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I wonder if the hats they sell work with the original 993tt rotor rings.
No. the mounting plane between hat and rotor-ring is different. The RB two-piece rotor setup mounts the hats to the center-plane of the ring, while Porsche 2-piece rotors mount the hats to the outer surface of the rings-- see the pics in Mark's post#1, those are all offset rotors. The theory is that center-plane mounting behaves better under thermal stress, and ventilates better.
Mark posted a link to RB's two-piece rotors to fit the 928-- their 928 hat and various ring options. What Mark is actually using is a custom hat to fit factory 993TT rings, and RB replacements for the factory rings. That works also, but doesn't have the advantages of center-mounting.
I can second Mark's recommendation for Racing Brake, great folks and great products. We upgraded our GT to GTS calipers (mo' power needs mo' brake) and fit a set of Racing Brake's 2516 two-piece rotors. Very high quality stuff and work great. We've pushed them much harder in the mountains than we could have with stock brakes, they just laughed.
what do they look like? are they the Brembo rings you use to mate to the hat? if so, that rotor is the same diameter as the GTS, 322mm, right? if it is a brembo ring, i think they have the replacements, and you can do what i did , by just using spacers and then using the brembo 332mm ring to get even MORE rotor diameter.
I believe they are stock 993TT 322mm 2-piece rotors, Ronn already had them installed when I got the car.
Jean-Louis did his 2:32.00 at RA with stock single-piston S brakes and Pagid Orange, and he never had brake fade.
So that tells me that Big Reds are already more than big enough for a fast track with a brake-zone of 150mph down to 75mph (..Turn 1), and 2 brake-zones of 150mph to 55mph (..Turn 5, and Canada), therefore, I'm not convinced the extra expense would be worth the extra swept area.
I believe they are stock 993TT 322mm 2-piece rotors, Ronn already had them installed when I got the car.
Jean-Louis did his 2:32.00 at RA with stock single-piston S brakes and Pagid Orange, and he never had brake fade.
So that tells me that Big Reds are already more than big enough for a fast track with a brake-zone of 150mph down to 75mph (..Turn 1), and 2 brake-zones of 150mph to 55mph (..Turn 5, and Canada), therefore, I'm not convinced the extra expense would be worth the extra swept area.
Its surely a good indication, but the true test is laguna. there is just more KE disspated there over a shorter time period . i also was able to get my car around laguna with S brakes in the 1:42 range... it wasnt fun, but it worked. Rons car driven by Joe at RA was spinning 1:32s that day as well, but we had some extreme heat and humidity.
i was running into some fade issues, getting to the limits at Laguna turn 1. the small percentage increase in mass was enough to solve the issue. enhanced further with the two piece rotors when i went to the 332mm. the aluminm hat wicks away heat VERY fast. bearing temps and hubs were much cooler after qual session
Originally Posted by jcorenman
No. the mounting plane between hat and rotor-ring is different. The RB two-piece rotor setup mounts the hats to the center-plane of the ring, while Porsche 2-piece rotors mount the hats to the outer surface of the rings-- see the pics in Mark's post#1, those are all offset rotors. The theory is that center-plane mounting behaves better under thermal stress, and ventilates better.
Mark posted a link to RB's two-piece rotors to fit the 928-- their 928 hat and various ring options. What Mark is actually using is a custom hat to fit factory 993TT rings, and RB replacements for the factory rings. That works also, but doesn't have the advantages of center-mounting.
I can second Mark's recommendation for Racing Brake, great folks and great products. We upgraded our GT to GTS calipers (mo' power needs mo' brake) and fit a set of Racing Brake's 2516 two-piece rotors. Very high quality stuff and work great. We've pushed them much harder in the mountains than we could have with stock brakes, they just laughed.
they are going to allow me to try the center mount rings with their hat soon. again, what i have in the picture, are the surface mount 332mm rings, that fit on brembo hats. i dont think they fit on porsche hats for the same surface mount. also i think the porsche dimention for the 993 ring is the 322mm you mention. the one im using now, is a match for the 332mm ring that brembo provides for other brake set ups.
Originally Posted by BC
I wonder if the hats they sell work with the original 993tt rotor rings.
see above .. do you have a picture of the rings and hats for the 993TT? they are probably very different.
Originally Posted by Basal Skull
394/390mm ccm's
now, those are biggies.... i think the most i could go with the new hat set up (brembo spec) would be a 340mm. there was no radiusing to use 332 with the porsche 964 turbo calipers (s4 like, but GTS radiused), so it stands to reason , i coud easly use a ring 8mm greater in diameter.
I must be too tired but this makes less sense now.
A 4 piston caliper upright for the 928 is from 86.5 to 95. These have the radial mount ears for any of the 4 piston calipers we normally use - s4 or GTS.
We can use 993tt rotors if we have hats made that align the 993tt rotors for use in this setup. The hats are deeper than the stock hats that come with the rotors stock.
I only have one set of 993tt rotors. And they are more expensive now than ever.
I must be too tired but this makes less sense now.
A 4 piston caliper upright for the 928 is from 86.5 to 95. These have the radial mount ears for any of the 4 piston calipers we normally use - s4 or GTS.
This is correct. Two different calipers, 86.5 thru 91 for 304mm rotors and 92-95 for GTS 322mm rotors. (Or spacers and a grinder )
Originally Posted by BC
We can use 993tt rotors if we have hats made that align the 993tt rotors for use in this setup. The hats are deeper than the stock hats that come with the rotors stock.
Also correct. The hats that come with the factory 993TT two-piece rotors are too shallow for the 928. Deeper hats have been made to fit 993TT 322mm rings to 86.5-95 928 hubs, with GTS calipers. It's an option, but requires reasonably-priced 993TT rotor rings. I have a pair of said hats, but went with RB's two-piece setup instead.
(Said hats might be available, if there is interest).
Originally Posted by BC
I only have one set of 993tt rotors. And they are more expensive now than ever.
And therein lies the rub. Personally I think it makes more sense to go with RB's center-mount two-piece setup.
can we see a picture of the "said 993TT " hats and rotors?
Originally Posted by jcorenman
This is correct. Two different calipers, 86.5 thru 91 for 304mm rotors and 92-95 for GTS 322mm rotors. (Or spacers and a grinder )
Also correct. The hats that come with the factory 993TT two-piece rotors are too shallow for the 928. Deeper hats have been made to fit 993TT 322mm rings to 86.5-95 928 hubs, with GTS calipers. It's an option, but requires reasonably-priced 993TT rotor rings. I have a pair of said hats, but went with RB's two-piece setup instead.
(Said hats might be available, if there is interest).
And therein lies the rub. Personally I think it makes more sense to go with RB's center-mount two-piece setup.
Also correct. The hats that come with the factory 993TT two-piece rotors are too shallow for the 928. Deeper hats have been made to fit 993TT 322mm rings to 86.5-95 928 hubs, with GTS calipers. It's an option, but requires reasonably-priced 993TT rotor rings. I have a pair of said hats, but went with RB's two-piece setup instead.
(Said hats might be available, if there is interest).
And RB does not make hats for these types of rotors because the rotors they make would mount to the hats differently - am I correct?
And RB does not make hats for these types of rotors because the rotors they make would mount to the hats differently - am I correct?
I am sure RB does not make hats for the 993TT stock rotor rings because they like their center-mount design better (as do I). That means the hats need to be taller, by roughly half the rotor thickness (the difference between center mount and surface mount). There is an illustration of the center-mount design at the bottom of this page: http://www.racingbrake.com/RB-Two-pi...p-9-p/2516.htm
Here's the RB 2516 setup on the front of our GT (with GTS calipers), the mounting surface is recessed to the ring center-plane. (Please pardon the dirt, it is winter and this is our "driver"):
And RB does not make hats for these types of rotors because the rotors they make would mount to the hats differently - am I correct?
actually, im using the 332mm surface mount rotors. I think they actuallly make surface mount rotors that fit the other sizes too, based on brembo specs.
Originally Posted by BC
I am interested Jim. I have aluminum hats for the 322s but they are pretty used.
the real question, and its where it gets a little confusing, there are 322mm rotors, GTS style, there is sufrace mount, and there is center mount and there is also narrow S4 pad swep size.
Originally Posted by jcorenman
Here you go. I took some measurements of these and new factory GTS rotors, will post tomorrow.
These look like charlies hats. for a GTS rotor, true? (surface mount, GTS caliper/pad size )
Originally Posted by jcorenman
I am sure RB does not make hats for the 993TT stock rotor rings because they like their center-mount design better (as do I). That means the hats need to be taller, by roughly half the rotor thickness (the difference between center mount and surface mount). There is an illustration of the center-mount design at the bottom of this page: http://www.racingbrake.com/RB-Two-pi...p-9-p/2516.htm
Here's the RB 2516 setup on the front of our GT (with GTS calipers), the mounting surface is recessed to the ring center-plane. (Please pardon the dirt, it is winter and this is our "driver"):
Here is the bigger than GTS , 332mm rotor diameter, but with a pad swept area for the S4 pad.
01-07-2018, 09:48 AM
Rons car driven by Joe at RA was spinning 1:32s that day as well, but we had some extreme heat and humidity.
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