Mikes Tip For The Day. Adding A Cobra Brake Booster.

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maybe i'm missing something? just cause it bolts in, doesn't mean it has the right amount of assist for a cobra master/caliper/disc setup. hell, my stock 89 booster bolted up just fine to cobra master, but that pedal was hard as a brick.

and yes, the tower got a little love from a 5lb sledge trying to get my cobra booster in, but if i had just taken my intake and valve cover off to start with i dont think it would have been necessary.
 
I wouldn't make the suggestion if the brake feel wasn't acceptable. My car will stop more than adequately from 40 MPH. The pedal is firm like you'd want it to be. Compared to the manual MC that was on the red car, this thing is the sht. Again,..what they changed in diaphragm diameter on my fairmont, they added piston stroke in the current fat boy mustang booster. Mine is flatter, and larger in diameter. I'm calling it a win.
 
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I wouldn't make the suggestion if the brake feel wasn't acceptable. My car will stop more than adequately from 40 MPH. The pedal is firm like you'd want it to be. Compared to the manual MC that was on the red car, this thing is the sht. Again,..what they changed in diaphragm diameter on my fairmont, they added piston stroke in the current fat boy mustang booster. Mine is flatter, and larger in diameter. I'm calling it a win.


How did/does brake-lock feel?
 
Found out some info that may be useful. I remember this thread because an alternative booster is always something that would appeal to many, but i needed to find some info first to do a little math

79-85 booster: single diaphragm 220mm booster
79-93 2.3L N/A : Same single diaphragm 220 booster
86-93 5.0 use dual diaphragm 152mm unit
94-04 use dual diaphragm 205mm booster

I did crosscheck part numbers, and an early fairmont booster is same as early fox booster.

So, i'll compare in terms of available booster surface area, which may correlate to increase in assist.


The Dual 152mm unit on the 87-93's offers the lowest level of assist with a surface area of 3629 cm^2. The early 220mm booster offers about 6% more surface area (3801 cm^2), while the dual 205mm unit offers a little less than 50% more booster surface area (6601^2) than the 87-93 unit.

So to summarize, the early booster should offer a slight improvement in boost assist if space is a concern and you don't want to try to shoehorn in an SN95 booster.
 
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I'll stick with my 93' Cobra booster since it's already in the car, however, one persons review on a booster leaves me skeptical. The booster install is a big PITA to have to do over in the event that Mikes interpretation of "good pedal feel" when braking is different than the majority.

My car will stop more than adequately from 40 MPH. I'm calling it a win.
Only 40 mph? Doesn't seem like much testing has happened
 
Since this has been revived, and since I have driven the car about 350 miles now,....I do have an update.

While I agree my statement was ambiguous, and is open to interpretation based on actual preference, I was comparing the existing booster to nothing as an alternative.

I had manual brakes in the red car.
That equates to "nothing".

So then,...here's the deal:

You cannot "lock" the brakes in this car, nor is the pedal "hard as a brick". I said that my brake pedal feel is very good,...and doesn't require any additional effort to get the car to stop. Now, stopping like a 2005 GTO,.or any late model.........not even close. That can be due to several factors however, none of which I have explored fully yet, but can be summed up in several possible scenarios:

#1. The booster is inadequate, and cannot assist in moving the required fluid to the four disc's currently on my car.(SN 95/ Cobra stuff on all four corners, Cobra MC, adj prop valve)
#1a. The booster is OLD...this is 38 yr old factory installed unit.
#2. I haven't got my brake bias adjuster dialed in to properly proportion brake pressure, and I'm giving the rear brakes too much bias...(unlikely, because I should be able to at least lock the rears instead,....but they are 315's after all,...and that is a giant amount of rolling mass for a 12" rotor to try and lock up...) Maybe I should throw the stock 185/15's back on and try it?
#3. The 6.5 qts of engine oil that I decided to apply to the entire underside of my car (to include the driver side front/rear brake systems especially) as a result of a -10 oil line failure, has fouled those two wheels, and now I have a "less than" with regard to optimal friction application when the pad meets the rotor. This is in spite of the fact that I thoroughly cleaned those two surfaces after my personal Exxon Valdeez moment **

** No indigenous wildlife was injured during this oil spill, and great care was taken to properly contain this enviro-hazard.
Our people labor tirelessly when my car decides to sht itself, and all necessary steps are taken to return our roads, and parking lots back to their normal, disgusting surface quality in the exact same condition that they were prior to being coated in brand new, synthetic 5w30 Syntec.


In hindsight,..The brake system seems good enough for a daily driver, but lacks the stopping power required for an absolute emergency panic stop, or if you wanted to track the car. It's not 100% definitive yet, I haven't even checked that the brakes are optimally bled, optimally biased, or that they are somehow compromised ...I've been too focused on trying to spin the tires, not stop them.
 
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