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View Full Version : Pinto Roll Center Gurus.....



Double W Racin'
09-06-2011, 06:01 PM
If I put a couple of shims under the upper control arm mounting points, would this raise the rollcenter due to decreasing the angle of the controll arm?

Steve Smith's Pony Stock book says to raise the lower control arm mounting point up 3/4". I was wondering if this is basically the same thing?

Double W Racin'
09-09-2011, 12:21 PM
C'mon, I know you're out there.

Will it help?

84Dave
09-09-2011, 02:24 PM
If you decrease the angle of the upper control arm, the 'moment-center' will move down closer to the pavement. If you further decrease the upper arm angle to horizontal, and the lower control-arm angle is also horizontal, the moment-center height will be right at the pavement. If the lower arm inside mount point were moved up .75", the moment center would in fact move upward away from the pavement. -Dave-

Dirtrunner35
09-09-2011, 08:33 PM
Someone has been reading Bob Bolles stuff, moment center. lol Why do you want to move it?

Double W Racin'
09-10-2011, 10:39 AM
Someone has been reading Bob Bolles stuff, moment center. lol Why do you want to move it?

To stop the car from rolling over on the RF so much. We have increased the RF rate and it is helping with the rollover but is also killing the tire. Was hoping that raising the rollcenter, it'd take some of the weight transfer out. Thus helping with the rollover and not torture the RF tire so much.

Just a tidbit more info... we are on asphault.

let-r-eat
09-11-2011, 02:15 AM
Is your lower control arm level now? What's your ride height now? What size tire? Measure from ground to center of lower control arm inner pivot.

You might want to move your roll center to the right toward passenger side? Have you figured out where it is now?

Double W Racin'
09-24-2011, 05:19 PM
I have to get off my A$$ and take all of the measurements. Is there a program (free is nice) that I can just plug in the measurements into that'll help?:o

drtlvr
09-25-2011, 08:52 AM
Performance trends is what I use. It's not free though.

Racedad
09-25-2011, 09:25 AM
Just some things we learned when we were struggling with overworking the RF:

Try raising your rear roll center.Or stiffen your RR spring.

Many times problems with over working the RF is due to the rear rolling too easy.I'll bet you get bigger improvements looking there first.

We even added rear panhard bars to our rear end to raise the roll centers on our S10 pickups.Worked like a charm till they outlawed it.The roll center becomes the panhard bar height which is easier to raise and lower than the spring eye height which is the roll center on a typical leaf spring setup.

Methods you can use to raise the rear roll center will allow you to keep the rear springs softer and keep the RR and LF loaded more.

Double W Racin'
09-27-2011, 11:26 AM
I was thinking of moving the roll center on the front first. Does anybody have a number for a taller upper ball joint?

joedoozer
09-27-2011, 02:20 PM
Here is a free set up program. It has a front roll center calculator in it.
http://www.4m.net/showthread.php?212276-Suspension-Setup-Tracking-Software

Old Rob
10-26-2011, 10:13 PM
You don't want to move the pivot point of the upper arms any higher. Longer upper ball joints will help. However no one makes a bolt in longer ball joint for the Pinto / Mustang II, upper or lower. If your rules allow get tubular arms with chrysler ball joints. Or you can bore out your stock arms and install (weld) the threaded sleeves for the Chrysler ball joints.