355 brake upgrade?

I'm not sure if I ever heard of anything like that, even on Hondas where there is a ton of aftermarket support. Without a larger caliper, and larger brake pads, would having a larger diameter rotor actually do anything besides add weight?

 

You can machine adapters to your stock calipers, so they fit bigger rotors - but - check the radius inside the stock calipers first, if it is possible to fit bigger rotors.

Bigger rotors = more brake effect with less power...

I think Movit has some 380 mm kit with both calipers and discs, front, and they also have big brakes for your rear. Anyone know the prices? 380 mm discs in front with 6-piston calipers, and 355 mm discs in rear with 4-piston calipers is usually a good combo...

Kimmo/Sweden.

 

I would use the 355 challenge brake setup. easy conversion and rotors available.

I believe the Movit is the carbon brakes and last I checked they were well over 10k an axle.

regards, Jim

 

Jay, there are 4 reasons NOT to use CH brakes:

1. Noisey....too much for a dailey driver..just ask Llenroc, if it hadn't been for his advice I would have made this mistake.

2. WAY to expensive

3. Will NOT work with regular street wheels unless you use spacers...will work with the CH Speedline wheels

4. CH hats have small mounting holes..you either have to re-drill all the holes to reuse lug bolts, or buy the CH wheel studs and caps..price??? ASTRONOMICAL!!!!

MoveIT makes a cast iron rotor big brake kit...

As for me, I'm running the BREMBO GT big brake kits front and rear(virtually the same as the CH w/out the noise)....using slotted StopTech rotors front and Brembo cross-drilled on rear w/no emergency brake system.

 

We have sold the Brembo Big Brake kits -- folks seem to love them, and have had no issues.

 

Bigger rotors with the same calipers and pads will not increase your braking torque. The surface area of the pad making contact with the rotor does not change with a bigger rotor, therefore the torque is the same.

What a bigger rotor will do for you is increase the braking system's ability to dissapate heat. So if you are experiencing brake fade due to heat, it will help solve this problem.

If you want more torque, the easiest thing to do is change your brake pad to something more aggressive.

If heat is your problem, I would try a fluid change first (Motul for a street car, SRF for the track) and different pads first, then consider a rotor and change.

My experience has been the the 355 brakes are adequate on the street but horrible on the track. They do need the Challenge car set-up for the track.

 

I put an AP Racing brake kit on my 348 recently.

6 pot calipers with 355mm discs for the 348 and 355.

They tend to activate the ABS more and lock the wheels, but they don't fade...they just keep going and going....

Company is horrible to deal with though. Real pain in the ass. Took me 12 weeks to get a set after they lost my initial set.
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Bruce----There are different studs to use CH wheels??

 

Robbie, the CH cars used studs and cap nuts..not lugbolts. The reason is that during quick tire changes the studs locate and hold the wheel...much easier than using the lugbolts that do not support the wheel or locate the wheel hub mounting holes.

The CH studs are smaller diameter than the street car lugbolt shaft, but the CH cap nut is the same diameter and taper as the lugbolt head.

The CH studs having a smaller shaft diam. required the aluminum brake rotor hats to be drilled accordingly(smaller than lugbolt diam.). So the CH brake rotor hats will not work with the lugbolt set-up.

The CH wheels however, have the same aluminum inserts as the street wheels , which allow you to use either the CH stud/cap nuts or the street lugbolts.

 

Brembo! IMO - Italian Car deserves Italian brakes. Don't forget the steel lines and super blue fluid.

 

Jay, you are spot-on with your thinking.

The physics are very simple. Same exact principle used when using a breaker bar for nut removal...1ft long breaker bar may cause you to work up a sweat to loosen a nut, but if you use a 4ft long breaker bar it comes off easily with very little energy input from you yet producing the same amount of torque.

Hence, the greater the diameter from the pivot/axis point the less energy required...less energy=less heat.

That is why on larger diameter rotors the break surface area of the rotor is not much bigger(i.e. proportional to the increase in diameter)....the hat gets bigger so as to dissipate the heat thus minimizing the heat transfer to the wheel bearings. The calipers are larger w/more pots which evenly distribute the heat in the caliper to the rotor.

Using the example of the breaker bar, I like to think of me being the caliper and the rotor being my breaker bar and the wheel mounting hub as the nut.

Hope this helps.....

 

I have Stoptech big brake upgrade on my 95 F355 and love them, also very inexpensive. You should check out their website Stoptech.com

 

I can't really agree with your analysis.
When you stop a 1400kg car from 100km/h to 0 km/h , you have to dissipate exactly the same amount of heat whatever is the size of the rotors.

If I take your breaker bar analogy, with a long bar you have to apply less force for the same torque BUT you have to travel more (the displacement is bigger at the extremity of a long bar) for a given rotation angle and then you will need the same amount of energy. A short bar will require more force BUT a smaller travel then the same energy . By definition, energy is Force X displacement.

That is exactly the same for the rotors. For the same acceptable torque by the tire, you will need less clamping force on a large rotor BUT the linear speed (angular speed X radius) is higher. Hence the same power, the same energy for the braking duration, and the same heat.

The interest of a larger rotor is that it is heavier, has more material, and the maximum temperature will be lower when submitted to the same amount of heat that a smaller rotor. Brakes with large rotors are less prone to fade because temperatures are lower than the ones with small rotors under the same braking conditions.

 

And the winner is??????????????? ERIC355 in France!!!!

My post #14 appears to be plausible, creditable, and factual, but it's NOT. That scenerio is to some degree held by those who do not understand how brake systems work. I am glad Eric was thinking and was willing to post his challenge to my claims.

Isaac Newton came up with the "law of motion" which ststes that a object in motion will stay in motion unless acted upon by an outside force. Because of his discovery we are able to measure/compute how much force it will take to stop an object of a given mass traveling at a given speed.

Anybody who works on brakes knows what brake rotors do. They provide a friction surface for the disc brake pads to rub against when the brakes are applied. The friction created by the pads rubbing against the rotor generates heat and brings the vehicle to a stop.

The underlying scientific principle here is that friction converts motion into heat, a LOT of heat! The amount of heat that is generated depends on the speed and weight of the vehicle, and how hard the brakes are applied.

Think of heat as a form of energy or power. A more familiar term is "horsepower." We all know what horsepower is, right? It is the stuff that spins the crankshaft when fuel is burned inside an engine. Combustion produces heat, and heat pushes the pistons that make the crankshaft go around. One horsepower is equal to 33,000 pounds-feet of torque per minute, or 550 pounds-feet per second.

We measure an engines horsepower output by hooking it up to a dyno and seeing how much force it can exert against the resistance created by the dyno. In effect, the dyno acts like a giant brake, so the engines power output is sometimes called its "brake" horsepower output.

By the same token, we can also measure how much horsepower a vehicles brakes must absorb when bringing the vehicle to a stop from a given speed. This is also called "brake" horsepower, but in this case it refers to the brake system, not the engine.

The brake systems on vehicles must be capable of absorbing a lot more horsepower than the engine typically produces because the heat (power) that is generated when braking occurs over a short period of time. Thus, a small car might only need 100 horsepower from the engine to accelerate from zero to a speed of 60 mph. If the driver slams on the brakes and comes to a screeching halt, the brakes have to absorb all the momentum in a much shorter period of time. This multiples the amount of horsepower that must be absorbed, as much as six times depending on the stopping distance. So a panic stop from 60 mph might require the brakes to absorb the equivalent of up to 600 horsepower!

Do not worry about the math because it depends on the speed and mass of the vehicle and the stopping distance. The important point is the brakes often have to absorb a great deal of heat in a very short period of time.

How much heat, you ask? Using more math, units of horsepower can be converted into units of heat energy called BTUs (British Thermal Units). One BTU is the amount of heat it takes to raise one pound of water one degree Fahrenheit.

If you multiply horsepower by the proper conversion factor, you discover that one horsepower generates 42.4 BTUs of heat per minute. If stopping a 4,000 lb. vehicle from 60 mph in roughly 150 feet requires 600 horsepower of force, it is the equivalent of 25,440 BTUs of heat, which is enough heat to raise 15 gallons of water from zero degrees to boiling! No wonder the brakes get so hot.

One thing all brake manufacturers monitor very closely when testing and evaluating pads and rotors is the temperature of the brakes. Every time the brakes are applied, the pads and rotors generate heat that must be absorbed and dissipated. A quick stop from 60 mph can easily push the rotor temperature up 150 or more degrees. Several hard stops in quick succession can push brake temperatures into the 600, 700 or even 800 degree range. Remember, the heavier the vehicle, the more heat it creates when it brakes.

When brake temperatures get too high, the pads and rotors are no longer able to absorb any more heat and lose their ability to create any additional friction. As the driver presses harder and harder on the brake pedal, he feels less and less response from his overheated brakes. Eventually, he loses his brakes altogether.

All brakes will fade beyond a certain temperature. Semi-metallic linings can usually take more heat than nonasbestos organic or low-met linings. Vented rotors can dissipate heat more rapidly than nonvented solid rotors. Thus, high performance cars and heavier vehicles often have vented rotors and semi-metallic front brake pads to handle high brake temperatures. But if the brakes get hot enough, even the best ones will fade.

Big rotors can obviously handle more heat than small rotors.

Vehicle manufacturers use a wide variety of different cooling rib configurations in their rotors. They do this to optimize cooling for different vehicle applications. So even though the brakes may appear to be identical on two different models, one may require increased cooling because the vehicle is heavier, has a more powerful engine, has less airflow around the brakes, etc.

The OEMs currently use almost 70 different rib configurations in their rotors. Some ribs are straight, some are curved and some are even segmented. Some rotors are directional and some are not. Some rotors have evenly spaced ribs while others do not. Some ribs radiate outward from the center and others go every which way.

One reason why they use so many different rib patterns is to maximize cooling and to reduce harmonics that contribute to brake squeal. Changing the rib design changes the airflow, cooling and noise characteristics of the rotor, which may make things better or worse depending on the application. That is why some aftermarket rotor manufacturers use the same basic design as the original, while others stick with more traditional venting.

Another critical area in brake systems of high performance cars is the 2 piece design where the hat and rotor assembly are indiviually made of different materials...the hat being aluminum and the rotor either cast iron or carbon ceramic. This hat aids in dissipating heat from the rotor and at the same time minimizes heat from the rotor being transferred into the hub,hub carrier, and wheel bearings....also a floating hat design allows the rotor to flex when it gets hot to reduce the risk of warping and cracking.

So why am I writing this long post???????????????? Brembo,AP,StopTech,MoveIT, and GiroDisc spend alot of time(and $$$$) developing and testing COMPLETE brake systems(calipers,rotors,hats,pads,brake lines,fluid,etc.) for a variety of vehicles along with the particular demands of either street or track use. So there is no need to reinvent the wheel(or brake system).....you may say the after market systems cost too much, but in the end they have been tested and won't let you down when it comes time to SLOW DOWN or STOP...

 

Nothing to add Bruce .....





except, why damn do you use these units ???? ..........

 

Most of the time people spend the $$$ for asthetics..the bling bling thingy. In my case it's for that(BIG TIME...lol), and occasionally I'll be at the track. But either way when the Georgia Highway Patrol pulls me over I want to stop effeciently so I can help support the State with my financial donation...lol

 

I understand for the brake parts .....

I was talking about your damn measurement units ...... so difficult to understand and convert here!!

 

After reading some of the the long winded responses above. I have to say that your post and break pictures are worthy of a thumbs up pal Nice set up, and thanks for the pictures.
Would it be worth while deactivating the ABS or not Angelis.

 

I have the Brembo BBK on all four corners (with parking brake), and it is fantastic. It's not cheap, but it's actually a fair market price, not the usual Ferrari markup. I know Daniel sent one out recently. It is absolutely the biggest kit you can get under the factory wheels. You would not believe how close the tolerance is in the front.

Do NOT deactivate the ABS. If the ABS is kicking in, it means the wheels are locking; that is to say the brake torque and pedal pressure are stopping the wheels. With the ABS disabled, the wheels would be fully locked.

The ABS has no idea what calipers/rotors/pads you are using. It simply monitors whether or not a wheel is locking up and releases the brake pressure for an instant if it is. If you put in a grippier pad, then you will lock the wheels with less force from your foot. You just have to adjust your braking technique if you want to stay out of it. But ABS stops better than even the best threshold brakers. It is not allowed in most race cars, but I assure you, if it were, they would use it. Don't buy into the track bravado talk and think that you will get better performance without it. You will not, and you could really have issues in low traction situations (ie rain).

 

OK, sorry I misunderstood....atleast you know now that I like some BLING BLING..

Yes it would be nice if the whole world would go metric.....I even confuse myself with the old British measurements....lol

 

A summary of this conclusion is in post #8

 

I just knocked out the wheel inserts from my CH wheels to send the wheels to podercoat. The wheel inserts are not the same as the ones in my stock 355 wheels. I have been told the CH wheels require a longer wheel bolt also. I am guessing as long as I use the CH wheel inserts with the CH wheels and a longer wheel bolt I should have no problems??