Upgrading Brakes and suspension

[dscott]

Rick, the problems you are hearing so far are typical. The stock system will work good until you upgrade any portion of it. Just adding the Granada setup usually does away with the brakes. One thing I have heard is some of the guys are using the master cylinder out of a Mustang GT. They have to change the reservoir to a truck style since the GT is tipped. I have used the electric system from the Buick GN and it works great in the car but it's expensive to setup. I have tried numerous master cylinders with no change. I think the rears are the key to all of this. Especially when the parking brake is used. It's also necessary to adjust the rear drum setups regularly. They are self adjusting but only if you use reverse alot. Keeping them properly adjusted will usually eliminate any problems on the stock 9" front and rear drum system.
Don

[rdorman]

Strange problem. I would love to get one of these cars to my house to track it down.

I know of a CR with the 11" front and rear, GM calipers, mustang master and booster (yes, you need the ranger resevior) and a GM proportioning valve and it would through you throw the window. Basically the same set up that folks are having trouble with.

I have got to think that some folks may have booster issues. But according to Don, that has not resolved the issue.

If the condition came on gradually, I could suspect glazing.

If it is like that out of the box then prehaps the valve being used is for a disc/drum setup. I would have to read up again but seems to me they delay the drums for a time until the discs kick in. Like I said, I have to go back and read up on it.

A line restriction or to small of a line could be an issue. Restrictive fittings etc. 3/16" is a good size to use for a brake system.

I am going to keep chewy on this.

For those of you whose four wheel disc systems are working good, I have some ideas for some serious race setups. Of course there are variances.

If you have a good system and just want a bit more, good fluid, bled often, and better pads are usually a good upgrade. A higher temp, higher CF in the front pad is usually the way to go since on the 'model' I am using for CR in a 1G stop the fronts are doing 65% of the work and with the same size rotor the temp rise in the front will just be that much faster. EBC, Hawk, and Porterfield all make good pads that without looking I would think would fit your application.

I don't know if I mentioned this before or not but the base line CR system I am working on is 6to1 peddle, 1" master, 60mm caliper pistons ( I have not been able to confirm if they are the 60mm or 2.5" ones yet), 11" rotors at all four corners. The system on paper seems to have to much rear brake but I am hearing little to support that which to me says there is another issue aside from the basic design. Plus modifications to the system seem to yeild little results for all, but work for some.

By the way, if you are using the GM metric calipers I see that U.S. Brake has a bolt on replacement with an over side caliper that will give you more front brake force. The Metric GM is 60mm where the over size one is 2.75". That may not sound like must but it is about 33% larger than the metric caliper and 21% larger than the 2.5. That is in area by the way. I have no clue if you can bolt on a metric where a standard one is. But if you combine the base system I described above with the oversize caliper and a front pad with a CF of about .1 more than the rear you will have a pretty well balanced system and reduced peddle effort.

If it was my car I would go through it with a fine tooth comb before I changed parts, there is NO reason the 'stock' setup I described above should not work well. Heck I recall one guy with 9" rotors on the front and drums out back and he said his system works fine! 11"ers all the way around has got to work better!

Are the caliper adaptors a stock or custom piece? Not having caliper normal to the rotor is a issue. Deflection is another. Any one getting pad taper? Hard to beleive how much more difficult it is to stop on a set of tapered pads. Measure the thickness front and rear on the pad, if it is not the same, it is tapered.

Any one have a set of hydrualic pressure guages? I would like to take reading at the master cylinder and every junction all the way out to the calipers. This would tell SO much. If that is all good then I would be looking for taper, glazing, deflection, runout, caliper normal to rotor, alignment, suspension condition, pushrod adjustment, peddle geometry, etc, etc, etc.

Doesn't it sound like a fun filled day!! Bring a gallon of brake fluid with you

Rick

[dscott]

Rick, the 11" front setup uses a custom bracket to adapt to the Mustang II spindle. I have bought the setup from 4 or 5 different companies and they are all the same. As I told you before I have also tried several Wilwood systems with no improvement. I don't recall ever having a problem with the stock setup, it's only after an upgrade. I'm checking on pressure guages.
Don

[rdorman]

After upgrade? From drums to disc? Or........
Thanks
Rick

[dscott]

Rick, could be either, both have the same results.
Don

[cobra427mnsi]

Rick

The CR that you know of with the good brakes, what size brake lines does it have? The CR manual says to use 3/16" brake lines. That is what I used. I wish I knew then ('92-'95 during the buid) what I know now. I thought I had to go by what the manual said. I would have probably gone with 1/4" lines and different brakes. I suppose its not too late, but alot of work now to change lines etc.

Paul

[cobra427mnsi]

Don or Rick

The guys with solid axles and disk rear ends. What rearend did they use to get disks ? Out of what car can you get an 8.8 with disk brakes that will fit under the CR . My rearend is out of a '92 mustang.

Paul

[dscott]

The newer 8.8 from the Mustang has the rear discs but it is 1 1/2" wider. There are several companies that make a kit to convert to rear disc (Wilwood, TSM, Stainless brakes, Etc). I've also seen people use Explorer rear disc. The 3/16 lines are more that sufficient.
Don

[rdorman]

I am with Don, 3/16 are fine. I would use 1/4 for hydrualic clutches. 1/8 is just to small!
Rick

[cobra427mnsi]

Don

Is that 1 1/2" wider in total or per side? If I were to use one, what backset would I need to use on the wheels? And would the mounting points (upper and lower arms) be the same as the '92) ?

Don and Rick, thanks for the replies !

Paul

[dscott]

Paul, the rear is 3/4" wider on each side, 1 1/2" total. The mounting points are the same. You would need to add the 3/4" to the backspace. For a 9 1/2" wheel the offset would be 5 1/4", you can adjust accordingly for different widths.
Don

[cobra427mnsi]

Don, thanks for the info .

Paul

[rdorman]

Any new info????
Rick

[petek]

New info from who? (or is it whom?)

I did try out an experiment with my CR. I cranked the proportioning valve all the way clockwise (which should, in effect, eliminate the delay that the valve creates). No change in braking.

So then I tried pulling the handbrake at 25 mph to see what would happen -- nothing.

I've a feeling that my rear discs need adjustment!

[rdorman]

Just in general. I have a lot of questions in these posts! It would be great to get some hard data such as pressures at the various points in the system.

I am with you on the rears, sounds like they need adjusted.

Thanks

Rick

[dscott]

Sorry guys, I haven't had time the last few weeks but I have ordered pressure gauges . Once I receive them I'll get some numbers posted.
Don

[rdorman]

Kewl!!!!

Can we get them at the master cylinder and then just downwind from the proportioning/metering valve and of course the calipers?

If you can, note the peddle force used in pounds and vacuum available at the booster. Big helps there to!

Thanks
Rick

[cobra427mnsi]

Glad to see that there is still some interest in this topic. Don, I got your new pedal and installed it. Can't test it out yet as the cobra is still on jack stands as I am rewiring the dash and firewall. It looked too cluttered so I when with an alternator with an internal regulator and the MSD ignition. Also moved the battery to the trunk. Oh ya, I am also intalling a new engine. A 427 co with solid roller cam and roller rockers. Can hardly wait to get her back on the road. Going to need better stopping power for sure now.

Paul

[rdorman]

Well sure there is still interest! Some times these things take some time but who wouldn't want a better product! Just so there is no confusion I am not affiliated with CR. Just a guy trying to help out!
Rick

[Jack21]

Thought I'd throw my hat into this one as I wrestled with the brakes issue also. My brakes, with the sticky 17" tires will lock the wheels if I stand on the pedal. Setup was selected with 15" wheels in mind.

The pedals are stock. Booster is a new OEM MII unit, with the vacuum line going to the #4 cylinder runner on the intake. (Vacuum line under the carb is used for the PCV)

Fronts are Stainless Steel Brakes MII upgrade setup. Uses Grenada 11" rotors, and SSBC 4 piston calipers. These calipers are the Kelsey-Hayes design, new from SSBC, originally used on '66 - '67 Mustang GT's. Purchased new font lines from SSB and they bolted right up. (Tie wrapped a piece of heater hose around brake hose to prevent chafing of brake hose by upper ball joint cotter pin.) Pads are from SSB. They're "Street" semi metallic. (Also puchased Street semi-metallic pads for T-bird Turbo Coupe from SSB to replace stock organic pads supplied with rear disk brake kit below.)

Rears are Ford Motorsport M-2300-C '79-up Mustang rear disk brake conversion kit. This was the recommendation from FMS tech support. The kit pirates the rear brakes off the '87 - '89 T-bird Turbo Coupe. Rotors are 10", and had to be re-drilled for 5 lug wheels. Calipers bolted right up with supplied brackets. Master cylinder bolted right up to MII booster without modification. Brake lines come out on the engine side. Kit includes adjustable rear brake valve, and modified proportioning valve. Kit also includes 2 sets of e-brake cables. I used the rubber covered ones. (SSBC may now carry this rear setup.)

My seup dialed in with the proportioning valve full open. Hope this helps some of you with what worked for me for brakes.