this has been buggin' me - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> General Rodding Tech
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 08-12-2008, 04:01 PM
Registered User
 
Join Date: Jul 2008
Location: Ashville,NY
Posts: 6
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
this has been buggin' me

Ok i want to give you guys a couple racing scenarios, here we go,
2 cars race against each other on a drag strip, one car has a 0-60mph time of 4.7 seconds and a 1/4 mile time of 13.5 seconds the second car hits 60 in 7.9 seconds and the quarter in 15.2 seconds. The cars 0-60 times are 3.2 seconds apart and there is a 1.7 second difference between their 1/4 mile times.
does this mean that the slower car gains 1.6 seconds on the faster car?
scenario 2: 2 cars are on a road course with the finish line being in the middle of
a reasonably long straightaway to make this easier the drivers are clones so they have the same driving skills and the cars are equal in handling.
But on car hits 60mph in 6.3 seconds,100mph in 13.4 seconds and the quarter in
14.3 seconds. The second is 4.7 seconds,13.4 seconds,and 13.5 seconds which
would win, the top ender or the acceleration fiend?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 08-12-2008, 08:01 PM
Registered User
 
Join Date: Jul 2008
Location: Melbourne-Australia
Posts: 39
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Scenario #1

The second (slower car) is slower over the entire quarter, it will be behind everywhere. By gain, do you mean time, or distance? There is a big difference.

Scenario #2

There is no answer to this, because neither the corner exit speed into the straight is given, or the length of the straight. So it is impossible to say.

The corner exit speed could be 20mph, or 120 mph into that straight, and the straight could be ten yards, or ten miles long.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 08-12-2008, 10:56 PM
TorkMonster400's Avatar
uninteresting default message
 
Last wiki edit: Working with chromed bolts
Last journal entry: A couple of pics of the car
Last photo:
Join Date: Mar 2008
Location: Fort Walton Beach Fl
Posts: 236
Wiki Edits: 4

Thanks: 0
Thanked 0 Times in 0 Posts
Cloning is still illegal! J/K
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 08-13-2008, 04:59 PM
Registered User
 
Join Date: Jul 2008
Location: Ashville,NY
Posts: 6
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Sorry for not clarifying that friend ,what i meant was by time.
and for the 2nd one we'll say the corner exit speed is 70mph and the length of the straight is half a mile.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 08-13-2008, 05:24 PM
Registered User
 
Join Date: Jul 2008
Location: Melbourne-Australia
Posts: 39
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
So a rolling quarter mile acceleration time starting off at 70mph.

That would depend on gearing and top speed. A drag race car that is geared to be quick over a standing quarter mile will run out of rpm and top speed pretty quick under those conditions.

Once a low geared drag car hits the rev limiter in top it is done. Something else that can shift to a taller gear, and keep on accelerating would likely get to the far end both sooner and be going faster when it got there.

Think about this.
Suppose you could only use one gear when racing the quarter mile, which gear would get you there quickest. First gear, or top gear ?
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 08-17-2008, 11:46 AM
Registered User
 
Last photo:
Join Date: Sep 2007
Location: Mississippi
Posts: 357
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
There really are many more important things to lose sleep over. There are so many variables involved in both scenarios....tire spin, engine specs, reaction time, shift points, and many more. It is quite possible for one vehicle to out-accelerate another on the bottom end; then the other to outrun it on top.
Going back to the 60's, when the 350 Chevy II's had to run the big block Mopars in the Super Stock wars, the Chevys had the rpms and the launch, due to being lighter; but many times the Mopars would come by them in the lights. That's just one instance......but it illustrates that it can and does happen.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 08-18-2008, 03:54 AM
Rubberman2003's Avatar
Member
 
Last photo:
Join Date: Sep 2002
Location: Ohio
Age: 29
Posts: 806
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
A real world example of this. I was at the track with my new Caliber srt-4. This car sucks in first and second gear. There were cars running a full second faster than i was in the 1/8 mile. But when we finished i was running over 1.5 mph than then. I was running them down hard. Just because my car is a slouch off the line, it really picks up in the back half though.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 08-18-2008, 08:25 AM
Member
 
Last photo:
Join Date: Nov 2004
Location: Lakeland FL
Age: 65
Posts: 4,110
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
the quicker 0-60mph car has alot more motor TQ ft/lbs to accelerate the car weight (and/or lower rear gears to multiple the available TQ)...

the slower car doesn't have enough peak rpms HP for the car weight to catch him (HP=TQ "measured over time and distance" aka: ET and MPH)
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 08-18-2008, 08:56 AM
Registered User
 
Last wiki edit: Wheelbase database Last photo:
Join Date: Jan 2007
Location: Virginia
Posts: 3,590
Wiki Edits: 1

Thanks: 6
Thanked 159 Times in 146 Posts
Quote:
Originally Posted by domesticsarethes&)t
Ok i want to give you guys a couple racing scenarios, here we go,
2 cars race against each other on a drag strip, one car has a 0-60mph time of 4.7 seconds and a 1/4 mile time of 13.5 seconds the second car hits 60 in 7.9 seconds and the quarter in 15.2 seconds. The cars 0-60 times are 3.2 seconds apart and there is a 1.7 second difference between their 1/4 mile times.
does this mean that the slower car gains 1.6 seconds on the faster car?
scenario 2: 2 cars are on a road course with the finish line being in the middle of
a reasonably long straightaway to make this easier the drivers are clones so they have the same driving skills and the cars are equal in handling.
But on car hits 60mph in 6.3 seconds,100mph in 13.4 seconds and the quarter in
14.3 seconds. The second is 4.7 seconds,13.4 seconds,and 13.5 seconds which
would win, the top ender or the acceleration fiend?
OK, fess up. This is a word problem on your math test, right?
Reply With Quote Quick reply to this message

Recent General Rodding Tech posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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


Similar Threads
Thread Thread Starter Forum Replies Last Post
need help in Vegas near UNLV bullheimer Hotrodders' Lounge 8 01-26-2004 05:02 PM


All times are GMT -6. The time now is 06:40 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.