Help improving braking power

[roosta]

I have a vintage FF, specifically a Merlyn.

Looking for ideas or recommendations to improving braking power. I currently have Girling master cylinders on front and back, manual brake bias adjustments.

[Hawke]

Roosta,

Can you lock all four wheels at high speed?

[S Lathrop]

What pads are you using?

What is the condition of the rotors?

Are the master cylinders and calipers performing as they should?

What are the sizes of the master cylinders?

What is the condition of the rotor surfaces?

If every thing is functioning correctly, your brakes should be just fine.

[Brian]

You could be using too high a temperature brake pad. I always use Hawk Black on vintage cars, it comes in at a lower temperature and has a lot of feel. The Merlyn club ford/vintage ford brake package has been perfected for decades. You won't easily improve on it.

Brian

[kea]

We sell many KFP Carbon-Kevlar Brake pads for club and vintage racing, particularly for single-seaters.
Many of those with Girling components, use the Blue (P4211) of Red (P1101) material
Proper braking is also effected by master cylinder size related to caliper size and both their conditions, pedal to push-rod location and bias settings.
For more pad information, please visit our web pages for that product.
http://www.racing-stuff.com/kfp%20magnum.htm

[roosta]

I'll do a bit of research this evening, and get a bit more info. I believe I have the Hawk Blues, but will look at the Girling bore size and such and get back to the group.

Thanks for the help.

[S Lathrop]

I suggested that you check the surface condition of your rotors. It was common to "glaze" the rotor surfaces when the newer, non asbestos, pads were installed or one changed between different pad manufacturers. You problem might be as simple as sanding the rotor surfaces. In any event, I would suggest that you sand the surfaces before you install new pads.

[TimH]

Hawk recommends steel wool on the rotors every time your change compounds.

[kea]

Steel wool won't solve the problem if the brake pads that you are replacing are late(r) model PFC materials. It takes more then that, from what I've seen and been told.
By the way, most pad manufactures can be changed back and forth will little serious attention to the brake disc's, except for PFC.

[R. Pare]

Looking for ideas or recommendations to improving braking power. .

First questions to answer are:

1 - What do you mean by "improved braking power" ?

2 - What "problem" do you think you have?

[roosta]

With limited testing on this vintage FF and running in my neighborhood, pedal pressure doesn't stop the car quickly. The only car I have to compare it to is a Skippy car that I drove in the 3 day formula class, which could grab the rotors and stop quickly.

I was told by one individual the pads need to heat up quite a bit before they are effective. Any advice would help.

[fitfan]

I've been running the KFP 'red' pads in my CF, and rather happy with them. wear ok - heat up good and don't go in and out with heat variation much = pretty consistent feel no matter the temp.

my advice without knowing any details....

bleed all four corners, pedal should be very stiff with minimal travel. make sure rotors are smooth (flat / not grooved in) and each caliper is closing and opening. new pads.

[racerdad2]

Heating up the pads is very important on your out lap. Dragging the brakes a bit. On and off the brakes.

When you watch racers on the out lap, you see them weaving back and forth to heat the tires and accelerating and decelerating to heat up the brakes.

I started a race behind a national champ and a first timer. Both on stickers. The National Champ had the stickers off in less than half a lap. He was very aggressive in building heat in the tires and brakes. The rookie still had stickers on at the green flag. The Champ ran away from everyone, knowing his brakes would work and his tires would stick.

It always takes me a lap to get up to speed it's about trusting your tires and brakes...

I race karts, too. I have to drag the brakes on the way to the grid and the green flag to build up heat in the pads. If not, I have to brake way early into the first turn.

You'll do well once you get on track. You'll be amazed how fast your car slows under threshold braking !

[roosta]

Monoposto rules don't restrict much on the rotors other than keeping them iron.
Is there any reason we cannot run cross drilled and scored rotors on vintage/club formula fords?

[Rondo]

Don't drill them out....they crack. Really fast!!!!

[kea]

Monoposto rules don't restrict much on the rotors other than keeping them iron.
Is there any reason we cannot run cross drilled and scored rotors on vintage/club formula fords?

Other then wearing out brake pads quicker (and maybe causing rotors to fail quicker), why would you want to ?

[Brian]

Because Porsche does?

[BeerBudgetRacing]

Get rotors that look like flowers, then you'll be unique.

http://tbmbrakes.com/

[marshall9]

Accelerate hard, brake hard on out lap, swerving not necessary. If you must, saw the wheel fast left and right to scrub the fronts. CONTROLLED rear wheel spin in the corners and acceleration push turning in. Heats up brakes and tires nicely . I have seen too many guys hit or get hit by drivers that think they must swerve back and forth the whole track width on the formation laps.

[roosta]

I found I actually have some scoured and worn rotors, so will getting new ones (or at a minimum turned back to flat). That should help, so need to replace the pads.

What about Hawk Blue pads vs the HT-14? Anyone have any experience with the HT14 pads?

[Daryl DeArman]

I have seen too many guys hit or get hit by drivers that think they must swerve back and forth the whole track width on the formation laps.

I like when they swerve all over the place. Just about half a lap in they've put just enough heat in the tires to pick up all the marbles off line

[roosta]

Just to follow up. I replaced the rotors, centered the calipers, and added new Hawk Blues. They seem to grab nicely. During a dusk test ride, the racing pads were sparking up a storm on one front caliper.. greatness.

[SpacemanSpiff]

Accelerate hard, brake hard on out lap, swerving not necessary. If you must, saw the wheel fast left and right to scrub the fronts. CONTROLLED rear wheel spin in the corners and acceleration push turning in. Heats up brakes and tires nicely . I have seen too many guys hit or get hit by drivers that think they must swerve back and forth the whole track width on the formation laps.

Not sure where I read it or how accurate it is, but supposedly accelerating and braking put substantially more load and therefore heat in tires. I suspect that it's easier to reach the traction limits of the tire (peak loads) in a straight line than in little wiggles.

[Albatross]

I have been racing my "Vintage" Crossle 20 F for 6 years since I bought it. I've raced it a bunch each year. I have been using the Hawk black since the first day of ownership because that's what was installed at the time and also another box of the Hawk came with the car. I have no complaints with the Hawk, they stop great once they are warmed up on the "out lap." The word is the rotors should show very little wear using the "black" pads and I can verify that as I haven't had to change the rotors yet after six years and many sets of pads+ even thought I had them on the machine for a slight cut of a couple of thousands recently to make sure they're true. Recommend that you don't drill'm or do anything "trick" to them. Not necessary. Get'm heated on the out lap and race hard! Good luck

[145inmy73]

Should you be able to lock up all 4 at speed easily?

[Daryl DeArman]

Should you be able to lock up all 4 at speed easily?

Easily is a subjective term.


Be able to without the quads of Godzilla, but not so easily it happens when you aren't trying to. Obviously you need enough modulation to decelerate at/very near the limit of the tires, but enough braking force to lock them up if you gave it a good try.

[Roland V. Johnson]

Check your brake bias also. Many people do not have enough rear brakes. I often use a big clamp from the brake pedal to the front bulkhead to pull the pedal down until the front wheels just cannot be turned by hand. The rears then should just be able to be rotated. If you do not have a big clamp you can put someone in the car and have them push the brakes, but it is hard to get a lot of people to maintain the same pedal pressure while you check the rears. Which modle Merlyn do you have?

[Raceworks]

I found I actually have some scoured and worn rotors, so will getting new ones (or at a minimum turned back to flat). That should help, so need to replace the pads.

What about Hawk Blue pads vs the HT-14? Anyone have any experience with the HT14 pads?

I can't speak for vintage cars, but I've run Hawk blues in Formula Mazda & modern FF's with good results. The Mazdas were kind of heavy and no matter what pad you had in them if you over-drove the car you'd end up roasting the brakes.

I can't find any info on the HT-14's. The HT-10's have an optimal operating temp of 500-1100 compared to the blue's 350-800. Either Hawk Blues or PFC-93's ought to work in any FF / CF car just fine.

You should be able to lock the wheels up if you really mash the pedal even with cold pads, especially with treaded tires or R60 Hoosiers.

Check that you don't have a mechanical interference problem, such as the bias adjuster cable hanging up on something when you hit the brakes.

Another possible culprit if the car is new to you or you haven't done a ground-up on it in a while is see if you have dirt or corrosion that's locked up the master cylinder or prevents it from going all the way down.