The 6UL SPEC E30 wheels are designed and built for motorsport use by 949Racing.This 15x7 aluminum wheel weighs 13.1 lbs, with a +15 offset, 4x100 lug pattern, and 57.1mm hub centric center bore has been optimized specifically for Spec E30 with a thicker outer flange and thicker inner barrel.
This version is hub centric for the E30. And because of the relatively low offset, no spacers are needed for maximum track width.
This also results in a nice wide lip which protects the spokes and valves in the event of car to car contact. No more shearing off valves when another car rubs you.
Speaking of valves, the 6UL wheel has a double valve design to allow the easy purging of air for those who use nitrogen.
Currently available in Charcoal, the 6UL Spec E30 wheel comes in a simple semi-gloss black finish
Note: This wheel will not fit Hondas or Miatas, it's only for BMW E30 vehicles.
Two valve holes
This makes it possible to perform a complete nitrogen purge. You may notice many high end tires stores now offer nitrogen. Nitrogen doesn't fluctuate pressure as much as your tires get hot and they hold air much longer. With a single valve, you still have some atmosphere in there when inflating with nitrogen. Two valves= 100% nitrogen.
You may also notice the lip is not a wide as some other import wheels, again for a reason. The best possible wheel structure has the spokes running straight from the mounting pad to the bell (outer rim). By bending the spokes back to create an artificially wide lip you add more material than is needed and weaken the basic structure. Straight spokes, smaller lip = strong and light. A wide lip looks neat so we will always try to engineer every 6UL to have a lip if possible.
Care and feeding of your 6UL wheels
Timeline of 6UL Wheels Generations
Gen 4 6UL 08/14-
This current design has the same great style as all previous 6UL's but features a flow formed outer rim barrel for a better strength to weight ratio and lower rotational moment. The entire wheel was redesignd from ground up to further enhance controlled dissipation of loads and increase fatigue life. Most sizes will see a 10-12% reduction in weight from the Gen 3 version.
The Gen 4 can be quickly identified by lug holes that line up symetrically with the valve hole centerline. Previous generation had lug holes clocked about 60° from the valve hole centerline.
Gen 3 6UL 03/12 - 6/13 (Discontinued)
For the generation III design, we increased the load capacity to 500kg and used the more stringent VIA test protocol. The wheels gained a few ounces and greater fatigue life. The Gen 3 can be identified by the VIA stamp near the valve hole. The Gen 1, 2 and 3 designs are all 100% compatible with each other and can be mixed on the same car. Color variations may occur between generations.
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.
Gen 2s can be identified by the " 6UL " embossed right on the face of the wheel. The center bore on all versions is 67.1mm, which allows the optional use of standard size hub centric rings.
6ULR 17" (Discontinued)
The 6ULR is also be LP cast like the gen 2 6UL but features a flow formed, or spun forged, (also known as rotary forged) outer rim or bell. This is a one piece design. The still molten aluminum wheel with it's center section already shaped is then spun. The outer rim is rolled between a mandrel and inner wheel form to slowly drawn into the final shape. With roll forming, the outer rim is actually formed under extreme pressure so its a form of hot forging. This pressure further aligns the grain structure in the outer rim area which allows the absolute minimum possible material be used for a given strength target. The mandrels are CNC so an engineer can precisely vary the thickness to a few thousandths of an inch based on the results of FEA (Finite Element Analysis).
Gen 1 6UL 01/07 - 07/08 (Discontinued)
The first generation wheels were gravity cast and T4 solution heat treated. The center bore on all versions was 59.1mm, except the Spec Miata version which was 54.1mm hubcentric. The gravity cast 6UL's proved to have a great strength to weight ratio. Gen 1 6UL does not have 6UL cast into the face.