Girodisc 2pc 348-355 Front rotors released

Eric,

I am a club sprint racer so I do not reach the repeat limit of even the OEM brakes with race pads and 3" ducts. So by your statement big brakes would not do much for me. I am not an engineer so please bare with me. At 100mph is about 150ft/sec travel. If a larger brake or more efficient brake can lock me up into ABS 0.1 seconds faster than stock that equals 1 car length (15 ft) on the race track. Therefore I effectively dive deeper in the corner by delaying braking 0.1 secs which may be all the margin needed in a close pass. Well maybe 0.2 secs is better but do see where I am going? So while a big brake and small brake get me to ABS and does not effect stopping distance since it is all about tire management what about the improved time to get to ABS due to larger big brake rotor torque and increased big caliper clamping forces? I know that brakes are not "stabbed" to lock-up but progressively applied for most stable efficient braking but does a big brake get me to threshold braking faster even if properly progressively used?

 

I would like to use the stock calipers on larger rotors too. Though I think the 'stock' caliper mounting bolts are a lateral configuration, so it would be hard to make an adapter due to holes being too close together IMO.

 

+1

Agree absolutely. Was at Laguna Seca 3 weeks ago and the ABS worked flawlessly, but only deep into the turn where it should.

 

You mean like this....14" front, 13" rear. Wilwood SRP drilled and slotted rotors, Wilwood Hats. Custom brackets, modified hats, and highly modifed rear rotors, since WW had limited rotor selection for that hat. Also, Goodridge hoses, and Wilwood 570 brake fluid. Hawk pads for the track and stock Brembo pads for the street.
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What size are these rotors??

 

That's sharp!

If you don't mind me asking, what "hat" would I order if (or would they work at all) I wanted the lightest realistic rotors for a daily-driven, non-raced 348 Spider?

Could scalloped rotors like these be ordered in some configuration to work on a 348 for street driving: http://www.stockcarproducts.com/brakes14g.htm

 

Did you want stock diameter or larger diameter rotors? The scalloped rotors are to narrow, they are for sprint cars, but cool none the less.

 

14" x 1.25" front; 13"x 1.10" rear. you could go with a 14 x 1.10 up front for a stock caliper but I have F-550 sport calipers up front, it uses a 14 x 1.25. The front conversion was super easy, the rear, was another story, 3 sets of rotors and 3 sets of hats to get something to fit over the large rear wheel hub area. Now, it can be done, but the rotor & hat still need alot of maching to get them to work. I'm sure if Wilwood gets enough requests for the rear rotor/hat combo they'll cut the rotors to size. Sure beats spending 6g's plus for a complete front/rear B-bo big brake kit

 

OK. Thanks. I would want the lightest (realistically) front rotors for a street 348. If my wife wants to drive the Spider, she'd appreciate lighter manual steering.

What else can I do besides lighter wheels...but lighter rotors? I wouldn't want to sacrifice street braking distance, but surely there are options, especially with a 2-piece rotor, lighter than OEM 348 front rotors.

 

Interesting.
If we do this for the 348-355 (and maybe 550, TR etc) Our kit will bolt right on and work with the rear ebrake without issue. We wont sell parts that require mods to the car.

Ill have to put a fire under the machinist to get some brackets cut and tested

Cheers
Eric

 

Throw some gas on that fire. I'll be looking at new front rotors soon. It would be great to give ya the business.


Darrell.

 

I think there'd be a market for brake kits that allowed the use of the OEM caliper and lightweight brake discs. A kit with an adapter bracket, lightweight rotor and maybe some stainless steel brake lines. IMO, all Ferraris, at least pre 360, could benefit from such a kit. The 355 caliper is a nice size as are, e.g., the 512 calipers. Such a kit would be great. I'd be down for a set for my 512 and 355. (The Brembo kit is too small for my $3k for 332 mm. I'd want at least 355mm/14")

What do you think Eric: Start a new thread to see how many folks would purchase the kit?

 

Kit already exists as stoptech front $2500ish or $5kish front and rear. Front's are 14" and do not require new master cylinder. Rumors from those who use stoptech say that the kits are well engineered to not need new master cylinders in general nor need rebiasing of brake balance.

 

Brembo makes a revised big brake kit (GT) for the 355 that has correct piston sizing. (F50 calipers with smaller piston sizing)

Stoptech has a nice big brake kit as well. Both work fine with the OE hydraulics and pedal set.

We designed a big brake kit at Girodisc utilizing AP racing 6 piston calipers of the correct size to work with the OE hydraulics and pedals....We never made it as we felt the competition was already too thick for that small market, and it wasnt worth the development-manufacturing cost.

I am working to get an extension bracket system to use the OE calipers with new Girodisc 2 pc rotors. The final sizing and details are still TBD. I need to be very sure that the repositioned calipers will not contact and surrounding equipment in bump/droop and full turn lock.

I also know that these brackets will see a great deal of stress due to the fact that they will be in axial/axial bolting condition, which is far from ideal. So the design, material, and finishing will have to be just right for us to be comfortable releasing it.

I am planning similar for 348-512TR-Testarossa-550/575. Just need to grow more arms to work fast enough.

Cheers
Eric

 

Pics of my 308 (aka "358") brakes: 380mm disc (just 13.2 pounds), aluminum bell (3.5 lbs) and eight piston brembos. Waiting on the 19" 3-piece wheels to install this ultimate system.

What size rotors are the new Brembo F355 kits?
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Reading all this with interest. Have ordered the Stoptech big brake front kit. Arriving in the next two months as they are out of stock. Would have been nice to go down a cheaper route but was sucked into this by a friend who swears by the Stoptech setup.

 

Please let us know how you like it. Stoptech is only 5 miles from me. Tell me if you can dive deeper into corners like my post that was not answered (missed) by Eric. I think there is more to big brakes than just repeat poundability but that is just intuitive thinking.

<<At 100mph is about 150ft/sec travel. If a larger brake or more efficient brake can lock me up into ABS 0.1 seconds faster than stock that equals 1 car length (15 ft) on the race track. Therefore I effectively dive deeper in the corner by delaying braking 0.1 secs which may be all the margin needed in a close pass. Well maybe 0.2 secs is better but do see where I am going? So while a big brake and small brake get me to ABS and does not effect stopping distance since it is all about tire management what about the improved time to get to ABS due to larger big brake rotor torque and increased big caliper clamping forces? I know that brakes are not "stabbed" to lock-up but progressively applied for most stable efficient braking but does a big brake get me to threshold braking faster even if properly progressively used?>>

 

This must be the one I missed, I will try to catch up today

Essentially you are exactly correct. Assume that the friction material is the same between a standard brake system and one with larger rotors and near identical piston size (number of pistons is irrelevant, only piston area matters)

The larger system will generate more brake torque at the same input brake line pressure as the standard system. This greater efficiency will means that you reach higher deceleration levels quicker.

The next benefit is thermal capacity and reserve. As example the standard system can be made to create higher levels of brake torque to match the larger brake system by using very aggressive racing pads. However it will simply 'burn out" meaning that it will run out of thermal capacity sooner and you will have fade, cracking, bearing damage etc... The larger brake unit has more capacity and is simply capable of sustaining braking longer. Now you can also go up in pad friction with the larger system, and staying within the thermal capacity for intended use, your efficiency over the standard system is very large indeed.

As for ultimate deceleration ability, if you are talking about a 355, it is determined by the ABS. Better tires and brakes simply get you to the threshold/locking point sooner, and let you stay there consistently for a longer time.

I hope this makes some sense. As you can see there are trade-offs that need to be addressed when choosing components. This is another reason why we start at the rotor and pad level to maximize what is already there.
Most people go to a brake kit for the "wow" value rather than really needing it. (I have bigger wheels and want to fill them in...). For those that really need more brakes, the kits on the market are pretty good now that they are within the right piston area window. Whether the ABS is still functioning properly once you change parts is another story...

Cheers
Eric

 

That is simply too much caliper and rotor for that car. The piston area of the Brembo 8p is way beyond what the OE 308 or 355 is designed to work with.

For the amount of work needed, it is also heavier than should be on those cars. More is better...is not always better.

Do you have a custom master cylinder setup? I would like to see pictures of that system mounted to the car.

Thant calipoer is great to slow a 3800 lb Murcielago, but is way overkill and not the correct match for the V8 Ferraris.

Eric

 

Can you locate matching "slotted" rears for the 355?

 

Sorry, No.

We can get the rear OE units, but they are tightly controlled for distribution, and our cost is just like everyones.

After we slot them, they end up costing us as much as we sell the fronts for. Nobody wants to pay more for the OE rears than our 2pc fronts.

It is a shame. We simply dont have an easy solution for the rear.

Eric

 

How much are the brembo OE rears?? Can you slot those??

 

Will do, though I feel it is going to enhance brake fade more than anything. Limitation as far as I know will always be the tyres tied to the ABS or ability of my foot to efficiently modulate the brakes.

 

I don't know that I'd agree Eric. Too much weight? Brake disc, hat and caliper weighing 28.7 pounds? The smaller StopTech hat and rotor alone weigh 16 pounds. In a nutshell, my 380mm 8 piston set up weighs about the same as others 355mm 4 piston kits. The Little Gallardo uses the same exact caliper and it's the V8 Ferrari competitor. The 8 piston Brembo also uses 4 pads per caliper which gives you twice the amount of "leading edge" which gives you the "bite" which drivers appreciate. The 8 piston is also a monobloc caliper, meaning not made of two pieces bolted together with heavy bolts. Ergo, she's lighter than one would expect. So, lightweight, good bite and ultimate power. What's wrong with that? My front tires will be 275mm. Rears at 345mm. Screw ABS. Will be using a larger bore Master but that's not such a big deal.

 

Here are some slotted rotors for the rear to match the fronts!!!

Link:

http://www.frozenrotors.com/products/power-slot-cryo/Ferrari/