911SC-1979 => 930 brake update

[Flojo]

Hello fellow friends!
I kindly need your help.
As I am not able to be much online and despite reading through some threads, its kinda picking bits and pieces regarding my envisaged task.

So I write to you from Germany and ask: is there a detailed parts/to-do list/tutorial for doing a brake update on a 1979 SC?
- It already has the green bilstein turbo shock struts
- it has 7x16 fuchs at front (8x16 rear)

I understand I need:
- pair of front 930-finned calipers (917-adopted-style)
- early 930 rotors (77-79) => do they fit my hubs?
- new partial brake line(s)
- ??
- ??

Thanks so much for your help in advance!

Regards, Flo

[James Brown]

try these guys VCI, they have conversion kits but i
m sure they can help with the parts you need Vehicle Craft Inc."VCI" Hi-Performance Brake Upgrades For Porsche Cars

[Flojo]

OK, thanks.

I found this:
Front: Installation of 930 front brakes on a 911
Rear: Installation of 930 rear brakes on a 911

What about the used whashers as spacers at the front?
And what about the rear cutting away the "noses"?
is that really a sound method for mounting the calipers?
Especially at the front... isn't that a "wobbly" way doing it?

[Bill Verburg]

Originally Posted by Flojo

Hello fellow friends!
I kindly need your help.
As I am not able to be much online and despite reading through some threads, its kinda picking bits and pieces regarding my envisaged task.

So I write to you from Germany and ask: is there a detailed parts/to-do list/tutorial for doing a brake update on a 1979 SC?
- It already has the green bilstein turbo shock struts
- it has 7x16 fuchs at front (8x16 rear)

I understand I need:
- pair of front 930-finned calipers (917-adopted-style)
- early 930 rotors (77-79) => do they fit my hubs?
- new partial brake line(s)
- ??
- ??

Thanks so much for your help in advance!

Regards, Flo

you need a pair of stock fronts and a pair of rears than have been machined to fit an SC/Carrera rear 3" mount, the rears from '78-86 are preferable as the '87-89 will also need to have the inlets machined to accept the earlier style banjo or further modify the trailing arm.

'78-80 2 piece rotors w/ floating hats work fine w/ any 911 hub, and yes you need new lines to connect to the chassis lines an alternative if you aren't wedded to Fuchs wheels is to use late high offset wheels w/ late 930('81-89 hubs and 1 piece non floating rotors. Alternatively VCI non floating hats and aftermarket rotors work fine w/ stock 911 hubs too.

In back once the calipers are machined, use stock 930 rear rotors, the splash shields no longer fit and the splash shield mounts need to be trimmed off and again new lines from the calipers to the chassis lines.

also need is a new 23.8mm m/c, use one from a '78-89 930 bolted to your stock vacuum booster

[Flojo]

Thanks Bill!

So the rear fitting is more to-do tahn up front.

Would it be OK if I only adapt the front with 930 calipers and leave the rear as ist is, with the new OEM M-calipers?

[Bill Verburg]

Originally Posted by Flojo

Thanks Bill!

So the rear fitting is more to-do tahn up front.

Would it be OK if I only adapt the front with 930 calipers and leave the rear as ist is, with the new OEM M-calipers?

yes, because the caliper and trailing arm both need some modification, the trailing arm is trviial but the caliper isn't

no, you must do something in back too the cheapest acceptable way to go is to use 3.2 Carrera rears, both the rotors and calipers, you end up w/ a little more front bias but it's ok

[Flojo]

Thanks Bil!

Btw: ist the switsh to a 964 caliper set (rear and front) an option for an early SC?
At least the calipers are lots cheaper here.

[Bill Verburg]

Originally Posted by Flojo

Thanks Bil!

Btw: ist the switsh to a 964 caliper set (rear and front) an option for an early SC?
At least the calipers are lots cheaper here.

It is, I used 964 calipers on 930 rotors for a few years, either is a good setup and each has it's own +/-, all in all the 930 on 930 is easier to to do than 964 on 930

biggest difference is wheels that work, 930/930 works w/ 7x15 and larger wheels, 964/930 needs 7x16 or larger

next biggest is the machining it's uncommon to find anyone that knows how to machine the 964 calipers

[mnez]

I did the 930 conversion on my 3.2. It wasn't cheap or super easy, but the results are great.

For the rears, the calipers need to have the mounting holes modified and relocated. Mine were done by VCI. They also reduced the outside fins. I further modified some of the fins on the back side to facilitate getting a wrench in to tighten the bottom mounting bolt. It's tough to get to. I believe I also used a couple of washers under the bolt head to make it more accessible.
VCI also supplies spacers to mount the caliper so that it is centered over the rotor.
I stuck the spacers on with some silicone just to keep them in place while assembling things. Longer mounting are needed.

Here are some pics I took of mine. You will see that the trailing arm needs some modification as well, to remove the dust shield mounting ears, and a bit scalloped out to clear the brake line banjo bolt, as Bill says.






For the fronts, the calipers bolt right on, but I ended up taking all of the outside fins off so that I could mount Fuchs with only a 3mm spacer. My 16" BBS wheels fit without a spacer.
For rotors you can use either the early 930 floating rotors, or an aftermarket hat/rotor kit. I went with a kit so I woudn't be married to expensive Porsche parts. I used a few washers to centre the caliper over the rotor, and longer bolts.

Here are some pics showing the size difference and the final install, with the fins ground off. I took off more than I needed to, hoping to not use a spacer with the Fuchs, but it didn't work out that way.





Lastly, as Bill says, you will need the larger 930 master cylinder, which bolts right to the booster. I assembled it dry, there's no need to mess around with bench bleeding. If the SC has the pressure limiter on the rear brake line (like the Carrera), just downstream of the master cylinder, it needs to be removed and replaced with a coupler.

[tshebib]

+1 for the 930 setup!!

Mike,
I thought slotted rotors were more expensive. Do you have slotted for the rear as well? I replaced front and rears with Zimmerman's (OEM I think) from a Canadian source. $196 each for the fronts and $198 each for the rears.
BTW, I'm a true believer in this 930 setup on our cars--no more brake fade and now I have the confidence to go even deeper into the corners than ever before.
Tom

[Flojo]

Thanks so much "mnez"!
I hope it's OK if I quote your pics on the german forum, to get the topic foreward?

Darn, no easy way through :-(
And there are other things on the list to do on my SC.

Too bad I'm not in the US, where it seems the scene is more familiar about this an the to-do's than anyone here in Germany (unless you buy yourself a golden calf in a tuning shop).

What kills my idea most is the adaptation of the rear calipers.
No DIY option for me.

I beleive there is not much of a chance of anyone selling a ready adapted caliper set for a fair price and willing to ship to Germany?

[mnez]

Originally Posted by tshebib

+1 for the 930 setup!!

Mike,
I thought slotted rotors were more expensive. Do you have slotted for the rear as well? I replaced front and rears with Zimmerman's (OEM I think) from a Canadian source. $196 each for the fronts and $198 each for the rears.
BTW, I'm a true believer in this 930 setup on our cars--no more brake fade and now I have the confidence to go even deeper into the corners than ever before.
Tom

Hi Tom,

Happy New Year!
The rears are Zimmerman OEM drilled 930 rotors. The fronts are VCI kits, with Coleman rotors I believe. They just came slotted.
What front rotors are you using, and your Can source?
I like them too!

[mnez]

Originally Posted by Flojo

Thanks so much "mnez"!
I hope it's OK if I quote your pics on the german forum, to get the topic foreward?

Darn, no easy way through :-(
And there are other things on the list to do on my SC.

Too bad I'm not in the US, where it seems the scene is more familiar about this an the to-do's than anyone here in Germany (unless you buy yourself a golden calf in a tuning shop).

What kills my idea most is the adaptation of the rear calipers.
No DIY option for me.

I beleive there is not much of a chance of anyone selling a ready adapted caliper set for a fair price and willing to ship to Germany?

Flo,

No problem using my pics.
If you don't have a convenient source for the rear caliper machine work, I have seen already modified rear calipers come up for sale from time to time in the classified section. You could try a WTB post there.

Good luck,
Mike

[Flojo]

Thanks Mike!
I'll do so.
Regards

[tshebib]

Originally Posted by mnez

Hi Tom,

Happy New Year!
The rears are Zimmerman OEM drilled 930 rotors. The fronts are VCI kits, with Coleman rotors I believe. They just came slotted.
What front rotors are you using, and your Can source?
I like them too!

Yes, Happy New Years!!

I asked for 1979 930 rotors. They bolt right up to the VCI hats similar to yours. Here's a link to the Canadian supplier
1979 Porsche 930 Disc Brake Rotor in Canada - Canada 1979 Porsche 930 Disc Brake Rotor
Calabogie this year?

[mnez]

Outstanding. Thanks Tom.
Too early to say on Calabogie. Too many balls in the air right now. I'd also like to get back to Tremblant this year.

[JJ 911SC]

Originally Posted by tshebib

... Here's a link to the Canadian supplier
1979 Porsche 930 Disc Brake Rotor in Canada - Canada 1979 Porsche 930 Disc Brake Rotor.

They are also available on the .com site at cheaper price but the .ca site shows a Sebro Rear Left (SEB1604554) & Sebro Rear Right (SEB1604555) while the .com only show SEB1604554 without mentioning a specific side. Same thing for the Zimmermann Rear Left (ZIM1604554) & Rear Right (ZIM1604555) .ca, only one on the .com.

If you look at the picture of the right & left on the .ca, the perforation has a different pattern so when they are installed they look the same. Ask me how I know

So this is a rare occasion that I would recommend to get it from .ca at a higher price.

[Brian 162]

I did the conversion as well. I sourced the rotors from VCI.
One thing I found was the front calipers weren't centered to the rotor. A spacer and longer bolt is required (Porsche factory part 2 per side).
It was the best upgrade I've done.
I also installed the larger master cylinder.

[Flojo]

I found this for a nice plugandplay swap...
Porsche 911 930 Speedster Turbo Suspension Package | eBay

unfortunately: too expensive, too far away...

[Bill Verburg]

Originally Posted by Flojo

I found this for a nice plugandplay swap...
Porsche 911 930 Speedster Turbo Suspension Package | eBay

unfortunately: too expensive, too far away...

and you can't use it easily anyway

the front is the later '81-89 setup w/ 1 piece rotors and extended hubs, these only work on a w/b or on a n/b w/ high offset wheels

the rears can be used by either modifying the pickup points for the trailing arms on your car or by striping the brake parts you want off the 930 arms