SUPPORT OUR SPONSOR

Go Back   Club Cobra > Club Cobra Tech Areas > Shop Talk

Welcome to Club Cobra!  The World's largest non biased Shelby Cobra related site!

  •  » Representation from nearly all Cobra/Daytona/GT40 manufacturers
  •  » Help from all over the world for your questions
  •  » Build logs for you and all members
  •  » Blogs
  •  » Image Gallery
  •  » Many thousands of members and nearly 1 million posts! 

YES! I want to register an account for free right now!  p.s.: For registered members this ad will NOT show

MMG Superformance
Nevada Classics
Main Menu
Nevada Classics
Nevada Classics
MMG Superformance
Advertise at CC
Banner Ad Rates
Keith Craft Racing
Keith Craft Racing
MMG Superformance
March 2024
S M T W T F S
          1 2
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31            
  #1 (permalink)  
Old 06-05-2011, 01:37 PM
fordracing65's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2010
Location: Tempe,AZ-High Point,NC, AZ
Cobra Make, Engine: Kirkham #684, 482FE, Mike Mccluskey build
Posts: 2,520
Send a message via Skype™ to fordracing65
Not Ranked     
Default 427w rear gears

What rear gears are you guys running with the 427w small block, assuming you have a 5 speed, i've heard everything from 4:10 to 3:27, thanks for any help.
__________________
PRIDEnJOY
Reply With Quote
  #2 (permalink)  
Old 06-05-2011, 03:16 PM
MFE III's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Apr 2006
Location: Los Angeles, ca
Cobra Make, Engine: Hurricane Motorsports, 427w
Posts: 437
Not Ranked     
Default

I'm running 3.73 with a .82 5th gear ratio. I'm taching about 3k rpms at 80 mph.
__________________
Hurricane Motorsports #1053; 427w
Reply With Quote
  #3 (permalink)  
Old 06-05-2011, 04:06 PM
fordracing65's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2010
Location: Tempe,AZ-High Point,NC, AZ
Cobra Make, Engine: Kirkham #684, 482FE, Mike Mccluskey build
Posts: 2,520
Send a message via Skype™ to fordracing65
Not Ranked     
Default

thanks, any info helps
__________________
PRIDEnJOY
Reply With Quote
  #4 (permalink)  
Old 06-05-2011, 05:23 PM
Zoom This's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2003
Location: Bainbridge Island, WA
Cobra Make, Engine:
Posts: 709
Not Ranked     
Default

Guess it all depends on what you are planning to do with the car. Race? Cruise? Long trips? In any case I'd venture to guess that most guys here have 5 speed trannies with an overdrive 5th gear. My SPF has 3.73:1 gears and a .64 OD with a 418W. At 70 mph I tach 2100 rpm...very liveable. Running 3000 rpm on the freeway at 65-75 can get old real fast. If I were to do it all over I'd keep my Tremec TKO 600 but opt for the .82 5th gear and a 3.27 rear gear. I've had my car on some very long road trips over the years and driving at 65-75 and loping along at 1800-2200 rpm is very liveable.
Reply With Quote
  #5 (permalink)  
Old 06-05-2011, 05:39 PM
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2005
Location: Perrysburg, OH
Cobra Make, Engine: SPF #298 427 FI
Posts: 497
Not Ranked     
Default

Just switched to a 3.73 from a 3.27. Not sure what my fith is but 70mph is about 2300-2500. Im glad i switched but didnt notice as much difference as I thought i would. I would go at least 3.73.
Reply With Quote
  #6 (permalink)  
Old 06-05-2011, 05:55 PM
charles roybal's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Mar 2006
Location: El Paso, tx
Cobra Make, Engine: FRR MKIII 408w
Posts: 340
Not Ranked     
Default

408w 530 hp 535 f/t. 3:27 TKO 500, 1st is usealbe, 70 mph in 5th is1,900-2000 PRM. very streetalble..... I can use 5th at 1,500RPM and she PULLS!!!!
Reply With Quote
  #7 (permalink)  
Old 06-05-2011, 06:06 PM
WardL's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Sep 2009
Location: Camarillo, CA
Cobra Make, Engine: SPF #2608, Roush 427SR T-W
Posts: 911
Not Ranked     
Default

In SPF 2608 made in 2007 I have the Dana rear end with the 3.46 rear end, 0.82 OD and 17" wheels. At 70 MPH in 5th the Dart 427 is turning over at 2,545. Of course 5th gear has plenty of reserve power for acceleration. With my limited experience, I'm very happy with the rear end ratio when starting off in 1st.
Reply With Quote
  #8 (permalink)  
Old 06-05-2011, 06:54 PM
fordracing65's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2010
Location: Tempe,AZ-High Point,NC, AZ
Cobra Make, Engine: Kirkham #684, 482FE, Mike Mccluskey build
Posts: 2,520
Send a message via Skype™ to fordracing65
Not Ranked     
Default

thanks, i was going to try a 4:10, i think it would be a mean street rear gear.
__________________
PRIDEnJOY
Reply With Quote
  #9 (permalink)  
Old 06-05-2011, 06:55 PM
209 209 is offline
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2007
Location: Earlimart, Ca
Cobra Make, Engine: Superformance 2765 Roush 427(POS) with cruise.
Posts: 221
Not Ranked     
Default

3.46 rear, .82 od, 15", 70mph 2500. 209
Reply With Quote
  #10 (permalink)  
Old 06-05-2011, 07:32 PM
Barnsnake's Avatar
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Nov 2003
Location: Parker County, Tx
Cobra Make, Engine: LoneStar LS427 , 427 Windsor
Posts: 381
Not Ranked     
Default

It will depend upon your rear tire diameter and 1st gear ratio, but while a 4.10 might be great for your high-winding cammer, the windsor will have TORQUE. With short tires on 17" wheels and a 4.10 rear gear, 1st gear will be useless for anything but parades and testing your rev limiter. You'll find yourself starting off in 2nd.
__________________
Jim
------------
A Gnat! Quick, get a sledgehammer!
Reply With Quote
  #11 (permalink)  
Old 06-05-2011, 08:14 PM
fordracing65's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2010
Location: Tempe,AZ-High Point,NC, AZ
Cobra Make, Engine: Kirkham #684, 482FE, Mike Mccluskey build
Posts: 2,520
Send a message via Skype™ to fordracing65
Not Ranked     
Default

thats what i figured, ive just had so many people with the 427w tell me so many different gear ratios for the street
__________________
PRIDEnJOY
Reply With Quote
  #12 (permalink)  
Old 06-05-2011, 08:20 PM
bobcowan's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2007
Location: Colorado Springs, CO
Cobra Make, Engine: Backdraft, supercharged Coyote
Posts: 2,430
Not Ranked     
Default

There is no perfect gear for every situation. Unless the car is dedicated to a specific purpose, it's always going to be a comprimise. Some people like more, and some less. Some people cruise at 80, and some at 60.

When I'm on tthe highway cruising at 80, I think a 3.27 or 3.08 would be perfect. But when I'm on the back roads, a 3.55 ro 3.73 would be better. I find that a 3.55 seems to fit most of my driving situations pretty well.
__________________
.boB "Iron Man"
NASA Rocky Mountain TTU #42
www.RacingtheExocet.com
BDR #1642 - Supercharged Coyote, 6 speed Auto
Reply With Quote
  #13 (permalink)  
Old 06-06-2011, 03:11 AM
xb-60's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Aug 2009
Location: Adelaide, SA
Cobra Make, Engine: AP 289FIA 'English' spec.
Posts: 13,139
Not Ranked     
Default

Have you looked at these Superformance pages:

Second Strike Gearing Calculator

http://www.secondstrike.com/Technical/GearingHelp.pdf

The second one in particular is well worth a read. Page four describes the desirability of not overpowering the tyres too much in second gear (ie not having the diff. ratio too short).

Cheers,
Glen
Reply With Quote
  #14 (permalink)  
Old 06-06-2011, 07:11 AM
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2004
Location: Kansas City, KS
Cobra Make, Engine: jbl
Posts: 2,291
Not Ranked     
Default

with the larger rear gears you shift through the gears so quick just driving around with the light wt. cobra and all the power. i don't have that much engine but do have a 3.73 in one and a 3.55 in the other, wouldn't go larger then 3.73 and could use a 3.55 or thereabouts real easy all day long. with a 3.73 or 3.55 you can accelerate in 2nd and skip shift to 4th pretty easy for street driving fyi.
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 03:14 AM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: CC Policy