History's Hardest Buttkicker

[Superman]

First, a thousand pardons for my current pathological obsession with the Porsche 917. Second, thanx millions for the great information posted recently in response to my 917 weight question.

My current question centers on how the 917 performs compared to all other road race cars, including the current generation ones. Certainly, modern F1 cars have engine and suspension systems that NASA could be proud of. Far superior to those technologies extant when the 917 was designed and built. Granted.

But I once heard that the 917 STILL holds the distance record at LeMans. Further, I think the 1100 hp (some say 1400 hp) generated by the 917/30 engine is significantly greater than the hp levels allowed in today's road races.

So, overall, inspite of technological advancements, and by reason of the limitations of modern race rules: Is the 917/30 the fastest full-on track car ever built?

Now there's a 'loaded' question, eh?

[Superman]

I know you guys are tired of my 917 questions, but I still hope someone knows this. So, BUMP.

Does the 917 hold the distance record at LeMans? Is this car faster than today's cars, at least in terms of acceleration?

[masraum]

Interesting, it'll be difficult to answer since that came around the time of the safety push in racing, so not only have measures been taken to slow the cars down and disable their capabilities, but many of the old tracks have been changed anywhere from a little to a lot to reduce speeds and make them safer to race on.

[Joe911]

Steve is correct - the circut has been slowed considerably with chicanes. This could account for the differences.

AN THE OTHER HAND - A DAY SURES GOES FASTER TO ME THAN IT DID BACK THEN! COULD THIS BE IT? On the other hand I think this means that I am getting old.

[kellzey]

Obsessed with the 917?

Buy one...

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http://project917xxxxxxxxxxxxxx.homestead.com/917v20.html

[1fastredsc]

I'd say with the power to weight ratio of the 917, current lemans prototypes couldn't hold a candle to a 917/30 in a straight line. In terms of handling, i'm not sure what kind of suspension is on the 917, but i'd say today's road race beasts are quicker in the twisties. As far as the F1 car, i don't think there's anything that can compare to a modern F1 car. I remember watching a video where the gentleman from Top Gear, Tiff Needle, got to drive a 91 or 93 (not sure which) F1 car. The thing got from a stand still to 60 mph in 3 sec flat. Not bad. It also got from 0-100 mph in 3.4 sec

[Wayne 962]

How much is that replica?

-Wayne

[emcon5]

Looks like that is the case, but not by much.

1971: 917 Marko/Van Lennep 5335.313KM

1988:1 JAGUAR XJR/9 Lammers/Dumfries/Wallace 5332,970KM

When did they put the 2 chicanes on the Mulsanne?

Tom

[Eric Coffey]

Originally posted by Superman
Does the 917 hold the distance record at LeMans? Is this car faster than today's cars, at least in terms of acceleration?

I am pretty sure the record still stands (3293 miles in 24 hours!) but that was in the days when the back (Mulsanne) straight was over 3 miles long, and wasn't broken up with chicanes (as mentioned previously). As far as acceleration goes, I think I remember seeing 0-60 times for the 917 listed in the low/mid 2's! That was with `70's rubber!

[jyl]

I seem to recall that the turbo-era F1 cars had >1,000 HP pushing <1,000 LBS and got from zero to 60 in 2-point-something seconds. I think even the 917/30 wouldn't accelerate like that.

As for cornering, the modern F1 cars certainly beat the 917 in sheer lateral g's given the light weight, big rubber (relative to weight), and 2+ gs of downforce.

So the one area where the 917 could win would be top speed. We can't compare actual track speeds due to safety mods - e.g. the Mulsanne Straight no longer being straight - but seems if we knew (or could estimate) the CD and frontal area, we could calculate theoretical top speed. Here's a W-A-G: the 1,100 HP 917/30 has power equal to the most powerful turbo F1 car, and the closed body should mean less aerodynamic drag than the open-wheel car, so the 917 had a theoretically higher top speed.

[billwagnon]

Note: Original 917 frames were made from aluminum. Prone to cracking, Porsche devised a method where the entire frame was pressurized. With a tire pressure gauge they would check for leaks, indicating the frame had cracked.

amazing! is it true? be sure you get a compression check if you're buying a 917!

[1fastredsc]

That replica brought tears to my eyes.

[pwd72s]

Anybody have a recent Guinness book handy? A 917 used to hold the record as the fastest race car...Mark Donahue driving. Tallegega (sp?) if memory serves...

[emcon5]

Originally posted by pwd72s
Anybody have a recent Guinness book handy? A 917 used to hold the record as the fastest race car...Mark Donahue driving. Tallegega (sp?) if memory serves...

Mark Donahue in 1975 set the World closed course speed record of 221mph at Talledega superspeedway in a 917/30. There is a picture of the car here:
http://www.unfairadvantageracing.com/gallery3.html

He died a week later in practice for the Austrian Grand Prix.

Tom

[Bob's Flat-Six]

Yes, Aug 9th 1975 Mark Donohue set a world record at Tallladega Speedway of 221.120 MPH in a 917/30, on the 2.66 mi banked oval. It was broken in 1986.
Quoteing Vic Elford again," I went flat out through the Mulsanne Kink, at night, in the rain, at 245 mph.
And that let me tell you was exciting to be able to do it. It took a few laps before I got to that point. But once I got up the courage to do it... It's difficult to say what it feels like. It's just unique. I think I was the only one who ever drove the long tail flat out through there. You've just done something that nobody else in the world has ever done. That nobody else in the world ever can."
Pretty fast for the 1970's and even today.
Cheers

[bell]

Originally posted by billwagnon
amazing! is it true? !

i have a friend who uses the custom tube frame on his race bike to store the gas he uses for the shifter.......also there is a bungee type ride down south that uses compressed gas inside the structure for the same reason.....to check for cracks
anyone know if porsche introduced this method?

[rcwaldo]

I know some people that worked on that era Porsche's with the aluminum frame work. They all say thats exactly how they know if a crack had developed. This was the only method they used since much of the frame work could no be seen for inspection.

They were actually quite dangerous to drive because of this. Even the earlier 962's were quite dangerous and left the drivers feet vulnerable. That is until the carbon 'tubs' were implemented.

What a great car with an illustrious history..

Chris

[pwd72s]

Guess we all have to admit this...for it's time, the 917 was "pretty fast"...

[82SC]

well the F1 cars in the early 90's had active suspension...that was some amzing stuff...can you imagine what the 917 could have done with that???

But it is hard to compare cars...the 917 is an absolute monster...but could it beat an F1 car on a twisty track...I doubt it...on a track with big straights maybe...endurance...probably...so many factors

Just like a shifter kart can beat a viper on a twisty track cuz of the handling...and the viper never gets to take advantage of its massive power

917 vs a 2003 bentley or audi R8...on the current Le Mans setup?
I think the newer cars would win cuz of the slower track...917's power is less of an advantage around the track and with the new aerodynamics...the lack in power is more then made up with handling...

remember the 917 handling was not the best...the added long tails...cut off the roof...did alot of things to cure the high speed instability

also tire technology has come a LONG way...

regardless interesting discussion...love to hear others opinions

Just for thought...at a recent event ALMS prototypes were SLOWER around laguna seca then 250cc karts...

[304065]

Man, the factory made 917 frames out of MAGNESIUM. The same stuff as some made incendiary bombs out of just 30 years earlier. . .

The Zlin series of Aerobatic airplanes have a pressurized wing spar that utilizes the same principle. If it cracks, the pressure drops.