January 28, 2015 5:31 pm - Published by

Wheels are a really funny one when it comes to a build, it can make it, or break it, be it the car you want to spend your days and nights dragging the floorpan along the tarmac in or that machine you want to howl around the track in. They can create and ruin many aspects of a car in an instant…

 

Today and in the past there has always been such a vast array of amazing and shocking “rims” ranging from the cult forming TSW Venoms, the brake fade specials – the SSR (Speed Star Racing) Mk1’s, to the tried and tested VW choice the BBS RM/RS.

 

I’ve always been a fan of something a little different and hopefully something that I’m not going to see everywhere. I’ve always adored the simple timeless designs, the aforementioned SSR Mk1 and the Watanabe RS to name a few. Both old wheels you’ll note. But when I spotted 949Racings offerings, much later than the production initially started I must add, I was a little taken aback. Not only by the design but also the construction. Resulting in a 15×8 wheel weighing only 5.2Kg not bad for a ‘relatively’ budget wheel!

I took this extract from 949Racing’s website

Gen 2 6UL   01/09 – 02/12 (Discontinued)

 The second generation 6UL wheels are low pressure (LP) cast and T6 heat treated. LP casting refers to the aluminum being forced into the wheel mold under pressure. This pressure eliminates the possibility of bubbles and voids in the aluminum casting. It also compacts the aluminum which allows a higher tensile strength to be achieved with the same material. Gravity cast tooling requires larger wall thickness to allow the molten aluminum to flow into all the small features and crevices of the mold during filling. The design benefit of the new LP technique is that the engineers can optimize the thickness of each part of the wheel without really needing to allow for material flow. This optimization reduces weight without any decrease in strength.

With a gravity cast wheel, the center hub area is the last part of the mold to be filled by the molten aluminum so it is more prone to unwanted porosity or voids. To combat this potential weakness, the hub area is overbuilt to ensure failsafe strength. With the new LP casting, the mold filling and density is the same throughout the wheel structure so the hub area can be further optimized and lightened.

While we kept the same unique 6UL look, the engineers needed to create an entirely new engineering drawing and tooling for the LP casting process. We took this opportunity to reevaluate every single area of the wheel, perform further FEA optimization, strengthened and lightened wherever possible. It takes trained eye and both wheels in hand to spot the differences but there were more than a dozen little tweaks to the Gen II compared to the Gen I.

The end result is a wheel that’s about 5% lighter with nearly twice the fatigue life and substantial gains in strength. The Gen II also end up being a bit stiffer and that’s directly creates more consistent contact patch loading. Few tuners ever think about this but a wheel that’s too soft and flexible will actually deflect under hard cornering loads enough to reduce active camber. Stiff wheels are good.”

Oh, and they are pretty beautiful…


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