I was wondering, the other day I was driving on german autobahn and took my car to 327km/h. But this time I said to myself how safe this really is? Tyres? What would it take on the road, bump wise let's say, to set us off flying? I must say must be age related but I am getting a bit uncomfortable flat out. You? Let's discuss how safe is going terminal velocity and what to watch out for.

 

It's not safe at all. The safest you COULD be doing that is on salt flats or an airstrip with a car prepped for those speeds (cage, etc). But obviously driving that fast on the Autobahn isn't safe at all. There are more dangerous things, but that's up there on the list.

That being said, hope you had fun!!!! We aren't exactly buying sports cars that can go that fast with safety in mind then running them in Texas Miles, Drag Races, Street Races, Road Racing, Mountain runs and just all out tomfoolery.

 

There's a reason my trackday toys have full cages, race seats, and fire systems... There's also a reason I decided to replace the 996TT with a cupcar... There's nothing smart about doing the speeds we all have done in these cars, even on the track... But it sure is fun...

Mike

 

Yeah I hear you guys but I was more wondering how safe is it in terms of what could upset the car to the point of losing it. Is a normal irregularity like a bump enough to send you flying or not. I am quite comfortable with car wiggling at 150mph and soaking bumps but at nearly 200mph I begin to wonder? I say this because there is no drama at all, but I wonder how light our cars become at this speed with lack of downforce?

 

Problem is I did it quite often-ish. Less so now. I usually stop at 170mph as I don't see much point taking it to max speed. Yeah is great fun but you need to be responsible as far as other cars are concerned. I only do it when the road is clear. But again as there is no drama in our cars I wonder what can catch you out? For an example can newish tyre fail? If it does do you stand a chance. If you hit a rabbit, is this enough to send you in a spin? If you hit a road bump will car fly off or behave same as at 150mph and regain ground? Interesting questions a? Who has been there done that and and has the t-shirt to prove it?

 

Let me put it like this...

On VIR, which has a long back straight where my particular 996TT could touch 180MPH if you had the stones to brake after the last brake marker and trail thru 14, I had an experience that changed my mind in regard to high speed runs. There is a crest at the top of the hill on the back straight and during one session back in 2008, I had a cross wind gust blew the car hard enough to force it to change lanes. That happened in excess of 160MPH. I'll have to dig up the data, but I remember pulling into the pits shaking because of it. Had I been overtaking another car, which I did a lot in my 996TT, I'd have most likely made contact with that car because my vehicle moved a half lane on its own, due to the wind.

Mike

 

I would think high speed stability & controllability would be more affected by how well your car is set up for such duty.Surely a properly modded suspension w/ high speed alignment specs would be more stable than a stock setup.Driver experience has to play a roll as well.I love speed as well in many different motorized forms & a good going over on each before letting it go is something I did & do regularly

 

Mike believe it or not myself and others have noticed a similar occurance without wind.Every 996 and 997 that i have driven seems to do it to some extent right around 170.I think it has something to do with the aerodynamics.The car will seem to drift left or right even in very little wind right at that speed.After that usually you can drive thru it and the car will become planted from there on.

 

Another way to look at safety and risk --

In the engineering world (at least the one I deal with), risk is generally assessed by a combination of likelihood and consequence. Obviously, anything with both a high likelihood and high consequence would be considered the highest risk. However, when human life is involved (i.e. high consequence), even lower likelihood failures are considered high risk.

For life safety, you generally want as many of the significant failure modes as possible to require multiple component failures (in other words, you want to have it so that multiple things have to go wrong simultaneously -- or in a row -- before human life is in serious jeopardy). Aviation accident investigations general take this path, as it's usually not just one thing that causes the crash.

I'd propose that if you're doing max speed in a Porsche down a highway, you're down to just one failure left (whether it be a tire, significant road upset, foreign object on the road, or other). But it must have been fun!

 

Prior to a run at 200 mph, I'd put the car up in the air and check every nut and bolt torque spec, tire pressure, tread depth, inspection for any tire damage, run the wheels/tires on a balance machine for both balance and trueness, brake pad wear etc. A lot of bad things can happen very quickly with one little mechnical failure at that speed. Now all you have to worry about is road conditions and other drivers.

 

Coming form a Rallying national UK status, it worries the $hit out of me too.Perhaps I'm getting old and perhaps that's why young ones are so competitive they haven't started in the worrying phase of their lives.
However, all it would take is a tooth on the box to shear ( big BHP pushing the transmission to its max), a wheel bearing to fail ( spinning much faster than normal, perhaps getting on in age as well) or even a tyre blow out and who know what would happen.

On track or a special stage I never give it a thought, but on the public road it,s constantly on my mind "what if this happens"

Good post this, nice one OP a different type of topic for a change.

 

no matter how safe your car is, safe you think you are or the road conditions, "$hit happens" and at those speeds the odds are def against you...Dan Wheldon - RIP

 

AMEN to that...

 

Well this was only during high wind gusts at one event in one session that it happened to me. I've had the car as fast in that same section, lap after lap, and it was rock solid.

My point in that example is you just don't know. There are circumstances that are far beyond your control. Animals come out of places you'd never expect them to. Tire belts separate. Weather conditions crop up. Things can, and sometimes do happen. Even on a clear stretch of road, all alone, with nothing to distract you.

Mike

 

First, I can't wait to be in that position some day with a TT that I hope to acquire. Perhaps the best speed analogy I could offer on the difference between 100mph & 200mph [sorry: 161kph & 322kph] was in a Road & Track article about a year ago...I can't recall the vehicle, specifically: At 100, a crash is bad enough; with a huge potential for damage and injury. But at 200, you have to think in terms of "airplane crash" - the physical dynamics are amplified geometrically.

That said, have fun and be as safe as you can - there is no such thing as 'completely controlled conditions'.