I just went out to the track this weekend after adding better pads and fluid and bigger MC. As I started pushing the car deeper into the braking zones the rears started locking up a little bit.

What would the next step down from a 40/40 proportioning valve be? 90-91 CRX si 2040? or 90-91 Civic EX 3540? Any other recommendations?

I found this in a search (thanks Tyson), but I'm still not sure which one would be the best step down in rear brake bias: http://www.norcalcrx.org/tyson/pics/brakepartslist.gif


Current brake/tire setup: 90 civic si, integra rear disk swap, 4040 valve, 15/16 MC, Hawk DTC 30 pads front and rear, brembo blank rotors, motul 600 fluid, goodrich ss brake lines. 205/50/15 Falken ZE-512 which are being replaced with Direzza ZII this weekend.

This car is primarily driven on track and occasionally to work when the weather is nice.

 

you may want to just use regular pads in the rear. At least that was what I was told by a lot of people, some running in Honda Challenge. Said a too aggressive pad would lock up the rear.

My set-up: DA front/rear disc, DA MC and booster, blank rotors, Carbotech XP8 pads in the front and BrakeBest pads in the rear, ATE Type 200 fluid, Techna-Fit ss brake lines

 

You didn't up your front brakes?

 

No, since I still drive the car on the street every once and a while I didn't want to go with anything more the DTC 30's up front. The next step down for hawk pads was the HP+ and I didn't think those would be enough.

Wouldn't lowering the rear bias with a different prop valve fix the issue?

 

rear pad is too aggressive. lowering the bias is, in effect, doing the same thing as using a less aggressive pad. if you're stuck on changing the mc,i believe there is a thread in the track forum

 

I'm certainly not stuck on changing the prop valve and I understand the reasoning on using a different pad f/r. I was just curious if anyone else had considered using a different prop valve than a 4040 and kept the same pads front and rear with similar bite and temp characteristics.

From all of my searches I couldn't find any info relating to the actual differences in bias between the different valves but I suppose I'll keep looking.

 

Your rear pads are applying too much friction, or your front not enough. You can fix this by either increasing the front brakes or reducing the rears to a point.

The proportioning valve works by engaging the rears after a certain amount of pressure applied to the front brakes is breached in the valve itself. Poor telemetry could also be a cause.

Are your rear wheels leaving the ground? What is the condition of your suspension? Suspension is often overlooked, and without it your brakes will flounder.

 

https://honda-tech.com/forums/showth...rtioning+valve

https://honda-tech.com/forums/showth...rtioning+valve

 

theres no prop valve that is used in a system with regular front brakes, and rear disc brakes.

its really no surprise your system is all wrong.

 

Tyson, I appreciate your responses to the thread, but the last part of this it quite unnecessary and unconstructive. Back when I did the rear disk swap in 2003 the 4040 valve was the only thing people used on any EF/ED when doing the swap. I am looking to improve my current setup and seeing if a different prop valve could be a solution.

It looks like the closest setup to mine is the 90-91 CRX Si's although they have a slightly larger front caliper piston & rotor. The 2040 may be a better option for my current setup but may not solve the issue.

BLUCIVIC I have read through those 2 threads you posted previously and there is a lot of great info. Although it looks like the actual bias of the various prop valves is still unknown.

I'll be seeing how the car reacts with the new tires soon and go from there. I may play around with different prop valves on the track to see what happens. Otherwise I may try my old axxis metal master rear pads and rotors or step up to the DTC60 up front for track days.

 

change the rear first since you already have it parts

 

its very constructive and relevant.

you added more brakes to the rear. youre complaining about rear brakes locking up first.

whats the surprise???

 

My $0.02

The prop valve from the CRX Si that came with rear brakes is as close as you could get to matching your current brake setup.
Every stock prop valve is biased for street use and the rears will lock up before the fronts in hard braking.
Good braking for normal stops, but not very balanced for occasional hard braking with weight lifted off the rear end.
Different pad compounds in front and rear are your friend.

 

For sure, that is the plan after the new tires. The pads/rotors still have enough life left in them to at least try it out. Thanks!

 

My point is that all your slightly jaded responses to this thread came with a hint of attitude that isn't needed to get the point across.

I also never complained, in fact the slight lockups made for a fun drive around the track, albeit not the fastest or safest. Thanks to responses I know what I'll be doing and will probably end up with a set of track and street pads. No harm done in my book.

Enjoy the rest of your week.

 

this is not true.

you never want the rears to lock up before the rears. street or track.
http://www.stoptech.com/technical-su...alance-matters

in fact, i have anecdotal evidence that there is a max relief pressure so the rears dont lock up. (as long as the rest of the system is as close to designed of course.) im pretty sure its part of the double pair of numbers code in the honda prop valve numbering, but not done enough testing to make a final statement.

 

^ that is right on a stock brake setup.
My comment was in regard to his rear setup. No stock prop valve is going to solve his issue.

 

So it turns out I still have the old rotors but threw away the pads when I was cleaning the garage. Which pads do you recommend I get for the rear?

Think the HP+ would be too much? The only turn I know that I was locking up on was a flat trail braking turn coming off of a straight so the issue isn't too severe.

Also, I think I may just step up to the 10.3" front brakes when these front pads wear out.

 

i'd spend $20 at autozone for some rear pads. if you want Hawks, get their street pad

 

Nice post. Makes me think of my set up and willow springs coming up too