Hey Guys,

Here are a few specs on my car that are relevant to my question:

92 DX Hatch (EH2)
Front and Rear Integra Disc Brakes
JDM ITR Master Cylinder (1' inch) and Brake Booster
Goodridge SS Brake Lines

Now, I know I need to use the 4040 prop valve off an RS (non abs) Teg. I currently have my stock prop valve on the car because I can't get the hard lines off without stripping them. My brakes do feel a little biased towards the front, which I understand. My question is this: Does a 4040 prop valve take stopping power from the front brakes and re-direct it to the rear brakes? Or, does it actually add more stopping power and send it to the rear brakes?

Thanks.

I am Batman.



Modified by litterbox at 3:53 PM 3/10/2005

 

From my understanding it splits the power from the front to the back. Did you try using a flare nut to take the hard lines off?

 

Yes I have a flared wrench and it still strips. I'm just going to wait till I do my swap and then get in the empty bay and cut the hard lines and reflare them all.

So it splits the stopping power?

 

it add's more power to the rear brakes without negative effects to the front. i had the same problem with my car and when i changed to the 4040 the car would brake a whole lot harder, and if i hit the brakes hard enough the rear would lock with the front also, but that was with me standing on the pedal.

 

Well right now my fronts lock when I jam on the pedal. I don't THINK the rears do. Wouldn't you want all 4 brakes to lock if any will lock?

 

yes that's what i'm saying the rear will lock up with the front, so i know that they didn't (the front) lose any power.

 

Gotcha. BUT, is it ideal for only the fronts to lock up, or all four?

 

well what they say is on a FF vehicle you what brake bias to the front, but from what the butt dyno tells me is that my car stops a whole lot better. it also depends on how you want to use you brakes also. with even (or close to it) brake distrubution on a FF drive car going into a corner using trail braking you get more understeer,with 4040 prop valve, but with the braking technique i use i brake hard before going to a corner then straighten out and acclerate before the apex.( i try to go staight from the apex rather than around if you get what i mean.) sure this works good on a turbo car but on a n/a car where high revs are a key factor you would want to be at higher revs, so you want to keep up momentum. not a good thing if you brake hard on corner entry. but if most of your racing is at the strip then 4 strong brakes works good, but that is just my opinion. it all comes down to the feel you like best.

 

maybe some one in the autocross forum can answer better, but this is what i can say from personal experience.

 

A proportioning valve limits the pressure to the rear brakes after a certain fluid pressure is attained. Before that transition point, line pressure is equal front & rear. Your initial brake bias (under light duty braking) is controlled exclusively by weight over the front & rear axles, the vehicles center of gravity, tire compound, pad compound, rotor size, and caliper piston size. The auto manufacturer builds your car with more front bias so that hard stops will be more stable (fronts lock up while rears still slow the car keeping it straight). Switching to a 40/40 creates more pressure in the rear lines only under hard braking. This is good, but if the rears lock up before the fronts, the car will start to spin (especially in a turn). The closer you can get to a 4 wheel simultaneous lock up, the shorter your stopping distances will be. Always error on the side of the forward bias (for safety's sake).

Some interesting facts:
Lowering your car increases forward bias
Adding weight to the rear of your car increases forward bias
Stickier tires also increase forward bias
Larger front brake rotors (with the same size caliper pistons) increases forward bias
Larger front caliper pistons increase forward bias

If you have these mods, you may want to look into increasing rear bias, and a 40/40 is a good start...

All you will ever need to know about brakes & brake systems can be found at http://www.stoptech.com. I've read their stuff from front to back.

 

Great info 94eg!, as always.

 

My current setup consists of an integra rear disc conversion with axxis ultimates in back, and stock 9.4" rotors w/ raybestos pads (not by choice ) up front. With the integra 40/40 valve, the brakes feel great when I first lay into them (cold stop). Once those rear pads (axxis ultimates) get heated up though, the tail end actually locks up first. It's really wierd, and doesn't happen until after 3 60mph-5mph stops in a row. I was really surprised at just how much grippier those pads got when they get up to temp.

From what I've heard, the 92-95 Si comes with a 40/30 valve. I wonder if this valve has a little less rear bias for the lighter rear end of the Civic HB chassis? That might explain the reason my 40/40 puts me so close to the edge of a rear wheel lock-up...

Just though I'de share...

 

Not trying to thread jack, just looking for some input. What do you think of this brake set-up:
93 LS rear disc
goodridge braided SS lines (fronts have teflon coating)
brembo 'blanks'
hawk performance pads (front and rear)
ITR 1" MC/BB
99-00 Si prop valve

All of this is on my 96 Ex coupe. I'm hoping to have some really nice stoping power with all this. I might have to upgrade my tires to put it all to the ground.

 

Sounds good to me...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC4life 96 &raquo;</TD></TR><TR><TD CLASS="quote">Not trying to thread jack, just looking for some input. What do you think of this brake set-up:
93 LS rear disc
goodridge braided SS lines (fronts have teflon coating)
brembo 'blanks'
hawk performance pads (front and rear)
ITR 1" MC/BB
99-00 Si prop valve

All of this is on my 96 Ex coupe. I'm hoping to have some really nice stoping power with all this. I might have to upgrade my tires to put it all to the ground. </TD></TR></TABLE>
That'll be one hell of a setup i'm sure. My current setup even without the correct prop valve, oem rotors and pads is NUTS. The 1inch mc and itr bb makes all the difference in the world.

 

Well Im still thinking of these kinda upgrade, as Im going to have a big 4 pot to the front soon, The only thing that keeps me away, is the MC/Booster. There is a fitting that comes out from a different direction then our LHD cars. say an jdm EK9 or ITR MC. people are modifying that tube to the right direction and i have seen someone have made a crack on it and personally I think it did affect the safety.

Please someone inspire me with option, If Im having a stock 98 DX MC and a 4040 p.valve, will it be enough for a spoon big 4 pot upgrade?

 

You have to ask yourself what those calipers were originally designed for. To get the system to operate at its full potential, you will need to reproduce the whole Spoon Type R brake system. This includes:

Larger front rotors (11")
Spoon Calipers
Larger rear rotors (Type R size)
4040 prop valve (If that is what the type R has)
1" master cylinder

Then you should be good to go...

 

Thanks, I did have DC2R's (99) 5 lug conversion, so all the parts are ready .hmm

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sinister6 &raquo;</TD></TR><TR><TD CLASS="quote">Well Im still thinking of these kinda upgrade, as Im going to have a big 4 pot to the front soon, The only thing that keeps me away, is the MC/Booster. There is a fitting that comes out from a different direction then our LHD cars. say an jdm EK9 or ITR MC. people are modifying that tube to the right direction and i have seen someone have made a crack on it and personally I think it did affect the safety.

Please someone inspire me with option, If Im having a stock 98 DX MC and a 4040 p.valve, will it be enough for a spoon big 4 pot upgrade? </TD></TR></TABLE>Are you talking about the one fitting that's on the other side of the MC? Because I have a jdm MC and the fitting is on the other side, but all you have to do is slowly/gently bend the hard brake line to make it fit.