here:

http://cgi.ebay.com/ebaymotors/Porsche-911...sspagenameZWDVW

Think it is OK?
anyone selling a spare 19mm?

Thanks.

Works OK - but it is only needed if using 4 Piston Calipers.

http://www.smartracing.net/pdfdocs/642106_...cylinderkit.pdf

Ken

I see 1 of 2 things:

1. You running mondo calipers such as Big Reds on all 4 corners

or

2. You believe the BS ad...bigger is not always better, even his line of "tiny 17mm" is just a selling point for those that do not know better...pure marketing BS as is the norm for many eBay sellers...

Thanks.
I have SC brakes and assumed need more than the stock 17mm.
at $100 this 23mm seems cheaper than anything else I can find at the moment.

From what I have read (I dont have a 23mm mc) you will need more force from your leg to get the same braking performance with the 23mm MC.

Unless you have really big legs, it may be an unsafe thing to do...to stop quick you will need to push alot harder than before.

Rich

On our track only car, we are using a 23mm master cylinder.

We have 4-piston (930) front brakes up front, and 914-4 front brake calipers in the rear.

With this much piston area (coupled with the fact that our 19mm MC started leaking) we went with the 23mm MC.

The pedal effort required is not that great, and caution must be taken to not lock up all 4 wheels. The brake performance is excellent.

Prior to running the 930 front calipers, we used 911SC fronts and 914 fronts in the back with a 19mm MC. The brake pedal effort was probably slightly less with the 19mm, but not that noticable. The pedal with the 23mm MC is definately not as firm (hard pedal) as the 19mm was.

In my current 914-6 conversion (911 Carrera fronts & spaced 914-4 rear) I will use a 19mm MC. I should have a good firm pedal with those piston areas and pad sizes.

I would only use the 23mm MC with 930 or bigger calipers (the reason to use such a large MC is to move a large amount of brake fluid).

just my $0.02

I have used 17, 19, 23 and if you really NEED to stop you cannot tell the difference.

I would stay with 17 or 19mm for a street car. The 23mm conversion requires brake line mods as well as peddle push rod changes.

Re-build your MC ??

Ken

So basically my old 17mm could work, a 19mm would feel better....
23mm might be overkill (unnecessary) only may lose some pedal feel.

I sent an email to the ebay seller to confirm it is an aftemarket brand.

Cobra94563:
I have a 19mm listed on E-Bay now,item number 8051437312 new. Dave

QUOTE (cobra94563 @ Mar 30 2006, 01:35 PM)

So basically my old 17mm could work, a 19mm would feel better.... 23mm might be overkill (unnecessary) only may lose some pedal feel. I sent an email to the ebay seller to confirm it is an aftemarket brand.

If you're still using stock calipers, the 17mm will work fine, though SOME people don't like the relatively long pedal travel required. The 19mm MAY feel better, in that you don't have to push the pedal as FAR, but will require you to push HARDER to stop. The 23mm will require you to push VERY hard to get good braking force, and the pedal will basically not move at all.

I have a 23mm on mine, but I have 930 calipers front and rear. Car stops great. And I have hand brake, too. That came from 911sc. Of course I have a great mechanic friend.

The 23mm master cylinder that Johnman refered to is an ate unit made for a Merc. It bolted right up, and except that it was a little longer and bigger in external diameter, it was an easy install. I will have to look, but it was under $200 and I got it from a p-car guy from the east coast somewhere.

Dale,
Your description sounds like the unit on ebay...Made by ATE, 23mm.
I tempted because it is $110 shipped.

I bought my 23MM from Smart Racing. Their kit comes with a longer rod and an extended line for the master cyl. It was $151.51 plus shipping. Going to install this weekend. Here is the link
23 MM Master Smart Racing

van914

QUOTE

It bolted right up, and except that it was a little longer and bigger in external diameter, it was an easy install.

Easy install....

I put it in and it was somewhat easy. The brake lines (from the reservoir) need to be re-bent and re-routed to clear the steering rack, the steel front axle tube needs a dent in it to clear the longer master cylinder (it fits aluminum front axle beams just fine), and I believe that the brake lines themselves need some tweaking to line up with the outlet ports on the 23mm MC.

The actuator rod also needs to be somewhat longer. I took a long bolt, ground the head off to a round ball end and used that.

The "kit" from smartracing comes with the longer rod and a 90degree plastic fitting to make connecting to the reservoir easier.

It sounds like a good price if you are willing to make your own actuator rod and fight with the brake fluid feed lines a bit.

Do not do this with stock calipers!!!!!!!

I wish you the best of luck.