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Trailing Arms - Atlas Axle
daveb666 - 4/7/16 at 06:10 PM

What is the desired angle for atlas axle trailing arms to sit at when the car is static and not under-load?

When I had my car setup by Procomp some time ago I recall them saying that mine were at the incorrect angle; if my memory serves me correctly they are pointing slightly up at the rear meaning that have already past the 'centre' point. This in turn reduces traction as the car is already 'squatting' as such.

Does that sound about right or have is that complete garbage?


Neville Jones - 4/7/16 at 06:20 PM

Procomp will want you to have the arms pointing up and forward from the axle, to counteract squat under acceleration and help grip exiting corners. Just like the Locosts.


daveb666 - 4/7/16 at 06:30 PM

Thanks Neville - iirc mine point upwards at the rear so are therefore the opposite of what they should be. Thanks.

Any guidance in 'the book' as to what angle they should be?


daveb666 - 6/7/16 at 07:25 PM

No-one? This site is called "Locost Builders" - does no-one help anyone anymore?!


blakep82 - 6/7/16 at 07:34 PM

As I understood it, bottom one parallel with the ground, top arm higher at the chassis end down toward the axle, so under hard acceleration the chassis pushes down on the axle, but under normal cruising works as it should.
I believe that's why drag cars actually lift the rear end up off the line, but I'm not 100% sold on that


Edit: this says the opposite to what I thought I read in the competition car suspension and brakes book

http://www.pro-touring.com/attachment.php?attachmentid=51895&d=1322684983

[Edited on 6/7/16 by blakep82]


daveb666 - 6/7/16 at 08:33 PM

Wow that's really helpful, thanks. My thoughts were like you though, I assumed they would be as a minimum horizontal, if not pointing upwards.


MikeRJ - 7/7/16 at 07:12 AM

quote:
Originally posted by blakep82
As I understood it, bottom one parallel with the ground, top arm higher at the chassis end down toward the axle,


Note that if the arms are not parallel, it will cause the whole axle to rotate as the suspension compresses, changing the nose angle.