why are e30 front struts at a angle?

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sweep
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Post Fri Jul 12, 2013 10:01 pm

As above aposed to modern shit been straight..just curios
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Post Fri Jul 12, 2013 10:02 pm

Morat
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Post Fri Jul 12, 2013 10:08 pm

If the wear is on the inner edge of the tyre you've got too much toe out; outer wear is too much toe in. Too much toe in is normally a by product of aggressively lowering your car.
Is that right? My car is lowered 35mm but I get the excessive wear on the inside of both rears.
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Post Fri Jul 12, 2013 10:11 pm

Might be camber wear, but a 35mm drop shouldn't wear that aggressively. The article does explain that both toe and camber contribute to inner tyre wear though.
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Post Fri Jul 12, 2013 10:15 pm

I mean from new the legs are angled forward.
Grrrmachine
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Post Fri Jul 12, 2013 10:21 pm

Yes, angling the strut forward is called Caster.

http://yospeed.com/wheel-alignment-expl ... aster-toe/
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hazd31
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Post Fri Jul 12, 2013 10:24 pm

castor = More grip

The more castor you have the more the inside rear wheel will lift giving you more front end grip as the back doesent push on so much
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Post Fri Jul 12, 2013 11:14 pm

Morat wrote:
If the wear is on the inner edge of the tyre you've got too much toe out; outer wear is too much toe in. Too much toe in is normally a by product of aggressively lowering your car.
Is that right? My car is lowered 35mm but I get the excessive wear on the inside of both rears.
The increase in camber outweighs the increase in toe in on the rear, so it only really wears the inner edge.

There is a big difference in the way a tyre wears due to camber and toe.
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harry_p
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Post Sat Jul 13, 2013 7:22 am

sweep wrote:As above aposed to modern shit been straight..just curios
All cars with a simple macpherson strut will have the top of the strut tilted back towards the bulkhead.

This means as the front wheel turns it tilts over, and gains more negative camber.

More castor means you can run less static camber, so you don't destroy the inner edges when cruising around on the motorway, but still have negative camber when cornering to stop the tyre rolling over and killin the outside edge when cornering hard.

A lot of modern cars will have double wishbone, or multilink suspension, and have fixed castor, but gain negative camber as the suspension compresses due to the geometry. I.e, on a double wishbone setup the upper wishbone is often shorter, so as the car rolls through a corner the upper wishbone moves through a tighter arc, pulling the top of the wheel inwards.
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harry_p
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Post Sat Jul 13, 2013 7:26 am

hazd31 wrote:castor = More grip

The more castor you have the more the inside rear wheel will lift giving you more front end grip as the back doesent push on so much
You what? :mad:

Castor is the way the front strut is inclined, and has nothing at all to do with the rear suspension.

The only component which increases inside rear wheel lift is a rear antiroll bar.
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hazd31
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Post Sat Jul 13, 2013 8:54 pm

the more castor the more the inside rear will lift

only way go karts go round corners

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Post Sun Jul 14, 2013 10:59 am

Go karts are designed to do that because they have a fixed live axle on the rear and need to lift the inside wheel to stop understeer and are only able to do this because of the high castor angles on the front struts and no suspension (no dampers no springs).

The clio is a bad example as cocking any wheel on a car will result in less grip. Especially true for a RWD car.