Brake booster/master discussion
 

So I have picked up some miata boosters and masters. Currently I have these (Stock 1.8 brakes):

Boosters:
NA/NB1 booster (lowest ratio)
NB2 non-sport (highest ratio)

Master:
7/8" NA/NB1
15/16" NB2 (didn't do anything with this, but I can try it on something if anyone is really interested)
1" Wilwood master
1" 929 master

After getting the 1" Wilwood and struggling with it on the NB1 booster(worked great on low grip tires, but got really difficult to threshold brake and do anything else with 205 NT-01s), I decided to pick up the others to try out new combinations:

-1" Wilwood is basically "plug & play" with the NB1 booster. The push rod is long enough to adjust into it just fine and the booster is sealed without the master, so there is no issues there. I have seen the 1" wilwood installed on some cars, but I have a hard time believing its using the NB1 booster without changing the pedal ratio or putting in larger calipers maybe...

-1" Wilwood was not so easy with NB2 booster. First the pushrod is much shorter on this booster, and I couldn't find pushrods anywhere online. I considered making one, but abandoned this due to a lack of properly sized acorn nuts (I may have found some on e-bay). Second problem is the NB2 booster is NOT sealed, so you have to figure that out. I think a gasket on the outside will work, but there is a stamped slit there that will need to be sealed independent of the gasket. The 1" wilwood's bore (on the outside, ie the part that fits into the booster) is too small to get an o-ring for it, but you maybe able to ghetto that... Has anyone gotten this combination to work?

-1" 929 master works for the most part on our car with the NB2 master. only issue I noticed is the front port is normally expecting a banjo bolt, but my brake line was a flare nut type. I didn't realize this wouldn't work well until I took a look in there and noticed the port is flared in the opposite direction (so the port looks like < and the flare nut looks like ">", but smaller). Tightening this down a lot seemed to stop any leak, but will that hold? is there a particular flare typethat works better (I think the ISO bubble might...) ? If so, did you buy the line or have to flare it yourself?

If anyone has suggestions/comments, please share. Also, share your experience with different combinations that worked well. I know a lot of people like the sport combo (middle booster + 15/16" master), but I figured that was due to simplicity more so than anything.

Once the air is out of the lines and the caliper pins arent jammed the ABS MSM master and booster feels decent the pedal is longer and softer than the NA setup. But that could be due to the ABS.

I'm going with the 929 master -- have one sitting on the bench.

Mazda sells the banjo adapter, part # towards the end of this thread:

Some interesting brake information (tech!) - Page 6 - MX-5 Miata Forum

It also shouldn't be too hard to get from a junkyard.

--Ian

Thanks for the help Codrus. I tested out the 929 master at CMP this weekend. It worked great, but as I suspected the larger booster maybe a bit too much for 205 NT-01s.

anyone have suggestions for sealing the NB2 booster with a 1" wilwood master cylinder?

949 has a bracket for it, is that what you're talking about?

Miata Race Master Cylinder kit

--Ian

no, not really. The bracket is only for mounting it on the booster. Sealing the booster is different. If you look at the 929 booster, it has an o-ring on the section that fits into the booster. That seals it so you don't have a vacuum leak:
http://ecx.images-amazon.com/images/...L._SL1500_.jpg

The wilwood 1" can't do that, because the section that would have the o-ring is not large enough for the 01+ boosters. The NA/NB1 booster works fine because its sealed without the master. Look at these two pictures, you can see inside the NB2 booster, while the NB1 has some kind of crimped/stamped piece.

NA/NB1:
http://ecx.images-amazon.com/images/...L._SL1500_.jpg
NB2:
https://www.miataturbo.net/attachmen...ine=1404733470

But doesnt that bracket cover the whole hole enough that you could RTV it together and have it seal?

yea seems so, just wondering if anyone has found a less ghetto way of doing it. plus you gotta pack that little gap with a sealant too.

might be over thinking it on my part.

Email Emilio and ask what they recommend doing with the 949 kit?

--Ian

I run the 1" willwood master with the nb1 booster. I also run sport brake fronts and 1.8 rears. XP10 front / xp8 rears.

I like the pedal throw and feel quite a bit, very firm. Granted I don't run as sticky of tires as you do (rivals vs your nt01's) so I haven't noticed hte issues you site with the sticker rubber and grabbier pedal.

My guess is that the sort front brake piston surface area helps tame the nb1/1" master feel down a bit making modulation easier. Just a thought.

well there is two things different (I ran the 1" wilwood on my 205 AD08s and it worked great, so I second that):

1) I have the non-sport calipers, so my caliper area is smaller (making the pedal firmer)
2) I am currently running xp8s which are really out matched by the NT01s. Higher fricition coefficient will require less line pressure for the same stopping force.

I do agree though, I am planning around with less than ideal setups. I think the 1" wilwood with the NB1 booster will be what I finally stick with. I am shopping pads right now and forcing myself to try a new brand as I have been using carbotechs for a long time now. DTC-60s are on the list, possibly HT-10s or PFC01.

I do think its worth while to figure out if there is a clean way to mount the wilwood on the NB2 boosters. Its nicer overall and the bleed screws are easier to get at. The 929 has something there, but I am not sure how to use it. I may put something together, but probably not in the near future.

I found the 929 master w/ larger booster to be pretty amazing too. I will revisit that setup in the future when I move up to a gripper tire.

Btw, forgot to respond to this. e-mailed emilio about it and his answer was "we did it". No details on how really.

In any case, I settled on the Wilwood with the NB1 booster. The ratio is VERY comfortable with DTC-60s on NT-01s. To add, the pedal is at the right height to be even with the gas pedal at/near threshold braking. I drove a buddies 94 miata with stock brakes and XP8s and wondered how I ever heel-toed with that.


In generally, I highly recommend moving to a 1" master cylinder for track driving.

I went with the 929 master on MSM booster. The dual banjo "N069-43-800" is no longer available. I double stacked the stock Miata banjo fitting and used a longer banjo bolt that was made for doubles. This ended up working better for the brake lines anyway as I now had more options to set the line position.

Are either of you using a non-ABS 929 master with 3 outlets? Raybestos/Dorman claim to have a non-ABS version, but says it still has 2 outlets, so I'm somewhat confused.

I am using the 929 master, but I put ABS in my car so I only want 2 outlets.

http://www.codrus.com/abs/929master.jpg

If you want to run it with a non-ABS setup, probably the easiest approach is to put in a tee. FM sells them.

Flyin' Miata : Chassis : Brakes : Metric brake tee

--Ian

I have two outlets out of the 929 master. I also have a tee, just like the one from FM.

I'm bumping this from the long dead because I can't find hardly any discussion or followup...

I've got an NB2 car (and booster) and trying to install this 1" Wilwood mc on it and running into issues.


Any insight or followup here?

I've been chasing down stuff lately too. I have an NB2 ABS Sport car and the pedal feel is pretty garbage compared to my fiance's track car (NB1, stock master and booster). Would really like a firmer pedal with less travel, just trying to sort out the right path forward for it.

fwiw - for sake of ease, I'm going with the 929 master...

ABS car or no?

1" 929 master would reduce the travel (moves more fluid per unit of travel than a 15/16) and bolt in place of the sport master with some relocation/fabrication of lines. Feel is a personal thing, so its best to plan on trying a few options to get it where you want.

I found a way to seal the 1" Wilwood master to the non-sealed brake booster. I was walking through Lowe's looking for things that might work and came across a toilet tank flapper. Sounds weird, I know, but it works. You'll have to cut off the chain (cut out entire ~1"circle) and remove the foam inside. Don't cut the other side as this will help create the seal. Put the cut side toward the master and the uncut side sticking out into the brake booster. This may sound confusing but I can post pictures if needed. Hope this helps! Link below if you want to go try it yourself.

https://www.homedepot.com/p/KOHLER-R...3064/202524246

Linky no work. Damn vigilink corupts it : kohler gp83064

There ya go. I heard you were able to seal the Wilwood master cylinder as well. Did you use a similar method/material?

Can you send pics of this seal set up please? I have Nb2 svt booster and wilwood master cylinder. I have modified the rod so it just pushes on master cylinder just when brake is applied but I have vacuum leak from booster and no assist.. with the method above, does this seal around the push rod? Do you need alot of Hondabond or similar gasket sealer?

I have the stock na 1.8 booster with wilwood master cylinder for now as it seals fine but I do not like the feel.

Any help appreciated. Thanks

We did not. We just recommend switching to a non-sealed, non-ABS booster if you have an ABS car and want to run the wilwood kit.

NB2 non-abs car with the 1" Wilwood with V8R adapter plate.

Sealed with RTV around the adapter plate to the master, then around the adapter plate to the booster, just around the hole (RTV not shown in this pic mind you).

https://cimg7.ibsrv.net/gimg/www.mia...768d39e0af.jpg

Thanks for that, I made up a gasket for either side today and used RTV . All working now. Thanks
https://cimg3.ibsrv.net/gimg/www.mia...17580b9da3.jpg
https://cimg1.ibsrv.net/gimg/www.mia...3697efae89.jpg

Any sort of mechanical practice like using a sealant like RTV on a component like a MC is a poor idea. There is a reason the engineers used a o-ring and not a gasket. The forces the booster has on the MC is trying to split the MC and booster apart. With enough time the flex on the components will cause the seal to fail. My 1" MC kit has bracket has noticeable flex even with a brace when I'm on the brakes. Be cautious, you don't want to just loose assist when you need it.