Front end geomerty - 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 03-20-2017, 11:47 AM
Registered User
 
Join Date: Nov 2006
Location: IOWA
Posts: 18
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Front end geomerty

I have a fiberglass 1932 3 window coupe with 350 SB and 9 inch rear end. It likes to wander a bit at 40mph and up. I set the toe in at 1/4".
I would like to know what a degree of pos. caster I should try to bring it under control.
You can drive it at 70mph but you have to be steering all the time. I also have adjusted the steering gear.

I would appreciate any help on this THANK YOU diesel doc

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 03-20-2017, 11:54 AM
astroracer's Avatar
Member
 
Last wiki edit: Crankshaft Coalition Wiki Last photo:
Join Date: Nov 2003
Location: Mid-Michigan
Posts: 2,310
Wiki Edits: 1

Thanks: 19
Thanked 198 Times in 180 Posts
Shoot for 5 to 7 degrees. That will get the caster trail to a point where the wheels will self-center.
Mark
Reply With Quote Quick reply to this message
The Following User Says Thank You to astroracer For This Useful Post:
techinspector1 (03-20-2017)
  #3 (permalink)  
Old 03-20-2017, 12:06 PM
techinspector1's Avatar
Member
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Zephyrhills, Florida, USA
Age: 75
Posts: 15,318
Wiki Edits: 326

Thanks: 1,496
Thanked 2,015 Times in 1,555 Posts
Next time you build a rod, use IFS and prevent all that monkey motion. Straight axle technology is 100+ years old.
Reply With Quote Quick reply to this message
The Following User Says Thank You to techinspector1 For This Useful Post:
PHWOARchild (03-27-2017)
 
  #4 (permalink)  
Old 03-20-2017, 03:41 PM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Last photo:
Join Date: Jul 2002
Location: Columbia, Mo
Age: 40
Posts: 5,829
Wiki Edits: 0

Thanks: 48
Thanked 380 Times in 312 Posts
I'd try 1/4 toe out and see what happens.

Toe out will typically make it more stable at speed and gives and indication of where to fix the problem.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 03-20-2017, 05:45 PM
techinspector1's Avatar
Member
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Zephyrhills, Florida, USA
Age: 75
Posts: 15,318
Wiki Edits: 326

Thanks: 1,496
Thanked 2,015 Times in 1,555 Posts
Try airing up the tires all around and see what happens.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 03-20-2017, 06:52 PM
39 master's Avatar
Registered User
 
Last photo:
Join Date: Oct 2015
Posts: 444
Wiki Edits: 0

Thanks: 0
Thanked 87 Times in 74 Posts
Solid axle

I'm with Astroracer, lay the kingpins back 7 degrees. I also assume you are using a Vega box. Check every tie rod and the box for any play. I've heard nothing but good reports on the Unisteer half rack to replace a worn out vega box. I've had three solid axle cars and when properly set up worked as well as any front end AND it"s strong.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 03-21-2017, 08:39 AM
454 Rattler's Avatar
NEVER SATISFIED !!
 
Last photo:
Join Date: Sep 2006
Location: Eagle River WI.
Age: 73
Posts: 1,417
Wiki Edits: 0

Thanks: 49
Thanked 129 Times in 115 Posts
I guess I missed it or something. What suspension do you have ? Is it a straight axle or independent suspension ?


454 RATTLER
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 03-21-2017, 08:52 AM
Registered User
 
Join Date: Nov 2006
Location: IOWA
Posts: 18
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
THANK's for the info!
I will try 7degree Pos., and the 1/4 toe out I don't know about that. I have checked every thing for play and nothing there, it's all tight.
As far as (IFS) I have not a clue what that is and there is no rag joint.
I will let you know how the toe out works.
THANKS AGAIN for the help
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 03-21-2017, 03:13 PM
Registered User
 
Join Date: Nov 2006
Location: IOWA
Posts: 18
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
It's a straight axel with a cross spring with steering gear mount on left and drag link crossing to right with the tie rod in front of the drag link
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 03-21-2017, 04:57 PM
39 master's Avatar
Registered User
 
Last photo:
Join Date: Oct 2015
Posts: 444
Wiki Edits: 0

Thanks: 0
Thanked 87 Times in 74 Posts
Sounds like your belly button solid axle front end. If you take it to a front end shop the only thing they can set is the caster (lay the kingpins back) and the toe. Camber would have to be set by bending the axle and unless you ran into something BIG the axle should not be bent. So, bottom line is to set the kingpins back with the upper and lower 4 bars or hairpins (whichever you have) then take it to a shop for the toe. I like to have mine set at 1/16 to 1/8 IN not out but that's up to you and the shop. Note that I said take it to a shop for the toe because I just can't get that close at home. Warning, it's a bit tricky messing with the 4 bars or hairpins...be careful.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 03-21-2017, 04:58 PM
Fasto44's Avatar
Registered User
 

Last journal entry: Old Shop Truck - '56 F-100
Last photo:
Join Date: Nov 2015
Location: Savannah, GA
Posts: 28
Wiki Edits: 0

Thanks: 13
Thanked 27 Times in 17 Posts
Do you have a panard bar that runs from the chassis to the opposite side of the front axle mounted to the bat wing? Without one of these the cross steering with pull and push the axle back and forth which leads to wander. My blown '34 had the same problem until I added a front panard...fixed the problem. BTW I was only running 1/8" toe in on each side (1/4" total).
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 03-21-2017, 06:57 PM
39 master's Avatar
Registered User
 
Last photo:
Join Date: Oct 2015
Posts: 444
Wiki Edits: 0

Thanks: 0
Thanked 87 Times in 74 Posts
front end

Good point Fasto. Some run a dead perch in place of one of the shackles instead of the panhard bar.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 03-22-2017, 06:07 PM
Member
 
Last photo:
Join Date: Dec 2004
Location: ohio
Age: 69
Posts: 789
Wiki Edits: 0

Thanks: 0
Thanked 73 Times in 69 Posts
1/4" toe in, or toe out is way to much. The original recommendation for that front end was 5 to 7 degrees caster, and 1/8" toe in, and that was with bias ply tires.

Radial tires do not need that much toe in, as the radial tires tend to run straighter than bias ply tires. Also unless the traction is exactly equal on both sides, the front end will tend to follow the the tire with the most traction with excessive toe in. When the traction changes, the front end will change side as to the dominant tire, and go off the other way. Setting the toe it to 1/16" or less seems to be the way to go, even to the point of very slightly toeing the tires out.

This is not just my experience with one car, I have built a bunch of cars, and trouble shot many more.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 03-23-2017, 06:21 AM
Registered User
 
Join Date: Nov 2011
Location: pennsylvania
Posts: 201
Wiki Edits: 0

Thanks: 0
Thanked 13 Times in 10 Posts
front end geometry

my car works best with 7` caster and 1/4" toe out with radial tires set at 30psi front and rear. 6" drop tube axle with corvair steering box. car shows no excessive wear on front tires. I drive the car on average of 4000 miles a year. make sure front and rear are square with each other
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 03-27-2017, 11:15 AM
Dclifton32's Avatar
Registered User
 
Last photo:
Join Date: Oct 2015
Posts: 209
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
I set my king pin's to 7deg's what a difference, car tracks down the road.
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:
Insurance
Please select your insurance company (Optional)

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
front end alignment for 79 t-bird Heidts front sus jenajean Suspension - Brakes - Steering 4 09-16-2014 08:58 AM
1953 Buick Special-front end rear end?? mbjeep Suspension - Brakes - Steering 8 12-06-2009 06:32 PM
34 Ford chassis w/MII front end - front tires rub heyjude076 General Rodding Tech 4 04-09-2009 07:46 PM
front end tilt using my all steel front end old c10 head Body - Exterior 5 05-02-2003 01:45 PM
Tables of rear end and front end dimensions willys36@aol.com Transmission - Rearend 1 08-21-2002 05:33 PM


All times are GMT -6. The time now is 04:10 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.