Brake Bias Adjustment

[BB767]

Hi All,

I have almost 4000 miles on the car with new (from FFR and Moser) Mustang GT disks front and rear, no power. I have the two different size master cylinders as supplied by FFR with the larger one on the front. Very happy with overall brake effectiveness, feel, and pressure required. Brakes pedal is nice and firm (normal). But, I am having problems setting the bias correctly.

On initial setup all four were locking up together. But I took an SCCA autocross class last fall and learned that the rears are now locking up before the front. So, I try adjusting the bias bar. I have read and reread the instructions and am pretty sure I am adjusting it correctly, but after adjusting it, the problem has not gone away. The rears are locking up sooner than the front and I am now near the end of the adjustment. The front cylinder rod is screwed as far out of the clevis as it will go without starting to loose thread engagement, the rear bar is screwed into the clevis as far as it will go without interfering with the crossbar.

Anybody else have this problem, and any solutions?

Thanks

[edwardb]

That's not how they're adjusted. You adjust the bias by turning the bar between the two clevises and moving the internal spherical bearing. This video is Tilton. But explains it perfectly. The Wilwood setup is exactly the same. I'd recommend returning the MC to clevis positions to how you had them originally.

[flynntuna]

Thanks for the tip. By the way here's the you tube video
https://youtu.be/ISLqGf0sMX0

[edwardb]

Thanks for the tip. By the way here's the you tube video
https://youtu.be/ISLqGf0sMX0

Oops. Forgot to paste the link. Thanks.

[BB767]

Wow, I had no idea! Wasn't very clear in the manual but makes perfect sense now, thank you.
Now, what are the procedures for the correct adjustment of the push rods that I have messed with? What exactly is their purpose other than to adjust the pedal engagement height, or is that it?

[edwardb]

Wow, I had no idea! Wasn't very clear in the manual but makes perfect sense now, thank you.
Now, what are the procedures for the correct adjustment of the push rods that I have messed with? What exactly is their purpose other than to adjust the pedal engagement height, or is that it?

I've always done them just like the instructions. With the spherical bearing on the balance bar centered, and the recommended gaps on the ends, set them both the same adjusting for the proper pedal height as you mentioned. At rest front and back are symmetrical. Then adjust the bias as needed with the balance bar.

[Caddy Dad]

I've always done them just like the instructions. With the spherical bearing on the balance bar centered, and the recommended gaps on the ends, set them both the same adjusting for the proper pedal height as you mentioned. At rest front and back are symmetrical. Then adjust the bias as needed with the balance bar.

I too was wondering about the balance bar adjustment. I backed off the jam nut and set screw on the right most MC clevis but the balance bar does not rotate by hand. Is this normal? I was thinking of picking up two appropriate size nuts, put them on the end of the balance bar as a jam nut and use that to thread the balance bar in and out. Once set, I'll remove the jam nuts. Thoughts?

[edwardb]

I too was wondering about the balance bar adjustment. I backed off the jam nut and set screw on the right most MC clevis but the balance bar does not rotate by hand. Is this normal? I was thinking of picking up two appropriate size nuts, put them on the end of the balance bar as a jam nut and use that to thread the balance bar in and out. Once set, I'll remove the jam nuts. Thoughts?

It's been a while since I've messed with that. But I don't remember anything except the jam nut and set screw on the one end. Should turn with those backed off as I recall.

[Richard Oben]

On every car we do with the Wilwood pedals we buy the remote adjuster. Drill a hole in the pedal box and mount it to the front of the tunnel. Owner can then play with adjustment as needed.

Ever watch a NASCAR race at the end? The driver turns a knob on the dash, BEFORE the burn out why? To get the bias off the rear for a great burnout. In the spec car we adjusted the bias based on fuel. In an endurance race we added a couple of click to the rear when it was packed full of fuel. Minor adjustments make a pretty big difference.

Hope this helps Richard.

[Caddy Dad]

On every car we do with the Wilwood pedals we buy the remote adjuster. Drill a hole in the pedal box and mount it to the front of the tunnel. Owner can then play with adjustment as needed.

Ever watch a NASCAR race at the end? The driver turns a knob on the dash, BEFORE the burn out why? To get the bias off the rear for a great burnout. In the spec car we adjusted the bias based on fuel. In an endurance race we added a couple of click to the rear when it was packed full of fuel. Minor adjustments make a pretty big difference.

Hope this helps Richard.

Hi Richard,
I've never heard of adding a remote bias adjuster to a roadster before, but I certainly like the concept. As a daily driver/weekend cruiser/autocross would I benefit from adding one?
Thanks!

[GWL]

Wilwood Bias Adjuster

https://www.wilwood.com/pedals/PedalList?mc=Remote%20Bias%20Adjuster

George

[edwardb]

Hi Richard,
I've never heard of adding a remote bias adjuster to a roadster before, but I certainly like the concept. As a daily driver/weekend cruiser/autocross would I benefit from adding one?
Thanks!

See those added to builds occasionally. They are a tight fit for the current footboxes, but guys obviously make them work. FWIW, for my mainly street driven builds, I've never touched the front/back bias after the initial checkout and adjustment if needed. So have never messed with installing one. Agree makes more sense for a car that's going to see the track.

[rich grsc]

Hi Richard,
I've never heard of adding a remote bias adjuster to a roadster before, but I certainly like the concept. As a daily driver/weekend cruiser/autocross would I benefit from adding one?
Thanks!
No. If it's a dedicated track car, then you may find a benefit, a street car once it's set there isn't a need to make changes.

[jcrumpley]

No. If it's a dedicated track car, then you may find a benefit, a street car once it's set there isn't a need to make changes.

If you use the adjuster, also buy the 90 degree adapter. That make the install easy.

[RR20AC]

Works great. Easy to adjust the bias.

[Richard Oben]

There are times we set it in the go cart stage and then cover up the whole thing. It is just that adjustment is difficult once the box is all buttoned up. But it is so easy to install and then adjust why not install it. It can be either driver or passenger mounted also, we generally do what RR20AC did with or without console.

Caddy Dad, I guess for a street only car it is not really needed, but sure is handy. HTH, JMHO, Richard.

[Caddy Dad]

Thanks for the insight. I have a bit more time before I need to figure this out. This is my first build and managing this project for scope creep is just like what I did as a defense contractor before I retired. Sometimes good ideas turn into major impacts. Decisions, decisions, sigh :-)

My apologies to BB767 for hijacking his thread.

[Avalanche325]

If you use the adjuster, also buy the 90 degree adapter. That make the install easy.

Open the 90 degree adapter up and load it with grease before you install it. Mine started getting pretty rusty inside.

I have my adjuster mounted out of site, under the dash, sort of above my right knee area. As rich stated, once adjusted you will rarely touch it. I have done a couple clicks with just new front tires, or rears, and when I changed pad compound. I autocross a lot and also do track days. But it is nice to have when you do need to adjust.

[BB767]

My apologies to BB767 for hijacking his thread.

No Problem, I got what I needed to know from Edward and it's always good to learn more!

[KenWilkinson]

I don't see or can't find this elusive 90 degree adapter. Can anyone offer a part number and vendor?

[Greg K]

90 degree adapter by Tilton should fit https://pitstopusa.com/i-5074333-tilton-remote-bias-adjuster-90-coupler-fits-3-8x-24-balance-bars.html