38D

Agreed. I liken the CGT to driving a 962. And would you drive a 962 in a helemt and a t-shirt?


Having driven a 300hp 914/6 for many years, that is definitely true. A mid-engined car has a low polar moment of intertia, which allows it to turn in faster, but also allows it to spin faster. One spin at the Glen in the car took all of 0.6 seconds to go from frontwards to backwards (timed off the video).

W8MM

You'll be happy to find out that the Carrera GT's factory-supplied tires squeal like a stuck pig during aggressive cornering. I find their characteristics to be quite benign regarding the shape of their slip-angle vs side-force curves. There is NO sudden break-over in the slip-angle plot where a small increase in angle-of-attack produces a drastic reduction of cornering force and, subsequently, a spin.

The CGT's tires are very well matched to the chassis and are one of the reasons the car is so delightful to drive. They stick like glue on the track and give plenty of audio feedback near their broad and well-behaved limit of traction.

W8MM

In days gone by, I was a hot-rodded 914/6 pilot, too. Tons and tons of track laps.

The Carrera GT is way better behaved in limit maneuvers than was my 914/6, no matter how much I had tweaked its 1970's suspension. The CGT excels in trail-braking balance while the 914/6 could be made either stable w/understeer or neutral, but wild.

It seemed that the only way to conquer the old semi-trailing-arm rear suspension foibles of those venerable buckets of bolts was to make the suspension so stiff (super-high spring rates) that the suspension barely deflected under the most severe loads. That way, if there is almost no suspension deflection, there would be almost no camber change, either. But, a 914/6 with that level of spring stiffness was intolerable as a street car because of its horrible ride characteristics.

The CGT, on the other hand, has ideal suspension geometry already designed by the factory, as well as a supple street ride owing to its push-rod suspension with aggressively low unsprung mass. The CGT may share the 914/6's low polar-moment-of-inertia induced yaw-quickness characteristics, but the CGT is an order of magnitude more sophisticated in its basic suspension design. This is a critical difference when discussing propensity to spin.

The thing that makes a 914/6 spin more quickly than a 911 of the same era is that they share the same "nasty" rear camber-steer characteristic but the 914 has a much lower polar moment. Neither car can smoothly tolerate much braking while cornering. They are both easy to upset by less-than-expert driver inputs. The 914/6 merely carries out the effects of its crankiness more quickly than could a 911 of similar age.

Since the CGT does not share the camber-change induced, non-intuitive reactions to driver inputs with the 914/6, its propensity to spin is not nearly as easy to stumble upon.

Any mid-engine car will rotate more quickly than a front- or rear-engined car if one is determined to start a spin. But, shouldn't the bottom line on "spinability" include how easy it is for the driver to start the spin, instead of only the subsequent yaw rate?

500

Mike, getting off-topic here, but that pictured 914 is beautiful. I like the subtle flares on the rear. I must admit my 914 knowledge is pretty sketchy, but were those flares from some sort of a factory special? Those "80's" style Fuchs work really nicely with overall look of the car.

Beautiful car none-the-less. Was it a restoration or a very nicely kept original?

W8MM

Hi Allan,

It was a "project car" done at Stoddard in Cleveland in the '80s. 2.8 liter high-compression, chin-mounted 914/6-GT-style oil cooler, big brakes, welded-on chassis reinforcement to suspension pick-ups, hand-rolled fender flares, etc.

gabbagabbahey

fwiw:

http://forums.vwvortex.com/zerothread?id=2588747

To Hell and Back
Off-again/on-again super-Corvette is definitely on, GM performance cars chief says

AutoWeek | Published 05/01/06, 2:38 pm et

"That off-again/on-again super-Corvette is definitely on, according to General Motors performance cars chief Tom Wallace.

Wallace, who replaced recently retired Corvette chief engineer Dave Hill, tells AutoWeek the biggest challenge facing the so-called Blue Devil Corvette is figuring out how to get 600 hp to the ground in such a way that it can be handled by a driver with the money to buy the car.

Wallace said GM is considering requiring that Blue Devil—and even Z06—buyers attend a driver school as part of the price of admission.

Mikey

Just a wild guess, but if Mike is the same age as Walter Rohrl, he either drives better than Walter or he never tested the limits on the CGT. The bottom line is the CGT lacks the safety features required to make it safe even for the most experienced drivers under “race” conditions. A false sense of speed, low feedback to the driver, same tires and brakes as a 450hp car (the GT2), minimal downforce compared to nearest competitors. The fact that the top drivers in the world can lap Leipzig without crashing one does not qualify it as safe in my mind.

W8MM

The pomposity of your posts is exceeded only by their level of factual distortions and misinformation.

Crazy Canuck

I agree.

Seems a lot of people have a hate-on for the CGT and some with Porsche. What's the point? The CGT is a fantastic car. It is superbly engineered and more capable than the majority of us on this forum. There's the rub. Porsche shouldn't dumb down the product to cater to those who do not take personal responsibility for their actions. That is lawyer speak. Protect me from myself. Bull****.

600hp is a lot of power and that power demands respect. If a driver does not do that or gets in over their head that is the driver's responsibility. If the driver buys the car without the skills to drive it at speed then again, that is the driver's responsibility.

I give a healthy respect to my 911 even with the grannies because I don't have the seat time yet to have acquired a high level of skill. It is no different than the respect I give at the controls of the 7 ton forklift at work or piloting the boat. Don't like the fact the car doesn't have electronic aids, don't buy it, don't drive it but don't push that down everyone else's throat and deny those willing and able to buy the way it is the opportunity to do so.

Mike, that is a damn nice 914 and the signal yellow on your car is perfect. There are way too many greys out there. It's great to see an enthusiast enjoying it.

38D

Exactly. You could put every wizbang gizmo on the car and give it a wing from a 747, and the car will still be "dangerous" if driven improperly. I can't think of a single DE instructor that doesn't race who is really qualified to drive a CGT at even 7/10ths on the track. Heck, at the Lime Rock race, there were probably 9 guys that really had the talent & experience to handle that kind of car (Deman, Chadwick, Chong, Stern, ***, Loles, Jarvis, Musante, Ventura), and that's out of 100 pretty darn experienced racers! Even for those guys, it would have taken quite a bit of time to get used to the capabilities of the car. I know that Ben has been called "very experienced" many times on this thread, but unless he had copious amounts of seat time (like 50+ days) in very high HP cars (over 450) and raced, I don't think he had the ability to handle a CGT even at 7/10ths (I wouldn't either). Does that mean that it's Porsche fault for selling the car? Heck no. It means that drivers need to show restraint when driving it, which may include not going as fast as possible, even on the straights.


Seriously nice 914. Looks pretty stock, but with a 2.8 and probably weighing in at 2300lbs, it must be a real sleeper. Mine was wee bit more more extroverted with it's 10"/11" slicks .

Mikey

Mike the following is tire size, downforce, weight and power data for a collection of fast cars. I have sorted them by hp/mm of rear tire . Look at the last column to the right (lbs/mm) on rear tires (based on a 60/40 weight distribution at 180MPH including downforce) and you will see the data you are looking for. The CGT is up there with the "supercar" except for how it is nailed to the ground at high speed. BTW, same data suggests the tire size is correct, only lacks downforce. The CGT should have looked like a FXX if it was made for racing. The CGT was made for the country club and Grand Touring, it is not in par with modern race cars and in fact deadly for most when used that way (considering the amount of power and lack of safety equipment.)

This data is easily available on the net, where I had no reliable downforce data I left it at 0.

Mikey

BTW Mike, in this is the “data” for what I normally run on the track: About 500lbs of rear downforce on 335 size tires in a 400hp car that weighs 2750lbs. Problem with this setup is excess tire wear off the track in combination with the extra camber, open pipes .. so not exactly a “daily driver” but it works well at the track. If I pull into the La Jolla Country club, it will cause quiet a stir

Nick

Mikey, GOOD STUFF! It is damning.

Mikey

Hi Nick, lunch this Friday at the La Jolla Country club?

38D

So you can come up with some whacky calculation and declare it to be scientific fact? Handling has a lot more to do with just downforce. It includes suspension type, spring stiffness, shock type & dampening, roll stiffness, tire size, size type, tire sidewall stiffness, etc, etc, etc. It's a system. You can't pull out one value from a system and declare it to be flawed.

I, like I suspect most people, am sad this accident happened. Like with most accidents, there was a chain of events that lead to a tragedy. Had pit out not released the car, it might not have happened. Had the car not swerved in front, things would have been fine. Had the concrete barrier not been there, it might have been fine. Had the driver hit the car, rather that try to swerve, it might have been fine. Had they been in full containment seats with a H&N device, they might have been fine. But it's all speculation. None of us will ever know.

Btw Mikey, what is you experience level? (and nice RS...is it real?)