source for 23mm master cylinder, who know the p/n Options

[davep]

Rich is correct about the 20mm. It was used on the 69 911S and pretty much everything that used the aluminum "S" caliper except for the 930. I still have a rebuild kit left for mine.

DaveP

[KenH]

You may have to use the alloy cross member to get the MC to fit.

Throw away the plastic tubes from the reservoir and fit in the "blue hose" from Pelican. Make everthing a LOT easier.

Ken

[ArtechnikA]

You may have to use the alloy cross member to get the MC to fit.

mine fit fine with the stock 911/914.6 suspension crossmember. i think i had to twist the metal feed tubes to an unusual orientation but it basically fit right in...

[givory]

Well, I'm going the other way: I was talked into a 23mm MC for my vintage racer with "S" fronts and "M" rears. Now I'm going back to a 19mm. I'm sure it took 600lbs of leg press to stop the car. The upside was I never locked the brakes. [And in my case, I too had to swap to the aluminum cross member to make it fit.] Has anyone else got any experience with this, or do I need more time in the gym??

Gavin

[ArtechnikA]

... I'm going back to a 19mm. I'm sure it took 600lbs of leg press to stop the car. ... in my case, I too had to swap to the aluminum cross member to make it fit.] Has anyone else got any experience with this, or do I need more time in the gym??

what kind of crossmember did you have before ? /4 or /6 ? i have no experience with 23's and /4's ...

what kind of brake pads were you using ?
i was using factory early 930 pads front.

you were using ventilated disks on all 4 corners ?

i never had a problem with excessive pedal effort, nor did my ex-, a woman small in stature...

IMO/IME, the biggest issue with the 19mm MC was running out of hydraulic capacity once everything got hot in a DE track session. if you don't experience this, the 19 sounds like it'd be a better match for you. most of us didn't automatically pitch the 19mm MC, although for me, there was a certain 'ALA' aspect to it (ALA i'm replacing all this stuff and the brake system is open and i have to bleed everything, i'm gonna put in the end-all and be done with it ...)

i'm not fixated on a certain 'set-up' selection of parts - use what works for you.

[TimT]

Both my cars have the alloy crossmember, Im working on a 935 type set up using troyer lower control arms and some other oval track stuff. This set up will use a crossmember made from some 4130 1.25 in sq tubing, so clearance should not be a problem.


Does anyone else have experience with the 23mm master? with big brakes?

[givory]

what kind of crossmember did you have before ? /4 or /6 ? i have no experience with 23's and /4's ...

...though I didn't put it in, I'll assume it's a \4 crossmember. It was only a matter of needing less than a CM more room.

what kind of brake pads were you using ?

... still on stock-type street pads [German brand - forgot the name]. Our home track [Mosport] is fast and open - easy on brakes. Races are short, often in cool weather. So I was more concerned about having brakes that worked cold on the first lap. Fade was never a problem. But I have ordered Hawk Blues.

you were using ventilated disks on all 4 corners ?

...yes. But I will go to solid rears when they wear out, to comply with the vintage spirit!

So maybe it's the street pads? It just seems there should be more pedal travel, and less effort. Fortunately, MC's are cheap - unlike almost everything else to do with this hobby - so I'll try a 19mm and report back.

Thanks,
Gavin



Gavin

[ArtechnikA]

So maybe it's the street pads? It just seems there should be more pedal travel, and less effort. Fortunately, MC's are cheap - unlike almost everything else to do with this hobby - so I'll try a 19mm and report back.

no, i don't think so. i don't mind a stiff pedal if the car is slowing down. hard pedal and no braking is a lose-lose situation!

i was wondering if you were on very hard racing pads (the infamous Ferodo DS-11, for instance ...)

soft street pads should give you very good braking, especially on cold rotors. the pad game is completely different than it used to be, so i have no contemporary experience (yet!) with the new exotic composite compounds. but it used to be that the claim to fame of the harder racing pads was that they didn't fade when hot, not that they necessarily stopped better, they'd just give you what they had, all day (at a commensurate cost in rotor life...) i know the new carbon and Kevlar compounds have changed this equation somewhat...

but i remember seeing an interview with a NASCAR crew chief that presented an interesting viewpoint. he was using soft pads for their fade-resistance. turns out their ability to slow the car was lots better than hard pads, so the car could be slowed later (more time on the gas) and harder (outbraking opportunity). that meant the driver could get -off- the brake sooner, and leave more time for them to cool.

if the net energy loss is the same, the more time available to cool the brakes will make them more fade resistant... kind of a win-win situation.

the tradeoff, i'm sure, is higher peak temps, because the net energy loss is -not- the same (you've spent more time on the gas, so yor corner entry speeds should be higher...) and since you're absorbing a lot of energy in a short time, the peak must be higher if the area under the curve remains the same. but the new pad materials seem to permit this.

interesting times indeed...

we'll do the first AX's and DE's on the pads i've got, but i'll be taking a spare set, and i'll need to do some research on what the best compromise pad is for the environment.

[otto]

Test Photo upload

[davep]

So what, exactly, does this photo show?
Enquiring minds want to know!

[steve@ottosvenice.com]

Thats our rebuilt caliper done in black and red polymer Mil Spec finish Steve

[rick 918-S]

Thats our rebuilt caliper done in black and red polymer Mil Spec finish Steve

Hey Steve, Is that a stock 914 caliper? Looks nice.
All you guys out there adding big brakes use caution. Dont forget, big calipers and vented rotors add unsprung weight. If your car is stock with stock wheels and maybe just a plus one size tire your stock brakes should be great. Where you get into trouble is when you start increasing the centrifical mass. (much wider, taller tires with a greater contact patch) a small diameter rotor will require more force applied. Not to slow the sprung weight. That didnt change. The additional force will be needed to counter the spinning mass of the over size tires and wheels. More HP doesnt require more brakes if you just ad more HP. The Brakes are not on the engine flywheel.

flame on guys.

[ArtechnikA]

More HP doesnt require more brakes if you just ad more HP. The Brakes are not on the engine flywheel.

flame one guys.

the presumption is that the HP will be put to use by making the car go faster.
if the purpose of additional power is -not- to make the car go faster, what is it ?

flame one what ?

[rick 918-S]

More HP doesnt require more brakes if you just ad more HP. The Brakes are not on the engine flywheel.

flame one guys.

the presumption is that the HP will be put to use by making the car go faster.
if the purpose of additional power is -not- to make the car go faster, what is it ?

flame one what ?

80 mph is 80 mph. The added hp will get you to 80 mph faster but your still only going 80 mph. If you havnt changed anything other than your ability to get to 80 mph in a shorter distance there is no need to ad big brakes. In fact because you now can get to speed faster you (= shorter distance) have even more time (= greater distance) to stop. When you start changing the things that increase traction, cornering grip, increasing weight sprung and unsprung, etc. thats when you need to be concerned you've exceeded the engineers design. Unless you just like bigger brakes. (IMG:style_emoticons/default/confused24.gif)

I ment flame on! (IMG:style_emoticons/default/laugh.gif)

[ArtechnikA]

80 mph is 80 mph. The added hp will get you to 80 mph faster but your still only going 80 mph.

i see.

so we don't really need better brakes -or- more power.

[rick 918-S]

80 mph is 80 mph. The added hp will get you to 80 mph faster but your still only going 80 mph.

i see.

so we don't really need better brakes -or- more power.

Add all the hp you can. If your doing it with the stock 4cyl. The stock brakes should be good to go. If you like big brakes with the ability to lock the wheels and slide like your on grease go for it. Look at the simple example of the 4 vs the 6. 6 added hp true but it added wieght, wider tires, heavier suspension. Porsche added the 911 brakes to compensate.

[seanery]

More speed = More brakes.

It doesn't matter if you have a 110 mph car and drive it at 110 mph all the time you'll wear out your brakes whether it's a 4 or 6. Bigger brakes offer some peace of mind, too.

I'm all for a brake upgrade if circumstances call for it. IMHO any -6 or larger should upgrade brakes in some manner dependant on driving style/use of car.

[d914]

has any one used a tilton mc, keeping in mine that I'm NOT the master fabricator.
I have one thats close to the 23 in size with remote res.

[0396]

To all,
Brad is setting me up with a 23 m/c .I should jhave it by next week?

Brad and I have discussed this a few times regarding 19 vs 23 and since I have a full set of Big Reds via Race Technologies, Brad agreed that 23 is the way to go IF one has these big brakes.
There are a few mods to be made...inlet tube / clearance and
a longer rod.

To my knowledge, Brad already has this under control.
Mybe Brad can chim in on this topic. (IMG:style_emoticons/default/cool.gif)

[Aaron Cox]

Hey Steve, Is that a stock 914 caliper?

has one bleeder valve. i believe its an m caliper, (i dont see the spacer tho (IMG:style_emoticons/default/idea.gif) ), or a stock 914 caliper