Uprated brakes

[Nordschleife]

KayGee

That Audiworld post is better than most of them over there.

It entirely misses several important points, or misunderstands. As the information appears to be largely sourced from Stoptech, its a bit light on things that Stoptech don't do, understandably.

Monobloc callipers are machined from solid billet Aero grade Aluminium. There are no internal pressures from casting and no additional stresses induced by having to bolt components together to make the entire calliper. This is quite important in a street environment where callipers are not dissassembled after every race.

One of the other points missed by the article is the one of making sure that the swept piston volume suits the characteristics of the ABS system. This is an area where its best to tread carefully. Even companies like Porsche 'forget' to recallibrate the ABS system from time to time.

Finally, be careful not to fall into the trap of believing that if 4 pistons are better than 2 pistons, then 6 are better than 4, and 8 better than 6......... this is partially true, particularly in the Audi environment. The 8 piston callipers from Brembo that Audi is attached to, have 4 small pads. The combined surface area of the pads is less than it is on some other 6 piston callipers which have 2 large pads. This can have un-sought for side effects - the tiny pads catch fire under enthusiastic driving, they last for a short time and they have a high replacement price. Which is nice for the Audi Service department.

Brakes are tricky, its best not to compromise on quality, after all when you need them, you really need them! And funnily enough, under German Autobahn driving conditions anyway, road brakes probably have a tougher time than racing brakes.

You will find that the people who have bought Mov'it brakes will know all this stuff. They were not covered in the Audiworld post. As far as US sourced systems are concerned, Stasis does a very good job. Stoptech is on a fast learning curve and has great support and great 'once over lightly' tewchnical info. They do not assume that their customers know what they are doing.

R+C

[KayGee]

Ryan is an S4 racer.

He spends a couple paragraphs on single peice vs two peice calipers and cast, forged and billet single peice calipers. Concluding forged is best, billet next and cast.

I agree about piston displacement and the ABS system, however the post is an exellent write up of what affects what in a brake system. Rather than talking puerly about each product.

Audi 8 pots are mentioned on the thread, rather than Ryans post along with their reputation for BBQing pads...wonder if the Aussies love them?

Ryan also points out the benefit of using Brembo/Porsche, copies of them (MOVIT/Stoptech) or Alcon (stassis) calipers is availability of pad choices and the cost reduction that is afforded by manufacturing scales.

Stassis use Alcon calipers and rotor hats which have great race pedigree.

And funnily enough, under German Autobahn driving conditions anyway, road brakes probably have a tougher time than racing brakes.

Autobahn driving is harder on brakes than circuit racing, disagree.

I agree with your summaries on both Stassis and Stoptech.

[Nordschleife]

Ryan is an S4 racer.

........... Concluding forged is best, billet next and cast.

Autobahn driving is harder on brakes than circuit racing, disagree.

Ryan may be a racer but it doesn't allow him to pull unsubstantiated facts out of the air and publish opinion as fact. A few facts to support his preference for forged callipers would be interesting. The life of a racing and street calliper are completely different.

His discusssion of internal veins in rotors is facile. You would be amazed at how much work goes into this, people actually do use CFD to model the aerodynamics.

As somebody who habitually drives on both track and autobahn, I know how tough the autobahn is. I don't know many race tracks where I have to brake from over 300 to 20 on cold brakes. Then 10 to 15 minutes later, do it again. On the race track one has the benefit of driving with brakes that are up to temperature, most braking effort involves reducing velocity by less than 150 km, not the almost 300 km of many autobahn stops. Sure race rotors glow red but they are not subjected to the shock heat cycles of autobahn driving.

This is not the case driving on British motorways where most of the time drivers are forced to stay below 140 kph, so the amount of braking effort is significantly reduced, and mostly less stressful than on the race track.

R+C

[KayGee]

Nordy,

I love reading you posts, they always entertain me. Ryan puts together a v. comprehensive, accurate and easily readable post. All you can do is attack whomever doesn't buy or praise MOV'IT brakes.

Ryan clearly isn't an aerodynamic engineer, has'nt got a desire to discuss a topic he doesn't know about so clearly says leave it to the brake companies who all seem to concentrating on producing curved vane rotors, so I assume they are better. Hardly facile IMO.

I guess MOVIT brakes don't like heat cycles.......Most people I know who warp rotors do so on the track or multiple high speeds stops in short times.

[Nordschleife]

Nordy,

All you can do is attack whomever doesn't buy or praise MOV'IT brakes.

Ryan clearly isn't an aerodynamic engineer, has'nt got a desire to discuss a topic he doesn't know about so clearly says leave it to the brake companies who all seem to concentrating on producing curved vane rotors, so I assume they are better. Hardly facile IMO.

I guess MOVIT brakes don't like heat cycles.......Most people I know who warp rotors do so on the track or multiple high speeds stops in short times.

I'm sorry, but for a list to be comprehensive and accurate it has to explain why opinions have been stated. Ryan does not do that. It is not helpful to say "X is the best" without explaining why. Furthermore his list is not comprehensive.

As far as Mov'it is concerned, I did not mention them, you did. You made a totally unwarranted assertion that is baseless and untrue.

Your comment about Mov'it brakes not liking heat cycles is equally off base. No brake system 'likes' heat cycles, but its what happens to them. Some products stand up to it better than others. The stock rotors fitted to the RS4 and RS6 are particularly bad at this. I have found that Mov'it brake systems do, indeed, stand up to stressful conditions comparatively well. Ask the contingent who took their cars to the RS track days at Hockenheim.

I'm not sure what your point about 'warped' rotors is. Most rotors are not warped, they have had pad material transferred to them.

R+C