Hi. I've been riding Ed's LS1 brakes on my front wheels since November. Much better over the originals. Anyways, I noticed back then that the pressure going to the passenger's side in the brake lines was much less than that going to the driver's side during bleeding. As a result, during hard braking the car tends to the left. I'm guessing the MC could be going bad.

Anyway... replace it and I'm done.

But wait!

Is it possible to put a larger bore master cylinder on the car to get more sensitivity/power out the brakes? Maybe I should just leave it alone and stick with the stock size?

Your sage advice appreciated (you know who you are).

 

Nobody has an aftermarket master cylinder?

 

If you're getting more/less pressure side to side you've got a restriction in the side with less pressure . Either the rubber line is failing (they come apart internally) or you've got a kinked steel line or something to restrict the flow . It's probably not the M/C . Maybe something in the prop vave but I doubt it .A larger M/C will give you more line pressure with the same size calipers .

 

I replaced the rubber lines with Earl's braided steel. Are there rubber lines somewhere else?

Basically I hear you saying:

1.) Check the lines from the MC for and kinks or bends.
2.) Consider replacing the prop valve.

That cover it?

 

The only rubber lines are all 4 going to the calipers and the one at the rear of the car that ties the hardline to the distribution block atop the dif.

 

No. This is wrong. You want more line pressure then simply press the pedal harder.


What a larger bore MC does is increases the volume of fuild in the MC so the pedal has to be pressed harder and deeper to get the same effect as a smaller bore with less effort applied. The larger bore increases the sensitivity but ALSO increases the effort needed to apply them.

 

Nice explanationBasically given the same pedal force: bigger bore=more volume less pressure and smaller bore= less volume, more pressure Force= Area x Pressure.

 

What would the benefits of a larger bore? Would it be easier to modulate (on a non-ABS car) at the limits? Would actual performance change? Shorter stopping distances?

I'm still learning this stuff, so please take it easy on me!

 

A larger bore for the systems we can use on these cars or any car for that matter would most likely reduce the effectiveness of the clamping action of the brake assemblies, like tidbit said without significantly higher pedal force. Since the brake systems are a closed system, by closed system I mean the pressure in released through the same lines as it is applied, the pressure in the system is doing the actual work, not the volume or amount of fluid the MC moves. Modulation of the pressure in an ABS equipped vehicle to keep the tire at the point just before lockup (most effective) occurs possiblly 100's of times in a second is virtually impossible without ABS by regulating pressure. Volume has little effect on automotive brakes other than increasing operator effort to achieve the same effect. The same as a hydraulic clutch, they use relatively small MCs with higher pressure lower volume to overcome the springs on the pressure plate.

http://www.tpub.com/content/engine/1...s/14037_67.htm

 

Thanks for the lesson!

 

Nice!

So really, if I wanted more pedal sensitivity, I would go for a smaller bore?

I am asking because I saw one of those 'Horsepower TV' shows last weekend where they installed a Willwood Master Cylinder on a car as an upgrade and I wondered if that might be the thing to do if I was looking at needing a new MC to begin with.

 

Facts-


Larger Bore= need to exert more force to apply the brakes. Better feel, better sensitivity when applying pedal pressure. WIfe will generally complain that too much effort is needed to press the pedal. You can press on them harder and get a better modulation feel, better sweet spot.


Smaller bore= less force needed to exert in pressing pedal- less sensitivity (power booster is strong feeling and you lose the sweet spot feeling in the pedal, but you gain less effort needed to apply the brakes. Your wife will NOT complain that the brake pedal feels hard and takes more strength to stop the car
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I run a smaller 15/16inch bore standard MC on my third gen even with my massive brakes. It has very good modulation. I did not opt to go to the larger 1inch bore.


In case you are not familiar with my car- here's a pic of my binders-

http://www.cardomain.com/member_page...52_74_full.jpg

 

WOW! I'm confused. I just purchased a Wilwood Tandem M/C with the 1-1/8 bore. That is what the wilwood tech recomended.

Here is a link.

http://www.wilwood.com/Products/006-...TCMC/index.asp