Roll Center Adjusters

theindustrialist · Feb 16, 2014

Does anyone know of any US manufactures that make roll center adjusters for the MKI Focus?

I found some made by Hardrace for sale in the UK for the ST225, with both an 18mm and 21mm ballpoint available.

The Chukker · Feb 16, 2014

I believe both Clint and jimyf had their roll centers corrected for their racecars.
I'll text them tomorrow and see if they can recall any relevant info.

theindustrialist · Feb 20, 2014

Any update?

The Chukker · Feb 20, 2014

I got ahold of Clint and he was going to send me pics of his custom mounts on his front subframe but he hasn't sent me anything yet. I'll give him a couple of days and see if he gets back to me.

Black05 · Feb 20, 2014

Woukd be interested in these also

theindustrialist · Feb 21, 2014

Cool, thank you.

FordFociSHO · Feb 21, 2014

Christ I hope this is what you're talking about. Took forever to find a combination of words that would bring it up in a search ... and I spent more time on here looking for it because I swore it was on FJ and not FF.

http://www.focusfanatics.com/forum/showthread.php?t=233122

It's probably not though now that I think of it.

And thinking of it,
If you're using a stock style front control arm, won't the arm get weak moving the BJ up or down?

The Chukker · Feb 21, 2014

FordFociSHO said:
Christ I hope this is what you're talking about. Took forever to find a combination of words that would bring it up in a search ... and I spent more time on here looking for it because I swore it was on FJ and not FF.

http://www.focusfanatics.com/forum/showthread.php?t=233122

It's probably not though now that I think of it.

And thinking of it,
If you're using a stock style front control arm, won't the arm get weak moving the BJ up or down?

^ good find.
This thread explains the need to correct your roll center on vehicles that have been lowered more than a couple of inches:
http://forums.focaljet.com/focus-road-racing/563246-why-too-low-too-bad.html

I realize it's not a popular idea in the Stance forum but I'm searching for a solution not preaching

If I don't hear from Clint in the next day or two I'll try to get ahold of him again.

FordFociSHO · Feb 21, 2014

I'm not a stance guy.

Function
--------
Form

I think I see what you're after though. The BJ thing still confuses me and I'm not sure how it applies.
Wait, are you talking like the plates Gold Coast had?
Move the BJ further from stock to add camber (negative)?

And I have this, just not sure where it came from. I know I made the chart, but I can't recall if it was from measurements I made or something I found, and if I found it what car was it from.
https://docs.google.com/spreadsheet/ccc?key=0AosorVY7Ysh4dGwwZFBHTGRZUGRoUEYwbjBEWWRFSGc&usp=sharing
A is suspension travel in mm I think.

*edit
Was reading. Roll center adjuster is a new one to me. I'm not sure if it applies to McPherson as it does to upper/lower types.
But found this post --> http://honda-tech.com/showpost.php?p=46632244&postcount=19
I think I can draw something like that. I'll post back when finished.

**edit

So the front LCA is ~14" from BJ center to bushing center (I had one lying on the garage floor).
That means if I draw a circle with a diameter of 14", toe will follow that line. And this is what that looks like (in mm's):

***edit

I took the width of a Focus minus the wheel width, 1,699 - 330.2 (both wheels). I figured that should come close to the center point of the BJ. Works out to about a 2:1 ratio, 1" drop results in a 2" drop of roll center. Here's what I come up with for roll centers (in mm's):

FordFociSHO · Feb 28, 2014

Did this just die out?
Are my calculations wrong? I stalled on them because I'm not sure if I need to go further or if what I have is accurate enough.

The Chukker · Feb 28, 2014

I texted Clint for further details on what he did to correct his roll center but he never replied.
I myself am not super slammed and I run a bit of additional negative camber both front and rear.
Unless a well engineered solution pops up I probably will do nothing regarding roll center; I have bigger fish to fry so to speak.

408wkash · Mar 1, 2014

The best way i can see this working, which i will be looking into down the road. The cfm lower control arms use a QA1 rod end and a pin that goes into the spindle. If you used the cfm control arm with a longer pin and spacer, which QA1 sells, would be ideal. I think getting cfm involved would be ideal. They can add it as an option to purchasing for lowered cars with the spacer length per purchase. This should work well i think.

The Chukker · Mar 1, 2014

408wkash said:
The best way i can see this working, which i will be looking into down the road. The cfm lower control arms use a QA1 rod end and a pin that goes into the spindle. If you used the cfm control arm with a longer pin and spacer, which QA1 sells, would be ideal. I think getting cfm involved would be ideal. They can add it as an option to purchasing for lowered cars with the spacer length per purchase. This should work well i think.

Kashus, that would be awesome; I just have too much on my plate right now to follow up on this. I suspect you will benefit from development on this sooner than I will

More updates in your build thread please!
--chaz

theindustrialist · Mar 1, 2014

I see what was meant with a longer pin for the cfm arms. A good idea.

408wkash · Mar 1, 2014

Yeah i wish i had the time and cash right now too lol. This will be in the next phase of my build where geometry is going to be addressed. Theindustrialist if your looking to do it that would probably be your best bet. Please post what you come up with! :thumbup:

GFXjamie · Mar 1, 2014

How about cfm arms and just add the spacer? There is still lots of threads being grabbed depending on how much it needs to be changed. I mean if were talking an inch spacer then ya for sure need longer shaft for pinch joint

Sent from my iPhone using Tapatalk

theindustrialist · Mar 2, 2014

Ideally I was looking into a way to do it with factory arms.
I'd like the ball joints at a more desirable angle with the car extremely low.

Roll Center Adjusters

theindustrialist

The Chukker

theindustrialist

The Chukker

Black05

theindustrialist

FordFociSHO

The Chukker

FordFociSHO

FordFociSHO

The Chukker

408wkash

The Chukker

theindustrialist

408wkash

GFXjamie

theindustrialist

Top Contributors this Month

Recommended Communities