Board Logo
Go To Bottom

Printable Version  
[ Total Views: 557 | Total Replies: 2 | Thread Id: 5161 ]
Author: Subject: caster shims.
Memberhick
Learner Dubber
*


Avatar


Posts: 18
Threads: 5
Registered: March 11th, 2003
Member Is Offline

Location: Brisbane
Theme: UltimaBB Pro Blue ( Default )

posted on April 9th, 2003 at 02:55 PM
caster shims.


i was hoping some one could tell me the benifit of using caster shims when i lower my front end.
Memberwhatnow
A.k.a.: Henry
Custom Title Time!
*****


Avatar


Posts: 1000
Threads: 54
Registered: January 11th, 2003
Member Is Offline

Location: armidale, northern tablelands NSW
Theme: UltimaBB Streamlined2
Mood: 14's are the new earlies.

posted on April 9th, 2003 at 05:27 PM


when you change the angle of the line between the front and rear suspension to the road (ie lower just the front end or lower the front more than the back etc) you change the characteristics of the suspension.
when you lower the front end of a beetle the caster angle is reduced which makes the car react quicker and more to movements in the steering or changes in the road.... great if you want to flick/slide through lots of tight corners but really dangerous if you want to drive at any medium to fast speed. (very unstable).
by adding castor shims you replace the castor lost when the front is lowered. this keeps the car as stable as it was.
on drag cars i think the trend is to increase the caster to more than stock to improve the high speed stabillity (they loose cornering abillity at the same time but there aren't too many corners on a drag strip).
talk to one of the bigger VW shops and they can give you advice on when to use shims and what thickness to add. if not try the cal-look forum http://www.cal-look.com  and go to the forum.
there are lots of really knowledgeable people there who can give you all the info you need to get it right.
hope this makes sense and is helpfull.
h.

[Edited on 9-4-2003 by whatnow]
MemberOvalGlen
Custom Title Time!
*****


Avatar


Posts: 1361
Threads: 46
Registered: August 27th, 2002
Member Is Offline

Location: Liverpool.
Theme: UltimaBB Pro Blue ( Default )
Mood: Change

posted on April 9th, 2003 at 08:53 PM


as h. said, but my extra 2 cents worth,
when the caster is set right the car pulls itself back to straight,
ie. you turn the corner and if you let go of steering wheel it returns to straight.
On a lowered car (without castor shims )
you turn a corner and you must pull the wheel back to straight or you will keep turning.




Regards,Glenn>
Member70AutoStik
Insano Dub Head
****


Avatar


Posts: 730
Threads: 18
Registered: August 30th, 2002
Member Is Offline

Location: Dandenong. Victoria
Theme: UltimaBB Pro Blue ( Default )

posted on April 9th, 2003 at 11:05 PM


I don't want to sound argumentative, whatnow, but I feel I should add something to your comments. Less castor will give quicker turning in, say, a slalom event, but can increase problems with high-speed turning. The castor increases the effective camber when the wheel is turned from straight, couteracting the tyre "rollover" (the same reason serious race cars have huge amounts of negative camber.) As the light-weight beetle is rather easy to turn at speed, a little more castor with otherwise stock geometry will actually improve handling on most setups (the tyre used has some effect here.)

Glen is right, it also produces more "self-correcting" force. It also helps to stabilise the car against the effects of wind, road camber and undulations. Most people who like to drive above granny-speed find an extra 1.5 degrees will really settle the car, but any more than 3 degrees total can be a bit of a problem (eg, can actually add bump-steer,) except on a strip car.
Memberhick
Learner Dubber
*


Avatar


Posts: 18
Threads: 5
Registered: March 11th, 2003
Member Is Offline

Location: Brisbane
Theme: UltimaBB Pro Blue ( Default )

posted on April 10th, 2003 at 06:42 AM


thank you very much. this forum is great.i am greatful for the replies.
Memberwhatnow
A.k.a.: Henry
Custom Title Time!
*****


Avatar


Posts: 1000
Threads: 54
Registered: January 11th, 2003
Member Is Offline

Location: armidale, northern tablelands NSW
Theme: UltimaBB Streamlined2
Mood: 14's are the new earlies.

posted on April 10th, 2003 at 12:57 PM


auto stick, glen, thanks for the extra info. i will keep that in mind when i finally get around to tuning my suspension (have to finish the car first :) ). castor was something i never thought of playing with other than trying to keep it stock.
MemberCraig Torrens
A.k.a.: Craig Torrens
Scirocco Rare
6 times Australian, 7 times State Hillclimb Class Champion
*********


Avatar


Posts: 8040
Threads: 347
Registered: January 10th, 2003
Member Is Offline

Location: Sydney
Theme: UltimaBB Pro Blue ( Default )
Mood: Time to go Salt lake racing, and actually achieve a result.

posted on April 15th, 2003 at 09:45 PM


more caster the better !! this will help with neg deg on your wheels when your turning (when you need it). I think stock is about 2deg, I've run up to 8 !! You do loose your turning circle though if your using wide wheels.





  Go To Top


Powered by GaiaBB, © 2011 The GaiaBB Group
(C) 2001-2025 Aussieveedubbers

[ Queries: 40 ] [ PHP: 1.6% - SQL: 98.4% ]