Brakes - advice wanted for improvements

[AdamIsAdam]

Hi all. I'm interested in improving my brakes, although I'm not sure if they need improving. I'll explain.

I have 13" 1993 Mustang cobra R brakes up front (calipers were rebuilt last year and system bled) and the FFR 11.65" rear brakes. I think the master cylinder is OEM Ford. It's non-power.

I didn't build the car. I have never owned a car without power brakes so I don't know what is considered normal/good.

The pedal requires a good amount effort. The car stops pretty well, but I'm not sure if the brakes can be better and/or be set up to require less pedal effort.

Suggestions?

[Gordon Levy]

Changing the master would be your first change. The other would be to make sure the Mustang proportioning valve was not used and if it was it needs to be removed.

[AdamIsAdam]

I don't see a valve. Can you make out the master cylinder brand? What would I change to?


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[Gordon Levy]

I have a wilwood that works great. The next upgrade would be pad compound, specifically the rears, beyond that would be a rear brake upgrade.

[Fman]

Hi all. I'm interested in improving my brakes, although I'm not sure if they need improving. I'll explain.

I have 13" 1993 Mustang cobra R brakes up front (calipers were rebuilt last year and system bled) and the FFR 11.8" rear brakes. I think the master cylinder is OEM Ford. It's non-power.

I didn't build the car. I have never owned a car without power brakes so I don't know what is considered normal/good.

The pedal requires a good amount effort. The car stops pretty well, but I'm not sure if the brakes can be better and/or be set up to require less pedal effort.

Suggestions?

Just another option, I went with upgraded Power Stop drilled and slotted rotors and pads on both front and rear of my build. I have about 400 miles on my car now and so far I have been pleased with braking performance for street driving. I have never driven a Cobra with Wilwood so I cant compare the two but for a fraction of the cost you could definitely consider a Power stop kit. They claim 30% improved braking over stock performance. I also notice manual brakes just have a different feel to them compared to power, they do require more pedal effort to brake.

https://www.powerstop.com/?gclid=Cjw...BoC_JIQAvD_BwE

[i.e.427]

I'm a big fan of power brakes on a street car.

[AdamIsAdam]

I have slotted rotors all the way around. See pictures. I just bought power stop Z26 carbon ceramic rear pads to put in. I have them on my GT350 and like them. I realize they are not a track pad. The current rear pads throw off a lot of dust. Front pads do not.

Remember, it could be me not being used to manual brakes. How much pedal effort is normal?

[Jeff Kleiner]

The big question is whether the pedal mod was done to change the leverage factor for manual vs. power brakes. If it’s still using an unmodified power brake pedal the effort will be extremely high.

Jeff

[AdamIsAdam]

Jeff,
I would not categorize the pedal effort as extremely high. It doesn't seem wrong. In fact, the more I think about this, the more I think it's just my direct comparison of getting out of a new GT350 (which has the best brakes I've ever experienced) then into the Cobra. But when I read others post about how their Wilwood brakes feel as good as power brakes, it just makes me wonder if I could make mine even better. Hence this thread.

I know the attention to detail on this build was very good. I'm digging through the receipts now. Hmm. I see Replicaparts 94+ Mustang Pedal Box for non-power brakes ($175).

Plus things like Russ Thompson's Gas Pedal Assembly, Brake Hose to frame bracket stainless kit for 5/8" OD hose ends, Braided Stainless brake hose kit, 5/8" round bulkhead fitting, 3AN, Russ Thompson's pedal pad kits for brake, clutch, and many other touches of an informed build (ie, solid offset rack mounting kit for steering rack, a solid roll bar (no exposed bolt) all brake and fuel lines run safely along frame protected from physical contact, etc.). I had the car inspected before buying and have had it totally torque checked twice by experienced techs in my 15 months of ownership and no one, myself included, have found any evidence of missed details or shut cuts.

But I'm always open to improvement suggestions!

[GoDadGo]

Adam,

What's the Piston Diameter of the Mustang Cobra Master Cylinder?
You may be able to easily reduce the pedal pressure by going with a smaller diameter unit.
https://www.summitracing.com/search/...n&fr=part-type

Steve

[NAZ]

Hi all. I'm interested in improving my brakes, although I'm not sure if they need improving. I'll explain.

I have 13" 1993 Mustang cobra R brakes up front (calipers were rebuilt last year and system bled) and the FFR 11.8" rear brakes. I think the master cylinder is OEM Ford. It's non-power.

I didn't build the car. I have never owned a car without power brakes so I don't know what is considered normal/good.

The pedal requires a good amount effort. The car stops pretty well, but I'm not sure if the brakes can be better and/or be set up to require less pedal effort.

Suggestions?

Perhaps you should start by articulating what your expectations are of a braking system. What's your definition of "better"? What constitutes an "improvement"? How does your Roadster's brakes differ from your GT350?

You say the car stops "pretty well", what does that mean? Can you lock up all four tires on your roadster? Does it stop straight? Are the brakes smooth and controllable?

If it's pedal effort, there are many good ideas above to guide you. If you can clearly identify what you need help with it would make it easier for folks to provide suggestions.

[AdamIsAdam]

Good point, @NAZ. I think I just want less pedal effort. The car stops perfectly straight and seems well balanced front to rear. Yes, I can lock them up if I tried.

I think it just makes me uneasy to have to press so hard, that's all. Like I said, maybe this is silly and it's just my needing to get comfortable with non-power brakes in a car with 5:1 power to weight ratio. I started this thread after reading others comments about how their Wilwood setup feels like power brakes. I'll go for a ride tomorrow and really brake hard a few times to share what I think.

Maybe I should just shut up and enjoy this great car.

[mike223]

Hi all. I'm interested in improving my brakes, although I'm not sure if they need improving. I'll explain.

I have 13" 1993 Mustang cobra R brakes up front (calipers were rebuilt last year and system bled) and the FFR 11.8" rear brakes. I think the master cylinder is OEM Ford. It's non-power.

I didn't build the car. I have never owned a car without power brakes so I don't know what is considered normal/good.

The pedal requires a good amount effort. The car stops pretty well, but I'm not sure if the brakes can be better and/or be set up to require less pedal effort.

Suggestions?

There's a lot to know.

I ran a CNC241 (Wilwood style bias bar setup) side by side master cylinder (MC) for years (3/4 x 5/8) with a 6:1 (modified) pedal - 1995 single piston fronts, 1989 TBird rear (IRS).

Stopped pretty well, but pedal pressure was a bit excessive and "pedal feel", to me, was like "stepping on a rock".


As I got used to the weight transfer characteristics of the car - I kept dialing out more + more rear brake bias, because I found it easier + easier to lock the rear brakes (weight transfer during braking).

Eventually I reached 50/50.


Did you know that a conventional tandem MC (like yours) produces twice as much pressure as a side by side (bias bar) MC for the same input pressure? It does.


Since I had reached ~50/50 pressure equilibrium (front + back), I decided I would try a conventional tandem MC.


I now use a 21mm MC with a 4:1 (unmodified - but somewhat rare OEM SN95 manual brake) pedal (SN95 pedal box).

It's everything I ever wanted, and it has "feel" - not like stepping on a rock.


I'm thinking a 6:1 pedal *might* be too much leverage (for a 21mm MC).


Your OEM Mustang MC is *probably* 15/16" bore (most common), and it might be bigger than that.


21mm is closer to 13/16" - it makes a big difference (14-16%).


The MC I'm using is Autozone NM1907 for maybe 1982 TBird / 1982 Granada, etc? - It has standard thread fittings.

I think you need the metric Mustang MC - try Advance Auto Parts / Carquest P/N MCA39637 - I think this is a 21mm bore MC that has metric brake line fittings (2- M10x1, M12x1).


Proceed with caution + test with caution.

Good Luck.

[AdamIsAdam]

I drove the car today after getting my new windshield installed. Brakes are fine. Maybe some day I'll play with a new master cylinder, but they are linear and strong, and very well balanced. They're just not power brakes.

Thanks for the suggestions.

[Bob Cowan]

When you get time, checking the brake pedal is the first thing I would do. Make sure the pedal ratio is correct; around 6.5:1. Also, I highly recommend the dog leg mod. Makes a huge improvement. http://www.norcal-cobras.com/project...rake_pedal.htm

Second, MC size should be about 7/8" or 15/16".

Then consider pad material. A lot of people use ceramics, which can be good and bad. Pick the right pad, resurface the rotors, and bed them in properly.

Lastly, avoid drilled and slotted rotors on a street car. Strictly for bling, and provides no functional improvement. The slots and holes create more noise, more dust, and can create a slight vibration felt through the pedal.

Drilled holes also create stress risers in the disc, and will propagate cracks. Where solid rotors will last 75K-100K miles, drilled rotors need to be replaced significantly sooner. Sometimes as often as every 20K miles. Keep a close eye on them, and replace the minute you see cracks starting.





Slots work like like a cheese slicer. Every time a slot passes over the pad, it "slices" off a very small amount of pad material. That works well on the track where the pads get really hot and can glaze. The slot removes that potential glazed are and keeps the pad surface fresh and functioning well. On the street, you won't/shouldn't be abusing your brakes enough to glaze a good pad. All you'll be doing is shortening the life of your pads, and creating a lot of dust.

These are my Wilwood racing brakes (Thanx, Gordon) on my FFR. Notice there are minimal slots, and no holes or dimples.



This is my Backdraft, strictly a street car.

[AdamIsAdam]

The big question is whether the pedal mod was done to change the leverage factor for manual vs. power brakes. If it’s still using an unmodified power brake pedal the effort will be extremely high.

Jeff

Jeff, Mike, others,
I verified with Mike Everson that I do have his modified brake pedal. At this point, I've decided I'd like to keep the manual brakes but would like to try different pads. I tried searching but got too many "build threads" and nothing just on pads. So I'll just keep posting here and ask for advice on pads.

I just bought and have yet to install rear Powerstop Z26 carbon-ceramic pads. I like them on my GT350 for street use for the low dust and strong stopping power. My current rears throw off a lot of dust but the fronts do not. Powerstop does not make them for my fronts, which again are supposedly the 1993 Mustang Cobra R 13" setup.

So, before I install the Powerstops in the rear, I thought I'd ask for input on pads on the fronts & rears. I would think a matching set would be better if possible. Assuming I do in fact have Cobra R 13" up front, it's hard to find that part listed as a 1993, most catalogs only list them for `94 SVT. Does anyone know if the parts are the same for 93 & 94 on SVT Cobra R's?

What pads do you all suggest for street use if I want better around town performance? Hawk Performance HPS? (I don't care about longevity or cost, safety and low dust are #1 and #2 in that order.)

Is this the right one for the front: HB111F.610
?
Is this the right one for the rear: HB580F.627 ?

[AdamIsAdam]

It's a total washout this weekend so I decided to spend some time in the garage swapping brake pads. The fronts are in but I ordered the wrong rears. I think these are the correct Hawk rears: Hawk Performance HB183F.585 HPS Performance Ceramic Brake Pad

It turns out the old rear pads are Hawk HP+. I ordered HPS to match the fronts.

But get this: check out the condition of my front pads! The inside front left rotor/pad looked like it wasn't even making contact with the entire pad and it almost looked like there was paint or something on the surface. I cleaned it up and installed the new pads. I'll bed them in and look forward to reporting back.
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