I'd like to know what the numbers that are stamped on Honda (and Acura) proportioning valves mean.

I know that part of it is the ratio of front to rear biasing, but there has to be more to it than that!

The reason I make that comment is that there is both a 30/30 valve and also 40/40! It would seem to me both would have a 1 to 1 bias and there must be something else that makes them different.

I've done a bunch of searching and I'm after more information that just installation recommendations or lists of what fits on what.

Wes Vann

 

4040 is off of a 4 wheel disc car.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jisu009 &raquo;</TD></TR><TR><TD CLASS="quote">4040 is off of a 4 wheel disc car.</TD></TR></TABLE>

So, by that logic, 3030 is off a 3 wheel, 3 disc car?

Andrew, who thinks that something is amiss

 

ttt, can't find the answer to this quesiton anywhere!! Does nobody know?? I am going to 4wh disc on my 91 sedan, I have a 30/30 stock. hows that different from a 40/40??

 

No one really knows.

In theory. It's the size of the front/rear size of the brake setup.

 

I believe Tyson and California dude have done some pressure testing on this. Maybe they'll pop-in and share their wisdom...

 

40/40 is very bad eye vision.

who knows what 4040 means. (i cant make any sense of it)
http://www.norcalcrx.org/tyson/brakepartslist.xls

i have 4040 valves for sale!

i do not have tickets into Jay-Z's 40/40 NY club for sale.

 

i believe it stands for how much pressure or fluid gets distributed between front and rear.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Cory Matthews &raquo;</TD></TR><TR><TD CLASS="quote">i believe it stands for how much pressure or fluid gets distributed between front and rear.</TD></TR></TABLE>

proportioning:
1. To adjust so that proper relations between parts are attained.
2. To form the parts of with balance or symmetry.

kinda like "proportioning". go figure...

but can you decipher the code?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">
Sorry, but your wrong. A proportioning valve works completely different than what you are saying. And it?s called a split point.

Proportioning valves were designed to help balance braking pressure on cars with front disk/rear drum brakes. Inertia and momentum cause weight to shift to the front of a vehicle when braking, in turn causing the rear axle to lift from the road lowering the traction between tires and road.

Disk brakes require higher hydraulic pressure than drums do because drums use a mechanical servo action to increase force applied to the brakes.

When the brakes are first applied under light/normal braking, the valve does NOTHING. Fluid enters the valve at the smaller piston area and passes straight through. Only when you apply significant braking force, it achieves pressure at the outlet side of the valve exerting greater backpressure than inlet pressure moving the piston back towards the inlet side against spring pressure, thus closing the center valve stem and blocking pressure to the outlet. This pressure is called the split point. As pressure increases from the master cylinder, inlet pressure at the proportioning valve overcomes the pressure at the large end of the piston and reopens the valve. Brake fluid then flows through the center of the valve, pressure rises at the outlet, and it closes again. THIS OCCURS SEVERAL TIMES PER SECOND.





It allows pressure to increase to the rear brakes, but at a lower rate than pressure to the front.

Proportioning valves are rated in a ratio like this: after the split point, pressure to the rear brakes will rise proportionally to the front brakes. If you were to get a valve rated at 100/200 (0.50) for every two PSI of hydraulic pressure at the front you will achieve 1 at the rear.



NOW, where this relates to the guy wanting to change his brake bias, I don't know how well it would work, but theoretically your could get yourself a fully adjustable proportioning valve and install it for the front brakes. I would start off at something small like 90% so you will only see a 10% drop in the front.</TD></TR></TABLE>


i think i got it. this is off the SRT-4 fourm. apparently 40/40 means equal amount of pressure split between front and back. it is purely a ratio.\

p.s. why not just put 1/1. beats me, maybe because after 40psi os pressure the valve does its job.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Cory Matthews &raquo;</TD></TR><TR><TD CLASS="quote">i think i got it. this is off the SRT-4 fourm. apparently 40/40 means equal amount of pressure split between front and back. it is purely a ratio.\

p.s. why not just put 1/1. beats me, maybe because after 40psi os pressure the valve does its job.</TD></TR></TABLE>

so whats a 3030 do?

that diagram is actually very similar to the internals of the prop valve. however, the final conclusion makes no sense.

 

maybe a 30/30 valve means the valve splits at 30 psi of pressure? i dunno im trying my best.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Cory Matthews &raquo;</TD></TR><TR><TD CLASS="quote">maybe a 30/30 valve means the valve splits at 30 psi of pressure? i dunno im trying my best. </TD></TR></TABLE>

no, i dont think so...

 

As much fun as Cory's explanation is, the del sol has a 1725 prop valve. So now I am even more confused as to what the letters mean.