Parts Catalog Accessories Catalog Tech Info Tech Forums
 
  Search our site:    
 Cart  | Project List | Order Status | Help    



Go Back   Pelican Parts Technical BBS > 1- Porsche Technical Forums > 911 / 930 Turbo & Super Charging Forum

Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Smart quod bastardus
 
fredmeister's Avatar
 
Join Date: Oct 2002
Location: Baltimore, MD, USA
Posts: 2,163
Garage
alternative rotors for 79 930 turbo

Anyone have experience with replacing the front rotors on a 78-79 930 turbo? they have "floating rotors" which are bolted to a hat that in turn gets bolted to the hubs.
Apparently the hubs were changed for later models 1980 and later to allow a cheaper one piece rotor.
Can a different rotor be made or machined to fit such as a 993 or some other model that would save some $$.
Any leads on this and a shop or dealer that does this work would be great.
Old 02-05-2007, 03:50 PM
  Pelican Parts Technical Article Directory    Reply With Quote #1 (permalink)
Registered User
 
PhatA55's Avatar
 
Join Date: Aug 2006
Location: Beech Grove, IN
Posts: 73
Garage
Subscribed because inquiring minds want to know.
__________________
--Mark--

1979 RoW 930
1999 BMW Z3

Quote:
Originally posted by randywebb
It is the people who have some kind of psychological problem and use the car (or some hierarchy they set up involving the cars) to try to elevate their personal sense of self-worth that irks me. I feel sorry for them of course, but they are difficult to put up with.
Old 02-05-2007, 06:43 PM
  Pelican Parts Technical Article Directory    Reply With Quote #2 (permalink)
Registered User
 
WydRyd's Avatar
 
Join Date: Mar 2002
Posts: 3,563
Don't know about just the rotors, but here are some nice upgrade options for the front:

993 TT caliper with 993 TT rotor.
996 TT caliper with 350 x 34 mm rotor.
Cayenne turbo caliper with 350 x 34 mm rotor.
Corvette Z-06 caliper with 355 x 32 mm rotor.

Then you can move the front callipers/rotors to the rear
__________________
Merv
'89 911 Turbo Cab
Protomotive MAP ECU, Twin Plugged Heads, GT2-EVO CAMs, 3.3L fully finned P&C's, ARP fasteners, C2T head gaskets, Titanium Retainers, Turbo spec valves, springs & guides, 964 splash valves, GT35R BB turbo, GSF Stainless Headers, Magnaflow Exhaust, Full bay Intercooler, TiAL 46mm w/gate, TiAL 50mm BOV, Apexi AVC-R EBC, SPEC Stage3+ Clutch kit, Crane CDI Ignition
Old 02-05-2007, 07:20 PM
  Pelican Parts Technical Article Directory    Reply With Quote #3 (permalink)
Registered User
 
dewolf's Avatar
 
Join Date: Jan 2007
Location: Australia
Posts: 5,563
What's the difference between the front and rear calipers. Mine uses the same brake pad front and back, are they all like that? Is it the piston size that's different?
__________________
In Heaven… the mechanics are German, the chefs are French, the police are British, the lovers are Italian and everything is organized by the Swiss.
In Hell…the mechanics are French, the police are German, the chefs are British, the lovers are Swiss and everything is organized by the Italians.
Old 02-05-2007, 09:00 PM
  Pelican Parts Technical Article Directory    Reply With Quote #4 (permalink)
Registered User
 
PhatA55's Avatar
 
Join Date: Aug 2006
Location: Beech Grove, IN
Posts: 73
Garage
Quote:
Originally posted by dewolf
What's the difference between the front and rear calipers. Mine uses the same brake pad front and back, are they all like that? Is it the piston size that's different?
It's not the calipers that are the issue, it's the rotors. Look at the cost difference for the 1978-80 turbo as opposed to later turbos. The front rotors will cost you over $800, that's JUST the rotors. The 1978-80 turbos get hosed on price more than any other model it seems. I wonder if they could be "upgraded" to 1981-89 brakes.
http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_BRKpad_pg4.htm#item11
__________________
--Mark--

1979 RoW 930
1999 BMW Z3

Quote:
Originally posted by randywebb
It is the people who have some kind of psychological problem and use the car (or some hierarchy they set up involving the cars) to try to elevate their personal sense of self-worth that irks me. I feel sorry for them of course, but they are difficult to put up with.
Old 02-06-2007, 03:42 AM
  Pelican Parts Technical Article Directory    Reply With Quote #5 (permalink)
Registered User
 
David's Avatar
 
Join Date: Apr 2002
Location: Houston (Clearlake), TX
Posts: 8,267
Garage
EDIT: forget what I just erased here and go to the thread

a good thread on the subject The ultimate brake upgrade page.
__________________
2014 Cayman S
2011 Cayenne Turbo
1979 930 (475 rwhp at 0.95 bar)

Last edited by David; 02-06-2007 at 03:50 AM..
Old 02-06-2007, 03:46 AM
  Pelican Parts Technical Article Directory    Reply With Quote #6 (permalink)
7.0:1 > 11.3:1
 
Join Date: Oct 2003
Location: Calgary
Posts: 1,682
Garage
I'm currently running Coleman rotors spec'd and purchased through VCI. They saved some $$ over stock replacement Brembo/Zimmerman's, and they bolt-on.

I was a little concerned about some bad press in some old posts but once I tried the rotors they performed just fine. I've got a little over one season on them, mostly track use.

Jim
Old 02-06-2007, 08:18 AM
  Pelican Parts Technical Article Directory    Reply With Quote #7 (permalink)
Registered User
 
Join Date: Nov 2000
Location: cincinnati,oh
Posts: 66
This is a subject that has interested me since I also own a car with these "orphan" rotors. In regard to upgrading these brakes, I think you are missing the point. These are great brakes, torn from the 917 race car. I love that. Like the fredmiester I to am left a little breathless at the cost of these rotors. I have found replacement rotors at VCI but don't have any idea how good are: http://www.vehiclecraft.com/Brakes/vciweb4.htm
I too would love a good option.

Last edited by turbodog; 02-06-2007 at 11:16 AM..
Old 02-06-2007, 09:25 AM
  Pelican Parts Technical Article Directory    Reply With Quote #8 (permalink)
Registered User
 
PhatA55's Avatar
 
Join Date: Aug 2006
Location: Beech Grove, IN
Posts: 73
Garage
I'm happy with the stock 930 brakes. I'm curious about the difference between 1977-80 brakes and 1981-89 brakes. Is one superior to the other? If not, what would it take to convert to the later style? Is it simply swapping the hub? I didn't see anything in the above threads that compared old style to new as far as OEM.
__________________
--Mark--

1979 RoW 930
1999 BMW Z3

Quote:
Originally posted by randywebb
It is the people who have some kind of psychological problem and use the car (or some hierarchy they set up involving the cars) to try to elevate their personal sense of self-worth that irks me. I feel sorry for them of course, but they are difficult to put up with.
Old 02-06-2007, 02:11 PM
  Pelican Parts Technical Article Directory    Reply With Quote #9 (permalink)
Smart quod bastardus
 
fredmeister's Avatar
 
Join Date: Oct 2002
Location: Baltimore, MD, USA
Posts: 2,163
Garage
as far as I know there is no difference in stopping ability between them as the calipers are the same and the rotors are the same dimensionally.
If you look at the floating rotor design, from a pure racing/standpoint they are better because of the fact that they float and are independent of the hub deflections and thermal stresses from a fixed rotor. But are they worth the expense is a better question.
The change should invovle a later style hub which would allow using the later rotors, but what is the break even point to do this as a hub is not cheap either.
There has to be a way of using a 993 or other model rotor and machine it to fit the floating "hat"......at least I hope so, but noone has chimed in yet to let us know if this is true.
__________________
1979 930 Turbo....3.4L, 7.5to1 comp, SC cams, B&B intercooler, Snow Perf water/meth injection, Rarlyl8 headers, Garret GTX turbo, 36mm ported intakes, Innovate Auxbox/LM-1, custom Manually Adjustable wastegate housing (0.8-1.1bar),--running 0.7bar max
---"When you're racing it's life! Anything else either before or after, is just waiting"
Old 02-06-2007, 04:03 PM
  Pelican Parts Technical Article Directory    Reply With Quote #10 (permalink)
Registered User
 
David's Avatar
 
Join Date: Apr 2002
Location: Houston (Clearlake), TX
Posts: 8,267
Garage
Quote:
Originally posted by Jim2
I'm currently running Coleman rotors spec'd and purchased through VCI. They saved some $$ over stock replacement Brembo/Zimmerman's, and they bolt-on.

I was a little concerned about some bad press in some old posts but once I tried the rotors they performed just fine. I've got a little over one season on them, mostly track use.

Jim
That's good info, thanks.

At this point I'm thinking of doing the big red fronts and move the 930 front calipers to the rear, but it's good to know there's a reasonable alternative.
__________________
2014 Cayman S
2011 Cayenne Turbo
1979 930 (475 rwhp at 0.95 bar)
Old 02-06-2007, 04:59 PM
  Pelican Parts Technical Article Directory    Reply With Quote #11 (permalink)
Registered User
 
PhatA55's Avatar
 
Join Date: Aug 2006
Location: Beech Grove, IN
Posts: 73
Garage
Quote:
Originally posted by fredmeister
The change should invovle a later style hub which would allow using the later rotors, but what is the break even point to do this as a hub is not cheap either.
The upgrade cost would only be the first time, though. After that you're just paying for rotors at less than half the cost.
__________________
--Mark--

1979 RoW 930
1999 BMW Z3

Quote:
Originally posted by randywebb
It is the people who have some kind of psychological problem and use the car (or some hierarchy they set up involving the cars) to try to elevate their personal sense of self-worth that irks me. I feel sorry for them of course, but they are difficult to put up with.
Old 02-06-2007, 05:39 PM
  Pelican Parts Technical Article Directory    Reply With Quote #12 (permalink)
Registered User
 
palle7688's Avatar
 
Join Date: Feb 2004
Location: Copenhagen, Denmark
Posts: 415
fredmeister, you are right. Change to newer type hub and rotor will do it.
Be sure to sell your hats to someboby with narrowbody car that wants 930 brakes. PM me if interested in selling, cheap offcause:-)
Someboby metioned calipers diffs, piston size is the diff.
__________________
You might not be happier owning a Porsche, but it certainly feels so driving one
Old 02-19-2007, 04:33 PM
  Pelican Parts Technical Article Directory    Reply With Quote #13 (permalink)
Smart quod bastardus
 
fredmeister's Avatar
 
Join Date: Oct 2002
Location: Baltimore, MD, USA
Posts: 2,163
Garage
Anyone out there no of machined rotors that could be made to fit these floating hats?
Would really like to do that than change over to the later style hubs and rotors. Floating hats and rotors would be nicer, as they do have "better" characterstics technically.
Someone must have found a better way to skin the cat out there.
__________________
1979 930 Turbo....3.4L, 7.5to1 comp, SC cams, B&B intercooler, Snow Perf water/meth injection, Rarlyl8 headers, Garret GTX turbo, 36mm ported intakes, Innovate Auxbox/LM-1, custom Manually Adjustable wastegate housing (0.8-1.1bar),--running 0.7bar max
---"When you're racing it's life! Anything else either before or after, is just waiting"
Old 02-19-2007, 04:48 PM
  Pelican Parts Technical Article Directory    Reply With Quote #14 (permalink)
Registered User
 
BoxxerSix's Avatar
 
Join Date: Jun 2006
Location: Ballston Spa, NY
Posts: 528
Quote:
Originally posted by fredmeister
Anyone out there no of machined rotors that could be made to fit these floating hats?
Would really like to do that than change over to the later style hubs and rotors. Floating hats and rotors would be nicer, as they do have "better" characterstics technically.
Someone must have found a better way to skin the cat out there.

What's the bolt circle patterns of the 930 rotor? Example, a common bolts pattern for some floating rotors is 8 on 7, that is 8 bolt hole pattern on center to a 7" circle. I don't know that off hand right now, but if I can get that info I can search through the brake companies that I distribute for and see what pops up...

i want to say it's a 12 on 8 but i don't know for sure
__________________
Adam Hennessy
Old 02-19-2007, 05:49 PM
  Pelican Parts Technical Article Directory    Reply With Quote #15 (permalink)
Smart quod bastardus
 
fredmeister's Avatar
 
Join Date: Oct 2002
Location: Baltimore, MD, USA
Posts: 2,163
Garage
I can try to find out, but I am not sure how because I would have to measure it and the rotors are currently on my car. I will see if it is called out in the spec manual.
Anyone else have a rotor off the car that could check this more easily than me?
thanks Adam, for the help in advance.
Fred
__________________
1979 930 Turbo....3.4L, 7.5to1 comp, SC cams, B&B intercooler, Snow Perf water/meth injection, Rarlyl8 headers, Garret GTX turbo, 36mm ported intakes, Innovate Auxbox/LM-1, custom Manually Adjustable wastegate housing (0.8-1.1bar),--running 0.7bar max
---"When you're racing it's life! Anything else either before or after, is just waiting"
Old 02-19-2007, 07:19 PM
  Pelican Parts Technical Article Directory    Reply With Quote #16 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 10:53 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2016 Pelican Parts - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.