total suspention compression travel?

[merc91]

i have a 1991 grand marquis and i'm wondering how far my suspention will compress in inches (like when hitting a massive bump for example). i'm looking to see the compression do determine soon to be bigger tire clearences.

thanks for the help with the noob questions, andy

[gadget73]

I don't know the figures, but if you look on the lower control arm, you'll find the bump stop. You may be able to use that to get your measurement.

[mrltd]

you spelled suspension wrong.

as gadget mentioned,measure the distance to the bumpstiop .

[merc91]

ha thanks, i'm kinda gone right now on pain meds with my gums torn apart and stitched up from wisdome teeth taken out... and they were down there deep... but i got some headway on the merc still even tho i can barely stand up.

[turbo2256b]

you get under the car with a tape measure ... i will go get my elephant

[Southern_Pride]

Bumpstop won't work. Wheel moves in an arc. Wheel moves farther than the arm at the bumpstop. How big of a tire do you want to run? And do you still have stock springs?

[gadget73]

Bumpstop won't work. Wheel moves in an arc. Wheel moves farther than the arm at the bumpstop.

right, but its a place to start. If you know the distance from the bump stop to where it hits, the distance from the lower control arm pivot to the bump, and the distance from the lower control arm pivot to the lower ball joint, you can calculate it fairly easily. Its just a matter of plugging in the numbers properly and using a bit of math.



basically you need to calculate the ratio from bump to pivot and from lower ball to pivot. Use that number and multiply the travel at the bump stop and you have your travel.

example:
travel at bump: 5 inch
bump to pivot 9 inch
wheel to pivot 16 inch

16/9 = 1.78
1.78 * 9 = 16

so in theory the travel at the end of the lower control arm ought to be 16 based on those random plucked out of my ass numbers. This will only give you how far the ball joint moves, which should be pretty close to total wheel movement. I don't know the math to accomodate for the changing angle at the spindle as the suspension travels through its arc. The tire also will move outward as it goes through the arc so beware going with too fat of a tire, your wheel trim won't appreciate it.

[Southern_Pride]

I'm not that good at math gadget. And your fender trim does not appreciate it. Neither do your sidewalls.

[turbo2256b]

Bah bah bah. To realy find out remove the spring so the suspension can be moved to its different positions. Might even wantto turn the wheels and check at full lock....or get the elephant I sugested earlier.

[gadget73]

I'm not that good at math gadget. And your fender trim does not appreciate it. Neither do your sidewalls.

yeah I've ripped a sidewall out of my tires. Need to swap those 1 1/4 spacers to the back. Annoyingly it means grinding the bullshit out of my calipers but I'm tired of the scraping noises.

[Pirate]

I'm thinking you have 34 inches of travel.

Oh, and Mikey, you spelled 'bumpstop' wrong.