Interesting Info About The 917

[unclebilly]

My son was 8 when these photos were taken…











These are not big cars. You can see the passenger seat in the last photo…

[javadog]

Originally Posted by Captain Ahab Jr

White Racers from Zuffenhausen is a a good book

Covers the development of the 904, 906, 907, 908, 910 race cars, not expensive too!

One day I'd love to write a Wingrove style book about the 909, never written anything longer than a school essay so could make for a fun retirement project

Just for balance, this was Ferrari's answer to the 909 hill climb car

https://en.wikipedia.org/wiki/Ferrari_212_E_Montagna



Late 60's European Hill Climb Championships were pioneering times for race cars

That was a heck of a car. I think it was based on the Dino 206 but had a little baby flat 12 in the back. I liked the looks of the Dino 206 better but…

I think Porsche also stuffed a flat eight in the back of a 910 chassis for hill climbs. Pretty sure they still have that car in the factory museum/garage.

[21blackjack JR]

Originally Posted by svandamme

But was that knob seventies era?
Ifrom what I read. The turbo on the 917 was pretty new at the time. With the injction pumps hacked for turbo fuel delivery.

Its one thing to change boost on the fly
But how did the oulp adjust on the fly?

Anybody who messed with mfi knows how much the system dislikes mods and changes to the specs

Honest question. Not trying to be smartass. Do you have any info on how it worked?

From my dad (Jim Torres): in the second picture one can see the boost knob, right of the steering wheel, exact one used on all the 934,935 and 962's as well as the 917-10 and 917-30, in the other image you can see some of the turbo plumbing and a glimpse of the wastegate. These pics are when it was owned by the previous owner getting ready for Porsche's 50th anniversary I hope this helps, the guy in the one picture is my dads engine man Kevin Celestine who has been doing our race engines for over three decades. Alain

[tdw28210]

Originally Posted by URY914

I also have a SUNOCO 917-30 press kit. I was given it by a SUNOCO employee when it was new. She worked at the local distributor and her husband worked for my father. He knew I was a racing car kid and he asked his wife for one for me. I also have some racing news letters that SUNOCO sent out internally. This should bring $$$.

Probably too late as I am just reading this now, but interested in the 917-30 press kit. I think I can marry it up with the actual car. It lives nearby and I know the owner.

[javadog]

Originally Posted by svandamme

But was that knob seventies era?
Ifrom what I read. The turbo on the 917 was pretty new at the time. With the injction pumps hacked for turbo fuel delivery.

Its one thing to change boost on the fly
But how did the oulp adjust on the fly?

Anybody who messed with mfi knows how much the system dislikes mods and changes to the specs

Honest question. Not trying to be smartass. Do you have any info on how it worked?

Two words. Boost enrichment.

Here’s a photo of a 935 engine. Note the hoses going from the intake plenum to the wastegate and also the fuel injection pump.



Now, here’s a photo of a 917/30 engine. Look at the top of the pump, to the right of where the injector lines attach.

[javadog]

One interesting little factoid about these engines is that if
you plumb the line going to the fuel injection pump above the throttle butterflies, when you shut the throttle you get an enriched fuel mixture for the engine, which helps it run cooler. That’s also what causes the flames that you’ll see out the exhaust on a closed throttle.

[rusnak]

Originally Posted by javadog

Wyer is pronounced like a two syllable version of wire. “Y er”

Piech is closer to “pee eck”

Agreed.

I thought it was really awful to leave out the great Hans Mezger. And Norbert Singer, who was credited by several sources to have contributed to the 917's dominance.

And then the Can Am series cars were only mentioned in a dismissive way at the end. No mention of the 917-10, 917-30 and the turbo charged era. In typical Porsche engineering fashion, they kept pushing the concept to the maximum. But the 917 didn't just "live on". It was developed relentlessly in later series. I think Mark Donohue's book "The Unfair Advantage" covers this era rather well.

I think the most interesting part of the story would be how the 917 racing program would almost bankrupt the small Porsche company. Perhaps that is why they did not run them as works cars? I forget now, but it might have been Peter Morgan in his book "Porsche 917, the Winning Formula" who suggested that VW secretely contributed funds to aid in "research" about air cooling as a way to help Porsche fund the 917 effort.

[javadog]

Piech was pretty focused on moving Porsche into the big leagues, until Ferry figured out he couldn’t afford to do everything Piech wanted to do….

Big changes at Porsche in 1972…

1973 ushered in a more pedestrian race car, one that was much cheaper, and also one they could build and sell to lots of people.

[rusnak]

Thinking about it some more, it might have been Karl Ludvigsen who penned that VW helped Porsche with the engine development money.

Piech was a fascinating guy. If not for his strong will, who knows where Porsche would be. Also, the Salzburg team was owned by Ferdinand Piech's mom's Porsche dealership. You have to wonder if Ferdinand was on the pit wall as well. It would be interesting to know more about her involvement in Porsche from the post WWII era to the 1970s Le Mans win.

[svandamme]

Originally Posted by 21blackjack JR

snip

thanks !

Originally Posted by javadog

Two words. Boost enrichment.

[/img]

yeah i know of boost enrichment, but we are talking variable boost here.

I know the pump was hacked so they used the barometric adjustment as boost enrichment.
But I wasn't aware they had cockpit control of the actual boost as well.
I figured boost control was something of the later electronic age..

[rusnak]

^ I thought Bosch manufactured a totally new pump for the turbo 917, which they called the "happy pump"?

[svandamme]

I'de have to look up the book again, but from what I remember they had hacked the pump's barometric control and used that for boost adjustment. You can actually see it in the picture above


That's a pretty standard looking pump frontend housing (the pump section is obviously double size for twice the lines) but no barometer on top
Pretty Sure Bosch was involved for all of that stuff as it was live R&D for everybody.. And perhaps that happy pump just meant they finally found the right tune , the right internal cam and settings ?

Anyone who has MFI knows what it means to have a happy pump, and unfortunately what it means when the pump isn't happy for your engine.

[javadog]

All of the turbo cars had adjustable boost.

The “happy” pump was just one that made Donohue happy when they arrived at settings that worked for him, when they were trying to make the turbo 917 engines driveable. The early attempts were less than successful. Initially, they did not map the correct fuel settings at every RPM and throttle position. That seems like a pretty basic idea now and it was the part throttle drivability that he was after.

[CurtEgerer]

Originally Posted by rusnak

Piech was a fascinating guy. If not for his strong will, who knows where Porsche would be.

Not to mention Audi - quattro was a far more significant car than the 917. Not only did its all-wheel drive/turbo format revolutionize rally racing, it is the great grandfather of every AWD road car to this day. quattro would not have happened without Piech.

[Captain Ahab Jr]

Originally Posted by CurtEgerer

Not to mention Audi - quattro was a far more significant car than the 917. Not only did its all-wheel drive/turbo format revolutionize rally racing, it is the great grandfather of every AWD road car to this day. quattro would not have happened without Piech.

I didn't know that

[javadog]

There’s an argument to be made that Piech is the most consequential automotive executive of his generation. He’s made the VW Audi brand into some thing of a powerhouse.

[rsrguy]

Now these guys.... Omg

https://youtu.be/Wxhmrvxnbjw

[svandamme]

meh replicrap makes baby jezus cry

[CurtEgerer]

Originally Posted by Captain Ahab Jr

I didn't know that

I think it was Jorg Bensinger, an Audi engineer who tested their AWD Iltis off-road vehicle who originally came up with the idea in 1976/77 But it was Piech who envisioned it as a way to turn Audi from a maker of semi-crappy economy cars nobody cared about to a company that would put AWD in everything they make and compete with M-B and BMW. Piech knew the way to do that was via rally racing.

[rsrguy]

Originally Posted by svandamme

meh replicrap makes baby jezus cry

Good thing you can buy the real thing then isn't it...? Us mere mortals can still have appreciation for labors of dedication and love such as this...