930 Caliper Question

[BURN-BROS]

I HAVE 930 CALIPERS THAT I RECENTLY PICKED UP. I AM CONSIDERING THE THOUGHT OF PUTTING THEM ON AN EARLIER 911 S SUSPENSION(1972). THE STRUTS ARE KONI AND I BELIEVE THAT THE MOUNTING FLANGE HOLES ARE THE SAME SPACING. THE QUESTION IS THE ROTORS. WILL THE 930 ROTORS BOLT ON TO THE EARLY HUBS AND MANTAIN ALIGNMENT WITH CENTERLINE OF CALIPER?

I KNOW SOMEONE OUT THERE IN PELICAN LAND KNOWS!

[Bill Verburg]

No need to shout

930 calipera have 3.5" mounts. if your struts have 3.5" mounts then they will bolt on. The '78-'80 rotor/hat setup will bolt on to the early hubs w/o any issues, however they are very hard to come by and very expensive. The rotors alone are a tad under $300ea. I switched to Big Reds and 993tt rotors because the rotors are half as expensive.

In the back you will have the opposite problem, ie, the '78-'89 rear rotor is a bolt on, is cheap and is readily available, however the calipers will need some fairly extensive machining. Contact VCI or Rennsport Systems for the details and prices.

You also ought to upgrade the m/c.

[jpachard]

Burn, I make rotor hats for turbo brakes. I charge 200.00 a pair vs. 450.00 that most other folks get for them. I can also perform the machining of the rear calipers if you are in need of that. I can send you photos of my setup if you are interested. Please pm me if you need any help with this.

Cheers, James

[BURN-BROS]

THANKS BILL, I APPRECIATE THE REPLY. WHAT WERE THE DIFFERENCES BETWEEN POST 80 BRAKE SYSTEM AND EARLIER?

I AM PLANNING ON A DUAL MASTER CYLINDER TO REALLY SET THE CAR UP RIGHT.

[BURN-BROS]

PACHARD, DO YOU HAVE A MACHINE SHOP? WHAT THER THINGS DO YOU OFFER?

[BURN-BROS]

OTHER....I MEAN

[jpachard]

Burn, Yes, I have a shop. I have a VMC with a 20 pocket ATC and a manual machine plus a lathe. Private -e-mail me(click on the envelope icon next to my username) so we can discuss what you need. I make several other products that are run on a few very sucessful PCA Club Racing cars here in the Northeast.

Cheers, James

[Mr9146]

Dude, ditch the capital letters.

[BURN-BROS]

LOL, I didn't realize I was shouting in forumspeak. Thanks for the heads up!

[Mr9146]

no problem ... thanks for joining us.

[Mike Feinstein]

James,

Thinking about doing a 930 upgrade this winter after the 3.6 goes in. I've been looking around and am reeling from sticker shock! Of course, the 3.6 ain't cheap and this is a lot to bite off in one year! A more cost effective solution here at the ol' BBS is welcome. I'd be very interested to learn more about what you can do (brake-wise).

Thanks,

[jpachard]

Mike et All,
I have come up with a solution for 930 rotors and hats that is quite a bit cheaper. I machined my own hats to fit Coleman rotors. I have found that these rotors work very well on our cars. While there have been stories of these warping I believe that it's improper bed in that is the cause of this problem, especially with Pagid pads. I have found these pads to be very fussy regarding bed in especially when it comes to new rotors. That said, The Coleman rotors were 159.00 per rotor plus my hats(200.00) which brings the total to just above 500.00 instead of 750.00 to 800.00 for other setups. If you would like to run the Brembo disks I can also manufacture hats for these too. In closing, I have run the coleman's at Road America for the Club Race and a few DE's at Limerock with no problems whatsoever. They also have the advantage of not being cross drilled so you eliminate that issue. if you have any further questions please feel free to pm me or respond to this thread. I can also perform the machining of the rear calipers for 200.00 per set. I hope this helps.

Cheers, James

[Bill Verburg]

Which set of rotors would you rather trust your life to?


They are both 304x32mm 930 front size.

[jpachard]

Bill, I guess a bunch of CART and IRL teams seem to think the're OK, as well as the NASCAR crowd. Plus the way the Brembo's are machined leaves one of the vent holes VERY close to the edge of the rotor. Have you tried to get a custom Brembo shipped overnight to the track during a race weekend? This for me is a big consideration when I run 30+ track days a year up and down the East Coast. Is the Brembo a better product, maybe, but their customer service is not so good, in my experience. I also would want to know how they would feel having their rotor machined post manufacture. Also, What rotor temps. are you running when you come in off the track? My 2800lb Carrera just sees 600 deg. F when I come in indicating I still have some room to play with. The Coleman's seem to have plenty of mass to dissapate the heat.

[Bill Verburg]

The Brembos in the picture are not the ones that I would recommend but they do show the internal structure that is used and the thickness of the face plates. Both are critical for stable long lasting rotors. I agree that the way the pictured ones are machined is not desireable. The correct Brembo 930 fronts are not like that. and are worth the $300 price tag relative to the Colemans. This of course is only my opinion.

Colemans are not the first choice of any front line team in the venues that you named. Brembo and Alcon are.

I am sorry that vendors of these things don't like to hear this but the Colemans are not the best choice. 322x32 Brembos are also only ~$150 a pop. and are a superior product to boot.

[jpachard]

Ok, How many track days( I have an hour meter in my car so we can get really scientific if we want, plus times at different tracks, pad compound etc.) do you have on you Brembo's? This would be an interesting comparison. Also, where do I get the Brembo's for 150.00?

Cheers, James

[Bill Verburg]

Here are the correct '79 930 rotors


another shot of the correct 304x32 rotor in a different application


PM me for a source, the last pair was $142 L and $150 R a month ago for the 322x32 993tt fronts

the 304s are ~$300ea don't ask me why.

I am sorry you feel so threatend by all this , I dont sell this stuff, I have no vested interest. If you want to be in the business sell a superior product not a cheap one. Though maybe some people will be happy, I wasn't.

[jpachard]

I'm not threatened, just want to get the fact s since many people have bashed the Coleman's with no real evidence( hard track usage, failures etc.) to prove they aren't a viable option. I guess I try to support American made products whenever I can, epecially when the customer service is so good. I should take a photo of mine on the car since they look a bit thicker than yours do. I had them custom spec'd so it would be intersting to see if they are indeed different.

Cheers, James

[Bill Verburg]

The air gap is large on the Colemans in the first picture. There are venues where that is desireable. The air gap issue is a compromise. In general the air gap wants to be larger where there is less braking, smaller where there is more. Larger in a lighter car, smaller in a heavier etc. Porsches tend to be heavier, faster and used where braking is intense. The smaller air gap w/ reinforcing ribs that also increase convective surface area are a big plus.

Lots of folks have used the Colemans, including me, it's just that there are better, if more expensive choices. As I said I switched form the 304s to the 322s solely becase of the rotor price. The down side is additional weight. Everything is a compromise.

[don911]

Bill,
Just curious why you're using Brembo rotors and not the factory 930 rotors. The factory rotors sound like they're around the same price as the Brembos. I thought the factory rotors are as good as it gets.
I used the factory rotors on my recent brake change. I did notice that the right rotor wasn't exactly the same as the left....from a manufacturing quality stand point. The left looked like a piece of art while the right was nice, just not nearly as nice as the left.