Author Topic: Gear change question  (Read 3917 times)

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c/pickup

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Gear change question
« on: March 25, 2006, 08:04:16 PM »
I have a question for you guys that I am sure someone can give me a pretty good guestimate prior to the change I am thinking of. If I can get around 170 or so using a 2.70 gear ratio in a dana 60 with a 727 in front of it. Can I expect to get around 185 or so if I change to a 2.30 ratio? And secondly, as I have not received my rule book as of yet, would this change pass inspection? Now this is for production pickup, not modified.Thanks guys, any info would be great.

Offline Bob Beatty

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Gear change question
« Reply #1 on: March 25, 2006, 10:10:44 PM »
c/pickup,   In choosing the final drive gear to run, I try to be turning about 400 RPM over peak horsepower out the back door.  We would have to know your rear tire diameter or runout to estimate speed at any given RPM (I say estimate because tire slippage is a factor).
Going from a 2.70 gear to a 2.30 is a very big step.
Bob Beatty
 
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 338.954 MPH
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Offline ddahlgren

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Gear change question
« Reply #2 on: March 26, 2006, 08:02:37 AM »
a shameless pug..
http://www.landracing.com/miva/merchant.mv?Screen=CTGY&Store_Code=L&Category_Code=OSM

Have the real answers to al the other gears nd how fast you might really go.. Plus 1/2 of the price goes to support this site..
Dave

Offline Freud

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Donated Books
« Reply #3 on: March 26, 2006, 11:30:56 AM »
Dave, sorry it has taken me so long to say THANK YOU for the books you donated to the Bonneville NW Reunion in February. Jon Amo gave them to me and they were door prizes.

I appreciate the donation but that appreciation was exceeded by the people that received the books.

Again, THANKS A MILLION.

FREUD
Since '63

Offline jimmy six

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gear changes
« Reply #4 on: March 26, 2006, 12:28:20 PM »
I'll ask a few questions.. Are you stuck to the 727? Are you willing to change the whole rear end?.
I it were me I would put in a 9" Ford rear.(it is legal) that will give you a 2.47. The I would use a standard  trans over drive where you can control the splits. With 5 & 6 speed over drive you usually get what you get.. Many of us use a Tex Racing or Jerico with overdrive which you can control all the gears. Remember you don't need to drive away, a push to 40 or 50 eliminates lower gears.
A GM 10 bolt is available with 2.29 gears if you can find one. That's an option too.
For the speed you may want to run 32" Dunlops may also be a way to go. I went 215 at 5700 RPM 2.56 rear and 32" tires in a roadster.
Sorry I just spent about $8-10,000 but that's a way to do it.
First GMC 6 powered Fuel roadster over 200, with 2 red hats. Pit crew for Patrick Tone's Super Stock #49 Camaro

Offline JackD

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When ?
« Reply #5 on: March 26, 2006, 01:33:16 PM »
When is somebody going to build a input shaft gear case with standard quick change gears to change the ratio ? Crower did it for a lot less than some other options. With all the automated mills that exist today you can turn them out in a hurry. Imagine a gear housing that you can bolt in place of the front carrier housing on a 9 inch Ford and select whatever drop in gears you want. You would have the additional advantage to clock it around to whatever offset you want. :wink:
"I would rather lose going fast enough to win than win going slow enough to lose."
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Offline Dynoroom

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Re: When ?
« Reply #6 on: March 26, 2006, 03:07:35 PM »
Quote from: JackD
When is somebody going to build a input shaft gear case with standard quick change gears to change the ratio ? Crower did it for a lot less than some other options. With all the automated mills that exist today you can turn them out in a hurry. Imagine a gear housing that you can bolt in place of the front carrier housing on a 9 inch Ford and select whatever drop in gears you want. You would have the additional advantage to clock it around to whatever offset you want. :wink:


The 505 roadster had that but being all wheel drive and not part of the "in" crowd it doesn't really matter. Nice feature though, just used std quick change gears. I guess they could still use it if the convert to 2 wheel drive. So much for innovation...
Michael LeFevers
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Offline JackD

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Tradition unhampered by evolution.
« Reply #7 on: March 26, 2006, 03:25:50 PM »
The Highboy Roadster has not beem perfected yet.
I suspect they have some way to go.
Once they get the body size established, I see a real surge in tecnology.
Sometimes time honored is just time lost.
I can hardly wait. Anybosy over 40 proably can't wait either. :wink:
"I would rather lose going fast enough to win than win going slow enough to lose."
"That horrible smell is dirty feet being held to the fire"

terry russell

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Gear change question
« Reply #8 on: March 26, 2006, 04:21:55 PM »
At 169 /- What was your rpm? At Maxton due to space 3.1 to 3.4 seam to work . The higher hp/$ rides 2.7 to 3.00. What motor you running. The Jesel tk. had 3.89 a nasscar motor and turns 9000 rpm.