930 Brake Upgrade Complete...

[Mike Feinstein]

After two long days in the garage, it's finally complete. There were only a few unexpected adjustments and they were minor. One...the ATE 23 mm MC had brake light switches with three prongs...my connectors only accept two. So I removed the new switches and installed the ones from my old MC. Had I known, I'd have had new ones on hand.

I managed to get all 4 wheels installed with no rubbing and no wheel spacers, but on the front left, it took some work. On the first try I had rubbing so I proceeded to grind down the face of the caliper beyond the machining that Steve Weiner did (beautiful job by the way). It was still barely rubbing after this exercise so I took a bold step. The factory caliper spacers are about 4mm thick. Looking at the mounted caliper it appeared to be off center just slightly toward the outside. So, I added another 2mm spacer which brought it just barely inside of center and gave the the clearance I needed. New pads still had plenty of room to install. On the right front I did the same thing and have no rubbing with no additional grinding required. Really looks nice.

The entire project including the first bleed (will bleed again next week after putting on some miles) took about 16 hours. Every bone in my body aches...must be age. Here's a few pics:

[beepbeep]

Very nice!

Just one question: did you have rear calipers counter-sunk (so that caliper spacers would be partially in those holes) and in that case, how much?

Reason that i'm askin is that we have exactly same calipers but no spacers yet, and are arguing wether to machine spacer-grooves in calipers or not.

Thanx!

[Mike Feinstein]

Goran,

Yes, the rear calipers were countersunk and spacers (6mm I believe) were used in the recesses.

[beepbeep]

Thank you for making this clear. Source of our calipers (well-renowed P-car shop) said to us that they don't need to be countersunk but my feeling is that forces on those bolts would be pretty big so there would be lot's of flexing w/o countersunk holes.

[dickster]

mike , thats great.

post your driving impressions when you can....???

[DanS911]

Beautiful!

[89911]

I didn't realize that the 7" fuchs would still be so close with a 930 upgrade. I know that the 6"s up front are out of the question. The 951 type 8"s up front will give you plenty of room along with the 951 7". Not looking to have you run out and spend anymore money. Its just nice to know all the facts about an upgraded. So your caliper is no longer perfectly centered over your rotor? I'm not sure if there is any issues with this since the pistons will extend to make up the difference. I assumed you took out the bias valve? If not, you should since it gives you entirely to much front braking. Once removed, the car grabs better at all four corners. Looks great!

[Mike Feinstein]

Unfortunately, 951 fronts are a scarce commodity these days. Wish I had some, but it looks like I'll get by with 911 7's.

As you mention, I removed the proportioning valve...just re-used the female/female connector and bent a new 12" hard line to the MC.

Regarding the position of the rotor under the caliper...it didn't "look" perfectly centered with the stock setup, so I hope that moving it in about 1 mm from the dead center won't cause any issues...as you say, the pistons are dynamic. With pistons fully recessed in the calipers, new Ferodo DS-2500 pads were easily installed.

[dean]

Good job Mike. That is a nice upgrade. I had to space the front wheels out .100" and file the fins off the calipers to make my 7" fuchs fit. Then I had to roll the fender lips

[jyl]

Those brakes are beautiful, Mike.

So you used the Rennsport kit then? Other than the wheel-caliper issue, was everything else a straightforward bolt-on?

How much will it cost to maintain that setup - i.e. when its time for new rotors or pads?

[Mike Feinstein]

Pretty much a straight forward installation. You have to grind or cut off the rear mounting ears for the stock backplate, etc., but it's pretty easy...just takes time.

I bought my calipers from a private party and sent them to Rennsport for machining and for his custom front rotors (Brembo) and hats. They are pricey (750) but Steve claims they'll last a very long time. I hope he's right. The rear rotors are stock Porsche parts.

There's a wide range of pad choices in almost any price range, so I'm not too concerned about replacing those.

[beepbeep]

Talking about pads, good thing is that they are exactly same in front and back...so if you wear fronts faster you can just switch pads and keep on driving.