new drag car does not drive straight after launch - 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> Suspension - Brakes - Steering
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 10-13-2007, 08:26 PM
Registered User
 
Join Date: Oct 2007
Location: newjersey
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
new drag car does not drive straight after launch

it is a new c/m tube car,4 link,strut,2350 lbs.,roadster vette,2005,505 ci,glide..it launches straits on wheel bars.when it gets down (after 60+ft)it wants to go to right under power.if i lift it goes straight.when i get on it again it drives to right.the builder is NOT HELPING ME TO MUCH .i think the problem is in the scaling of the original set up.i followed his instr.to the "T" but i think he may have screwed up,by mistake.all settings are OKOK.ft end align is good,toe is good.4link is ok,rear is square in car,pinion is 1.5 dwn,bars are ok length,everthing is checked over/over!!.initial scaling--rear wts--are left rr-630lbs/rt rr-581lbs--top rt bar neatral.lt ft-648lbs/rt ft 497lbs..the final settings he wanted were 21 more lbs on rt rear by shortening top rt link.i did this,car drives rt.added more preload,it still went rt(not on launch)the whlbrs are steering it.i think i need to set it up on scales initially whith the rear wts the same,by raising lt frt sprg to add wt to rt rr.the rear lt/rt wts same//top rt bar neatral/THAN add my 21lbs. preload to rt side.anybodys thoughts on this?i cant be dragging it to the track to make one run!!!!HELP.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 10-13-2007, 10:05 PM
RCastle's Avatar
Come Home Safe Soldier
 

Last journal entry: Headers
Last photo:
Join Date: Aug 2004
Location: Louisville,Kentucky
Age: 43
Posts: 848
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post this in the suspension forum if you have not already.I wish I knew a little more about tube chassis set ups,as that is the route I will be taking soon.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 10-14-2007, 05:56 AM
poncho62's Avatar
Out of the Loop Moderator
 
Last wiki edit: Streetbeasts links
Last journal entry: at car show
Last photo:
Join Date: Oct 2003
Location: Hanover, Ontario, Canada
Age: 62
Posts: 16,902
Wiki Edits: 5

Thanks: 21
Thanked 276 Times in 220 Posts
moving it there..............
__________________
Ontario Rodders

Budget RVs
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 10-15-2007, 05:00 AM
bluebu's Avatar
Member
 
Last photo:
Join Date: Mar 2005
Location: South Carolina
Age: 53
Posts: 134
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Not seeing the car it's a hard call. How close are your wheelie bars to the track and how long are they? What kind of 60 ft. times are you getting?

Could be a number of things going on but I'd look at the basics first, the wheelie bars. It could be hitting the bars too hard and unloading the rear tires. The other thing is plain ole driver error. Not to be insulting or anything but it's a new car and I know that if you put a hundred right handed drivers in something that stands up 99 of them, if they let the wheel move at all while it's in the air, will turn it to the right. Lefties come down and find themselves going left! lol

Mark dead straight on your wheel with tape, like the pro stock boys do, and when she lifts make double sure that the wheel is dead on before she settles back down.

If neither of these things solves the problem THEN I'd start looking at tires and preload.

Peg
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 10-15-2007, 06:20 AM
Beenaway2long's Avatar
or Jeff, or Doc, or...
 

Last journal entry: Results of the Camaro
Last photo:
Join Date: Nov 2003
Location: Syracuse, NY-well, just North
Age: 51
Posts: 988
Wiki Edits: 0

Thanks: 0
Thanked 4 Times in 3 Posts
First thought:

Are YOU in the car when scaling? Or the same weight in the seat. If not, your scale #s are worthless.

Assuming you are in the car, With 50# more on the left rear, its providing more traction on the tire. I would preload the right rear more. MORE PRELOAD WILL CHANGE YOUR WHEELIE BAR HEIGHT. Be sure to readjust accordingly.

Tire pressure?

Out of the groove? (Real easy to do)

How is the front when its coming up? Is it level? Or is it left side high?

Shock adjustments make a HUGE difference side to side. You COULD have one click too stiff on the right rear side.

You really need a video of the car to tell more.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 10-15-2007, 06:36 AM
BillyShope's Avatar
Philippines Cowboy
 

Last journal entry: THE TRACTION DYNO
Last photo:
Join Date: Jan 2004
Location: Orlando, FL
Age: 78
Posts: 875
Wiki Edits: 0

Thanks: 0
Thanked 13 Times in 7 Posts
Quote:
Originally Posted by adamcorvette1236
i cant be dragging it to the track to make one run!!!!
No, and you don't have to! You can measure rear wheel loads and make adjustments in your shop without even starting the engine. Before you ever load it up to go to the strip, you can know that your rear tires will be equally loaded on launch and that the car will not veer to the right...or left.

See Pages 4, 5, and 6 of my site:

http://home.earthlink.net/~whshope
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 10-17-2007, 07:50 PM
Registered User
 
Join Date: Oct 2007
Location: newjersey
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
adamcorvette1236car does not drive straight

thanks for your input.you are all right.i think the chassis builder left out one step on my setting up on the scales. here is my plan to re scale set up. car on scales,race ready,driver in,loaded fuel,water,etc.etc..(just like we did it before).buttt! now i will make the rear wheel weights left to right BEFORE i add the 21lbs rt/top bar preload the the same.... you all can see the origanal set up on the site.this will be the NEW set up now..all done on the scales-race ready,drvr in.----left +right rear weights equal.ride heights all set.than i will add the preload to right top bar plus 21 lbs(as per builders specs.)this should be 1.5 flats on rt/top bar.anti roll bar neautral setting.tires are 102 " both circ,lt/rt will run 5lbs lbs. lt/rt.,shocks set --lt 3 bot.frm loose/rt 2 bot.frm.loose.top set 7 in middle on ext.. .wheel bars height to bolt center left 5.25/right 5.0.(these are the heights he wanted).the car did leave straight and ok untill it settled down to go,then it drove to right. ..will put tape on steer wheel (just never did now,always did before).if you guys have any more thoughts please reply,i think it will be ok now???ha ha .will go to maple grove on 10/27--etown on 10/28.i will let you know how i make out on 10/29 monday.thanks for your help.boy i love this web site!! ADAM
Reply With Quote Quick reply to this message

Recent Suspension - Brakes - Steering 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
what is the fastest (factory) car you have ever driven? badknuckles Hotrodders' Lounge 320 12-09-2011 01:32 AM
Headers for my drag car Quarter Flash Engine 17 12-20-2006 02:47 PM
Monza Drag Car Question Quarter Flash Suspension - Brakes - Steering 8 10-30-2006 03:30 PM
It's all in the details... Nightfire Hotrodders' Lounge 18 09-16-2006 09:53 PM
Let my buddy drive my car...WOW Rubberman2003 Hotrodders' Lounge 17 10-08-2004 01:11 AM


All times are GMT -6. The time now is 06:01 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.