BrakeExpert

This is a thread to talk about the Honda prop valves and theories of brake bias.

Kozy.

I'll kick off with the drum prop valve discussion carried over from the other thread. BrakeExpert you claim that in your not insignificant experience that you have never needed to change out a drum prop valve when performing a rear disc conversion.

How do you come to this conclusion?

98civdx

46210-S04-952 VALVE ASSY., PROPORTIONING 1998 INTEGRA RS
46210-S04-902 VALVE ASSY., PROPORTIONING 2000 CIVIC CX Hatch
46210-S04-902 VALVE ASSY., PROPORTIONING 2000 CIVIC DX Hatch
46210-S04-902 VALVE ASSY., PROPORTIONING 2000 CIVIC DX Coupe
46210-S04-902 VALVE ASSY., PROPORTIONING 2000 CIVIC HX Coupe
46210-S04-902 VALVE ASSY., PROPORTIONING 2000 CIVIC SI Coupe
46210-S04-912 VALVE ASSY., PROPORTIONING 2000 CIVIC DX Sedan
46210-S04-912 VALVE ASSY., PROPORTIONING 2000 CIVIC DX-V Sedan
46210-S04-912 VALVE ASSY., PROPORTIONING 2000 CIVIC LX Sedan
46210-S04-922 VALVE ASSY., PROPORTIONING 2000 CIVIC GX Sedan
46210-S04-962 VALVE ASSY., PROPORTIONING 2000 CIVIC EX Coupe

Kozy.

From the Japanese EPC for the 99-00 model EK.

EK2: 240mm/drums - 46210-S04-802
EK4: 262mm/240mm - 46210-S04-812
EK9: 282mm/260mm - 46210-S10-862

Libertariat

In for this discussion for sure. I'm beginning to think my rear calipers are largely under worked. BrakeExpert and I painted the rotors/calipers when we did my front/rear upgrade, and the rear paint too a LONG time to wear off. I even was lifting the E-brake on the highway.

Edit: Komodo, I should get you to ship me one of those CTR prop valves

Kozy.

I'm sure it could be arranged if people want them. For the cost involved though (think Type R tax, shipping, import taxes yada yada), an aftermarket adjustable type would be a much better investment.

What part of the rotors did you paint?

Libertariat

You're right, I think wilwood makes a nice one

I painted the entire surface of the rotor, hats, and the edges of the rotor where the veins come out. Wearing the paint off with the pads proved to be interesting, haha. But they look very nice

Kozy.

I'm not sure whether to laugh or cry. I'll simply use this:

Libertariat

I was skeptical at first, but BrakeExpert says he does it all the time. The paint wore off after a few stops. Wasn't really a big deal. A light coat of paint comes off really easily. And that edge that normally rusts where the pad doesn't contact has a thin line of paint too, so it's a nice subtle aesthetic touch.

got-vtec?

iTrader: (4)

which prop valve should be used when converting to rear disc?

m_shake

Always wondered why the Integra Type R(USDM) used 46210-S10-A52, which is the same used in the 97-01 CR-V w/abs....which has rear drums lol

Kozy.

BrakeExpert appears to be curiously absent from the thread he started on the subject...

Since there is so much mystery shrouding the factory fittes valves, the default answer to this question shall now be, on my part at least, 'An aftermaket adjustable one'.

A drum prop will 'work' if your definition of 'working' is simply that the rear brakes do not lock up. If you want to get the best performance out of your new setup (why else would you be doing it?) then an adjustable valve is the only way to go.

98civdx

He started the thread 1 day ago, give the guy a break. We all have lives outside of honda-tech.

You don't think a adjustible valve is little overkill for most people?


I've said this in the past, however, when my buddy swapped to rear disk (99 ex coupe) we did swap the proportioning valve at first. We took the car a drive and did some "stop tests". I drove the car aswell, he drove there, I drove back, both times.
We then went back and swapped in a 99-00 SI valve. Drove back to the same spot, driving the car the same way as before. Did our best to stop the same way as before. He couldn't tell a diference, nor could I.

I'll soon be putting in 99-00 SI brakes in my dx, front and rear and I plan to keep the dx valve. UNLESS, someone can show me proof there is a benefit to replacing it.

Libertariat

Indeed, give it a break. I know Mike personally and he's got a lot of **** going on.

We're all a little skeptical Komodo, the difficult part is testing. I've got a pretty radical front/rear conversion on my car and I can tell you that all I know is that the car brakes well in autocross, I've got no other means to test it out otherwise since I don't have prop valves to play with or a space where I can test it safely.

94eg!

iTrader: (2)

^Because it has a completely different weight distribution with more weight over the rear end. This is why it would need more pressure in the rear than a Civic drum setup....it has more rear traction under heavy braking.

Ever notice that the Honda pilot has larger diameter rear brakes than front?


I think the fact is Honda did not use a rear-disc specific prop valve on the US Si. Probably just leaves us with an overly front biased setup (which is not unsafe). Still it would be great to see a real difference test. Or actual performance tests on a real car with all these ridiculous combos.

94eg!

iTrader: (2)

Here are some interesting facts....

The UK EK2 prop valve is not available in the US.

The UK EK4 prop valve is found on the US 96-97 EX 4D & LX-4D-ABS Sedans. Both have rear drums. It's also found on several 98-02 Accords. It's a 4-port ABS valve so you can't use it on the US spec Si which is non ABS and uses a 6-port valve. http://www.hondapartsnow.com/genuine...0-S04-812.html

The UK EK9 prop valve is found on 01-02 Accord EX's. It is also a 4-port ABS valve and cannot be used on the US Si. http://www.hondapartsnow.com/genuine...0-S10-862.html

Kozy.

You are right, apologies to Mike, just little eager that's all.

In context, not at all. If you've gone to all the hassle of performing a full upgrade on your braking system front and rear (people do generally upgrade the fronts before doing a rear disc swap right?) then what is adding an adjustable prop to really get 100% out if it all? To me, that would be like dropping a full IHE in the engine bay along with uprated cams and cam gears, then just running it on the stock ECU.

The prop valve, like a remap, should be the part that brings everything else together. With out it you'll have a hash if components that may or may not work better than the factory setup. Whilst I used to believe that fitting the appropriate factory valve in was good enough it seems to be becoming apparent that none of them are really optimised for anything.

Libertariat

$45 isn't exactly "pricey"

http://www.chasebays.com/product/acu...***-style-3824

If this is the right part:


Looks like you'd have to flare new lines though.

Edit, there's also this one for $83:

http://www.chasebays.com/product/hon...rtioning-valve

98civdx

That is what I am starting to think, but it also makes me wonder why didn't the other models get the same valve. Only coupes (non EX) and the hatch shares the same valve.

Libertariat

A lot of the threads I'm seeing on other forums and such are all saying that you can change brake bias by changing the pads/discs on either end of the car to fit.

Presumably, such that bigger rear brakes and more aggressive rear pads do alter the bias a bit even though the same fluid is going there.

94eg!

iTrader: (2)

Sorry but it's no good with the OEM master cylinder until we have a 6 port option. Otherwise we loose the dual channel feature of our OEM braking system. The best I've seen is where someone replaced the 6-port OEM valve with two T fittings (keeping the two cross-brake channels separate). Then they routed completely new hard lines from either tee to the rear brakes through the cabin. The hard lines ran through the dashboard to the center console where either line had a two-port adjustable wilwood valve spliced into it.

Of course this is only ideal IF you believe each valve operates exactly the same.

Kozy.

Oh undoubtedly, but it is still a bit hit and miss unless you have a way of comparing different setups vs weight distribution, weight transfer etc etc.

Even then, you're still limited to a fixed bias. With an adjustable valve (pretty affordable as you have found) you can adjust according to conditions, forwards for your sunny weekend track excursions on high grip tyres, and backwards for your normal rainy day to day driving on street rubber.

Libertariat

Also more from what I've read, to get those adjustable prop valves to work you need to buy two for our hondas, one for each side.

Kozy.

Good observation. There are some twin port valves available, but to run a single one you would have to re route the lines so that one MC port feeds through a T the front brakes, and one feeds through the valve and into a T to the rear brakes. Obviously this would necessitate ABS removal, but if you've gone for big changes over stock this won't be working optimally anyway and may well hinder performance.

The twin ports are more expensive but factor in the faffing about with lines then it's probably the better option

94eg!

iTrader: (2)

I thought I covered that in my previous post. lol

BTW: Adjusting bias via pads, rotors and calipers only makes changes to initial bias. Proportioning is something different. Remember the prop valve doesn't start limiting rear line pressure till about 50% foot pressure. Before that, it allows the same pressure front to rear.

I think Brake-Swap-Expert gets those two things mixed up. Just cause he's moved the prop valve discussion to a "proportioning thread", doesn't mean BIAS is any less relevent in his "Brake Swap" thread. Brake performance is all about bias.