3040 VS 4040 proportioning valve swap theory...

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posol

RETIRED
Theroy time. :lol:

Ok, so as most of you know, i'm doing a massive brake upgrade on the hatch.

fronts:
11" blanks/ wilwood 4-piston calipers, goodridge lines, wilwood pads

rear:
11" blanks, non-vented (oem style) with oem-style nissin calipers, goodridge lines, axis pads

master/booster:
91 civic ex 4-door 15/16" master, stock eg dx brake booster (yes, it bolts right into the booster for those of you who are wondering and has the same outlets for the hardlines-- no bending/etc.-- best way to get a 15/16th in there)


and now, for the purpose of the question: to use the 3040 (stock.. or 4030, whatever its called) or the 4040 (from a DA teg non-abs).

Money aside, (i have the 4040 already), so this isn't a money issue.



Now, from my understanding, the way a ppv works is like this:

4040:
under normal braking, it splits the fluid up pretty much evenly.
but under hard braking, it sends more to the front to prevent locking the rears (due to extreme weight transfer)

3040:
under normal braking, it splits the fluid up pretty much evenly.
but under hard braking, it sends more to the front to prevent locking the rears (due to extreme weight transfer), a little more than he 4040 would, thus making the 4040 have more fluid getting to the rear brakes under hard stops.


if i'm wrong in those assumptions, please correct me. i'm still a n00b when it comes to brakes.

now, with my setup, i'm using an overly large rear. in fact, my rears are probably equivilent to an ITR's fronts, minus the heat factor of being non-vented.

my fronts are huge, though, as well, and with the 4-piston setup, it should stop very well. but will the 4040 still send too much to the rears and lock me up too soon, and cause my ass end to get loose during braking?

I hope i explained my self clearly.

The whole point of this is that i don't want to swap it out after and go through the whol bleeding process if i don't have to. plus, the blue smirf gizz brake fluid i have isn't exactly easy to come by at autozone or something.. gotta get it from E who gets it from his mom who gets it from work... lol


so, which would you start with-- the 3040, or the 4040, given the above setup.
 
I think with the upgrades for both the front and back the ratios will be fairly close to the original disk set up. I would go with th 4040. everthing i have ever read say swap the valve.

I just mounted a 4040 in the del sol. no engine, no lines = piece of cake. One small issue was the bracket on the 4040 had to be swaped with the original. That cost me $20 for a set of tamper proof screw drivers..... oh well.
 
If the 4040 Prop. Valve is going to send that much fluid to the rears, i'd say it's a safe bet to stick with the 3040 (or 4030 whichever) but people seems to like the 4040 but then again i've never seen anyone with such an overkill of a brake setup
 
sorry, i was not clear. I mean your new set up to a stock si set up(4040) will be closer than your new disks to a stock disk/drum set up(3040).
 
Originally posted by abdelsol@Jun 13 2005, 05:21 PM
sorry, i was not clear. I mean your new set up to a stock si set up(4040) will be closer than your new disks to a stock disk/drum set up(3040).
[post=511762]Quoted post[/post]​


this is still not clear to me at all....
 
Originally posted by B16RacerN2NR@Jun 13 2005, 05:18 PM
If the 4040 Prop. Valve is going to send that much fluid to the rears, i'd say it's a safe bet to stick with the 3040 (or 4030 whichever) but people seems to like the 4040 but then again i've never seen anyone with such an overkill of a brake setup
[post=511757]Quoted post[/post]​


right... most people don't have a large rear disc... even ITR's run a 11.1" front and 10.2 rear. i have a full 11" in the rear, which leas me to think that i would want to throw a little less fluid at it, no?
 
i dont think itr rears are the stock 9.5's like the rest, i think they are a little bigger. not 100% sure but i could be wrong.

i saw stick with the 4040. cause, and this is what makes sense to me, since you have bigger rears, they will lessen the weight transfer to the front. therefore being ok and not gonna lock up on you. but im again not sure on if this is the case. maybe search the roadrace forum or something on h-t. find some die hard racer that knows tons of brake theory or something.
 
Originally posted by pissedoffsol+Jun 13 2005, 05:02 PM-->
B16RacerN2NR
@Jun 13 2005, 05:18 PM
If the 4040 Prop. Valve is going to send that much fluid to the rears, i'd say it's a safe bet to stick with the 3040 (or 4030 whichever) but people seems to like the 4040 but then again i've never seen anyone with such an overkill of a brake setup
[post=511757]Quoted post[/post]​


right... most people don't have a large rear disc... even ITR's run a 11" front and 9.x rear. i have a full 11" in the rear, which leas me to think that i would want to throw a little less fluid at it, no?
[post=511785]Quoted post[/post]​

correct
 
bah, im getting 50/50 results back... e says do the 4040, wildbill says to leave the 3040 in there... lol
 
Originally posted by GSRCRXsi@Jun 13 2005, 06:12 PM
i dont think itr rears are the stock 9.5's like the rest, i think they are a little bigger. not 100% sure but i could be wrong.
[post=511788]Quoted post[/post]​



yeah the ITR has 11.1" fronts and 10.2" rears

and B i agree with bill, keep the 30 in there and see how it is...
your rears are automaticly going to have more grab cuz of the larger size, so if they were getting the proper ammount of fluid in a normal smaller rear brake setup then they would definatly lock up early when the weight is transfered off of them while braking....
with the 30 they will be getting a little less pressure so they wont be working to their full potential, but it should keep them from locking early
drive it like that for a little while get yourself use to it... if it sucks ass then try the 4040
like i was telling you tonight no prop valve that honda makes is goign to be 100% right for the car, because honda doesnt make anything (that i know of) with equal sized fronts and rears
the adjustable prop valve is an option, but lets be serious, this is just an autoX beater... no real need to go that crazy

cliffs:
keep the 30 in there for now.... drive the car.... learn the brakes.... if they suck.... try the 4040
 
Originally posted by E_SolSi+Jun 14 2005, 12:32 AM-->
@Jun 13 2005, 06:12 PM
i dont think itr rears are the stock 9.5's like the rest, i think they are a little bigger. not 100% sure but i could be wrong.
[post=511788]Quoted post[/post]​



yeah the ITR has 11.1" fronts and 10.2" rears

and B i agree with bill, keep the 30 in there and see how it is...
your rears are automaticly going to have more grab cuz of the larger size, so if they were getting the proper ammount of fluid in a normal smaller rear brake setup then they would definatly lock up early when the weight is transfered off of them while braking....
with the 30 they will be getting a little less pressure so they wont be working to their full potential, but it should keep them from locking early
drive it like that for a little while get yourself use to it... if it sucks ass then try the 4040
like i was telling you tonight no prop valve that honda makes is goign to be 100% right for the car, because honda doesnt make anything (that i know of) with equal sized fronts and rears
the adjustable prop valve is an option, but lets be serious, this is just an autoX beater... no real need to go that crazy

cliffs:
keep the 30 in there for now.... drive the car.... learn the brakes.... if they suck.... try the 4040
[post=511937]Quoted post[/post]​


Your last statement sums it up, do whatever if it's wrong change it.

I looked around and one of the primary reason for the bias to the front brakes in a disk/drum set up is heat. Drum brakes do not disipate the heat as well as disk. So to reduce fade in the rears there is less fluid.

Your correct that the rears willl grab better than the stock, but so will the fronts.

In your new set up, even with the large rears the fronts have even more stopping power. Your ratio of size is similar to the itr set up, just bigger. I would go with the 4040 or contact someone like Fast Brakes and get an experts opinion..... We are all using the swag method to make recomendations.
 
hmm that makes sense, but (not trying to threadjack, im stickin with the theme here) if per say the rears are a stock size, like DA rear disk's in an EF hatch that originally had drums in the rear, with either si fronts or da fronts-- would that setup benefit more from the 4040 because of the "stock" size differences between the front and rears? and because the rears arent so big that they would be prone to lock up with weight shifted off of them?
 
yes, a simple oem rear disc conversion, moving to the 4040 is the right thing to do.

i dunno...

i think i'm going to put the 4040 in there :(
 
why dont you contact fastbrakes and see what they have to say on all of this
 
Would the size of and number of pistons in the caliper determine how much fluid it needs over the size of the disc?
 
Originally posted by E_SolSi@Jun 14 2005, 11:01 AM
why dont you contact fastbrakes and see what they have to say on all of this
[post=511999]Quoted post[/post]​


email sent
 
Originally posted by pissedoffsol@Jun 14 2005, 08:25 AM
yes, a simple oem rear disc conversion, moving to the 4040 is the right thing to do.

i dunno...

i think i'm going to put the 4040 in there :(
[post=511976]Quoted post[/post]​



i would put the 40/40 on, when upgrading an integra to these brakes which already has the 40/40 would you change the 40/40 to a 30/40? i dont think so and i have never heard of anyone doing this that have done brake upgrades like yours.
 
how many other people do you know with 11" rears though?
 
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