hick Learner Dubber
18 posts · joined Mar 2003 ·
i was hoping some one could tell me the benifit of using caster shims when i lower my front end.
caster shims.
whatnow Custom Title Time!
1,000 posts · joined Jan 2003 ·
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]
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]
OvalGlen Custom Title Time!
1,361 posts · joined Aug 2002 ·
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.
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>
70AutoStik Insano Dub Head
730 posts · joined Aug 2002 ·
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.
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.
hick Learner Dubber
18 posts · joined Mar 2003 ·
thank you very much. this forum is great.i am greatful for the replies.
whatnow Custom Title Time!
1,000 posts · joined Jan 2003 ·
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.
Craig Torrens 6 times Australian, 7 times State Hillclimb Class Champion
8,040 posts · joined Jan 2003 ·
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.