Okay - most of the parts for my new brake setup should be on the car by next weekend. This includes a change over to 4-wheel disk brakes, oem honda calipers, brembo oem replacement disks, panther pads (****, I still need to call and order those) and blah, blah.. From what I have heard, because my car originally had drums in the back and I am going to be switching over to disks all around with a different fluid capacity I should change proportioning valves over from honda "3030" model to honda "4040" model - that sounds simple enough and straighfoward to me. My real concern is the master cylinder/booster. Most of the hybrid honda people automatically switch over to the 1" MC/booster that can be found in the GSR and type-R (from what I have heard, my stock MC is 13/16th's, and the Si and Gs/Rs are 15/16ths). I have, however, talked to someone with a similar generation cx who has swapped over to the Si brake setup with his stock MC/Booster. He said that it has worked fine for him, but he has not much track use with this setup. To make a long story short - short of being a cheep *** and not buying the mc/booster, and then finding out I have too much pressure but not enough volume going through the lines to stop the car, then tearing apart the car to install those parts - what can I do other than talk to people doing the setup??

Just to confuse me more - here is the text from a Grassroots Motorsports article on brakes- more specifically the MC..

"Increasing the master cylinder piston diameter will decrease the amount of pressure generated in the fluid for a given input force. Small changes here make a big difference. Decreaseing the master cylinder piston diameter works the same principle in reverse. Giving the relationship between master cylinder piston diameter and hybraulic force, it may seem desirable to use the smallest master cylinder possible. However, since there will always be some compliance within the system, the braking system has to have enough additional hybraulic fluid on hand to fill all the extra volume caused by the flexing of components duing the compliance phase. Unfortunately, this is accomplished by increasing the diameter of the master cylinder - which, we just learned, reduces the pressure generated. Therefore, one has to make sure that the master cylinder has a large enough diameter to meet the fluid volume requirements of the system, but is small enough to generate the pressure required. (There's never an easy answer, is there?)

ceas..


[Modified by ceas, 3:01 PM 1/13/2002]

 

Remember that the length of the stroke through the master cylinder has as much to do with the volume of fluid that it will move, as does the area of the cylinder itself. I will preface this by saying that I have never done the conversion that you describe but I would be kind of surprised if volume became a big issue. Braided steel lines (reasonable investment, given all of your other purchases ) will take some of the give out of the system, as well. HOWEVER, to be on the safe side, it would probably be worth swapping the MC that is engineered to work with the calipers that you will be using, while you are doing the whole project. FWIW.

Best of luck with the project!

Kirk

PS - from your post, it seems like you already have a TON more understanding than a lot of people who do stuff like you describe!

 

Try before you buy. It might not be as bad as you think, but then again, since I have no experience with a drum -> disk swap, I'm pulling this out of my ***. Just swap them, and test to see how far the pedal goes. If it's really spongy, then you'll know you need a bigger MC. If not, then you can live with yours if you want.

Warren

 

Thanks - I have called up Honda, and from what the parts people tell me (I know, take it with a grain of salt) is that the actual stroke of the cylinder is the same - it is just the diameter is different. I will be getting the stainless steel lines - so that "should" limit my compliance factor - hard lines from mc to hard body prop. valve - hard lines from there to each individual wheelwheel, and then stainless steel lines from there to the calipers. All that leaves is the difference in capacity of the calipers - from stock cx to the Integra-R that I will be installing.. Fronts should be around the same capacity - as both are single piston calipers, and while the size IS different - it is just a single piston caliper so the difference cannot be too great - but on the rear I am going from a tiny wheel cylinder to a single piston caliper - that will be the area where I get the larger increase in capacity.

ceas..

 

That is what I think I am going to end up doing - Just taking it around the block and making sure it will actually stop before I try taking it anywhere. I do need to keep in mind, however, that with new lines, pads, and disks the way that the pedal feels the first day is not the way it will feel in a week..

ceas..

 

Choose components carefully - match them up - you have to get up pretty early in the morning to beat the engineer at his own game (the brake engineer at honduh, in this case).

-Ryan

 

Stock proportioning valve will be O.K.
Stock booster will be O.K. It just eases pedal pressure.
Do the master cylinder. Do the steel braided lines.
Double check pedal height after m/c swap.
Pedal height is very important.

 

This is REALLY good advice.

Kirk

 

Here is my two cents on the subject. I have a 97cx hatch that I upgraded to Type-R brakes. I kept the stock master cylinder and booster but changed the prop. valve and the lines to stainless lines. I have yet to Auto-X but have done some emergency braking and found out that the car but it stops on a dime. The brake pedal has a little give in but I think it allows me to modulate the brakes better. The only thing IM thinking of adding is a master cylinder brace. Hope it helps if you have any other questions email me. One last thing I have compared it to a friend’s car with Type-r brakes and ITR MC/booster and my car stops just as well. Hope it Helps.

Kyle

 

I have driven Kyle's car and must say the brakes are VERY nice!! I think he is using Hawk HP+'s as well so those have something to do with the braking.

I drive a 92Si Hybrid with '00 Si brakes, GSR MS/Booster/Prop valve and I cannot even compare the two. The ITR upgrade is the way to go.

HTH.

 

OEM (especially honda) parts are engineered very well. Stick with 'em. If they work great for 100K miles, why replace it with an aftermarket part who's longevity is questionable?

Ryan - who learned this lesson the hard way many times over

 

I have a EG coupe with the EX/Si brakes. It came with a weird mix of parts from the factory. I actually have the calipers from a del Sol. It had drums in the rear. It has the 13/16 MC (added in edit-wrong! it has a '7/8"' MC). When I swapped in the rear discs from a 'teg, I didn't change the porportioning valve. It was better but the rears were not being used enough. It has to do with the amount of fluid that the cyclinders need to move the pads/shoes. Anyway, I purchased a new Honda porp. valve for the 1994 Civic Si which only came disc/disc. It made a huge difference. You really want to get the valve. Other than that, I am using Goodrich lines, Motul fluid & Porterfield pads.


[Modified by civicrr, 11:55 AM 1/15/2002]