Floaty at Speed???
10-18-2013, 05:05 PM
#46
The feeling one gets from a car with the engine mounted right beside the steering wheels is never going to be the same as with the engine by the driving wheels. With the front engine, steering inputs work against all that mass immediately. There's a great deal of inertial resistance to steering inputs. Hence the car feels steady, solid. The faster you travel, the less steering input is required to generate these forces. Hence you feel this more the faster you go. What you're feeling is inertial. It has nothing to do with lift. Its not "floaty". Its just that you've come to associate and expect certain things based on long experience. Things that no longer apply now that you're in a 991. So, relax. Go do a Driver's Skills Day. Do some DE. You'll see.
10-18-2013, 08:03 PM
#47
Pro
Thread Starter
The feeling one gets from a car with the engine mounted right beside the steering wheels is never going to be the same as with the engine by the driving wheels. With the front engine, steering inputs work against all that mass immediately. There's a great deal of inertial resistance to steering inputs. Hence the car feels steady, solid. The faster you travel, the less steering input is required to generate these forces. Hence you feel this more the faster you go. What you're feeling is inertial. It has nothing to do with lift. Its not "floaty". Its just that you've come to associate and expect certain things based on long experience. Things that no longer apply now that you're in a 991. So, relax. Go do a Driver's Skills Day. Do some DE. You'll see.
10-18-2013, 10:23 PM
#48
Every car design has its compromises, fans and detractors. The Boxster, Cayman and 914, all mid-engine cars, because the main mass is central have a low polar moment of inertia. In plain English, they're able to change direction real fast. People love this because a car that is eager to change direction always feels balanced and ready to do whatever you want. But ask yourself, what is a spin? A spin is a car rotating on its (vertical) axis. Which cars then will spin the fastest? The cars with low polar moment. Boxster, Cayman, 914. I know, it seems counterintuitive, but physics is physics. You want to drive a car that will spin so suddenly, so fast, it will literally make your head spin? Drive a 914.
Your BMW, with the mass up front, the same wheels trying to steer while controlling all that mass, you feel it in the steering. It feels solid because of all the mass/inertia. You drive a 911, much less mass up front, the steering feels lithe and super-quick. The feeling is incredible. But unlike the BMW where you feel the car through the steering, with the 911 you feel the road. The car you feel through the seat. Because the mass is behind you. This is all much less obvious with the newer cars, to the point where some who've never driven a 914 or an air-cooled 911 might be wondering what in the world I'm talking about! Because they have made great strides over the years. But its all still true, just refined down to where its harder for the average person to notice, at least that is until you start running out of traction.
This is where the 911 really starts to shine. Again, what I'm going to say here is much more evident in the older cars, but trust me, its still there, if greatly tamed and muted, in today's 991. Because the 911 has all that mass out back you can't help but feel it. In corners, it telegraphs to you the need for respect, to be decisive, and you will feel in the seat that big rear end wanting to come around if you even think about easing off. The car is telling you loud and clear that you better watch out. The older the car the louder and clearer and the more incessant it is. The 991 whispers discretely, diplomatically, and with a marvelous accent that somehow manages to be sexy and German at the same time. But its the same conversation.
An awful lot of people who've driven 911's, of any vintage, will tell you no other car carries on this conversation anywhere near as well. It is the foundation on which all those World's Best Driver's Car wins are built. It is, in a very real sense, what this car is all about. No other car so richly rewards time spent behind the wheel getting to know it. Keep driving. You two have a lot to talk about.
Your BMW, with the mass up front, the same wheels trying to steer while controlling all that mass, you feel it in the steering. It feels solid because of all the mass/inertia. You drive a 911, much less mass up front, the steering feels lithe and super-quick. The feeling is incredible. But unlike the BMW where you feel the car through the steering, with the 911 you feel the road. The car you feel through the seat. Because the mass is behind you. This is all much less obvious with the newer cars, to the point where some who've never driven a 914 or an air-cooled 911 might be wondering what in the world I'm talking about! Because they have made great strides over the years. But its all still true, just refined down to where its harder for the average person to notice, at least that is until you start running out of traction.
This is where the 911 really starts to shine. Again, what I'm going to say here is much more evident in the older cars, but trust me, its still there, if greatly tamed and muted, in today's 991. Because the 911 has all that mass out back you can't help but feel it. In corners, it telegraphs to you the need for respect, to be decisive, and you will feel in the seat that big rear end wanting to come around if you even think about easing off. The car is telling you loud and clear that you better watch out. The older the car the louder and clearer and the more incessant it is. The 991 whispers discretely, diplomatically, and with a marvelous accent that somehow manages to be sexy and German at the same time. But its the same conversation.
An awful lot of people who've driven 911's, of any vintage, will tell you no other car carries on this conversation anywhere near as well. It is the foundation on which all those World's Best Driver's Car wins are built. It is, in a very real sense, what this car is all about. No other car so richly rewards time spent behind the wheel getting to know it. Keep driving. You two have a lot to talk about.
10-19-2013, 11:40 PM
#49
Pro
Thread Starter
Thanks Chuck, I found this to be educating and enlightening. I really appreciate this perspective on the different dynamics involved with these to different setups.
A interesting experience occurred today that I was told about in theory, and it proved itself to be actuality. I went around a almost 90 degree turn today and something very intriguing occurred. My tires were cold but I went through this turn pretty fast but with no power added....The oversteer occurred. I assume if I added a little bit of power, the rear would have squatted and planted itself. This could be coincidence that I was just too hot and the tires were too cold, but it felt in my opinion that culprit was no power involved.
This just proves to me more that as soon as I can I need to get on a track and learn.
A interesting experience occurred today that I was told about in theory, and it proved itself to be actuality. I went around a almost 90 degree turn today and something very intriguing occurred. My tires were cold but I went through this turn pretty fast but with no power added....The oversteer occurred. I assume if I added a little bit of power, the rear would have squatted and planted itself. This could be coincidence that I was just too hot and the tires were too cold, but it felt in my opinion that culprit was no power involved.
This just proves to me more that as soon as I can I need to get on a track and learn.
10-20-2013, 12:17 AM
#50
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^I'd say PSM and TV got you around that 90 without incident.
10-20-2013, 12:27 AM
#51
Pro
Thread Starter
10-20-2013, 12:42 PM
#52
Three Wheelin'
Great post chuck !
10-20-2013, 02:45 PM
#53
Thanks Chuck, I found this to be educating and enlightening. I really appreciate this perspective on the different dynamics involved with these to different setups.
A interesting experience occurred today that I was told about in theory, and it proved itself to be actuality. I went around a almost 90 degree turn today and something very intriguing occurred. My tires were cold but I went through this turn pretty fast but with no power added....The oversteer occurred. I assume if I added a little bit of power, the rear would have squatted and planted itself. This could be coincidence that I was just too hot and the tires were too cold, but it felt in my opinion that culprit was no power involved.
This just proves to me more that as soon as I can I need to get on a track and learn.
A interesting experience occurred today that I was told about in theory, and it proved itself to be actuality. I went around a almost 90 degree turn today and something very intriguing occurred. My tires were cold but I went through this turn pretty fast but with no power added....The oversteer occurred. I assume if I added a little bit of power, the rear would have squatted and planted itself. This could be coincidence that I was just too hot and the tires were too cold, but it felt in my opinion that culprit was no power involved.
This just proves to me more that as soon as I can I need to get on a track and learn.
10-20-2013, 06:49 PM
#54
Pro
Thread Starter
Probably repeating myself, but try to find a Driver Skills Day before going on the track. Both Porsche and BMWCCA do them, and in many regions they are nearly identical- instruction and practice with threshold braking, threshold cornering, throttle steer, controlling weight transfer, looking ahead and the late apex line. You'll get much more individual instruction and seat time, and a lot more time spent at the limit- or sliding beyond- at DS than DE. One of the most important skills drivers need to develop is smoothness. Remember I mentioned earlier about how small inputs can quickly load the suspension at high speed? That's why you want to learn and practice at lower speeds first.
10-21-2013, 01:54 AM
#55
I like big beers. A good local Porter or Dunkelweizen.
10-21-2013, 05:20 AM
#56
Three Wheelin'
The DE advice is as much for you as my way of repaying all the Instructors who helped me to learn, advance, eventually become an Instructor myself. Like every Novice, I thought I already knew how to drive, just needed track time. Wrong. If you have not had real one on one instruction and seat time you do not know what you're doing. Literally. Its like the Donald Rumsfeld line about "known knowns.... unknown unknowns." You literally don't even know what you don't know! So you get in a car that does 140 like nobody's business, go around a curve, feeling fine and dandy in your blissful ignorance. Meanwhile your Instructor sitting beside you is having a near-death experience, gripping the armrest so hard his fingernails are about THIS CLOSE to ripping through the leather, because HE knows you're off-line, apexing way early, lifting where you shouldn't be, and if you make just ONE MORE error we're gonna be praying that PSM is all its cracked up to be. Oh God! Did I just say cracked up! Please God! No! NOOOO!!!! That anyway is exactly what its like with a lot of novices. But take the same novice, first time on the track, but this ones done Driver Skills first- well you would not believe the difference. Night and day. Better line. Better eyes. Better inputs. More at ease, more attentive and more receptive.
I like big beers. A good local Porter or Dunkelweizen.
I like big beers. A good local Porter or Dunkelweizen.
I was all late breaking, fast in, understeer, early apex, compromised exit speed 15-20 years ago.
To this very day, after many hours of instructors shouting in my ears, I still have to make a conscious effort to brake early, slow in, late apex, early throttle, fast out. This is soooo much safer too when you apply it on the road !
10-21-2013, 01:52 PM
#57
I'm still novice, but less novice as you describe. But still I recognize what you write.
I was all late breaking, fast in, understeer, early apex, compromised exit speed 15-20 years ago.
To this very day, after many hours of instructors shouting in my ears, I still have to make a conscious effort to brake early, slow in, late apex, early throttle, fast out. This is soooo much safer too when you apply it on the road !
I was all late breaking, fast in, understeer, early apex, compromised exit speed 15-20 years ago.
To this very day, after many hours of instructors shouting in my ears, I still have to make a conscious effort to brake early, slow in, late apex, early throttle, fast out. This is soooo much safer too when you apply it on the road !
A lot of people, once they learn to drive, are surprised to realize that the exact same techniques taught on the track make everyday street driving so much easier and safer. One student, who went on to racing, told me how amazing it was when he realized the exact same late-apex line we teach is the one he follows when pulling his trailered race car with his truck. People love to parse the differences in the way different cars handle, between models and brands, fwd, rwd, awd, front engine, rear engine, etc. or between street driving, track, autocross and racing. And yes there are differences. But the bedrock reality is that the basic physics of driving is such that once you learn correctly you realize the fundamental skills apply to all cars in all situations. They're always telling us to slow down, when the fact is we'd have a lot fewer accidents if everyone knew how to drive faster.
10-21-2013, 03:47 PM
#58
Three Wheelin'
High performance driver training should be obliged. Knowledge of basic physics at work is a must. Most people are just clueless passengers that happen to sit behind the wheel.
