23mm Master Cyl. Upgrade??

[magistro]

I'm in the process of upgrading my master cylindar to a 23mm of M-Benz type in my 914 race car (Boxster Calipers front & rear). It appears that the actuating rod at the brake pedal is approximately 20mm short. Does this rod/plunger have this much adjustment? If not, has anybody come up with fix to make new larger master cyl. work??? Thank you.

[John Rogers]

I had to make a new extension for mine when I installed a 23mm M/C. I used a barrel nut and a new piece of rod and so far it has worked for two years w/o any troubles. I tapered the end that goes into the M/C so it was pretty close to what the original had and it has not worn any. Good luck.

[rice_killer]

explain this 23mm mc please. my stock master yl is in need of a rebuild and i would rather upgrade to a bigger one.
which MB MC fits a 914??

[campbellcj]

Originally posted by rice_killer
explain this 23mm mc please. my stock master yl is in need of a rebuild and i would rather upgrade to a bigger one.
which MB MC fits a 914??

You probably know this, but most folks say you don't want a 23mm M/C with stock 914 brakes...even most of the 911 brakes, and the BMW 320 calipers, are fine with the 19mm flavor (stock 914 is 17mm). The 23 is best matched to the really big brakes (4-piston kinda stuff).

[rice_killer]

ahh well nm then, i have bmw's in the front.

[john walker's workshop]

part #002 430 9301. you will have to fab a tight 90° filler pipe for the frontmost fluid inlet. no more firewall flex, as it butts up tight to the crossmember. last one i did was on a race car with 911 aluminum S fronts and BMW rear calipers. firm, high pedal.

[roadtrp204]

For those that think a bigger master cylinder alone is an upgrade, read this article and understand it. www.pelicanparts.com/techarticles/914_BMW_calipers/brake_calc2.htm

There is a balance ratio that needs to be maintained for you to be able to exert enough force on the brake pads.

Moddification of the braking system without proper knowledge is playing with yours and the lives everyone else on the road or track around you!

[rice_killer]

roadtrp204, thanks very much for that link, it solved alot of questions i had.
i awalys knew i would need a bigger master cyl for the bmw brakes, but i never heard of a Mb Mc being used before, as is why i asked.
sence i need to rebuild my mc anyways, i will just buy a 19mm one from pelican.
thanks everyone.

rebuild kit alone is $55 and a new rebuilt 19mm mc is $100 so its worth it.

[John Rogers]

On our nearly stock 914 I went to BMW calipers on the front and to maintain the same pedal feel, I had to use a 19mm M/C. The same on my race car, but then I used BMW calipers on the rear of the race along with the front and the pedal went about 50% before it became solid. This was with corerct rod to piston clearance and a tee installed. That did not feel real well with me so I used the 23mm M/C and there is about an inch of pedal travel now and it feels very similar to our 1987 930. I have talked to several others that have done the same thing as I did and they are all happy. On a stock calipered system a 23mm would make you really have to stomp the pedal to get the correct stopping power. Good luck.

[Eduardo Castrejón Elbjorn]

And what about with A calipers front and stock rear ?
which master cylinder is the best
Thanks

[Dave at Pelican Parts]

I would suggest the 19mm M/C, even with A calipers in the front. The 21mm one would be another option (another M-Bz part), but I think the 19mm one should be sufficient.

It also has the advantage of being easily available, and relatively cheap.

--DD

[oredith]

Does anyone know the part # for the 25mm audi M/C's?.. i believe i will be needing the 25mm to move the Volvo 4 piston brakes i have in the front, and the M-calipers in the rear.. the 23mm will probably -work-.. but i think i'll get a lot of pedal travel before it firms up..

that, or i'll just have to dish out the dough and buy the tilton dual M/C.. :|

TIA,