:06:22 PM »
Exactly, you get torque multiplication through a reduction drive & the opposite through an overdrive. Unless you have enough HP on tap to overcome that you're at a loss when overdriving to a lower axle ratio.
Can somebody come up with some real numbers here??
  Sid.

Offline floydjer

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Re: Quickchange horse power drain
« Reply #9 on: December 07, 2016, 12:26:23 PM »
Real numbers will come from real testing. Whole lot of variables to consider.  But gear reduction is always your friend.
I`d never advocate drugs,alcohol,violence or insanity to anyone...But they work for me.

Offline bearingburner

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Re: Quickchange horse power drain
« Reply #10 on: December 07, 2016, 05:26:42 PM »
Ron couldn't you adapt a v belt pulley to the input shaft and belt up an electric motor. Then by reading the motor amperage you would know the horsepower. By changing motor pulleys you could see the change in HP for different pinion speeds. You also could see the effect of cold and warm rearend lubricant.

Offline Interested Observer

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Re: Quickchange horse power drain
« Reply #11 on: December 07, 2016, 05:55:30 PM »
Ron couldn't you adapt a v belt pulley to the input shaft and belt up an electric motor. Then by reading the motor amperage you would know the horsepower. By changing motor pulleys you could see the change in HP for different pinion speeds. You also could see the effect of cold and warm rearend lubricant.

That would give an idea of fluid friction loss but not include loaded gear mesh loss, which is probably considerably larger and proportional to the input/output operating torque.

Offline ronnieroadster

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Re: Quickchange horse power drain
« Reply #12 on: December 07, 2016, 10:09:02 PM »
Ron couldn't you adapt a v belt pulley to the input shaft and belt up an electric motor. Then by reading the motor amperage you would know the horsepower. By changing motor pulleys you could see the change in HP for different pinion speeds. You also could see the effect of cold and warm rearend lubricant.




  Having the rear end under load would take a lot more HP to turn and thats the unknown I was hoping to sort of get a number on.  Dynorooms numbers are real world and his example is an eye opener on the percentage of loss.
« Last Edit: December 07, 2016, 10:12:47 PM by ronnieroadster »
Working in the shop I use the 'F' word a lot. No not that word these words Focus and Finish go Fast and Flathead Ford!
 ECTA  XF/BGRMR Record 179.8561
 LTA    XF/BGRMR  Record 200.921 First  Ever Ford Flathead Roadster to hit 200 MPH burning gasoline July 2018
 SCTA  XF/BGRMR Record 205.744  First gas burning Ford flathead powered roadster to top 200 MPH at Bonneville August 7, 2021 top speed 219.717
 SCTA  XXF/BGRMR Record 216.131 plus a Red Hat
"Life Member of the Bonneville 200 MPH Club"

Offline ronnieroadster

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Re: Quickchange horse power drain
« Reply #13 on: December 07, 2016, 10:11:28 PM »
I have run my setup on an engine dyno & a chassis dyno. We have a Winters Extreamliner quick change and my calculations show a 25% loss through the drive line.


  

  Your numbers show what I was looking for. One question what transmiion did you use?
Working in the shop I use the 'F' word a lot. No not that word these words Focus and Finish go Fast and Flathead Ford!
 ECTA  XF/BGRMR Record 179.8561
 LTA    XF/BGRMR  Record 200.921 First  Ever Ford Flathead Roadster to hit 200 MPH burning gasoline July 2018
 SCTA  XF/BGRMR Record 205.744  First gas burning Ford flathead powered roadster to top 200 MPH at Bonneville August 7, 2021 top speed 219.717
 SCTA  XXF/BGRMR Record 216.131 plus a Red Hat
"Life Member of the Bonneville 200 MPH Club"

Offline Dynoroom

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Re: Quickchange horse power drain
« Reply #14 on: December 07, 2016, 11:53:42 PM »
I have run my setup on an engine dyno & a chassis dyno. We have a Winters Extreamliner quick change and my calculations show a 25% loss through the drive line.
 Your numbers show what I was looking for. One question what transmiion did you use?

Jerico 5 speed
Michael LeFevers
Kugel and LeFevers Pontiac Firebird

Without Data You're Just Another Guy With An Opinion!

Racing is just a series of "Problem Solving" events that allow you to spend money & make noise...