Geometry set up

Discussions relating to MX5 Tyre choice, Wheels, Brakes Suspension components and other items to keep you going around corners, stuck to the ground or stopping on a dime.

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tonys1100s
Tentative sideways sliding....
Tentative sideways sliding....
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Geometry set up

Post by tonys1100s » Sun Oct 17, 2010 7:12 pm

Having just fitted lowered shocks and springs, 15" wheels and front and rear braces to my NA, I want to get the geometry checked/set up. Is this something that can be done by any competent tyre shop, or does it need a real specialist? Either way, any recommendations? Ideally Henderson/West Auckland.

Gravelben
I have stars and not afraid to use them
I have stars and not afraid to use them
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Location: Southland

Post by Gravelben » Sun Oct 17, 2010 11:14 pm

Assuming you're not talking about corner-weighting with adjustable height suspension, any competent tyre shop should be fine.

I've had good results from my local Firestone shop who are happy to set my cars up to my specs (rather than official manufacturer specs with massive tolerances) and take the time to do it right.

I don't know if you have an alignment spec in mind already, but if not here is a basic setup:

Castor: Max (at least 4.5°)
Front camber: -1°
Rear camber: -1.5°
Front toe: 1mm in
Rear toe: 1mm in

You can experiment from there and make things more extreme if you want (plenty of people run more negative camber for track use), but its a good starting point.


PS if the shocks/springs are brand new it may pay to let them settle a bit before getting the car set up.

aidwano
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See my 5 and raise you.
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Post by aidwano » Mon Oct 18, 2010 6:08 pm

Whats the reason behind maxing out the castor?

Gravelben
I have stars and not afraid to use them
I have stars and not afraid to use them
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Location: Southland

Post by Gravelben » Mon Oct 18, 2010 7:35 pm

More castor effectively means a greater increase of negative camber as the wheels are turned - giving you the advantage of the extra camber in the corners when you need it, without compromising the contact patch (affects braking, tyre wear etc) in a straight line.

Habanero666
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Post by Habanero666 » Thu Oct 21, 2010 12:58 am

Gravelben wrote:More castor effectively means a greater increase of negative camber as the wheels are turned - giving you the advantage of the extra camber in the corners when you need it, without compromising the contact patch (affects braking, tyre wear etc) in a straight line.

It also results in greater stability at speed ( less darty).
Tires aren't cheap!

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