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NZ Made Strap-Drive System (Designed by Prosport Auto)

THE PROBLEM:

Over the past year, several Porsche customers have come to us wanting to convert to an ENDLESS disc brake system because of the advanced performance (longevity, pedal feel, temperature resistance etc) that ENDLESS products provide.

The Porsche factory disc design is drilled and while this is good for performance, it does cause cracking very quickly through those drilled holes. There are current aftermarket disc solutions for these cars, but often the hats wear out quickly where the bobbins float, causing their 2-piece replacement option to become expensive with hats becoming an additional consumable item also.

ABOVE: Drilled style disc that promotes cracking with track use

Whilst ENDLESS do make high calibre replacement 2-piece hats for Porsche, these parts can take a long time to make it to the customers hands (manufacturing is only done in specific batches), and can sometimes be more expensive than every budget allows for.

In wanting to provide a solution for every level of customer and every budget, this situation posed a challenge that we wanted to find a solution for! Not only for Porsche customers, but for every other (vehicle) customer who wanted a high-quality solution like ENDLESS, but without the wait-time or price tag attached.

So, rather than turning these customers away we set out in finding an alternative high-performance solution which would meet drivers needs, and solve a few additional very common disc brake performance problems along the way.

THE METHODOLOGY:

We started working on a solution for Porsche, because that's where the problem originated from, and this is where we knew we could get some good product testing from once we had a proto-type ready to go.

We got talking with Jason Liefting at JLDesign and we discussed our options. We talked about (the old) V8Supercar strap-drive setup, the advantages it offered and the reasons for our belief in this being the best solution for not just the Porsche 997 GT3 Cup cars, but any other type of race vehicle.

The strap-drive system allows for longer hat life, and provides a ultra high-performance, lower cost replacement for ongoing OEM + aftermarket disc brake systems.

With our problem-solving caps on we got to work, and are happy to have come up with a NZ designed prototype to test on our strap-drive guinea pig - a Porsche 997 GT3 cup car.

BELOW: NZ Made & Designed Prosport Auto Strap Drive hat (in place on front wheels)

The strap-drive system offers reduced knockoff, because the straps have very little flex. This also improves pedal feel. The reason it also allows for less wearing on hats is because there are no free moving parts to wear out.

With a strap-drive system, you can use multiple sets of discs with the same set of hats. Because there is no "shock" from the hat to disc assembly through bobbins that have excessive clearance or wear, the outcome is less cracking on discs.

Our Prosport Auto designed hats and straps are made in New Zealand. Hats are manufactured using 6061 grade aluminium, and straps from special grade stainless steel. Our mounting hardware are aircraft grade fasteners and bolts. We use a drilled shank bolt and then split pin each individually, so they can rotate independently.

For the Prosport Auto strap-drive assembly, we designed a brand new hat from an existing Porsche setup, and developed from our own Solidworks drawing. The hat features spare bolt holes, so these can be used on either side of the car.

BELOW: Solidworks render of the Prosport Auto Strap Drive hat/disc design

We approached ENDLESS Japan about producing the discs for Prosport Auto with our requirements and to our specifications, and went through our options on the disc we should use with ENDLESS engineers. We supplied them with the final drawings of what we wanted, and they confirmed manufacture for us which we then commissioned.

We confirmed the disc design and durability using a factory Porsche hat and ENDLESS Pads before continuing on to our strap-drive hat testing.

BELOW: Completed Prosport Auto Strap Drive hat with ENDLESS disc

BELOW: Clearance between pad and straps, no pad modification required

THE SOLUTION:

Testing of the new system has taken place with our guinea pig Porsche 997 GT3 Driver (currently racing with the new system in the 2014/2015 season of GTRNZ and Porsche Drivers Club).

BELOW: Fitment on our "guinea pig" Porsche 997 GT3 Cup Car

We have had all positive results so far with our testing, with no manufacture or performance problems.

The guinea pig Porsche currently has had 24 sessions (8x Practice, 4x Qualifying and 12x Races) on the strap drive setup, with some light crazing showing on the discs which is normal.

We are using the high friction ENDLESS N05U competition compound for extra bite and stopping power, and this high friction causes a little extra heat, but the disc wear is near non-existent.

Results after the bed-in procedure has been completed

We will be reviewing the disc setup after another race round at Taupo Motorsport Park this weekend, following another full weekend of racing and double-stinting for the car.

We are now currently developing the system for a Ferrari 430 GT3, and will look to roll out the new strap-drive system for additional vehicles, custom made for each chassis following the successful testing of this.

THE FUTURE:

This Prosport Auto strap drive design and concept can be applied to any vehicle, not only a Porsche 997 GT3 Cup car.

If you have a race vehicle that suffers from poor hat life or excessive knock-off, then this system could be perfect for that application.

If you're interested in knowing more about whether a Prosport Auto strap drive system would be right for you, or you have any other questions on your braking performance feel free to contact Mike at Prosport Auto on (09) 238 3560.