Question about Big Red brake conversion on early car.

pjv911 · pjv911's Garage

Well the time has come that I will begin assembling my 69` 911 project car . I will be starting within a few weeks . I have allready aquired a set of big red brakes with the correct adapters , rotors and hubs . What I dont have are the correct flexable brake hoses . Wouls anyone here happen to know which ones to buy and where ? I want to buy these asap . Im trying to make sure I have everything before I dig in . I was going to pm Bill Verburg but figured he is likely getting tired of repeat brake questions . I have allready tapped his brain a few times in the past . Anyone know ?

Kurt Williams

BTW here is few pics of the struts and brakes in case it helps any.

Jeff Alton · 01-29-2006, 03:06 PM

My guess is that VCI could help you out. Brembo supplied me with Goodridge hoses with my GTP kit which uses a similar caliper design...

Cheers

pjv911 · pjv911's Garage

Im just so lazy I was hoping to get a part # or order # . By chance do you know if there are different options . By all means I want DOT approved hoses . Would actually prefer rubber oem type but braided ss lines would be ok too .
I was also wondering about my master cylinder situation . I was told by Kelly Moss Racing (where my brakes and suspension came from) that I might want to retain the orig 19mm master and see if I still have good pedal feel . I was told that there is much more feedback and pedal control with the 19mm over the comon 23mm upgrade . Any other opinions ? I did buy the 23mm unit just in case but .......

Kurt Williams

mjshira · 01-29-2006, 03:20 PM

I do know you'll need to run some spacers to make these fit, 17 inch wheels too. Bill is the man when it comes to these questions. I have also been told that 930 brakes are the more "natural" swap as they'll fit under older rims.

good luck

pjv911 · pjv911's Garage

I have HRE 540 series wheels to handle the clearance issues .

Jeff Alton · 01-29-2006, 03:31 PM

MHO is that the 19 will be too small. I used the 23 on mine and it was *just* okay. mind you I have 40/44 pistons in the front, I went to a Fabcar twin mc set up.........

Call Steve Wiener at Rensportsytems, he will probably have the lines on the shelf.

Cheers

North Coast Cab · North Coast Cab's Garage

Kurt,
The flexible brake lines do not need to be changed, although you should have already upgraded from the rubber to the stainless lines. What youo need is a diferent hard line that goes from the flexible line to the caliper. The size of the front calipers look like Big Reds, but the brake fitting looks like the one off the 928S4. Can you clarify the caliper? If it is a Big Red, or 993 Big Black you can use a standard Napa M10x1.0 line and bend to suite. If it is the 928S4 you need the banjo type fitting with the bolt that has a hole in it. I believe those are M10x1.0 sized as well. You can search the internet for a source for those. One foot will be the perfect length.

John

pjv911 · pjv911's Garage

Thanks Jeff . I will find Steves # and call him tommorow . I would also welcome anyone else opinion too . I too think the 23mm is the way to go but was also considering the twin master setup as you use . I should note that this car will be used on the street . And my pedal cluster is the 88/89 carrera type for use with the G50 tranny . Where did you buy your master from and is it street car friendly ? I will have more weight in the back than desired because the engine/tranny combo is much heavier than desired (C2 Turbo/G50) . Im afraid I will need a little more bias towards the rear brakes . The twin setup offers excellent bias adjustments , right ?

Kurt Williams

Jeff Alton · 01-29-2006, 03:55 PM

Well....................... I have the fabcar one that I got from SRP. It is a little pricey but works like a hot damn. You can change cylinders fairly cheaply and it has a bias adjuster as well. It is non-power so it needs a heavy push on the pedal, but I love the feel of it. That could just be me, some folks may hate it, I don't know. The pedal is rock hard and easy to modulate. The late G50 pedal cluster may create an obstacle or two, not sure on that though.

Steve's number is 503.244.0990

Cheers

patkeefe · 01-29-2006, 03:57 PM

Kurt:
I have some S4's in the garage, but I'm too lazy to go look at the line sizes
Pat

Jeff Alton · 01-29-2006, 03:57 PM

Here is a couple of pics of the MC..

cheers

Bill Verburg · Bill Verburg's Garage

first, those don't appear to be Big Reds, they are red yes, but they appear to be 964 calipers that have been modified for use on a 911 and painted red.

If they are 964 calipers, then a 19mm m/c is too small, the 20.6mm boosted version from a later Carrera is ok and will be adequate, but the 23mm boosted version wil give you a much better pedal. It will be harder and easier to modulate.

There are different ways to plumb them. Some like to run a flex line from the chassis to the caliper like this, you still want to have a hold at the strut though

This eliminates the need for an extra hard line

Some like to run flex from the chassis to the strut and then hard from the strut to the chassis like this

Obviously the way you do it will affect the length needed

Either way use 10x1.0 fitting on 3/16" line w/ metric bubble flares.

Bigger true Big Red and S4 calipers need fittings w/ the shorter barrels on the fittings, I posted the difference once but search doesn't appear to be working just now

these are the ones you want for the 964 calipers

Jeff needs the dual m/c because the kit he has comes w/ too much front bias, this is not an issue w/ the 964s even w/ some extra weight in the back.

pjv911 · pjv911's Garage

Bill , can you tell from the following images what these are ?

pjv911 · pjv911's Garage

Here is a few more Bill.

pjv911 · pjv911's Garage

Bill the brake pads are Pagid U1842 fronts and U1204 rears . Are these ok for street use ? Using rotor sizes and pad part #`s they appear to be 96-98 993 twin turbo brakes . But still not sure now that you mentioned they look like 964 units. I was told they were tt big reds .

Kurt Williams

Bill Verburg · Bill Verburg's Garage

the fronts are Big Reds then U1842 is the caliper size designation for them, the compound is Orange RS4-4

the rears still look like the small 964, 965 or 993 rear calipers

the size U1203 that I see confirms that size for the rear caliper, U1204 is the correct size for the true Big Red rear which is the same size as a 993 front.

In that case you definitely want the 23mm m/c

The RS4-4 isn't the best street pad, I have used them for that though, biggest problem is the noise they make, it can get embarassing.

pjv911 · pjv911's Garage

Bill does your line/hose recommendation still go for the big reds ? Or just for the 964 calipers .

Kurt

pjv911 · pjv911's Garage

Also I will add anti squeal compound to the backs of the pads . Should I also chamfer the leading egdes ? Are these pads ok for easy driving where the temps will stay fairly cool ? I would like to try using them at first to see how they feel . These performance pads are pretty expensive so I think its worth a shot .

Kurt

Bill Verburg · Bill Verburg's Garage

Same, you can do it either way, the single flex line way means a longer flex line is all.
The Big Red caliper just needs the short 10mm fittings, the long ones won't seat correctly.

Just out of curiosity, what are the cast #s in the throats at the bleed end,

I have a set of true Big Reds from a 993 RS in front of me

the fronts are 05 and 20.5248
the rears are 03 and 20.4701

pjv911 · pjv911's Garage

Just looked over my front struts and there is no provision to attach a hard line to them . So I guess my only option is a flex line directly to the chassis as pictured above . Is there a certain lengh needed that is predetermined ? Or am I going to have to do some measuring ?

Kurt