968 Big (REALLY BIG) brake and wheel questions, whats compatible?
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I have a bit of a monster on my hands, 1992 968 with a GM LS2 in it, over 400hp and going to roughly 575hp. I just bought the car I had intended on building on a 944 chassis I had around. Though I have not had a 951 in a few years it occurred to me that the 968 will take the 993TT rotor and caliper with an adapter. SO, if that is the case it would also take an upgrade to the 993TT would it not? I am thinking of using Stoptech 355mm rotors and their ST60 caliper. Can anyone confirm or deny?
Next, I had the chance to ride in a 968 Turbo RS owned by Bruce before it went to Texas. IIRC correctly that car had 18x10 front wheels and 18x11 Rear wheels. Tire sizes 265 front, 305 rear. All under stock factory fenders. My thinking is get the specs of those wheels and simply add 1 1/2 or 2" to the outside. The plan, if there is ever a plan for a new project, is to use the GT2 style 968 flares. In a perfect world I'd fit 305/35/18's in the front and 335/35/18's in the rear.
Any thoughts or info are welcome.
Next, I had the chance to ride in a 968 Turbo RS owned by Bruce before it went to Texas. IIRC correctly that car had 18x10 front wheels and 18x11 Rear wheels. Tire sizes 265 front, 305 rear. All under stock factory fenders. My thinking is get the specs of those wheels and simply add 1 1/2 or 2" to the outside. The plan, if there is ever a plan for a new project, is to use the GT2 style 968 flares. In a perfect world I'd fit 305/35/18's in the front and 335/35/18's in the rear.
Any thoughts or info are welcome.
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I have a Lindsey Racing big red kit on my 3.0L turbo car. They work wonderfully. I run 14psi @ 410HP and the brakes work great for a full day HPDE at Sebring even in the summer.
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I had that kit years ago, it just seems like for roughly equal money I can get a larger system. The Porsche parts have gotten expensive over the years and have not changed. I always had problems with the 993TT rotors cracking.
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Why not source some 996/997 GT3 six piston calipers and run Cayenne 335mm rotors? It's cheap (relatively) and is a very effective setup. The hardest part will be getting the adapters for the calipers.
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I have a guy that will make me the adapters for free, the rotors are bolt on with a suitable backspacing? I think I'm going to want to go larger than 335mm, mostly for the appearance of it.
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Also, what spindles/hubs do you have? M030 are radial mount, non-M030 are axial. Each one has its limitation for calipers.
Only on M030 spindles do Big Reds bolt-on, IIRC.
Big Reds were hot stuff fifteen to twenty years ago. But they cannot keep up with modern tire technology on cars with more power than a 993TT.
FWIW, Big Reds are essentially a M030/GTS caliper designed for a larger rotor and have the same 36/44mm piston size IIRC.
Anything appreciably larger than a 993TT caliper/rotor is going to require an 18" wheel minimum, sometimes a 19" unless you have 18s designed for high clearance.
A good idea on paper, but the ceramic pucks crack very easily. It is necessary to always have spares (for each piston size) or to rebuild the calipers with pistons that don't require the insulator.
Plenty of documentation on the GT3 forums. If you're looking for a real brake upgrade, I don't think they are worth it. They aren't a motorsport caliper to begin with.
Nice job integrating the 993 headlights!
Last edited by FrenchToast; 05-04-2017 at 02:23 AM.
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What brakes do you have now? What is the problem? Overheating, fade, overpowered?
Also, what spindles/hubs do you have? M030 are radial mount, non-M030 are axial. Each one has its limitation for calipers.
Only on M030 spindles do Big Reds bolt-on, IIRC.
Big Reds were hot stuff fifteen to twenty years ago. But they cannot keep up with modern tire technology on cars with more power than a 993TT.
FWIW, Big Reds are essentially a M030/GTS caliper designed for a larger rotor and have the same 36/44mm piston size IIRC.
Anything appreciably larger than a 993TT caliper/rotor is going to require an 18" wheel minimum, sometimes a 19" unless you have 18s designed for high clearance.
Fine for the street perhaps, but if you do any regular track driving I wouldn't recommend them. All the Porsche six-piston street calipers have ceramic pucks as a heat insulator.
A good idea on paper, but the ceramic pucks crack very easily. It is necessary to always have spares (for each piston size) or to rebuild the calipers with pistons that don't require the insulator.
Plenty of documentation on the GT3 forums. If you're looking for a real brake upgrade, I don't think they are worth it. They aren't a motorsport caliper to begin with.
Nice job integrating the 993 headlights!
Also, what spindles/hubs do you have? M030 are radial mount, non-M030 are axial. Each one has its limitation for calipers.
Only on M030 spindles do Big Reds bolt-on, IIRC.
Big Reds were hot stuff fifteen to twenty years ago. But they cannot keep up with modern tire technology on cars with more power than a 993TT.
FWIW, Big Reds are essentially a M030/GTS caliper designed for a larger rotor and have the same 36/44mm piston size IIRC.
Anything appreciably larger than a 993TT caliper/rotor is going to require an 18" wheel minimum, sometimes a 19" unless you have 18s designed for high clearance.
Fine for the street perhaps, but if you do any regular track driving I wouldn't recommend them. All the Porsche six-piston street calipers have ceramic pucks as a heat insulator.
A good idea on paper, but the ceramic pucks crack very easily. It is necessary to always have spares (for each piston size) or to rebuild the calipers with pistons that don't require the insulator.
Plenty of documentation on the GT3 forums. If you're looking for a real brake upgrade, I don't think they are worth it. They aren't a motorsport caliper to begin with.
Nice job integrating the 993 headlights!
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https://rennlist.com/forums/991-gt3-...-products.html
These guys should have all the #s.
As far as I know this is the holy grail of brakes. https://www.essexparts.com/news-blog...-radical-story
These guys should have all the #s.
As far as I know this is the holy grail of brakes. https://www.essexparts.com/news-blog...-radical-story
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Part of this is for looks, the car is on 18" wheels. Likely 19's are going on the winter with a widebody kit as few tires in the widths I want are available in 18". Even 328mm rotors start to look small behind larger wheels. The days of 17" wheels being top spec are far behind us. My wifes leased civic has 18"s. The other part is performance, the car will be a street legal track car but trending toward the extreme end of what you would put on the street. As the car has twice the displacement, number of cylinders and HP I figured this plate was appropriate.
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Part of this is for looks, the car is on 18" wheels. Likely 19's are going on the winter with a widebody kit as few tires in the widths I want are available in 18". Even 328mm rotors start to look small behind larger wheels. The days of 17" wheels being top spec are far behind us. My wifes leased civic has 18"s. The other part is performance, the car will be a street legal track car but trending toward the extreme end of what you would put on the street. As the car has twice the displacement, number of cylinders and HP I figured this plate was appropriate.
I think most professional production-based track cars all run 18" wheels at the maximum (at least in the front). As such, some of the best brake systems out there are designed to fit under a motorsport, high clearance 18" wheel.
While part of it is surely regulation, I think 18" wheels likely provide a good compromise of brake rotor size and sidewall flex.
For track tires 18" has a very good selection - probably the best. However I cannot say for high performance street tires.
In other words, maximum (for all intents and purposes) performance is achievable with 18" wheels. 19" is not necessary. Not to mention 19" is going to be more expensive in both the wheels and tires department. And most likely weigh more.
If you only want 19" because they are bigger than what a Civic has, then that is silly. The Civic only has 18s for the looks.