1988 Porsche 928 S4 Coupe 2-door 5.0l Clean Project Car on 2040-cars

Auto blog

Is the skill of rev matching being lost to computers?

If the ability to drive a vehicle equipped with a manual gearbox is becoming a lost art, then the skill of being able to match revs on downshifts is the stuff they would teach at the automotive equivalent of the Shaolin Temple. The usefulness of rev matching in street driving is limited most of the time – aside from sounding cool and impressing your friends. But out on a race track or the occasional fast, windy road, its benefits are abundantly clear. While in motion, the engine speed and wheel speed of a vehicle with a manual transmission are kept in sync when the clutch is engaged (i.e. when the clutch pedal is not being pressed down). However, when changing gear, that mechanical link is severed briefly, and the synchronization between the motor and wheels is broken. When upshifting during acceleration, this isn't much of an issue, as there's typically not a huge disparity between engine speed and wheel speed as a car accelerates. Rev-matching downshifts is the stuff they would teach at the automotive equivalent of the Shaolin Temple. But when slowing down and downshifting – as you might do when approaching a corner at a high rate of speed – that gap of time caused by the disengagement of the clutch from the engine causes the revs to drop. Without bringing up the revs somehow to help the engine speed match the wheel speed in the gear you're about to use, you'll typically get a sudden jolt when re-engaging the clutch as physics brings everything back into sync. That jolt can be a big problem when you're moving along swiftly, causing instability or even a loss of traction, particularly in rear-wheel-drive cars. So the point of rev matching is to blip the throttle simultaneously as you downshift gears in order to bring the engine speed to a closer match with the wheel speed before you re-engage the clutch in that lower gear, in turn providing a much smoother downshift. When braking is thrown in, you get heel-toe downshifting, which involves some dexterity to use all three pedals at the same time with just two feet – clutch in, slow the car while revving, clutch out. However, even if you're aware of heel-toe technique and the basic elements of how to perform a rev match, perfecting it to the point of making it useful can be difficult.

Porsche Mission E Concept puts Tesla Model S in its sights [w/video] [UPDATE]

UPDATE: The Mission E might not top the Tesla in driving distance after all. The Porsche's nearly 311-mile range is on the European testing cycle, but the original story compares it to Teslas on the US evaluation. According to Tesla, a Model S 85D is rated at the equivalent of 328 miles in Europe, and the P85D is at 305 miles. The new 90 kWh battery can add an additional six percent to those figures. Porsche might not be saying it directly, but anyone taking even a quick glance can see the Germans are taking aim at Tesla with the freshly unveiled Mission E concept at the Frankfurt Motor Show. With over 590 horsepower, this electric sedan doesn't have quite as much electric grunt as a Model S, but the claimed 310.7 miles of range would outdo even the latest take on Elon Musk's four-door with a 90 kWh battery. For those keeping track, a Ludicrous Speed-equipped Tesla might still be the ultimate victor in a drag race because the E's sprint to 62 takes "under 3.5 seconds." To power the Mission E, Porsche's engineers use two permanent magnet synchronous motors, and they are similar to what's found on the company's 919 Hybrid LMP1 racecar. In a single unit, the devices can both accelerate and recover braking energy. All-wheel drive with torque vectoring and four-wheel steering help the electric sedan lap the Nordschleife in less than eight minutes, the company claims. Capable of hitting 124 mph in less than 12 seconds, the Mission E is undoubtedly quick, but its speed in charging is especially impressive too. The concept utilizes an 800-volt system that Porsche claims can charge the sedan to 80 percent in just 15 minutes, assuming you can find a source for that much energy. That would be enough to offer about 249 miles of range in less time than getting a cup of coffee at a busy Starbucks. The E could also use a traditional 400-volt charger or power up inductively. The Mission E's design looks like a futuristic Panamera as filtered through the style of the 918 and a next-gen Star Wars Stormtrooper helmet. In an especially cool touch, the charging port is hidden in a movable panel ahead of the driver's door on the front fender. Also, like like lots of four-door concepts in recent memory, the design sports suicide doors with no B-pillars. To keep weight to a minimum, the body mixes aluminum, steel, and carbon-fiber reinforced polymer. Also present are carbon-fiber wheels.

Porsche 918 Spyder gets tiny recall for rear control arms

As the recent US recall of a single Koenigsegg Agera shows, even low-production supercars aren't immune from safety campaigns. Now, there's another example that even the fastest cars can have their faults. The Porsche 918 Spyder is a pretty fantastic vehicle for its ability to mix hybrid fuel economy and incredible amounts of power, but Porsche has a problem on a few units of its halo model.
According to the recall document from the National Highway Traffic Safety Administration, Porsche needs to inspect and possibly repair five 918s in the US because the rear axle control arms may break, which could cause a loss of control while driving. In the full defect notice, Porsche says that it first noticed the problem on June 26 when the parts failed during "heavy duty durability testing (extreme race conditions)" at the Nardo test track in Italy. It transported the components back to the company's lab for inspection, and on July 18 it issued a stop-sale to inspect the suspension parts on the supercar. The automaker also contacted owners by phone to warn them not to use the car on track, until repaired.
The affected 918s will be inspected, and if the cars have the bad parts, the control arms are will be replaced. Obviously, this will be done at no cost to owners. According to a Porsche spokesperson speaking to Autoblog, in addition to the five US cars potentially affected, there were 45 worldwide. All of the cars have now been checked. Scroll down to read the report from the regulator or download the full defect notice as a PDF, here.