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2008 Rear Suspension Part II: Toe Change/Bumpsteer
2008 Rear Suspension Part II: Toe Change/Bumpsteer
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Old 09-02-08, 09:30 PM   #11
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Default Re: 2008 rear suspension part II: Toe change/Bumpsteer

Clint,

might be overlooking something here. Since this is a semi-parallel multi-link suspension with no turning, the distance from the subframe to the hub body also changes as the suspension goes through its travel (the diagonal across the parallelogram gets longer and shorter). Without modelling this as well, you cannot say whether there is toe-in or toe-out at any given point based solely on the angle of the toe link.

I'm also wondering what the roll center height looks like for the new rear.

Frank
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Old 09-03-08, 03:32 AM   #12
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Default Re: 2008 rear suspension part II: Toe change/Bumpsteer

Quote:
Originally Posted by caveguru View Post
Clint,

might be overlooking something here. Since this is a semi-parallel multi-link suspension with no turning, the distance from the subframe to the hub body also changes as the suspension goes through its travel (the diagonal across the parallelogram gets longer and shorter). Without modelling this as well, you cannot say whether there is toe-in or toe-out at any given point based solely on the angle of the toe link.

I'm also wondering what the roll center height looks like for the new rear.

Frank
correct and correct or you could just cheap out like us and instead of expensive software just throw the thing on a rack and watch what it does when you move the suspension about.

No idea on RC height. I have not calculated it yet.
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Old 09-03-08, 05:55 AM   #13
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Default Re: 2008 rear suspension part II: Toe change/Bumpsteer

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Originally Posted by Turninconcepts.com View Post
correct and correct or you could just cheap out like us and instead of expensive software just throw the thing on a rack and watch what it does when you move the suspension about.

No idea on RC height. I have not calculated it yet.
this would be neat- did you have the alignment rack all set up with the car on it, except for the springs removed, and used the lift to move the car up and down? That would be pretty cool to see exactly what the toe changes to as you move through the travel...

...are you planning on adding the calculations for the u&l ca's?

Frank
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Old 09-03-08, 07:18 AM   #14
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Default Re: 2008 rear suspension part II: Toe change/Bumpsteer

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Originally Posted by caveguru View Post
this would be neat- did you have the alignment rack all set up with the car on it, except for the springs removed, and used the lift to move the car up and down? That would be pretty cool to see exactly what the toe changes to as you move through the travel...

...are you planning on adding the calculations for the u&l ca's?

Frank
No, we had the car jacked up with the spring off and jacked up the suspension to watch what it did. The movement of the wheel to toe in was clear as the suspension moved through its range of motion.
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Old 09-03-08, 07:33 AM   #15
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Default Re: 2008 Rear Suspension Part II: Toe Change/Bumpsteer

Thanks for providing this information Clint, I've added this and the previous thread to a new "technical threads of interest" sticky.
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Old 09-03-08, 07:35 AM   #16
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Default Re: 2008 rear suspension part II: Toe change/Bumpsteer

Quote:
Originally Posted by caveguru View Post
this would be neat- did you have the alignment rack all set up with the car on it, except for the springs removed, and used the lift to move the car up and down? That would be pretty cool to see exactly what the toe changes to as you move through the travel...

...are you planning on adding the calculations for the u&l ca's?

Frank
Additionally, it was noticed by our guy we use for alignment as his setup is one that can load the suspension and take measurements.
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Old 09-03-08, 09:44 AM   #17
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Default Re: 2008 rear suspension part II: Toe change/Bumpsteer

Quote:
Originally Posted by caveguru View Post
Clint,

might be overlooking something here. Since this is a semi-parallel multi-link suspension with no turning, the distance from the subframe to the hub body also changes as the suspension goes through its travel (the diagonal across the parallelogram gets longer and shorter). Without modelling this as well, you cannot say whether there is toe-in or toe-out at any given point based solely on the angle of the toe link.

I'm also wondering what the roll center height looks like for the new rear.

Frank
I was gonna write the same thing today. Thought about it well I was sleeping I guess.

Watching what it does in real time is the way to see though.
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Old 09-03-08, 09:56 AM   #18
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Default Re: 2008 Rear Suspension Part II: Toe Change/Bumpsteer

have you used the whiteline rear camber bushing?
dave
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Old 09-03-08, 11:56 AM   #19
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Default Re: 2008 Rear Suspension Part II: Toe Change/Bumpsteer

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Originally Posted by M.S.P.T View Post
have you used the whiteline rear camber bushing?
dave
We have, yes. I think we've got a how-to bouncing around here somewhere.
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Old 09-03-08, 12:31 PM   #20
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Default Re: 2008 Rear Suspension Part II: Toe Change/Bumpsteer

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Originally Posted by Turninconcepts.com View Post
We have, yes. I think we've got a how-to bouncing around here somewhere.

you guys sell them i need a set
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