Dba 4000 Rotors

[TURBO4LT]

If you follow the bed in procedure they come good pretty quick, you need to heat cycle the rotors and bed the pads in, they will be pretty spongy till this is done. There should be instructions on the pads and rotors.

[Iconic Bionic]

Took about 200kms before optimal braking was achieved with the ferodo pad combination. Dont be afraid to use them from the start. If they need to be used, then be sure to use them.

My rears were fitted the day before the Snowies cruise and then got a 1300km punish.

I.B.

[trevs]

cheers guys ive followed instructions on the pads and rotors I was just wondering how long it took other ppl ive noticed that the pads on the front arent making full contact with the rotor yet only done about 40km on them so far but even with only about 50 percent contact they still feel better than the sh*ty ford rotors

thanks trev

[EZ2CME]

I took it easy on them for 200kms and then after that the next drive I had they copped a canning.

Edited 30/11/08 10:16 AM by EZ2CME

[aiboart]

Despite following the Ferodo bedding in procedure it took 200km to get the system to a reasonable though not very acceptable state. This may or may not have anything to do with urban speeds being too low to enable proper bedding.

At the 300km point the FF pads felt as if that had a higher friction coefficient and a more linear response when cold than the factory premium pads, however they seemed to be well below the ultimate friction coefficient of the the Factory premium pads when warm. I can state that I was not too happy with the FF's at this stage.

At 450km the pads seem to be catching up to the Factory premiums in maximum braking power. Pedal pressure was vastly reduced at the threshold and the braking was becoming impressive again. The FF's are slightly more effective when cold and this is noticable during a medium brake application after a prolonged cruise.

The FF's may still be behind the factory premiums when warm or they may not. It is difficult to tell without G-Tech data.The fact is, by being so linear the Ferodo's may well enable significantly better braking, but still seem less impressive than a pad that surges during a braking event due to the build up of heat; a surge always seems more impressive and more dramatic than a linear event, even though the linear event is typically far more effective at getting the job done.

Regards,

aa

[xr6tinscotland]

Im looking into getting some DBA 4000 series rotors for my 2005 BA turbo ute to get rid of the brake shudder, is the drilled and slotted DBA 4000 series rotors any good or are they just good looking as dont know whether to go for drilled and slotted or just the slotted rotors.

What pads do you think goes best with these rotors? Im also planning to change the brake lines for braided lines, hopefully that makes a difference

[aiboart]

The DBA web site recomentds slotted.

http://www.dba.com.au/2006/consdocs/C006.asp

Pads there are many to choose from.

Many here like Ferodo Formula (TS-2000 related to DS-2000), Bendix Ultimate etc.

Welcome to the forum.

Regards,

aa

From the DBA site...

EVERYTHING YOU WANTED TO ASK ABOUT CROSS-DRILLED & SLOTTED PERFORMANCE DISC BRAKE ROTORS

Disc Brakes Australia (DBA) frankly answers questions about the company’s popular range of slotted and cross-drilled Street Series rotors.

WHAT ARE DBA STREET SERIES ENHANCED

PERFORMANCE ROTORS?

DBA Street Series is the name given to Disc Brakes Australia’s entry level range of direct replacement rotors. This range includes standard rotors to fit almost every make and model on the road, plus enhanced performance variants that incorporate cross-drilling and slotting yet are still aimed at the price conscious end of the market.

All the enhanced performance rotors are manufactured in Australia by Disc Brakes Australia and are designed to give greater stopping power and improved appearance. Equally importantly, these rotors can be easily fitted to road cars in place of conventional discs. They bring to the affordable end of the 'street' market the sort of braking technology normally associated with expensive high-performance machines.

DBA also manufactures and sells two high-end rotor ranges (the 4000 Series and 5000 Series) aimed at those involved in motor sport and other extreme driving applications.

CAN I USE THESE ROTORS FOR MOTOR SPORT?

No. The range of DBA Street Series rotors are designed (and warranted) for street use only. With the enhanced performance versions of the DBA Street Series product, we’ve carefully found a balance between extra performance and the safety, durability and affordability required by everyday street users. The sort of motor sport which road cars tend to be involved with (club lap dashes and sprint races) is particularly hard on rotors, usually involving a set of cold brakes into the first corner and, at the end, a car parked with the rotors still at 500 degrees Celsius. In such circumstances it is easy to warp discs, or even to weld the pads onto the disc surface. DBA’s premium rotors (the 4000 Series

and 5000 Series) incorporate Thermal Stability Profiling and other technology to enhance their ability to handle such extreme treatment.

WHAT DOES ‘CROSS-DRILLED AND SLOTTED’ MEAN?

The expression 'cross drilled and slotted' refers to two separate processes, and the enhanced performance versions of DBA Street Series rotors incorporate one (DBA Slotted) or both (DBA Gold).

The first procedure involves drilling holes through the friction surfaces of the rotor and the second refers to milling a series of grooves from the centre of the disc toward the edge. The processes are aimed at making the disc better ventilated and more effective. And let’s not forget the cosmetic side: DBA Street Series rotors look aggressive and purposeful, particularly with today’s open-patterned alloy wheels.

DOES A DISC NEED TO BE CROSS-DRILLED AND SLOTTED?

Not necessarily. The processes achieve slightly different ends.

Let’s talk about cross-drilling first. When the friction surfaces of a rotor are smooth and flat, there is no means of escape for the gases and dust that build up between pad and rotor. At very high braking temperatures, the bonding agents used in some brake pads can produce a gas which creates a pneumatic cushion between pad and rotor, giving a driver a normal pedal feel but reducing the amount of friction being generated. This is not a huge problem in normal motoring but is an important consideration in street performance applications.

The bigger the pads and the higher the braking temperatures, the more likely the problem. The drill holes assist with this 'out gassing'. The holes are also commonly labelled 'cooling holes' because of the improvements they make in this

area. Better cooling means less fade during repeated heavy brake applications.

Obviously, the holes reduce mass. They also help dissipate water when driving in poor weather.

WHAT DOES SLOTTING DO?

Slotting increases the bite of the pads. This helps pull the car up more quickly. Used on its own, the process doesn’t involve removing as much metal as cross-drilling, so it doesn’t result in as great a weight saving. However, slotting can be as effective as cross-drilling in combating the problem of 'outgassing', particularly with the nine uni-directional slots fitted to each side of DBA Slotted rotors. The slots pump away gas and restore full contact.

The 'micro-shaving' effect of the slots also serves to de-glaze the pads (this is why the edges of the slots on DBA Street Series rotors are not chamfered or 'radiused'). It also tends to even out the wear across the brake pad faces, increasing the effective contact area. This can extend rotor life.

HOW DO THE TWO APPROACHES COMPARE IN PERFORMANCE?

Research has shown the overall stopping power provided by the DBA Slotted and DBA Gold rotors is remarkably similar. Because of their lighter weight and increased cooling, the DBA Gold rotors recover more quickly and have the edge in situations where there is hard braking in short bursts.

The major advantage of the DBA Slotted is an ability to absorb and dissipate heat more evenly and to sustain higher temperatures for longer. That makes them particularly good for continuous heaving braking situation, such as experienced when driving down a mountain or when towing.

DO THE SLOTS NEED TO BE LEFT-HANDED AND RIGHTHANDED TO WORK PROPERLY?

Conventional wisdom once said so ñ and also dictated that all slots to be swept back from the centre in the same direction. However, with computer modelling we’ve managed to make the slots on the DBA Gold rotors work in combination with the cross-drilling. This enables us to use four grooves arranged in a mirror-image pattern, creating a disc that works equally effectively in either direction (which is to say, on either side of the car). To provide maximum efficiency with slotting only, the DBA Slotted rotors have non-interchangeable left-handed and right-handed patterns.

IS A CROSS-DRILLED AND SLOTTED DISC BRAKE ROTOR

WEAKER?

Removing any metal from a rotor can potentially weaken it but working in the DBA Gold’s favour is Disc Brakes Australia’s policy of safe, conservative designs (our discs are even over-engineered, some suggest), and the basic strength of the case iron alloy used.

At DBA, we spent two years getting all aspects right before launching the product to the public. This research and development included perfecting the symmetrical hole pattern which ensures that the discs have correct balance, optimum cooling properties and sufficient contact area with the pads.

We’ve also put a lot of time into programming our computer-controlled (CNC) milling machines to carefully shape the edges of the holes to avoid tearing up brake pads. And we are using manufacturing equipment accurate to within three one-millionths of a metre. Some potential buyers have expressed concern about the likelihood of cracking. This is reasonable, as even standard factory rotors can suffer cracking under extreme use or abuse. Proper bedding of

both rotors and pads minimises this risk.

The weakest or most crack-prone part of the rotor is the outer edge, which is the normal course of expanding and contracting with heat, endures more movement then the centre of the disc, which is obviously smaller and is reinforced by the central hub or hat.This is why DBA Street Series road discs do not follow the practice of some racing rotors, which have holes right at the outer edge or run slots off the edge of the disc.

Reports from a few owners confirm the very occasional appearance of very small cracks around the holes. These are caused by localised stresses and in no way detract from the reliability, durability or ‘stop-ability' of the disc. And a recent change on some discs from a chamfered hole profile (one with a 45-degree bevelled edge) to a ‘radiused' one (with a continuous curve between the friction surface and the opening) has further reduced these incidences.

Some rotors have been returned with more serious structural cracking, however the number equates to less than 0.2 per cent of rotors shipped. And of these, most were used in motor sport applications, something they were not designed or warranted for. To be frank, most of these owners would have destroyed non-drilled rotors under the same conditions. They were simply asking too much of their standard braking system and should have upgraded to our purpose-built motor sport rotors and possibly bigger calipers as well.

HOW MUCH METAL IS TAKEN AWAY WITH CROSS-DRILLING

AND SLOTTING?

On a typical large sedan/wagon street vehicle we take away 180 grams from each cross-drilled and slotted disc, or less than 2 per cent of its total weight. Multiply this by four and you have your total vehicle weight saving 720 grams.

Although this is the sort of gain that a Formula 1 team would spend thousands of dollars attempting to achieve, it is not enormously relevant with a conventional car in normal road conditions. That’s one reason we have not over-stressed the benefits of lower mass in our marketing. The other reason is a

fear that people will mistakenly associate ‘lighter’ with ‘less safe’.

CAN I EXPECT DRAMATICALLY IMPROVED BRAKING?

DBA Street Series rotors will deliver better braking performance than conventional discs, but in most cases the improvement should be described as ‘significant’ or ‘worthwhile’ rather than ‘dramatic’.

There are several reasons why it is difficult to quantify exactly how much performance improvement DBA Street Series rotors can bring in typical road applications. It varies with the model of car, its kerb weight, the type of pads used (and how well they have been bedded in), the type of braking system into

which the new rotors are being incorporated and the inherit effectiveness of the standard rotors being replaced.

Testing every type of vehicle under all conditions is clearly not possible. Nevertheless, we have tried a wide sample in varied situations. We have also interviewed as many owners as possible and are yet to talk to one who hasn’t been pleased with the improvement.

To get an additional expert view, Disc Brakes Australia commissioned respected advanced driving instructor (and three-time Australian NSW Hillclimb Champion) Peter Finlay to conduct a series of independent tests.

Finlay - the proprietor of Australian Nationwide Defensive Driving School - compared the stopping distances and general braking performance achieved with DBA Gold rotors and conventional ‘factory’ rotors under identical conditions.

During tests using Sydney’s Famous Oran Park Raceway as a closed and safe environment, a Holden/GM Late model camira fitted with the DBA Gold cross-drilled and slotted product averaged a theoretical efficiency of 97 per cent over ten stops from 100 km/h. It recorded a best stop of 38.6 metres. The average stopping distance from 100 km/h was 40.4 metres. This compared with 42.6 metres (90.25 per cent theoretical efficiency) for the same car tested under similar conditions with standard rotors.

On both occasions, the car was fitted with similar brake pads, tyres and wheels. Finlay was the sole driver throughout and supervised the testing procedure to ensure a valid comparison.

The Finlay report noted that the DBA Gold rotors provided greater consistency from stop to stop and delivered good pedal feel. The ability to pull up the car 2.2 metres, or 5 per cent, is significant. Such a distance could easily be the difference between an accident and a near miss. However, it can’t be classified as a universal gain. Some cars may demonstrate less of an improvement with enhanced versions of DBA Street Series rotors while other cars, or perhaps other testing conditions, might reveal a bigger performance gain.

We feel, for example, that the DBA Street Series advantage would have increased even further if the speeds were higher and the cool-down period between stops was reduced (Finlay drove a 1 km cooldown loop between stops). On the other hand, the way the tests were conducted and the speed

chosen - 100 km/h - is entirely relevant to everyday road requirements, as was the choice of Australia’s best selling car for the test.

ARE THERE TRADE-OFFS?

When a car-manufacturer designs a disc rotor, the aim is to please the ‘average’ owner, placing high priority on such things as quietness, durability and low production costs.

When enthusiasts change their cars to improve performance they always have to accept some tradeoffs. After all, there’s no such thing as something for nothing. In this case, the main trade-off for improved braking is higher purchase price. The extra cost is due to there being a great deal more production work in manufacturing rotors that are slotted, or crossdrilled and slotted. The specialist nature of the product also adds to the expense, reducing production

economies of scale.

However, we’ve done our best to keep the price premiums as small as possible, using innovative lowvolume manufacturing techniques. Many customers feel the additional cost of the DBA Slotted or DBA

Gold rotors is justified by the enhanced performance alone, and consider that the attractive appearance is merely a bonus. In an emergency situation, every buyer will appreciate the extra stopping power even if they rarely drive hard enough to utilise it.

As any driver knows, the ability to pull up a car even one metre sooner can save a life. Something to note about slotting: as the rotor wears, the slotting becomes shallower and therefore less effective. The DBA Street Series slots are tailored to each rotor type, but typically they are about 1.5mm deep x 3mm wide. By the time the rotor has reached ‘minimum thickness’ (we are careful to point out that the slots are not intended as a wear indicator), there is not much slot left. To make them deeper would risk weakening the rotor.

In contrast, the holes remain effective in combating ‘out-gassing’ for the whole life of the disc. As with slots, the pattern is unique for each rotor type, typically we have between 24 and 36 holes per disc face, each with a diameter of 5mm. To counter the tendency for cracks to form between holes, we previously put just one hole per vane on ventilated discs to ensure the walls between the vanes would act as a strengthening barrier between the holes. The increasing adoption of the patented Kangaroo Paw ventilation system on DBA Street Series rotors, however, has made this more complex.

The Kangaroo Paw system doesn’t use traditional vanes - it uses a series of diamond shaped pillars to promote greater airflow. The holes now need to be positioned next to these pillars. In a manufacturing sense this is more complex, but from a buyer’s point of view it gives a disc that is stronger as well as better cooled. Each hole is chamfered or ‘radiused’ around its opening to reduce pad abrasion and provide a smooth transition between hole and friction area.

Under some circumstances a small clicking noise may occur as a result of the pads running across the holes.

ARE CROSS-DRILLED AND SLOTTED ROTORS HARD ON BRAKE PADS?

A more powerful engine uses more fuel, and it stands to reason that if brakes do more work, or generate more energy, they must suffer more wear. In the original planning stage we predicted a 10 per cent increase in pad wear. After all, the holes and slots would be abrasive on the pads and, with less metal-to-pad friction area, we expected more rotor wear too.

Yet the on-road results have surprised us. In normal usage, pad wear is generally no greater, and rotor wear is sometimes extended.

Testing on high-mileage taxis has shown a totally unexpected benefit. One leading taxi company using DBA Street Series rotors on its fleet has reported that they can last up to 150,000km with no machining.

This is three times the company norm, and has been achieved without any additional pad wear (the pads continue to be changed at the normal 25,000km intervals).

The reason for the improvement relates to the shaving effect of the slots, which ensure improved contact between pad and rotors, plus the lower running temperatures. Should high-mileage DBA Street Series rotors require machining, this must be performed on a modern, high-speed, low-feed brake lathe. The correct procedure is for the technician to machine from the hub to the outer edge, taking 0.25mm (.001’) in each pass.

A word of caution: machine in the one direction only: when feeding back, the technician should withdraw the tools and recommence from the hub to avoid tip damage and repeat until required finish is achieved. Cross-drilling and slotting remove not only weight but also friction surface (or ‘swept’ area). The figures are relatively small and the enhanced performance shows that the reduction in swept area is more than made up for by the improved ventilation that cross-drilling and slotting achieves.

For the record, the four disc rotors on a typical big sedan have a total swept area of 351.5cm2. The cross-drilling on a DBA Gold rotor removes 22.9cm2, while the slots take away another 5.4cm2. That’s a total of 28.3cm2, or 8.1 per cent of the surface area.

DOES DBA MAKE ENHANCED PERFORMANCE VERSIONS OF

DBA STREET SERIES ROTORS FOR MY CAR?

Hopefully, yes. There are DBA Street Series rotors available to fit thousands of different models and an increasing number of these are now available in enhanced performance versions.

GMH, Ford and popular Subaru, Toyota, Honda, Daihatsu, Mazda and Mitsubishi cars and light commercials are among the many models covered and the plan is to continue to increase the DBA Street Series range.

Check with your local brake specialist for extra availability or view the full DBA catalogue

DO I NEED TO MAKE OTHER CHANGES TO FIT THESE NEW ROTORS?

No, just choose the exact model DBA specifies for your car. The diameter and thickness specifications of all DBA Street Series rotors are the same as with original equipment components, so they bolt straight into the standard braking system.

The ‘minimum thickness’ (stamped onto the disc) also remains the same, as the rotor’s improved cooling properties compensate for the slightly reduced mass.

However you must remember that, as you are asking your brake system to do more work, it must be in first class condition. This means the caliper slides, caliper springs and disc brake pistons must be operating freely, while a general check of all other parts of the system is a good idea. We recommend you use brake fluid of at least Dot 4 standard and new, high quality brake pads. These can be any pads made by a recognised manufacturer, but make sure you observe the recommended ‘bedding-in’ procedures.

Equally important: if you remove and reinstall the pads for inspection, make sure you put them back the same way they came out. If reversed, the slightly raised lip of what was previously the pad’s trailing edge can catch in the groove, causing increased heat and noise.

Lastly, we don’t recommend mixing conventional and DBA Street Series rotors on the same axle. The difference in performance from side-to-side will upset the braking balance of the vehicle.

DBA STREET SERIES ROTORS ARE COLOURED. WHAT’S THE STORY?

To give the enhanced performance versions of DBA Street Series rotors an even greater visual appeal, Disc Brakes Australia uses a high-temperature paint on the hats and outer edges. This gives a two tone gold-and-silver effect on DBA Gold rotors and an attractive grey and silver finish on DBA Slotted discs.

Although developed primarily for cosmetic enhancement, the coating has the added the benefit of inhibiting the surface rust that can develop on rotors.

TELL ME ABOUT DBA’S QUALITY CREDENTIALS

DBA is one of Australia’s most awarded component companies and has the largest single share of the local market for replacement rotors. It manufactures in a state-of-the-art facility near the 2000 Olympics complex in Sydney and takes the attitude that, with brakes, second best is not nearly good enough.

Therefore, DBA was a pioneer in attaining certification to the internationally respected ISO 9001 and QS 9000 quality standards. It has now been awarded the new and even more demanding TS16949:2002 standard, an international quality benchmark that will replace QS 9000 throughout the motor industry at the end of 2006.

DBA uses ‘factory’ components as the minimum target and aims to exceed their quality by a large a margin as possible. DBA is a multiple winner of the prestigious ‘AAAA Manufacturer of the Year’ award. It is also an original equipment and/or replacement part supplier to some of the world’s largest car companies.

[senna_T]

Since the drilled discs are prone to cracking under heavy street use here in Oz, I believe the issue would be more common in a colder environment like yours David.

Slotters are the better option, drilled just look pretty!

[Iconic Bionic]

A popular choice and topic at the moment is the DBA 4000 setup. Definately slotted and not drilled as above. Pads, whatever you fancy, but the Ferodo DS 2000 I run and cant fault them.

And a very warm welcome from the other side of the world.

I.B.

[Erko]

Is this our first UK based T owner???

WELCOME ABOARD MATE.

DBA 4000 Slotted + Ferodo DS2500 is a great combo, change your fluid regularly and fit some braided lines if you like. If you are super keen there is always the Brembo option but obviously more $$$