Best manual brake setup

G

GN SBS

Member
Joined
May 28, 2001
My powermaster is on the way out and I've decided to swap to manual brakes for safety and simplicity's sake.

Mach.80 has a great post here on his approach that uses a Wildwood manual master (Willwood 260-9439) and a G-body adapter from Drag Race Brakes. His total cost was $340 shipped and:
This modification worked great! The brake has a terriffic feel, not artifficial. The pedel is not too hard like I feared. My 105lb. wife drove the car and had absolutly no problem. Pedel travel is great. A perfect ballance of travel, feel, and pressure.
Click to expand...

Are there other good aftermarket manual brake solutions I should consider? Drawbacks to the Wildwood setup I might not be aware of?

For simplicity's sake I'm not inclined to do a junkyard swap from another GM car.

As a reference point, my GN will be pretty darn close to 9.99 on E85 this season. It does see street miles, but not many and I'm not commuting in it or anything.

Thanks for any and all feedback!
Scott
 
You definitely don't need the adapter no matter which MC you choose. Your powermaster setup already comes with the adapter you need. I went with the S-10 manual master cylinder. It works fine. I have my pedal setup for a 7:1 ratio. Actually I made a spare pedal with an adjustable pushrod... interested?
I'm at work right now. I can post pics of my setup this evening
 
I run the manual S-10 master cylinder, too. I am going to switch to a Wilwood, though. I am going to sell the car, and don't want the liability of the push rod falling out the back. It has worked great for me, but I want to make it fool-proof. Any mastercylinder will bolt right up the the factory PM firewall adaptor. I also have Wilwood front breaks, and braided hoses front and rear. Pedal pressure is very acceptable, even in stop and go traffic.
 
this is what i was wanting to do to mine but didn't find all the info i thought i needed and didn't want to tackle it blindly.... looks like i'm gonna have a vac. brake set-up for sale real soon :)
 
If someone would be willing to go into detail about modifying a pedal to change the ratio, and creating an adjustable (and SAFE) pushrod, it would be greatly appreciated. Honestly it seems like every brake system out there comes with its own set of headaches and at this point I want it simple and reliable. Manual would be great but I just have a few questions about the things I mentioned above. If you have the time and energy to do a little write-up or take pictures, it would be a great help.
 
OK, for the sake of the archives, I went out to the garage and did some measurments. These are rough numbers taken with a tape measure.
Vacuum pedal 3.5:1 pedal ratio
Vacuum pedal (unused hole) 5:1 pedal ratio
PM pedal 4:1 pedal ratio
The pic below is a spare pedal that I made, Which I would sell for $60 plus shipping, has a 7:1 pedal ratio and an adjustable pushrod.
The other pic is the stock powermaster adapter. This is why nobody on this site at least should need to buy any billet fancy adapter. You already have one. This one is missing the rubber cup/grommet that also helps in pushrod retention. HTH, Scott
 

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Appreciate the pix. Maybe I can find an aftermarket master cylinder that includes an adjustable pushrod and eliminate one headache. Then I'll just have to work on the pedal.
 
Scott Atk said:
Ken, Do you know what your pedal ratio worked out to?
Click to expand...

Scott,
I used a "PM ratio" (what ever the heck that is;) ) I.E. I used the stock P/M pivot point for the push rod. I am going to re-locate the pivot point higher (closer to the pedal pivot, to increase travel and ratio) when I install a Willwood M/C. I might just remove the S-10 M/C and drill the rear piston deeper to retain the push rod. My biggest concern is the push rod falling out of the master cylinder (because the S-10 master cylinder only has a drill start in the back of it) and not having any brakes. I have driven my car in rush hour traffic (including about 20 miles today) and the brakes work great. Pedal pressure is a bit high using the stock PM pivot point, though. I also need to lower my pedal (shorten the push-rod) about 3". I adjusted the push rod so that it would return the pedal against the stop and keep about 1/8" of piston depression. I need to just make damn sure the push rod is seated into the rear piston further so it never falls out. Hasn't happened, "yet", though. Been that way for about two years. I really don't drive the car that much. I did start driving it yesterday, and wnat to get a few things sorted out. Brakes being one of them. Just peace of mind is all. (I also want to pull the 3.8 and install a 4.1 and twin 60mm turbos.:eek: :biggrin: ) When I pull things apart, I can take pictures if anyone wants them. I just have a few "projects" that are more pressing right now.:mad:
 
should work. You may need a rod end or something similar to attach to the stud on the pedal. I'm sure that Wilwood master is nice, but I paid like 35.00 for the S-10 manual master that works great.
 
Turbo6Chicago said:
According to Summit, that Wilwood part number (260-9439) comes with a pushrod. Can it be used? Or would I still need to make an adjustable one?

Wilwood 260-9439 - Wilwood Aluminum Tandem Master Cylinders - summitracing.com
Click to expand...

See this helpful input from the thread I reference above:

So, when I got back from my trip I got to work. The adapter fit perfect to the firewall the MC fit perfect to the adapter. I used a tube bender to swap the location of the brake lines. The MC even came with the adapters and all the fitting to complete the install.

The only fabrication was to the push rod. I had to cut the rod that comes installed in the 7/8" bore MC. I had to cut the rod that came from the PM. I used a die the same thred as the MC pushrod to die the PM shortened rod. I then used a coupler and a locking nut, from your hardware store, to create an adjustable rod.

Now, I also drilled and tapped a hole in the brake pedel and installed a bolt. This gave me a 6:1 ratio instead of the 5:1 the powermaster used. HOWEVER, I did this for nothing because, I had too much pedel travel. So I ended up using the origional PM mounting point.
Click to expand...

Scott: did you use a different ratio for the fabbed pedal you actually installed in your car? Trying to zone in on the best ratio for this setup.

Thanks to all, this is a great thread.
 
Turbo6Chicago said:
According to Summit, that Wilwood part number (260-9439) comes with a pushrod. Can it be used? Or would I still need to make an adjustable one?..............]
Click to expand...

The pushrod will not work as is, it will fit the MC but the clevis will not work on the pedal.

What we do is remove the exsisting rod from the car, measure what the final installed rod length should be, cut and weld the stock pin end to the MC end.

Also, the Wilwood MC mounting holes will NOT line up with the factory firewall mounting plate from the PM.:mad:
 
Nick Micale said:
The pushrod will not work as is, it will fit the MC but the clevis will not work on the pedal.

What we do is remove the exsisting rod from the car, measure what the final installed rod length should be, cut and weld the stock pin end to the MC end.

Also, the Wilwood MC mounting holes will NOT line up with the factory firewall mounting plate from the PM.:mad:
Click to expand...

Thanks for that last piece of advice Nick, you're always good for a gem or two. I'll likely order the adapter that Mach0.8 recommends.

Nick, what pedal ratio do you shoot for? Any pearls of wisdom about getting the pedal set up?

What bore size works best: 7/8" or 1" or others?
 
Here's another option from MP Brakes that Frank-G recommended in an old Parts-for-Sale post. Anyone using this, do chime in.

See questions in my post above. -Scott
 
It's all about preference. Your pedal ratio needs to match up to your MC bore size and what an acceptable "feel" is for you. The 7:1 pedal that I pictured above will give you a nice soft feel but it will have considerably more pedal travel vs. a stock PM pedal ratio. The S-10 MC is I believe a 15/16" bore. HTH, Scott
 
I'm also thinking about doing this.

Can we get a list going on who's using what size master cylinder bore with what pedal ratio, and if they are using manual wheel cylinders, and or oversize piston front calipers.
 
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