need a measurement...

This is no big deal, I won't even have my car for 2 weeks but.....

If any of you are in your shop could you measure the something for me? I was wondering, if your lower front A arm is parallel to the ground, how high is the center of the hub? What I would need is the height of the A arm and the hieght of the center point of the hub. I believe the ideal ride height is achieved when the lower A arm is level. If that is the case, the ride height is dictated by tire size.

Maybe easier, if your car is sitting on the tires, and your lower arms are level, how much clearance do you have and what tires are you running?

I was sitting around today examining the tire choices we have and I just want to make sure I didn't end up to high off the ground.

Don't go to to much trouble, I was just curious. I will need to order tires soon.:D

Thanks
Dean

Okay, I just realized, the center of the hub is half of the tire height, duh.
 
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Rob

Lifetime Supporter
Hi Dean,
I'm on dolleys currently, so can't give you this dim. sorry....
However, just wanted to mention, ideal static ride height has the A arm just below level. This permits normal range of motion through the level position (i.e. through the max arc of the swing.
 

Fran Hall RCR

GT40s Sponsor
Guys.....the hub height is always going to be half the diameter of the tire.

The angle of the control arm raises and lowers the chassis not the hub height.
 
If Bill's hub measured 11 7/8's, Assuming his lower arm is just below level (lower at the tub than at the ball joint), what is the ride height? I am going to guess around 4.5 inches, right? That is the number I am really looking for. Bill's tire is almost 24 inches tall. If I run the Goodyear slicks that are 25.5 inches tall, it will raise my ride height 3/4 in. That is why I was looking for the info. I don't want to buy a tire that is to tall.

Thanks for your help.
I don't even have my car yet and I am already driving Fran crazy!
 

Fran Hall RCR

GT40s Sponsor
I hadn't noticed.......HHHHMMMM!!!!

Dont forget that the tyre compresses under load so the radius given in manufacturers specs is unloaded......
A 205/60/15 is shown as being 24.7 inches...so Bills should be 12.35 unloaded.....his measurement is 11 7/8.....so 1/2 inch loss.....
 
Dean;
Fran is absolutely correct...the rolling radius of the tire is most important, so you may need to borrow a set of tires at proper inflation to get a really good measurement. I wouldn't fiddle too much with the lower arm....try to keep it as level as possible as changes here are going to affect your virtual swingarm and ultimately roll center.... also, if you set up the suspension correctly with the lower arm level you will find as you drop the arm camber will go positive since I am assuming that your upper arm is shorter. If the lower arm is level I would simply find a tire size the puts you where you want to be as far as ride height, and go from there, as this is probably the simplest solution.
Hope this all helps
Cheers
Phil
 
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