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Location:
Brisbane
Registered:
May 2002
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Suspension questions
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Mon, 20 October 2003 10:40
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In regards to a McPherson strut setup (such as on a RA6X celica / MA61 Supra / MX62 cressida and prbly heaps of others)...
In general -ve camber is good, +ve caster is good right? For a street setup what would you suggest to be good amounts, I know its a bit like asking how long a peice of string is, just after a bit of an idea. I was thinking around -3deg camber +4deg caster?
Also is there a general rule for toe in?
How do you get -ve camber in a McPherson strut setup? Is the only way via adjustable strut tops? Also why does my cars specs say it should have +ve camber (1deg 4 mins  ) wouldn't this be shocking for handling?  (I realize this will become slightly more -ve once you get a person in the car but wont this still be very +ve?)
Moving on, Caster is adjusted via the length of strut bars right, does adjusting this a fair bit (from say 1deg -> 4deg) put stress on the lower arm pivot bush and promote wear to a large extent?
Hmm well thats about the extent of my questions! If anyone has anygood links on McPherson strut setup, I'd be interested 
Cheers
Wilbo
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Location:
Brisbane
Registered:
May 2002
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Re: Suspension questions
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Mon, 20 October 2003 12:12
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3 deg camber is a LOT, and I'd suggest too much for a street-driven car, unless you like paying for new tyres and/or enjoy the feeling of unstable braking.
Camber can be set with adjustable strut-tops, but you generally don't get much adjustment with them before the springs foul the strut tower. The other method is eccentric bushes on the lower control arms.
As for castor, more is better provided you can deal with heavy steering.
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Location:
Brisbane
Registered:
November 2002
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Re: Suspension questions
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Mon, 20 October 2003 12:17
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Sam has 5 degrees on his Fiat when he does sprint days, and about 3 degrees on his street tyres.
I wouldn't run 3 degrees on the street myself - if you drive hard enough to have benefit from it then you're driving too damn fast!
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Location:
Brisbane
Registered:
May 2002
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Re: Suspension questions
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Mon, 20 October 2003 12:29
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Exhibit A: Sam's decimated front tyres after the last sprint day. I rest my case your honour.
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Location:
Menai area of Sydney
Registered:
June 2003
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Re: Suspension questions
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Mon, 20 October 2003 13:43
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Check Whiteline etc - you should be able to get camber pins for the strut/steering knuckle junction.
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Location:
Brisbane
Registered:
May 2002
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Re: Suspension questions
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Mon, 20 October 2003 13:56
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| Scorpion wrote on Mon, 20 October 2003 23:43 |
get camber pins for the strut/steering knuckle junction.
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What the? How do these work?
Also doubtful whiteline would have them, its hopefully for a Cressida man, not exactly sports performance 
Cheers
Wilbo
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Location:
Menai area of Sydney
Registered:
June 2003
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Re: Suspension questions
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Mon, 20 October 2003 14:11
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As Norbie indicated, they're an offsetting bolt. Where the bottom of the McPherson strut bolts to the steering knuckle, there are usually two large bolts, the ones that people often have trouble getting undone. The camber pins are basically a replacement bolt with a bulge (cam) in them that enables you to vary the vertical angle (camber) of the steering knuckle. Normally used to replace the top bolt but can be used to replace the bottom bolt. The pins normally come in standard diameters from 10mm up to 17mm. I think one of those should suit your car.
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Location:
Montrose, VIC
Registered:
May 2002
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Re: Suspension questions
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Tue, 21 October 2003 01:30
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Other ways to change the camber are:
Lengthen the lower arm - sometimes you can do this by swapping an arm from a different car to one slightly longer
Go to Pedders and get them to bend your strut - a bit nasty, and not a lot of adjustment, but better than nothing
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Location:
Madrid - Spain
Registered:
August 2002
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Re: Suspension questions
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Tue, 21 October 2003 03:25
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0-2 degrees of chamber is about all you want on a road car.
Caster depends on what size tyre you are using. What you are really concerned is how far forward of the tyre contact patch is the projection of the strut line.
Toe depends on lots of stuff such as suspension joint stiffness, tyre drag, speed etc. Best to keep with the factory settings unless you start changine things drastically.
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Location:
Brisbane
Registered:
May 2002
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Re: Suspension questions
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Tue, 21 October 2003 08:09
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| Scorpion wrote on Tue, 21 October 2003 00:11 |
As Norbie indicated, they're an offsetting bolt. Where the bottom of the McPherson strut bolts to the steering knuckle, there are usually two large bolts, the ones that people often have trouble getting undone. The camber pins are basically a replacement bolt with a bulge (cam) in them that enables you to vary the vertical angle (camber) of the steering knuckle. Normally used to replace the top bolt but can be used to replace the bottom bolt. The pins normally come in standard diameters from 10mm up to 17mm. I think one of those should suit your car.
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I though Norbie was reffering to cams that fit at the lower arm / crossmember, not the strut steering nuckle?
Cheers
Wilbo
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Location:
Brisbane
Registered:
May 2002
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Re: Suspension questions
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Tue, 21 October 2003 10:00
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Yes, I was actually. As you can see there are many ways to change the camber on a McPherson strut front end. 
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Location:
Campbelltown, NSW
Registered:
November 2002
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Re: Suspension questions
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Tue, 21 October 2003 11:49
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i have been told to stay away from offset bushes in your lower arms. as it is all good when going in a straight line but when u crank up the lateral g's (push it hard round a corner) the bushes flex thus loosing and additional camber u have put in.
just my 2cent worth
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Location:
Madrid - Spain
Registered:
August 2002
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Re: Suspension questions
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Wed, 22 October 2003 03:52
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I have offset bushes for my lower control arms, big steel puppies. I can't see them flexing much
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