6/8 piston caliper and disc upgrade for F355

Going to upgrade to bigger 4 pot calipers because of the 355mm rotors I'm installing. Will also upgrade the brake fluid (I use SRF in my Elise) and the hoses to steel braided. We're also working on a good ducting solution. Will leave the rear calipers alone but will groove the rear rotors.

 

I'm interested....

 

Some basics about brakes:

Braided lines will not improve your braking. They give an ever so slightly firmer feel at the pedal, but will not change your ability to stop shorter or reduce heat. I am comparing new rubber to new stainless. If you have worn rubber lines swelling can occur, the wear is your problem, not the material. Stainless steel is used in racing for durability, not to stop faster. Stainless lines are also replaced more often as you can't detect wear as you would in a rubber line.

Larger rotors and calipers will not necessarily make you stop any sooner. The biggest advantage of a bigger rotor is the reduction in heat build up. It helps on lap 15, not on lap 5. Thats why most people install air ducts first before changing their rotors.

You seem unsure if the 996TT had ceramic or steel. Look at the calipers. With Porsche, ceramic brakes are always paired with a yellow caliper. Just a yellow caliper is not an indication of ceramic, however, as you can still run a yellow caliper with steel. All things being equal, a Porsche will outbrake other cars due to its weight dristribution of 40/60 front to rear. Why do you think they had brake mods done? What mods are you referring to?

Sensible upgrade path for brakes:

1) Improve driving ability, use brakes less
2) Hi performance fluid
3) Hi performance pad (note Pagid has several formulas, which are you using?)
4) Air ducts for cooling
5) Caliper/rotor change

About improving lap times:

Short stopping distances don't matter a whole lot, relatively speaking. Time isn't lost because you can't slow down fast enough, its lost because you slow down too much. My hunch is you were 'outbraked' because they could carry faster speeds than you through the turn. They did not need to slow down as much as you so they began their braking later. Read any book on racing and you'll see the braking zone is far down on the list for areas to look for speed.

I'm not trying to pick on you, just trying to save you a little money. I went through a similar progression with my 911. It currently wears 930 rotors and calipers in a 2500 lb car, but I am still 'outbraked' by better drivers in Miatas.

 

I keep being puzzled by how often people jump at changing the front calipers without consideration of the rest of the brake SYSTEM. Unless the total piston area of the replacement 6,8, or 10 piston caliper is the same then you will significantly impact pedal feel and travel, and front-rear brake balance. On their own I don't see how lots of little pistons would be better at heat-dissipation and I would not expect that new calipers offer a big increase in pad swept-area.

 

Dennis, Slashmatt, Rob, & John are spot-on here.

 

While multiple factors figure into how quickly a car can stop, incuding suspension geometry, tire contact patch, weight distribution, etc., the reality is every factor can be modified/optimized. Yes, putting bigger tires on the car, e.g., 245 or 255 mm front and 315 mm rear will help.

Out of the box the 355 has good weight distribution for braking, as do mostl mid-engined/rear engined cars.

But, when you are "optimizing" each link in the system, there can be no denying basic physics: (1) a larger disc gives greater brake leverage for stopping; (2) a larger caliper with more piston surface area/more pistons will result in increased and more even clamping force, and (3) multiple brake pad systems give more bite and better feel.

The reality is the over two ton mercedes stop as quick as a 360, have mushy (by comparison) suspensions and are front heavy. They clearly benefit from the larger rotors and 8 piston calipers which allow them to stop so quick.

If anyone is interested, I have a new 355 mm brake kit for a 355. I bought it thinking/hoping it might fit a 308 project (nope!) Kit includes red F50 style brake calipers, cross drilled 355mm discos and alum hats which together weigh only about 14 lbs! Brake adapters and pads are also included.

 

You're right, and no offence was taken. This is a good post. The pagids were 4-2-1 and do a great job of hauling off the speed. There are better pads out there though.

I guess my point is I could either adapt to the current brakes and learn to drive the car better with them, or, upgfrade the brakes so I can take that issue out of the total equation. I don't have the time to settle for the current brakes because I can only track the car a couple of times a year. We can't just turn up to the track here with our road cars. We have to get permits to drive in china, police escort, etc etc. The next time I put my 355 on the track, I want it to have a fast track spec.

Thanks for all the replies, I hope people found this thread interesting.

 

I've got a new, four wheel brake kit for the 355 that I will not be using. It features 355 mm brake cross drilled brake discs up front and red F50 style brake calipers. The rear brakes are 332 MM and also use F50 style calipers. The brake discs are mounted to aluminum brake hats. The brakes actually weigh less, overall, than the OEM brakes and are MUCH MUCH bigger. Red calipers, giant cross drilled rotors. Looks and performance. $4600 takes the whole system.

 

tonyyoshi.
_________

I saw your vid where you drove the zhuhai circuit.

your brakes are not your problem. you , no offense , just need
to drive better.

 

I'm glad you said it. I really didn't want to... You are 100% correct.

 

for the 2nd time, that was at the end of all the sessions and was purely to record the sound of the exhaust. 1 355 had already crashed that morning. my tyres were shagged from driving at 280kmh all the way from hk to the track. ignore the video. i was going roughly 40 seconds slower in that video that i was the day before. also, if any of you beagle eyed couch potatoes had noticed, i did'nt even push it.