So I am planning on the following brake setup for my 98 Civic LX:

Front:
-11.8" Prelude rotors
-23T bracket milled
-ITR calipers

Rear:
-9.4" Si rotors
-Si calipers

I am trying to figure out if I should go with a 1" or 15/16" master cylinder? Also, is there a mc that I can use in conjunction with my stock civic booster?

 

I would prefer not to have to bend up new brake lines, I have heard the 98-01 integra master cylinder will bolt up to the stock booster without having to move the hard lines?

 

It boils down to how stiff you want the pedal. I've got a 1" MC and I have no issues whatsoever with my 10.5" rotors and S2000 calipers. I would honestly recommend the 1" MC considering that's what the ITR came with (IIRC)

Leave the brake booster alone.

Correct, you need a MC from a 98+ integra. Will bolt right on with no need for adjusting the hard lines. The 1" MC was also from any ABS integra from 98+ too, so you don't have to look for an ITR MC. Just look on ebay and make sure that the brake lines go to the right places in the pictures on whichever ones you find.

I think I got my MC for like $75 on ebay. People want like $150 sometimes for an ITR MC when the ABS integra is the same freaking part and are a dime a dozen at junkyards.

 

Thanks a lot! Im going to probably buy the mc and 40/40 proportioning valve off the fleabayz.

As far as the 40/40 prop valve, only the ones from the DX, HX and Si will work correct? IIRC the EX unit had a different part number.

 

You do not need a proportioning valve.

 

I am doing a drum to disk swap, wouldn't the stock proportioning valve cause the rear wheels to lock up faster with the rear disk conversion?

 

Nope. I didn't need one. I changed from the teeny-tiny DX fronts to s2000 calipers/cougar rotors, and at the same time to integra rears. Brakes perfect.

And BrakeExpert (Mike) has had everything on his 97' Sedan from NSX front/rears to Ferarri Front brakes, cadillac brakes, etc and has never found a need to change the prop valve.

Trust me, you don't need one.

 

From what I know you do have to upgrade the prop valve if you have 96-00 Civic EX, some people say you can get away with using the stock one, but the upgraded prop valve would be recommended. I believe the LX shares the same prop valve as the Si and HX. Dont want to thread jack you, but I have 96 EX with the rear disk brake conversion. Till this day i havent changed the prop valve yet and let me tell you that my braking is shitty!!!! Its bad when your DD, which is my automatic Integra LS brakes WAY better than my 400+hp civic!!! So what OEM Brake booster and MC combo can i go with to have optimal braking in my car?? Oh and here is a good link I found that may answer your prop valve question.

http://www.d-series.org/forums/suspe...ion-how-9.html

 

In your case the 99-00 si prop valve would be the way to go.

To the OP, if you go with the 1" integra master you will also want to use the integra booster. The civic one will work, but from experience the brake feels WAAAY better after swapping the booster. If you use the 15/16 master you will keep the civic booster but your pedal throw will be slightly longer.

Another tidbit: if you have a 96-00 hatchback your proportioning valve is the same as the 99-00 civic si. That is why Libertariat didn't have to change his prop valve. If you are swapping rear discs on a coupe you will want to change to an SI prop valve.

 

somewhat true. any 96-00 civics with the smaller 9.5" front brakes and rear drums have the same prop valve as the si.

 

Thank you for the correction.

So its safe to say if your car came with 9.5 front rotors and are doing a rear disc conversion with larger front brakes also you will not need to change the prop valve.

 

Like I mentioned above, I have a 1998 Civic LX (4Dr) and I'm pretty sure I need to upgrade the prop valve. Cruizinmax, youre right that Libertariat has the same prop out of the 99-00 Si.

Also Cruizinmax, would I need to rebend the brake lines if I switch to the integra booster? And what do you mean when you say the brakes feel way better with the integra booster vs the stock one?

Thanks again everyone!

 

We have the same prop valve:

46210-S04-902 DX/LX/GX/HX/CX/SI
46210-S04-962 EX (non-ABS)
46210-S04-852 EX (ABS)

 

Hang on, so drum models have the same prop valve as the disc models? So far as I know, drums require a lot less pressure than discs, plus there needs to be some kid of residual pressure valve?

 

BrakeExpert has been doing wild-*** brake setups on 92-00 Civics for over 5 years now. Of the 44+ setups he's made he says he sees no purpose and couldn't tell a difference for swapping out the prop valve on any 96-00 he's worked on.

The 92-95 is different, there he says you must have the 40/40 prop valve.

 

I think the only exception might be the 96-00 civic EX. Its the only one from honda with the different prov valve part number.

 

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


look at the part numbers. The LX does run a different prop valve based on part numbers. What the exact difference is? I don't know.

 

If you use the integra master with the square reservoir (I think its 98-01) it is completely interchangeable with the civic one. No need to bend lines or anything. The integra booster for those same years is also interchangeable with the civic one.

What I mean by feels better is it require less effort to push the pedal and is more linear. The integra master and civic booster felt like under very hard braking the booster ran out of assist. You could feel at 90% braking the pedal got very hard. Almost as if the brake pedal was hitting the floorboard, to get that last 10% of braking force took significantly more effort. Swapping to the integra booster totally changed that feeling. On R compound tires it wasn't possible to brake at the tires threshold, now this is never an issue.

 

Does he frequent these forums? I would like to question him on this, all the technical stuff I have seen on this subject suggests drums and disks have completely different pressure requirements so to say that they use the same proportioning valve seems a little strange.

If he is going to make that kind of statement, then I would like to know the tests he conducted to come to that conclusion. Has he actually tested the brake force available at the wheels, can he confirm that a disc swap with a drum prop valve develops the right bias under threshold braking? That would be conclusive proof that the props were the same. Short of that then frankly, I don't believe him.

 

You're exactly right, they do have different pressure requirements. Drums require a LOT more pressure than disks do. That doesn't mean you need a new prop valve though. And no, he doesn't visit any forums that I know of.

I can tell you exactly what kind of tests he's done: Fabbing 44+ brake setups for DX/EX knuckles, anything from Ferrari brakes to NSX fronts/rears and he's never even remotely thought he needed to change the prop valve on his 97 LX. He doesn't race his car, but he does build brake setups for a few shifter cart and HPDE teams that have dedicated track cars. His 97 LX stops on a DIME. He can literally put your face on the dashboard. I've ridden in his car. The first time I rode with him he had Ferrari F430 brakes, the second time he had switched back to 2000 NSX brakes since he liked them better,

Look, I've got the same Prop valve as the OP does and the same prop valve that BrakeExpert has in his 97 LX.

I've put 15,000 Miles, 10 autocross events, and 1 autocross school on radically different than OEM brakes and the car brakes amazingly.

I've got s2000 front calipers and integra rears. If I needed a new prop valve to get maximum braking performance don't you think me or the half-dozen autocross vets I've let drive my car might have noticed?

Why are you so adamant about spending money/time replacing your proportioning valve when myself, my brake guy, and many other people have done brake conversions on 96-00 and not swapped the prop valve.

Have you already got a new prop valve and feel slighted? You don't need one.

 

I have a full disc setup as stock, no modifications other than brake pads so no need to change anything at all. I'm not biased or trying to justify anything. I'm just sceptical of fabricators that dish out opinion as fact, that's all.

The physics says that the pressure requirements are different, so I just do not understand how you can swap from one brake type to another and not change the prop valve. You have it the wrong way round by the way, discs require higher pressure (think of how useless handbrakes are with discs vs drums. Same force applied by your arm, far less effect at the tyre), so in all likeliness retaining a drum prop on a disc conversion will see the rear brakes doing far less work than they could be. Sure it will work, the same way putting thumping great rotors and calipers with race pads on the front then chucking pattern part rear pads on the piddly rear discs. It will stop you just fine, and if you're happy with that setup then great, loads of people are.

Is it the best though? Probably not.

 

What part of my personal experience is opinion? I've been running this setup for over a year with NO PROBLEMS.

And you're right, I did have ti backwards. Either way, it works. All I'm saying is it's NOT NEEDED for good braking performance. How much do you think you stand to gain by pushing more fluid to the rear brakes anyway? If that's what you're trying to do?

A lot of pro-class autocross guys and HPDE people run drums in the rear for the very reason that rear brake bias is really a non-issue for hondas as the performance gains are very minute whether you swap the prop valve or not.

I've never said that the prop valve would harm the braking setup, merely that it is purely unnecessary.

Also, the conventional wisdom is that if you have too aggressive of a pad on a typical honda, you lock up the rear brakes. I've almost never seen anyone recommend aggressive pads in the rear for that very reason. It's like the people who worry about the rear inside tire lifting in a turn. How much effort should you put into keeping that tire on the ground? None.

Edit: Here's what BrakeExpert says regarding rear prop valves:

 

I didn't say it would cause problems, it would only under work the rear brakes. As you say, the drums are plenty effective enough, so it seems nonsensical to go to all the effort of a disc swap, then render the whole lot worse than stock by giving them the wrong line pressure.

BrakeExpert has a hold on the residual pressure function, but still makes no mention of the actual pressure metering the valve does.

 

Good discussion so far. Well hopefully I'll be putting it to the test this weekend. I just purchased 40/40 prop valve off a 99 Si to put on my 96 Ex with rear disk brakes. Like I stated earlier in the thread, my braking is not the greatest. So ill put the new prop valve on and let yall know if it did improve my braking.

 

I'll be looking forward to hearing your results. If you like the results I may be tempted to source an Si prop valve

If you would, take a passenger along before and after.

Do 5-10 60mph-0mph stops with him using a stop watch. Have him/her start the watch on reaction and stop it on full stop.

Then swap out the prop valve and compare the results.

I hope you have sticky tires and can avoid locking them up.