V8hoonin

Hello fellow peoples, i recently did the ctsv brake swap with a 17/16 300zx BMC however my brake pedal feels a little stiff, I'm using a factory 240sx brake booster and I want to upgrade to a bigger one, I know ppl do the 300zx brake booster or the 240sx with ABS brake booster but I wanted to know if there was another car out there that we can use the brake booster from? Couldn't find anything online so I'm making a thread any info will help.

majgoldfish

An automatic S14 brake booster is larger too, and will give more assist in braking.
Was your car originally auto or manual?

V8hoonin

Originally manual

TheRealSy90

Are you sure you aren't wanting to upgrade the brake master cylinder? I think that would make a larger impact on brake feel than changing the booster.

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V8hoonin

Bump, anyone do anything different? Think I'm just gonna order a 300zx booster

TheRealSy90

... You mean master cylinder?

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V8hoonin

I have a 17/16 brake Master cylinder with upgraded brakes, the pedal feels stiff af so I need a bigger booster

TheRealSy90

Ah, yeah I totally skipped over the part of you already having the z32 BMC. I changed from an s13 booster to a dual diaphragm S14 booster (I believe the ABS booster is the dual diaphragm) for turbo downpipe clearance, and I do believe it also made my brake pedal feel a little bit softer. Is yours stiff just at idle or also when driving around at higher rpms? You could also try going to a smaller diameter BMC maybe? I think that would soften it up some.

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V8hoonin

It's stiff no matter what, really not liking the feel, was thinking about getting a z32 dual diaphragm booster but wanted to see if there was another booster ppl use

supersayianjim

Bumping this thread, ordered a s14 booster, but i have a z32 booster on the shelf, any opinions?

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http://www.240sxforums.com/forums/rb...ject-s-rb.html

burnsauto

this doesn't sound like a booster issues. This may be helpful to you. cts-v calipers may look great behind your wheels, be reasonably affordable, and give you the idea that bigger is better...but if the math isn't done correctly, it may be worse than the original brakes on the car. Things like vehicle weight, pad compound, tires, and driving conditions will all dictate a proper setup.

This link may contain info you already know, but may help you in your quest for better braking.

https://www.joesracing.com/master-cylinder-math/

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NiSilS14

try a 1" z32 bmc. a bigger booster may help but a bigger bmc outputs less hydraulic pressure thus giving you a stiffer pedal

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@adamcs14

slider2828

This is similar as what NiSilS14 just said. 1" or 15/16 is probably best feel.

But everyone on the right track... Its the BMC proportion you need to change. I had 1" from Z32 and felt horrible, still too stuff. Went with a 15/16 from Z31 and it was perfect.

https://zilvia.net/f/showthread.php?t=55708

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Wookie384

I went Z32 brakes and 17/16 BMC, the pedal was stupid stiff until I swapped in the dual diaphragm Z32 Brake Booster, and now the pedal feels much better. Get the the dual diaphragm Z32 booster.

e30gangsta

Here is some info from www.alphaomegaracing.com Maybe this info can help some people in this thread.

TECHNICAL / SIZE COMPARISON

Car Caliper Piston Sizes Rotor Sizes Pad Sizes Master Cylinder Size

Silvia 180sx/S13 1x57mm 52x20mm 137x53x17mm 13/16"

Silvia/200sx S14,S15 4x40mm 280x30mm 119x71x14mm 15/16"

300zx Z32 Turbo 4x40mm 280x30mm 119x71x14mm 17/16"

350z Z33 Brembo 2x38mm + 2x44mm 324x30mm 120x74x14mm 17/16"

Skyline R32 GTST 4x40mm 280x30mm 119x71x14mm 16/16"

Skyline R32 GTR (NON Brembo) 4x40mm 296x32mm 119x71x14mm 16/16"

Skyline R33 GTS25T
4x40mm 296x30mm 119x71x14mm 15/16"

Skyline R34 GTT
4x40mm 310x30mm 119x71x14mm 16/16"

Skyline R32,R33,R34 GTR Brembo
2x38mm + 2x44mm 324x30mm 120x74x14mm 17/16"

Evo 5, 6, 7, 8, 9
2x40mm + 2x46mm 320x32mm 132x77x14mm 17/16"

ALPHA OMEGA
Evo 350mm Brembo
2x40mm + 2x46mm 350x32mm 132x77x14mm 17/16"
recommended

Wookie384

OP has the 17/16" BMC already installed. No need to change to another BMC, because regardless if you're using a 15/16", 1" or 17/16" you will need an ABS/Auto S-chassis Brake booster or Z32 Brake booster. Just go to your local junk yard and pick one up, to avoid picking a wrong one try to find a Z32 one.

slider2828

Well either he has to pair a bigger booster to the MC or pair the MC to the smaller booster... Its the same in the end

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brndck

there is also a 1" pathfinder/xterra master that is useful, but it puts the lines on the farther side (closer to the drivers side fender, farther away from the engine) this is very useful if you have a turbo/downpipe right next to the BMC, but you'll have to re-do your brake lines.

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Biggoude

Hi guys,
A lil late on this but did you find answers for your question?
Does anyone know if a Z33 booster fit a S13?

I broke my booster while braking and hurt a little a bike but everything is fine for both of us fortunately.

But now I'd like to change for a new or at least not 30yo booster cause things could have been very worst if it broke on my previous brake as I was very fast coming at the red light with people :s

Seems I can't find new / aftermarket booster for S13 CA18 but there are remanufactured ones for S13 KA24, would it fit?

Have Z33 front / Z32 rear for information.
I agree with comments, way to go is ABS S13 or S14 booster (seems valve is farther than s13) or even Z32 (but it seems it requires minor modification on firewall).

If not then I guess I'll go again with spare s13 booster and lets pray it lasts.. who knows

Thanks if anyone knows

slider2828

For brake feel 15/16 z31 brake booster. You can get a remanufactured one with 3 flare insert style. Rockauto

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Biggoude

Was looking for remanufactured one, seems only Cardone brand is remanufacturing it but.. saw lot of people having issue with it..
I guess it'll be complicated to find something.
Z31 is probably fine but still 30yo booster..
That's why I ask if someone tested with Z33 booster, not very old so can be bought used from someone
Thanks for information.

NashT

I dont think the booster is necessarily your issue.
Bigger MC bore is not a great idea honestly bc you get less pressure but more volume.
Those CTS-V calipers need both- volume and pressure, especially depending on which ones your running 4 piston/ 6 piston.

Check this link before you spend anymore cash on a booster:

https://www.chasebays.com/collection...itsubishi-ae86

Also read this as MC bore size info may be helpful along with his booster recommendations (but focussed on Z32 swaps- but if your running 4 piston may indeed help)

https://importnut.net/300zxbrakeswap.htm#compare

Biggoude

Hello,
If you're replying to me then I don't understand your answer
My MC + booster broke, that's it. In fact they overheated, probably due to the header (low mount but no protection).
MC was leaking cause the plastic protection on a side just melt.
And booster broke I don't know how but probably heat too so maybe the diaphragm inside burnt, then when I pressed the brake air was leaking from the booster and fked my AFR so idle was very inconsistent.

Thanks for links but I already ordered both MC and booster from a 350z (big booster for ABS and Brembo) so I'll reply here soon if it fits well or not so people know

For information, there are 2 settings : booster size (double diaphragm or single) and MC bore size.
Both have an impact on the way braking works.
But in reality you only know when trying, theory is only theory.
My 350z booster is double diaphragm and MC is 1"1/16 si keep you posted how this setup works with my 350z front calipers and z32 rear (without ABS lines).

TheVinylKingz

I’m bringing it back from
The dead ! ....

FRONT 300ZX Break upgrade “ONLY” ———use a Z31 BMC “15/16” (Buy at Autozone $90)... or PickyO Parts ($dirt cheap)

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S13 SR, S14 KA

MrMigs

Did the z33 booster ever end up fitting?

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Cheap parts for sale: http://zilvia.net/f/showthread.php?t=534430