Notices

Big red brake upgrade without the red - Interested?

 
Old 02-06-2009, 12:48 AM
  #1  
mark kibort
Addict
Rennlist Member
Thread Starter
 
mark kibort's Avatar
 
Join Date: Feb 2003
Location: saratoga, ca
Posts: 29,754
Likes: 0
Received 1 Like on 1 Post
Default Big red brake upgrade without the red - Interested?

The guys from the racing board said you guys might be interested in an easy upgrade to your brake system if you have a 951 with the 928 style S4 brakes.

You can turn your S4 brakes into the Big blacks with a set of radial spacers! S4 calipers and S4 pads are more than enough pad. the difference is the diameter. If you look at the stoptech ST40 13" set up, they use the exact same pads as the 928S4. The only difference is the diameter. If you have the same offset as the 928S4 rotor, you can use the 964T turbo rotors.
You will have more than enough brake to deal with the fade and better stoping power.

A little background on the S4 calipers, is that they are the same size as the Ferrari F50 calipers, that fit on 14" rotors. the pads are almost the same. Its all about diameter with brakes, and our calipers are very capable. This is a way to basically get Big Red brakes, by only buying replacement rotors and these spacers.

We are trying to get a group buy as I can supply the spacers to allow the modification . the difference in buying replacement rotors, pads vs this kit might only be a couple of hundred bucks.

If we can get 5-10 takers, the cost would be around $725 shipped, or $480 without pads. this is the cast hole rotors, 322mm, spacers to move the calipers out, and longer GTS caliper bolts. (and with pads, pagid black or orange racing pads)

Let me know if there is an interest

Mark
Attached Images  

Last edited by mark kibort; 02-06-2009 at 01:24 AM.
mark kibort is offline  
Old 02-06-2009, 02:31 AM
  #2  
ehall
Addict
Lifetime Rennlist
Member
 
ehall's Avatar
 
Join Date: Jun 2003
Location: long gone.....
Posts: 17,413
Likes: 0
Received 0 Likes on 0 Posts
Default

Wow. This is pretty cool. gonna have to think on it.
ehall is offline  
Old 02-06-2009, 03:52 AM
  #3  
Olli Snellman
Super User
 
Olli Snellman's Avatar
 
Join Date: Jun 2001
Location: Finland
Posts: 4,479
Likes: 0
Received 0 Likes on 0 Posts
Default

Iam not sure did i get it right. So you are using a S4/951S caliper with bigger rotor than S4/951S normally use. It would be good to put a picture of that caliper adapter here, so we can see how it is done. I suppose this is quite easy to do, you just need longer caliper bolts and a spacer type of adapter between caliper & spindle, which moves caliper outwards to accept a bigger rotor.So if the price is almost 500$ for that, it's IMHO quite expensive. You can have suitable spacer done at local machine shop about 50-100$ depending material to be used. I can understand 500$ price tag if you offer adapters for non S 951 models which use axial attachment calipers.
Olli Snellman is offline  
Old 02-06-2009, 04:44 AM
  #4  
333pg333
Addict
Rennlist Member
 
333pg333's Avatar
 
Join Date: Feb 2006
Location: Australia
Posts: 18,498
Received 2 Likes on 2 Posts
Default

Mark is working off the principle of leverage here. You go up in rotor size to increase the potential for exerting greater leverage and apply the same pad size as our standard Medium Blacks. There's no reason why it shouldn't work better? On face value the Big Reds offer the largest jump in pad area cm2 over the next size down. ie 112.5 cm2 vs 151cm2. This is a big jump up in swept area, but he would contend that this extra area is down towards the hub and not nearly as efficient as on the outside of the rotor. Plus Porsche never repeated this format pad. They went wider rather than higher.
I guess the only possible downside is extra unsprung weight of the rotor plus more inertia to have to turn and stop. Having said that, all modern supercars have bigger rotors than even the large 995 drilled 332mm discs.
So you're saying that for $725 shipped Cont US you get the 2 drilled Porsche rotors and the adapters? That sounds pretty good for you US guys?
333pg333 is offline  
Old 02-06-2009, 06:26 AM
  #5  
azmi951
Super User
 
azmi951's Avatar
 
Join Date: Apr 2004
Location: Tucson AZ, Dallas Tx sometimes
Posts: 2,961
Likes: 0
Received 0 Likes on 0 Posts
Default

I will take a bolt and spacer kit since I dont need rotos for a little while but would liek to get in on this.

The larger rotors will have a much greater heat capacity due to more mass thus prolonging fade as well as greater heat dissapation due to the longer vanes and larger diameter. The larger diameter increases the velocity of the air at the exit to the vanes causing lower pressure and a tiny bit more airflow too. Remeber the area increase is the square of the radius and the area is what will determine brake cooling.

There is a lot of little details in the physics of why this is a good system. They all combine to make a very good cheap big brake kit.
azmi951 is offline  
Old 02-06-2009, 06:26 AM
  #6  
mikeroz
User
 
mikeroz's Avatar
 
Join Date: Jan 2007
Location: UK
Posts: 73
Likes: 0
Received 0 Likes on 0 Posts
Default

Mark,
This seems like an excellent idea, especially for me as I've recently had my M030 calipers fully rebuilt and powder coated (they look great) but didn't replace my rotors because they looked OK.
Because the cost of shipping heavy rotors across the water to UK would be quite expensive, would you be prepared to supply just the adaptor kit plus part number for the rotors?
If so, how much would these cost excluding shipping? If you give me the weigths I can work out shipping costs from USPS website; i've had enough things shipped from the US to know my way around their website.
Cheers
Mike
mikeroz is offline  
Old 02-06-2009, 06:45 AM
  #7  
edh
User
 
edh's Avatar
 
Join Date: Mar 2004
Location: UK
Posts: 70
Likes: 0
Received 0 Likes on 0 Posts
Default

Looks interesting - Do you need to go to 17"s with this mod?
edh is offline  
Old 02-06-2009, 08:03 AM
  #8  
Diver944
User
 
Diver944's Avatar
 
Join Date: Nov 2001
Location: UK
Posts: 529
Likes: 0
Received 0 Likes on 0 Posts
Default

A guy in the UK with S4 brakes on his 993 did this a few years ago and wrote a nice website with his findings. As well as using an 11mm spacer so the S4 calliper fitted over the 322mm disks he then went a step further and modified the calliper so that Big Black pads would fit inside the S4 calliper

http://www.sandher.com/Mark_Cole_BrakesMod.htm

Here's what they looked like

Diver944 is offline  
Old 02-06-2009, 09:21 AM
  #9  
Chris White
Addict
Rennlist Member

Rennlist Small
Business Sponsor

 
Chris White's Avatar
 
Join Date: Jul 2001
Location: Marietta, NY
Posts: 7,396
Likes: 0
Received 0 Likes on 0 Posts
Default

A little info here –
Big Reds and Big Black (S4 caliper and 951S caliper) are the same casting, the only difference is that the big reds are set up for use on the trailing edge of the rotor and the black on the leading edge – all you have to do is swap the bleeders and the crossover pipe (5 minutes) and they are the same.
The cost of Marks kit is really the rotors – not cheap parts and the shipping is not cheap either!
Most likely you will have to run 17” wheels – it all depends on the casting of the wheel.
Chris White is offline  
Old 02-06-2009, 09:38 AM
  #10  
Olli Snellman
Super User
 
Olli Snellman's Avatar
 
Join Date: Jun 2001
Location: Finland
Posts: 4,479
Likes: 0
Received 0 Likes on 0 Posts
Default

If you need only adapters, they are basically a block of aluminium/iron with holes drilled to them. I suppose most of us can even fabricate them ourselves, so the cost is few $/€ per side. Also longer bolts can be found very easily locally.I bought longer (high grade)bolts for 4€.

Here's picture of spacers which can be found from the URL Paul sent.

I suppose no rocket science with these


I suppose these are the spacers Mark use


Last edited by Olli Snellman; 02-06-2009 at 10:17 AM.
Olli Snellman is offline  
Old 02-06-2009, 11:38 AM
  #11  
PorscheDoc
Addict
Rennlist Member


Rennlist
Site Sponsor
 
PorscheDoc's Avatar
 
Join Date: Sep 2003
Location: Under Your Car
Posts: 8,027
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Chris White View Post
A little info here –
Big Reds and Big Black (S4 caliper and 951S caliper) are the same casting, the only difference is that the big reds are set up for use on the trailing edge of the rotor and the black on the leading edge – all you have to do is swap the bleeders and the crossover pipe (5 minutes) and they are the same.
The cost of Marks kit is really the rotors – not cheap parts and the shipping is not cheap either!
Most likely you will have to run 17” wheels – it all depends on the casting of the wheel.
One other difference, the big reds/blacks use a deeper pad holder. If you try and shove big red brake pads in a 951S caliper, they stick out the top and you can't shut the gate.

FWIW, I ran S4 calipers, and 3.6L rotors, and had horrible brake squeal (like ear shattering brake squeal). Tried numerous sets of different pads to no avail. I attributed it to the s4 pad not covering the entire width of the 965 rotor, but that was a guess. I finally pulled them and went back to stock calipers.
PorscheDoc is offline  
Old 02-06-2009, 12:55 PM
  #12  
milani
User
 
Join Date: Mar 2007
Location: Canada
Posts: 79
Likes: 0
Received 0 Likes on 0 Posts
Default

Very interesting, but I assume this kit wouldn't fit under the Turbo's stock 16 inch wheels (i.e. the Club Sports on the Turbo S).

Also very interesting that the S4 calipers are the same size as the calipers on the F50. That's a quite the fun fact!
milani is offline  
Old 02-06-2009, 12:56 PM
  #13  
Techno Duck
Super User
 
Techno Duck's Avatar
 
Join Date: Jun 2003
Location: San Diego, CA
Posts: 9,971
Likes: 0
Received 0 Likes on 0 Posts
Default

If you could perhaps come up with an integral adapter to go from axial to radial mount i would be interested in that, but either way am interested in just the adapters also. Alot of us 951 guys are just using adapters to go with larger front calipers as the Turbo S / 968 M030 front radial mount spindles go for 2x-3x the cost of normal axial mount spindles. I have S4 calipers waiting to go on my car but have not bough the adapters for them yet. If i would get a one piece adapter i would much rather do that then deal with having two different adapters stacked on each other (not a big deal, but if i can simplify the mounting that would be nice). I am interested in doing this because i would like the extra thermal capacity aswell as increase the swept radius as mentioned. I actually thought about buying the big blacks, but figure not really worth it cost wise..but this makes for a viable cost / performance option.
Techno Duck is offline  
Old 02-06-2009, 02:38 PM
  #14  
Kool
Part of the IN Crowd
Rennlist Member
 
Kool's Avatar
 
Join Date: Feb 2002
Location: Simpsonville, SC
Posts: 4,637
Likes: 0
Received 0 Likes on 0 Posts
Default

I thought Big Reds(993TT) and Big Blacks(928 GTS) were the same. And 928 S4/951S(Medium Blacks) were the same?
Kool is offline  
Old 02-06-2009, 02:42 PM
  #15  
Techno Duck
Super User
 
Techno Duck's Avatar
 
Join Date: Jun 2003
Location: San Diego, CA
Posts: 9,971
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Kool View Post
I thought Big Reds(993TT) and Big Blacks(928 GTS) were the same. And 928 S4/951S(Medium Blacks) were the same?
That is right. What is being done here with the adapters is allowing you to use the S4 / 951S caliper with the larger diameter rotor of the Big Red / Big Blacks. The rotor diameter difference is 304mm vs 322mm, thickness is the same. I guess the point with the F50is that it used the same sized S4 / 951S caliper with a 14'' rotor (355mm) diameter rotor.

Last edited by Techno Duck; 02-06-2009 at 06:28 PM.
Techno Duck is offline  

Thread Tools
Search this Thread
Quick Reply: Big red brake upgrade without the red - Interested?


Contact Us - About Us - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: