Challenge: Beat Strega

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BoKu

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Bob Pond spent millions trying to do a scratch built Unlimited. Best speed they could ever get was 400 mph. It would have taken tens of millions of dollars more to ever make it competitive for the Gold, if ever.
These days there are several 1K+ HP engines to choose from, but they are relatively recent developments. Back then, the auto industry was still stuck in what we now call the "Malaise Era," and high-output motors were not exactly thick on the ground. Taking two of the best of what was available probably seemed like a reasonable approach, but the operational and logistical complications probably doomed the program. Also, the tiny unflapped high aspect wing was the most efficient way to carry the thing, but it necessitated high landing speeds and left little margin for error.

This year, the faster Sport airplanes this year were nipping at 400 MPH, and none of them were multi-million dollar airplanes.

I agree that the Unlimited class should call for a minimum weight, but I also think it should be a good deal less than it is now. It should reward crashworthiness without penalizing innovation.
 

BJC

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Why not make the unlimited category truly...unlimited? Just have basic safety rules about cockpit crashworthiness, emergency egress, fuel reserve, definition of prop and piston engine, and then let folks bring whatever they want.
Why not have a truely unlimited class? "Here is the runway that you will need to operate from, here are the pylons that you will need to fly around, and here is the crowd dead line. Line up, and let's race."

This year, the faster Sport airplanes this year were nipping at 400 MPH, and none of them were multi-million dollar airplanes.
Jeff's Glasair III would have finished (speed wise) in fifth or sixth place in the Unlimited Gold the last few years that he raced. He has qualified at over 410 MPH.

I agree that the Unlimited class should call for a minimum weight, but I also think it should be a good deal less than it is now. It should reward crashworthiness without penalizing innovation.
Why? Leave the details to the competitors.


BJC
 

BoKu

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Why not have a truely unlimited class? "Here is the runway that you will need to operate from, here are the pylons that you will need to fly around, and here is the crowd dead line. Line up, and let's race."...
My concern is primarily for pilot safety. What we saw in the F1 auto racing world was that complete freedom to innovate was great for the advancement of the sport, but it took a brutal toll on drivers.

A couple years ago I was in the stands at Reno when a Thunder Mustang made an emergency landing and cartwheeled. I saw with my own eyes the pilot's feet hanging out in the breeze when the dust settled. The entire nose, from spinner to rudder pedals, had broken away, leaving the pilot sitting there unprotected. He was fortunately (relatively) unhurt, but it could have been very bad. Later, watching still frames from video of the crash, I saw that the wings had split open in the crash, liberating copious sheets of liquid gasoline into the debris trail. Again, fortune prevailed and there was no fire. Not much would have had to be very different in order to treat the entire grandstand to the sight, sound, and smell of a pilot roasting alive while trapped in tangled burning wreckage.

On the basis of that accident and several others, my version of the Unlimited class would require a substantial steel safety cage around the pilot, and also require minimum technical standards for fuel containment. It would have a minimum empty weight that ensures that no team is unfairly penalized by those requirements.

--Bob K.
 

Himat

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But we don't want that, do we? The rules are easy enough, it has to be prop-driven with a piston engine and the minimum empty weight is 4500 pounds. The rest is wide open. Your airplane has to fly for about ten minutes. So the challenge then becomes this: if money was no object how would you put up a real contender in Unlimited air racing?
Find if there is an available engine in the 1000hp+ class.
Then I would evaluate the Embraer/Short Tucano, Pilatus PC7/9/21 and similar airframes to see if one of them is suitable to be powered by said piston engine. A competitive airframe might be developed along these lines and should be that similar to the old warbirds that there is a chance it would not be outlawed by a rule change.
 

Himat

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Actually, I think a new direction.
It says piston and prop. It does not say that is the only source of power. How installing a couple of JATO units...
Or a jet engine or two...

Tim
A L-39 Albatros with a small piston engine in the nose?
Let the piston engine be supercharged and cooled by bleed air from the turbofan. The turbofan is then carried just as “ancillary equipment” to make the piston engine work. One race before being outlawed?:gig:
 

rv6ejguy

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Find if there is an available engine in the 1000hp+ class.
Then I would evaluate the Embraer/Short Tucano, Pilatus PC7/9/21 and similar airframes to see if one of them is suitable to be powered by said piston engine. A competitive airframe might be developed along these lines and should be that similar to the old warbirds that there is a chance it would not be outlawed by a rule change.
These airframes are massively draggy compared to what's in sport class now. I bet you'd need well over 4000 hp to run with Strega in Unlimited.
 

BoKu

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The big Warbirds ARE the attraction...
As I've posted elsewhere, air racing has traditionally been something that we've done using the social, economic, and mechanical leftovers of World War II. And by now we have used up most of that stuff. The degree to which air racing persists will be directly related to its ability to adapt to the social and economic conditions that prevail in the modern world.

Not to go all touchy-feely on this, but I think RARA should do some focus groups and surveys to figure out exactly why the warbird Unlimiteds have been such an attraction, and figure out if they can foster a racing class that meets those needs, and if so, how.

Some possible candidates to explore:

* That big engine sound. F1 has its tortured shriek, NASCAR thunders, but only Reno Unlimiteds have the throaty baying-at-the-moon howl of the Merlin.

* The pit show. The uncowled engines are a visual delight of exotic materials and elegant packaging.

* Money. The Unlimited racers looks, smell, and feel like cubic yards of dollars.

* Community. Friendships, rivalries, loyalties.

* Speed. Unlike Jet and its artificial limitations (straight wings, not too much power, nothing that the jet czars think challenges their hierarchy), Unlimited comes up against real physical limitations of transonic drag, and there are still opportunities for innovation to chip away at what is possible.

* Commonality. Pretty much everyone has a reciprocating engine in their car, but nobody has one that's powered by a jet. Which is kind of ironic, because the jet racers are spending somewhere between a tenth and a quarter of what it costs to race unlimited.
 

Tiger Tim

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I myself was thinking the next generation ultimate unlimited would probably look an awful lot like a big Nemesis NXT with a little Tsunami DNA in there.

The P-38 layout had been mentioned earlier but I think it has too many intersections, each one chipping away at your top speed. That and the centre pod being basically just cargo on a racer since its original purpose was a place to hold the guns so unless CG starts a racing league I don't imagine dogfighting will be part of the event.

What about a more extreme approach, maybe something slanted entirely towards preserving laminar flow over it? Would a big pusher have any advantage?
 

Victor Bravo

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air racing has traditionally been something that we've done using the social, economic, and mechanical leftovers of World War II. And by now we have used up most of that stuff. The degree to which air racing persists will be directly related to its ability to adapt to the social and economic conditions that prevail in the modern world.
There you go flaunting that four-digit IQ again... but you forgot to include the word "cultural" IMHO. The unlimited racing guys are basically hot-rodder personalities using hot-rodder mentality. "Hey Bubba, can we put a big bock V8 in that VW???" That's their culture, for whatever reason and with whatever good/bad/ugly comes with it.

The Formula One guys and now the Sport Class guys fortunately have a few spoonfuls of "Honda tuner punk", and F-1 car creativity, and EAA homebuilder thrown into that DNA mix.

So any research or demographic studies that RARA or whoever does should address all of these factors. They may learn that the average Reno race fan in 2017 is not the same old white guy with a copy of Hot Rod magazine sitting on the seat of his 427 Corvette any more. Or they may realize that the next generation of fans may be the Honda tuner punks and the guys building a V-twin powered Luciole in the EAA chapter group-build hangar.

(slightly off-topic but a good illustration): We went through something similar to this with the Soaring Society of America. The people who were part of the "old soaring" culture never led SSA to change or move forward, and this has made the SSA far less releveant, powerful, etc. as it once was. Many many opportunities were missed or squandered. All of the advances in laminar flow, low drag, efficient flight, low power flight, etc. came directly out of sailplane and motorglider design and development. The soaring world had every opportunity to position itself as the leader and go-to resource in these areas, and had every opportunity to publicize itself as such. But a "yacht club" mentality and little or no focus on the future of soaring has left the sport as the same exotic pursuit and oddball demographic as it was in the 1970's.
 
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Toobuilder

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I wonder if a Merlin PSRU could be hung on the back of a 2000 HP V-8 "easily", or would it be a whole new development excercise to tame the TV demons. After all, a 2000 hp automotive based engine that lasts for 15 minutes is just a phone call and credit card away... Getting it to turn a prop for 15 minutes is the issue I think.

Stuff that sucker in a NXT and I think thats the basic recipe. IIRC, The NXT is designed to 550 MPH. In contrast, I'd expect the G-III airframe is near the wall.
 

BoKu

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I myself was thinking the next generation ultimate unlimited would probably look an awful lot like a big Nemesis NXT with a little Tsunami DNA in there...
I've been thinking exactly the same thing.

RacerXX_web.jpg

...The Formula One guys and now the Sport Class guys fortunately have a few spoonfuls of "Honda tuner punk", and F-1 car creativity, and EAA homebuilder thrown into that DNA mix.
Just so! They are the ones I feel I can relate to when I go to the races.

...The people who were part of the "old soaring" culture never led SSA to change or move forward, and this has made the SSA far less releveant, powerful, etc. as it once was...
Some day we can trade Larry Sanderson stories.
 
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TFF

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Although they would be faster just because of the knowledge we have, the proposals are pretty much back to the GeeBee, Turner Laired, Mr Mulligan pre war days. The Top Fuel V8s are not watercooled if that is what 2000 hp engines people are thinking about; they are cast without water jackets. Someone could revive the Papa 51 engine, R-985s are still cheap could be hot rodded, gearbox on a V16 Bugatti?
 

Aesquire

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The Thunder Mustang engine is good for about 750hp? Reliably.

You want to be able to fly it to the race, or not? 2 different paths, each with their merits. I'd argue for more experience/training/feel time with the "fly it in, fly it home, fly it a lot" camp, but the Full Race "we're hoping to be first, and make all the laps" camp has it's points.

IF you stick with "Piston Only" and can lower the minimum weight rule, then.

I'll say that a hypothetical 1200hp engine Would be "Enough"... with a sane minimum of mass, high aspect ratio wings of big enough area to be optimized for the turns, and more than big enough tail surfaces to handle mondo torque, and unplanned snap rolls at 300 ft and 400 mph.

BoKu's Racer XX looks about right.

What's on the market for high Hp engines, that really exist? ( designing for a dream engine is a fool's errand. Can be fun, though. )
 

Victor Bravo

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If you are flying your airplane to and from the race, then you really didn't come to race :)

Many years ago a former Formula One air racer, Ralph Wise, built a very small F-1 sized airplane with a racing V8 in the front. He was going to go after the high dollar unlimited guys by using small size and drag reduction instead of displacement and dollars. I believe that he found out that the unlimited guys were never going to let him race in their class (because of the small size of the aircraft), and so he did not continue to develop the project. The unlimiteds eventually put that unwritten rule into the official rules when they saw what a hot-rodded Glasair or Lancair was capable of, and whatever threat they saw in the Pond Racer.

One or two of the Yak-11 racers managed to go pretty fast when they put a 2800 or 3350 on it. Bob Yancey, "Yancey's Yak" or ManiYak or Perestroika or something. And that was with the original Yak flat-bottomed airfoil and low aspect ratio everything. It always seemed to me that a purposely designed low drag racer about that size, with a moderately hot-rodded 2800 on it, would be very competitive.

"In Thrust We Trust" is all well and good, but at those speeds I believe drag is going to be a bigger factor than just horsepower. One of our HBA aero experts can feel free to correct me if I'm wrong.
 

wwalton

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Just looked over the rules of competition from RARA or whatever the latest iteration is. Jet class is set up for 8.1 mile course at 515 MPH to give a 4g acceleration and Unlimited is 500 over 8.0 for 4gs. Seems that I remember the FAA setting a max speed to limit acceleration at some point. So this is all limited air racing it's just that at this point the prop/piston/4500lbs is not capable of exceeding the course yet. Maybe just change the name to somewhat limited warbird racing show.

Actually the unlimited formula is awesome and I also feel privileged to have watched what may have been the last real race among these monsters.

I can report that at 7:30am when the first F1 heat is getting underway there are not many people coming into the grandstands. Since that's where my internet lie I appreciate the crowd that shows up in the afternoon to watch the unlimiteds run.
 

Toobuilder

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...The Top Fuel V8s are not watercooled if that is what 2000 hp engines people are thinking about; they are cast without water jackets....
Top Fuel engines make 10,000 hp and have a lifespan of five seconds. Thats not what I'm talking about. The link I posted earlier shows a used, junkyard 4.8 LS engine boosted to make over 1200 HP, which it survived many dozens of dyno runs. Does that equate to 15 minutes of life on the course, probably not. But it does allow one to extrapolate that to the GM Performance LS-X block. The LS-X is the big brother to the entire LS family and is designed for big inches and a lot of internal stress. Load the block with high quality components, top it with some good heads, tie it all together with premium fasteners, and throw 30+ pounds of boost at it... I believe you will get your 15 minutes.

All of it is a credit card away.
 

rv6ejguy

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I was approached at Reno this year to collaborate on a new V8 powered Sport class racer which I believe will progress over the next couple of years. About all I can say at this point but we hope to move well beyond what is currently possible with legacy aircraft engines. This may eventually show the way for some new Unlimited designs with regards to non-aircraft engine possibilities.
 
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