Vous êtes ici : PassionPorsche > laguna seca

laguna seca

Page 1 sur 712345Dernière page »

Porsche 962 Wastegate Nirvana at Laguna Seca

Skylar Robinson, son of famous American racer Chip Robinson, puts on a show in a raucous Porsche 962 making a peculiar series of noises. The 2.8-liter, twin-turbo six in the middle of his IMSA GTP racer squeaks and roars, and when the full 750 horsepower arrives in one big lump, it fires the car down Laguna Seca’s straighter sections at a pant-wetting pace. More exciting than the raw speed, going by the comments beneath the video, is the distinct « choo-choo-choo » noise echoing in the cabin, often referred to as ‘wastegate chatter’.

What’s A Wastegate?

The wastegate is, essentially, a valve which diverts exhaust gasses away from a turbocharger to keep it from spinning too quickly and, therefore, increasing boost pressure too much. The valve is controlled by a pressure actuator, which is linked to the turbocharger, and the wastegate is held shut by a spring inside the actuator. When the boost pressure exceeds the pre-set maximum, it compresses this spring, progressively opening the wastegate to bleed off excess pressure, regulating the impeller’s speed, and ensuring the turbocharger and the motor aren’t damaged.

How Does it Differ From Compressor Surge?

Though the fluttering noise made by this 962’s engine might be referred to as wastegate chatter, it is technically known as compressor surge. When the throttle plate closes, the combination of the lack of airflow, consequent rise in pressure, and the high speed of the compressor cause the compressor blades to effectively lose their “grip” on the air. Aerodynamically speaking, the air separates from the back of the compressor blades, allowing some air to escape back out through the compressor. The resulting pressure drop in the intercooler piping allows the blades to “grip” again which, under the residual momentum of the turbo, will increase the pressure and the cycle repeats. This is what causes that remarkable flutter sound that will crack a smile across the stoniest of faces.

Facebooktwittergoogle_pluspinterestlinkedinmailFacebooktwittergoogle_pluspinterestlinkedinmail

Pour consulter l'article original et complet, cliquez ici.

RS Spyders Duel at Laguna Seca

At Rennsport V, a collection of mouth-watering classics set out to run for stands full of fans. Some drivers take the whole affair casually; parading and showing off their wares, while others—unable to divorce themselves from their competitive instincts—take it much more seriously.

Jeroen Bleekemolen is part of this second category, and shows that the RS Spyder has enough performance to run circles around GT3s, GT2s, 962s, and even a few Daytona Prototypes. It’s striking to see just where this featherweight LMP2 Porsche excels, where the others can match it, and how the RS remains remarkably fast, even with a mismatched gearset and plenty of short-shifting.

Bleekemolen has to give some of the production-based racers a wide berth, but generally speaking, they’re not much of a challenge, and all he has to do is pick a decent spot to overtake. With the power, downforce, and braking to be fast just about everywhere, he’s got plenty of options to choose from. His difficulties lie ahead with the prototypes.

The RS is no slouch in a straight line

In fact, its ability to outdrag just about every machine here supports that, but it has to be noted that Bleekemolen is carrying far more entry and exit speed everywhere else, too. The engine in his RS Spyder is so friendly, he never has to correct much oversteer except on his first lap. Take, for instance, his spat with a contemporary Daytona Prototype—one of the few powered by a Porsche flat-six. After the two exit the Corkscrew at roughly the same speed (6:55), the RS effortlessly nips around the outside—and these cars make similar amounts of power! Even in the slowest sections, Bleekemolen is clearly comfortable deploying all 503 horsepower to the pavement; the 3.4-liter V8 is so tractable.

In an ego-shattering pass, Bleekemolen nips around the outside of a comparable car without any drama.

The 962 Are Much Harder to Pass

The Porsches which prove more difficult to pass are the 962s. Aided by gobs of turbocharged turbo in the mid-range, the 962s here can keep Bleekemolen working quite hard to find a way around. Additionally, the poor rearward visibility and wide track of these ’80s legends makes them a challenge to overtake in a safe fashion, as we see specifically at 7:25. Only at the last moment can Bleekemolen pass with his Porsche’s most arguable advantage: braking.

After briefly struggling with a few of the force-fed 962s, he comes upon another RS Spyder driving just as quickly and defensively. Quite fairly, the man in the purple RS squeezes Bleekemolen into Turn 6 (12:18), and holds a defensive line up the hill, through the Corkscrew, and even into Turn 9. Though Bleekemolen scythed fairly easily though most of the field, this man makes him work quite hard. Only on the front straight can our man get by in a standard overtaking maneuver which was probably facilitated by the other party.

Nevertheless, it’s a great duel we haven’t seen for over a decade, a clinical demonstration of this Porsche’s strengths, and a clear argument for why these beautiful machines were some of the best analog thoroughbreds to come out of the Porsche stable. It’s just a pity the LMP2 cost cap effectively killed these beauties.

Facebooktwittergoogle_pluspinterestlinkedinmailFacebooktwittergoogle_pluspinterestlinkedinmail

Pour consulter l'article original et complet, cliquez ici.

Vic Elford to Speak at the Blackhawk Museum in March

UPDATE: We first saw the announcement for this show during the first week in January. Since then, the museum has removed information about the event. We’re not quite sure what’s going on, but once we get in-touch with someone, we’ll update this page. For now, we found the video below. It’s a recording of the last time Vic gave this presentation in 2016. For those that don’t live in the Bay Area, this might be even better!

For those fortunate enough to live in the Bay Area, mark your calendars for what will be an eye-opening chat from one of Porsche’s racing greats: Mr. Vic Elford. One of the world’s most versatile racing drivers, Elford hails from that era when Grand Prix drivers could hop from sports car, to rally car (often a 911), and back into their F1 steed without a sponsor batting an eyelash; from an era when drivers were friends and would stop their own race to help a stricken competitor out of a burning car.

During his well-rounded career, the Londoner snagged fastest laps at Sebring, Laguna Seca, and the Targa Florio among others, started the 911’s racing program, and won the world’s first rallycross event. He was nearly hit by a plane at Sebring, and played a pivotal role in shaping the 911 into one of the foremost racing cars for pros and amateurs alike over the last half-century. With a wealth of knowledge, decades of experience, and that infectious pride found in men and women of great achievement, listening to him is something anyone with an interest in Porsche’s racing heritage ought to set aside some time for.

At the Blackhawk Museum on March 10th, Elford will discuss all things Porsche. For more information on the event, visit the Blackhawk Museum’ page. We sincerely hope to see you there!

Facebooktwittergoogle_pluspinterestlinkedinmailFacebooktwittergoogle_pluspinterestlinkedinmail

Pour consulter l'article original et complet, cliquez ici.

What We Learned About Rod Emory’s 356RSR Project At SEMA

Originally sketched out by Rod Emory way back in 2012, the 356 RSR Outlaw has been a project that he’s wanted to build for quite a while. When Henrique Cisneros, owner of Momo, spotted the sketch in Rod’s archives, he knew that it had to be built. From the word go, Henrique and Rod have been collaborating on this wild monster of a hot rod 356. The plan is to have the car ready for full display at Porsche Rennsport Reunion VI next summer, but they wanted to show off a bit of the work that’s been done already. As it sits right now, the car is essentially a bare tub with the engine and transmission mocked up and mounted in the chassis. This is going to be a mega car, and we can’t wait to see the finished product. We sat down with Rod and his father Gary at SEMA last week, and this is what we’ve learned about the car.

1. The Chassis of Rod Emory’s 356 RSR Outlaw

Merging an early 1990s 911 with a 356 is never an easy task. This 356 started life as a 1959-built B T5 Coupe for the 1960 model year. It doesn’t appear to have been anything particularly special, and judging by the condition of some of the panels it was going to need a lot of work, regardless. Relax purists, this isn’t a car to mourn the loss of. Instead, celebrate that it has risen from the ashes on its way to becoming something far better thanks to Rod’s help. If you look closely at some of the photos, you can see where the 356 ends and 964 begins. The tunnel, rear seat area, suspension pickup points, and engine compartment rails are lifted straight from the 1990s. However, the floor pans, front trunk compartment, and obviously the bodywork, are pure 1950s. Interestingly, the wheelbase of this 356 has actually been stretched about an inch and a half with the front moving slightly forward and the rear moving slightly back. Further, the engine frame has been shortened a bit from 964 configuration, as it no longer has to fit six full cylinders (more on that in point 2 below).

The Emory team merged the two Porsches – 356 and 964 – digitally before making any cuts. This is actually the second 356 hat that Emory has built to fit a 964 chassis (the first being their now-legendary Carrera 4-based 356C4S project), so they’re probably getting pretty good at it by now. The intent there was to make the merge points as close as possible without needing any additional filler metal. « There were certain areas where we had to bridge the metal, but the goal was to use as much of the factory either 964 or 356 metal« , says Rod.

2. The 356 RSR Outlaw’s Engine

By now we’ve all heard of Dean Polopolus and his infamous four-cylinder 911-based engines. They’re lightweight, they’re simple to source parts for, they pack a punch, and they’re quite expensive. Rod has stepped things up a bit with this Porsche, the case, crank, and cams are all custom for a 964-based four-cylinder engine. Moreover, this engine will use custom pistons and cylinders, which in six-cylinder format would total up to 4.0 liters. As a four cylinder, this engine will run somewhere around 2.65 liters.

While the engine was displayed at SEMA with individual throttle bodies and trumpet intake stacks, the production version will actually feature a twin-turbocharged, twin-intercooled forced induction setup. Pulling air through ducts in the rear quarter panels, custom amber ducts will direct that intake through intercoolers on each side of the engine at the back before being spun up by a set of small turbos and shoved into a custom intake plenum. In total, Rod says the aim is to create around 350 horsepower from the 1/3rds reduced aircooled beast.

3. The 356 RSR’s Transmission

By using the 964 platform, the original goal was to use a G64 style manual transmission. Once the project started to unfold, however, it was determined that a proper motorsport-based sequential manual would be better suited, and the old standard Quaife 61G gearbox was drafted in for use. While at SEMA, however, an empty G50 case was used for mock-up purposes. Can you just imagine banging gears with a sequential while listening to the turbos whistle behind you? This is going to be one spectacular Porsche when complete.

4. The Wheels

Working with Momo, Rod & Gary pulled a number of vintage centerlock designs from the 1980s and 1990s out of their archives to provide inspiration for the wheels on this car. These are custom 935-inspired 5-spoke wheels that fall right in line with Momo’s Heritage line of wheels. In fact, they were displaying a set of similar 6-spoke wheels at their booth (photo below) which fits a Porsche 5X130 bolt pattern. By using 993 RSR uprights front and rear, the center-lock hubs insert into a large bearing that is the same on all four corners. According to Rod, a 5-spoke wheel will be available from Momo soon, and we think they would look absolutely bonkers on your 964 or 993.

5. The Bodywork of the 356 RSR

While the greenhouse, doors, and front trunk area are easily recognizable as pure 356 right now, this Porsche will be completely transformed once the full silhouette-racer bodywork is installed. Judging by the sketches, this car will feature a lot of 935-inspired design work, with vents, inlets, louvers, and flares everywhere you look. For ease of use, the front and rear bodywork will be one-piece aluminum lift-off affairs with quick disconnect mounting points. Melding 356 and 935 and 964 into one monster doesn’t sound like much of a good idea, until it’s been implemented by the visionary mind of Rod Emory. There’s a fine line between insane and genius, and this car (as well as its builder) toe that line every day.

Rod Emory Porsche 356 RSR

The post What We Learned About Rod Emory’s 356RSR Project At SEMA appeared first on FLATSIXES.

Facebooktwittergoogle_pluspinterestlinkedinmailFacebooktwittergoogle_pluspinterestlinkedinmail

Pour consulter l'article original et complet, cliquez ici.

Watch a 908LH Pursue a 917 Around Laguna Seca!

In hot pursuit of a Gulf 917, Gunnar Jeannette hustles this beautifully-kept 908LH around a slippery Laguna Seca at last year’s Rennsport Reunion; keeping his car on the knife’s edge and keeping us on our toes the whole time.

Though the mellifluous flat-eight soundtrack might keep most motoring fans glued to the screen, the technically-minded will stick around for the clever aerodynamics at work on this classic Porsche. In fact, it was the 908LH which marked Porsche’s move towards mastering the wing business that took off in the late sixties.

The rear ailerons are controlled by a series of shafts linked to the rear suspension wishbone. When the suspension compresses over bumps and during lateral loading, the movable aerodynamics change their angle of attack and generate some rear downforce, as described in greater detail here. When the speeds increased and the car wasn’t loaded laterally, the aero profile would change to help with top speed; this system was designed to keep the car slippery on the straights and sticky in the corners.

Even with all the rear downforce, Jeannette has to work hard to keep the tail underneath him.

To take that sort of lateral loading, in those days, was nothing short of incredible. It’s those sort of cornering forces that Jeannette needs in order to keep in touch with a 917 at a power circuit like Laguna Seca. There might be a serious disparity between the two cars in sheer thrust, but plenty of pretty, tail-out antics help Jeannette keep the mighty 917 from becoming a speck on the horizon—for a while, anyways.

The post Watch a 908LH Pursue a 917 Around Laguna Seca! appeared first on FLATSIXES.

Facebooktwittergoogle_pluspinterestlinkedinmailFacebooktwittergoogle_pluspinterestlinkedinmail

Pour consulter l'article original et complet, cliquez ici.

Page 1 sur 712345Dernière page »

Suivez-nous…

Catégories

Archives

Amazon Music