Club Cobra GasN Exhaust  

Go Back   Club Cobra > Cobra Talk Areas > ALL COBRA TALK

MMG Superformance
Nevada Classics
Keith Craft Racing
Main Menu
Module Jump:
Nevada Classics
Nevada Classics
MMG Superformance
Advertise at CC
Banner Ad Rates
MMG Superformance
MMG Superformance
MMG Superformance
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 11-15-2008, 09:11 AM
sparks's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2002
Location: caledonia, il
Cobra Make, Engine: #1459 w/460(sold)New(used),spf w/427s.o.(sold)
Posts: 578
Not Ranked     
Question Horsepower To Weight

ME AND MY FRIEND R ARGUING THAT A 550 HP (fe)COBRA WILL KEEP UP WITH HIS O8'(650HP)ACR VIPER.I TOLD HIM THAT A 500-600LB. DIFF. IS HUGE. WHAT IS THE GENERAL RULE FOR HP LOSS DUE TO WEIGHT????
THE RACE WOULD ONLY GO TO AROUND 125 OR SO.
Reply With Quote
  #2 (permalink)  
Old 11-15-2008, 09:23 AM
Snakebit's Avatar
Club Cobra Member
Visit my Photo Gallery

 
Join Date: Nov 1999
Location: Salem,, NJ
Cobra Make, Engine: ERA 289 FIA #2100 Rio Red Wimbledon White Stripes 302 stroked to 331 Webers Richmond Road Race 5 speed
Posts: 779
Not Ranked     
Default

A lot has to do with tires and suspension. The heavier car may stick to the track better. The lighter car can have all the horse power in the world, but if it can't get the tires to hook up its useless.

Put the Viper next to the Cobra and see who draws the crowd!
__________________
Snakebit
Reply With Quote
  #3 (permalink)  
Old 11-15-2008, 09:27 AM
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2002
Location: Chicago 'Burb, Il
Cobra Make, Engine: SPF#1245 w/ 1966 427 SO
Posts: 1,167
Not Ranked     
Default

Craig- The weight difference should be a lot more than 500-600 lbs. It should be closer to 1000 lbs difference since Vipers weigh in at around 3400 lbs.

Where Vipers, Vettes, etc....usually get Cobra's is off the starting line. This is mostly due to their superior tires (I think Vipers have sticky, low profile 345's on the back). We Cobra guys have to keep from spinning our tires too much when taking off. In my experience, I usually end up overtaking them by the time I'm thru 2nd gear.

Stick some BFG drag radials, or some sticky AVONS on the back, and you will be good to go!

Last edited by TerrysSPF; 11-15-2008 at 09:30 AM..
Reply With Quote
  #4 (permalink)  
Old 11-15-2008, 09:33 AM
sparks's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2002
Location: caledonia, il
Cobra Make, Engine: #1459 w/460(sold)New(used),spf w/427s.o.(sold)
Posts: 578
Not Ranked     
Default

The New Acr's Come W/a Track Tire.they Make You Sign Something That Says U Will Not Drive Car In The Rain!!!!!i Usually Would Race From A Roll On.your Rite About Which Car Would Get More Att. And Def. Sound Better. A Viper Sounds Like A Johndeer W/ Bad Exhaust.
Reply With Quote
  #5 (permalink)  
Old 11-15-2008, 09:38 AM
CC Member
Visit my Photo Gallery

 
Join Date: Apr 1999
Location: cleveland, OH
Cobra Make, Engine: CSX4000, 427
Posts: 1,999
Not Ranked     
Default

2 years ago, I was given the oppurtunity to drive a hennessey viper, i think venom 650. No comparison to my cobra. Viper was actually disappointing. My cobra was so much more explosive, "out-of-control" type acceleration than the viper.
__________________
"After jumping into an early lead, Miles pitted for no reason. He let the entire field go by before re-entering the race. The crowd was jumping up and down as he stunned the Chevrolet drivers by easily passing the entire field to finish second behind MacDonald's other team Cobra. The Corvette people were completely demoralized."
Reply With Quote
  #6 (permalink)  
Old 11-15-2008, 09:40 AM
sparks's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2002
Location: caledonia, il
Cobra Make, Engine: #1459 w/460(sold)New(used),spf w/427s.o.(sold)
Posts: 578
Not Ranked     
Default

but there is a general ratio,rite??
Reply With Quote
  #7 (permalink)  
Old 11-15-2008, 09:47 AM
Jerry Clayton's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2005
Location: Bartlett, Ill
Cobra Make, Engine: Everett-Morrison LS1
Posts: 2,448
Not Ranked     
Default

Weight has no effect on horsepower
Reply With Quote
  #8 (permalink)  
Old 11-15-2008, 09:54 AM
sparks's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2002
Location: caledonia, il
Cobra Make, Engine: #1459 w/460(sold)New(used),spf w/427s.o.(sold)
Posts: 578
Not Ranked     
Default

then why a 4000lb. car is not as fast as 3000lb car w/ same engine?????
or r you gettin all engineer on me?
Reply With Quote
  #9 (permalink)  
Old 11-15-2008, 10:08 AM
Silverback51's Avatar
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Jun 2007
Location: Covington, wa
Cobra Make, Engine: Superformance # 532, 466 BB, 560HP
Posts: 3,027
Not Ranked     
Default

Quote:
Originally Posted by sparks View Post
then why a 4000lb. car is not as fast as 3000lb car w/ same engine?????
or r you gettin all engineer on me?
He is correct, that weight has no relationship to HP.

It does however take more HP to move a heavier car at the same rate of acceleration as a lighter car.
Reply With Quote
  #10 (permalink)  
Old 11-15-2008, 10:17 AM
sparks's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2002
Location: caledonia, il
Cobra Make, Engine: #1459 w/460(sold)New(used),spf w/427s.o.(sold)
Posts: 578
Not Ranked     
Default

OK,that being said!how much more hp would it take to move a 3k lb. car vs a 4k lb car??
Reply With Quote
  #11 (permalink)  
Old 11-15-2008, 10:23 AM
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Jul 2000
Location: Las Vegas, NV
Cobra Make, Engine: ERA 427 SO
Posts: 1,126
Not Ranked     
Default

If the Viper weighed 3500 and the Cobra weighed 2500, it would take 40% more power in the Viper for it to have the same power to weight ratio (and acceleration, all else equal, which it's not) as the Cobra. If your friend has a 550 HP Cobra, the Viper would have to have 770 HP to have the same potential for acceleration (assuming no wheelspin and similar traction).
__________________
Ken
Reply With Quote
  #12 (permalink)  
Old 11-15-2008, 10:29 AM
sparks's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2002
Location: caledonia, il
Cobra Make, Engine: #1459 w/460(sold)New(used),spf w/427s.o.(sold)
Posts: 578
Not Ranked     
Default

not to mention he drinks alot of bud lite and he is about 50lbs. hev. than me!
Reply With Quote
  #13 (permalink)  
Old 11-15-2008, 10:39 AM
CC Member
Visit my Photo Gallery

 
Join Date: Nov 2000
Location: Flower Mound, TX, tx
Cobra Make, Engine: Lonestar LS 427, Keith Craft 501,Toploader
Posts: 883
Not Ranked     
Default

Weight has EVERYTHING to do with comparing speed vs. horsepower. To compare, you divide the cars' weight into it's hp. So, your Cobra's power is 4.73 per # and it doesn't matter what kind of engine you have, and your buddy's Viper is 5.23 per #. So I wouldn't race him, he'll eat you up. I've been told that 13#'s equals 1hp.
__________________
" It ain't no big deal"
Reply With Quote
  #14 (permalink)  
Old 11-15-2008, 10:54 AM
392cobra's Avatar
6th Generation Texan
Visit my Photo Gallery

 
Join Date: Feb 2002
Location: Devil's Backbone,RR 32, TX
Cobra Make, Engine: Lone Star Classics #240,Candy Apple Red,Keith Craft 418w - 602 HP,584 TQ
Posts: 8,157
Not Ranked     
Default

Tim,
It's 4.73 lbs per horsepower for the Cobra. 5.23 lbs. per horsepower for the Viper.

The Cobra has the advantage.
Reply With Quote
  #15 (permalink)  
Old 11-15-2008, 10:56 AM
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Jul 2000
Location: Las Vegas, NV
Cobra Make, Engine: ERA 427 SO
Posts: 1,126
Not Ranked     
Default

A minor correction, weight has a lot to do with acceleration vs. horsepower, not speed vs horsepower.
If the Cobra has 4.73 lbs/HP, it will out accelerate the Viper with 5.23 lbs/HP. Lower lbs/HP is better in this case.
__________________
Ken
Reply With Quote
  #16 (permalink)  
Old 11-15-2008, 11:42 AM
Tommy's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2002
Location: Dadeville, AL
Cobra Make, Engine: Sold my EM.
Posts: 2,433
Not Ranked     
Default

A Google search reveals a lot of interesting articles on the subject of torque, horsepower, weight, elapsed time (ET) and trap speed (TS). In general, weight is very important for both ET and TS. Torque is more important for calculating ET and horsepower is more important for calculating TS. ... One web site has a horsepower estimator based on weight, ET and TS. It says a 2500# car (e.g., a Cobra) can run an 11 second ET with a TS of 125 MPH with 376 HP at the flywheel. It also says a 3400# car (e.g., a Viper) needs 511 HP at the flywheel to run the same ET and TS. Based on that, it looks like a Cobra could give up 135 HP to a Viper and still keep up or beat him.
__________________
Tommy
Cheetah tribute completed 2021 (TommysCars.Weebly.com)
Previously owned EM Cobra
"Never attribute to malice that which is adequately explained by stupidity." - Hanlon's Razor
Reply With Quote
  #17 (permalink)  
Old 11-15-2008, 02:12 PM
CC Member
Visit my Photo Gallery

 
Join Date: Nov 2000
Location: Flower Mound, TX, tx
Cobra Make, Engine: Lonestar LS 427, Keith Craft 501,Toploader
Posts: 883
Not Ranked     
Default

No, Fred you have it backwards. The Cobra has 4.73 hp per pound and the Viper has 5.23 hp per pound. The Viper has the advantage.
__________________
" It ain't no big deal"
Reply With Quote
  #18 (permalink)  
Old 11-15-2008, 02:35 PM
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2002
Location: Chicago 'Burb, Il
Cobra Make, Engine: SPF#1245 w/ 1966 427 SO
Posts: 1,167
Not Ranked     
Default

Tim- Actually, I think what that calculation tells you is that the Cobra only has to push 4.73 lbs for every HP it produces (actually, I got 4.36 when I did the math - 2400 divided by 550), and the Viper has to push 5.23 lbs for every HP it has.

-Edge goes to the Cobra.
Reply With Quote
  #19 (permalink)  
Old 11-15-2008, 02:35 PM
CC Member
Visit my Photo Gallery

 
Join Date: Apr 1999
Location: cleveland, OH
Cobra Make, Engine: CSX4000, 427
Posts: 1,999
Not Ranked     
Default

Quote:
Originally Posted by Tim Brewer View Post
No, Fred you have it backwards. The Cobra has 4.73 hp per pound and the Viper has 5.23 hp per pound. The Viper has the advantage.

Then the cobra should have about ( 4.73 hp/lb x 2400 lbs ) 11,000 hp. What a ride.

The viper would have (5.23 hp/lb x 3400 lbs ) 18,000 hp, even a wilder ride.

The viper would be faster.
__________________
"After jumping into an early lead, Miles pitted for no reason. He let the entire field go by before re-entering the race. The crowd was jumping up and down as he stunned the Chevrolet drivers by easily passing the entire field to finish second behind MacDonald's other team Cobra. The Corvette people were completely demoralized."
Reply With Quote
  #20 (permalink)  
Old 11-15-2008, 02:40 PM
sparks's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2002
Location: caledonia, il
Cobra Make, Engine: #1459 w/460(sold)New(used),spf w/427s.o.(sold)
Posts: 578
Not Ranked     
Default

now i'm really confused??????????????????????????????
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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 11:42 PM.


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
Links monetized by VigLink