Noted American wheels manufacturer Morr Wheels has created quite a name for themselves with their range of exclusive wheel kits for BMW vehicles. The company’s latest offering is the 20 inch Morr SpunForged VS8.2 wheel which was fitted onto this stunning BMW F10 5-Series in white. The successor of the MonoForged VS8, the new SpunForged VS8.2 wheel is designed to enhance the performance of the vehicle without adding any extra weight to it.
The SpunForged VS8.2 from the MORR Alloys line is crafted out of T6061-T6 aluminum alloy. The 7-spoke monoblock wheel is created using Morr’s proprietary “SpunForged Technology” which allows the wheel to be stronger yet lighter than the company’s previous offerings. Approximately 2.26 lbs lighter than its predecessors, the new SpunForged wheel weighs just 19.52 lbs thanks to the extensive use of a number of advanced techniques used in the manufacturing process.
Through the use of Vehicle Specific Weight Optimization, Vehicle Specific Load Ratings, Finite Element Analysis and Vehicle Specific Profiles, the Morr was able to slim down the new wheel by almost ten percent. Standard finishes offered in the line include Midnight Black, Signature Black, Signature Silver, Smoked Titanium and Sparking Silver with two custom finish options including a Satin Black finish and a Gloss Black finish. The SpunForged VS8.2 retails at a very special price and is available on special order through AC Gruppen.
Tire Pressure Hints
Tire inflation pressure may have gained greater awareness in the public's mind in the last two years, but it has always been a priority for the enthusiast. Obviously, when going to an autocross or track day, tire pressures are one of the items that will be checked and set by anyone who is at all serious. Most manufacturers recommend checking tire pressures weekly or monthly but, like flossing one's teeth, checking tire pressures on a daily driver is one of those things that is very easy to forever do "tomorrow."
Driving in an ordinary manner may not reveal even a completely flat tire on a light car with today's high-performance, low-profile structures. A visual check with a walk-around of the car at least each morning is the easiest and most basic way of preventing trouble. A flat tire will be obvious, though simply sagging pressures will be considerably less so. On one project car around the office, I noticed a rear tire looked a bit low and guessed it had 12 psi. It turned out to be completely flat and, while the original puncture was repairable, driving on it had made the expensive tire scrap. Neither driver nor passengers had detected anything amiss. Similar misfortune has befallen several other cars, so it's definitely worth taking some precautions.
Even tires in perfect condition lose air over time and should be checked periodically. It may be easier to remember if you buy a quality gauge and keep it in the glovebox rather than in your toolbox. A quality, trustworthy gauge makes it more pleasant than with the uncertainty of the gas station's beater, though in european car's tire-pressure-gauge test (July 2000), four randomly selected gas station air hose pressure gauges were checked, and none was in error to a degree that would lead to a dangerous condition. Since then, the Porsche(R)-approved gauge we chose as our favorite has been seen all over the place, from The Tire Rack to local auto parts stores, at very affordable prices.
Some people aren't sure where to set their tire pressures. The one thing that is certain is that the maximum inflation pressure on the sidewall is not the right one to use. The vehicle manufacturer's recommendation is always a good starting point. It will be somewhere in the car. This used to be a sticker in the driver's door jamb, but more and more it's located on the back of the gas filler door. If that fails, the information should be in the owner's manual. Sometimes, there will be a range specified, or two different recommendations, depending on load. Anywhere between these numbers should be safe.
Changing the tire size or going to a plus-size fitment will change the required inflation pressure somewhat. Within the range of optional OE tire sizes, the vehicle manufacturer's recommendations should be followed. For sizes outside the range, the tire manufacturer should be able to help. Yokohama, for instance, includes pressure recommendations for stock and plus-sizes, by vehicle, in its annual Fitment Guide, which your tire dealer should have a copy of. Typically, these are 0-3 psi higher for a Plus-one or Plus-two fitment. Also listed are maximum load ratings at maximum inflation pressure for each size of each tire Yokohama makes.
If the recommendations you find leave you with a range and you want to know more specifically, you can experiment. Air, after all, is free. A change of 2-3 psi can completely change a vehicle. An underinflated tire will ride smoothly but feel sluggish, have mushy turn-in and go around corners with high slip angles or just not much grip at all. An overinflated tire will feel harsh on impact and over smaller bumps, and while responding crisply, will lack grip when pushed hard. To an experienced person, these characteristics are obvious even from the passenger seat. Try the minimum and maximum of your target range, and maybe slightly outside it, and decide what you like.
In the event that you aren't able to find a recommendation for your car, or the tires on your car are so different from those that were originally fitted from the manufacturer as to be incomparable, we received the following rule of thumb from Oscar Pereda, an engineer for BFGoodrich. He calls it a "realistic starting point," saying it has never been just right, but is a good place to start. The rule is:
(Vehicle Weight in lb/100) + 2 psi at heavier end + 2 psi all around if suspension and alignment are stock.
Example: Stock 911, 3,000 lb.
(3000/100) = 30 psi
Add 2 psi all around = 32 psi
Add 2 psi to heavy end = 34 psi at rear
With modified suspension, the result is 30 psi front, 32 psi rear.
"There is no 'golden' tire pressure," Oscar said. The optimal setting depends on the individual driver and his preferences. For those inclined to find the ultimate setup for track use, Oscar provided additional instructions. First, get a skidpad, and plan to be dizzy. Take your dramamine. Drive in a circle, first one direction, then the other. Measure and record tire temperature distributions with a probe-type pyrometer that actually penetrates the rubber, not the "aim and click" infrared type. You want bulk temperature, not surface temperature, because the surface cools rapidly while the inner temperature is more stable. When measuring tire temperatures, if center is hotter or cooler than shoulders, there is too much or too little pressure, respectively.
Adjust pressures in 2-psi increments and record all adjustments. Adjust pressures by differences. If you start at 30 psi, and want to take out 2 psi, but the tires have heated up and are at 33 psi, set them at 31 psi rather than 28. The sum of all the changes made will be very close to the change from your initial cold setting. To check this, leave the tires alone at the end of the day, let them cool, and check the pressures in the morning. If at any point during the day you "reset" your pressures to some arbitrary starting place, you are suddenly lost, and all the work you have done that day is gone.
The ideal caster and toe alignment settings will give even tire pressures all across the tread. This can be determined in the same way as the optimum tire pressure. You'll never get the tire temperatures perfectly even, but the best you can do is the best you can do, which is the point of the exercise. What works best will vary from car to car depending on camber curves, body roll, ride height and other factors.
Which tire pressure gauge to use? Oscar told us that, in general, less expensive gauges tend to deviate more at higher pressures. To run the vehicle manufacturer's recommended pressure, accuracy is more important. To dial in a car, precision and repeatability are more important.
For more information, consult your tire manufacturer. The better tire company websites have extensive technical information. Another good source is the Rubber Manufacturer's Association. http://rma.org/tiresafety/
We couldn't help but share this beautifully paired photo shoot we did with this 2010 Porsche Cayenne S. It went out with our Niche Sportiva's which are a 3 piece custom forged wheel. This wheel is set to be custom tailored to order and is available in 18"-26" x 7"-17". With a million in one possible finishes you can get this wheel anyway you desire. The 5 spoke really adds to the body and style of the Cayenne, hope you enjoy the photos.