Quickest time around a closed course ?

[bdk]

http://en.wikipedia.org/wiki/Scaled_Composites_Pond_Racer

Unfortunately the rules have changed so I don't think the Pond Racer would be allowed to compete with the Unlimiteds.

[retroaviation]

Unfortunately the rules have changed so I don't think the Pond Racer would be allowed to compete with the Unlimiteds.

Yeah, there's a 4,000 lb minimum weight now. That was started because of the Pond Racer and the Thunder Mustang competing in the Unlimited Class, getting substantially thrown around in the wake of the "real" airplanes. There is also a 300 mph minimum qualifying speed now as well.

Gary

[Dudley Henriques]

What's the best technique for the quickest time around a closed course ?

1. The shortest possible route around the course pulling limit / max g turns around the pylons ?

2. A slightly wider route requiring less G in turns reducing induced drag losses and possibly a higher average indicated airspeed.

Thanks

Never raced Reno, but a few hours in high performance prop fighters.

Basically speaking, the race turn scenario is a bit different that a maximum turn scenario for a fighter seeking the BEST path around a race course.
Aerodynamically, you get your best turn rate and shortest turn radius at a fighter's corner velocity where you marry max available g to a specific airspeed. But the race scenario is a bit different. You don't necessarily want your best radius and rate making your way around a race course. There are WAY too many variables involved in a race.
First off, you are above your corner speed rounding a pylon (or you better be anyway so forget corner speed as your prime factor.
Above corner, you are g limited and g is a HUGE factor in a race and perhaps not for the reason you might be thinking.
The ability to pull g is important, but pulling g causes drag which is the last thing a race pilot wants. So the bottom line is to find the right combination of g and airspeed that finds the smoothest path through the corner considering engine parameters and flight safety considerations.
Add to this that a race pilot will be playing the vertical plane as well on the course as conditions permit. Energy management and SMOOTH flying, laying off as much g as possible (planning well ahead of the airplane) will get you around the course about as fast as possible.
Dudley Henriques

[muddyboots]

Didn't someone try and put some Learjet wings on a Mustang years ago ?

Yes. It was called Miss Ashley II. Griffon engine with contra rotating props. Disentigrated right in front of our eyes while coming to the home pylon.

http://tbirds.hp.infoseek.co.jp/accid2.jpg

Gary

I hope that is the pilot under a chute ...

[aseanaero]

Thanks for that Dudley , good explanation.

I was watching Extreme Air on cable last week which was about Reno 1999 and it was driving me crazy watching the pilot of Voodoo playing with the tweedle valve every 5 seconds , has anyone automated engine temp control for water injection now or are the pilots still spending 50% of their time playing with that tweedle valve ?

[aseanaero]

I hope that is the pilot under a chute ...

Looks like a wing and part of the nose to me ...

[Dudley Henriques]

Thanks for that Dudley , good explanation.

I was watching Extreme Air on cable last week which was about Reno 1999 and it was driving me crazy watching the pilot of Voodoo playing with the tweedle valve every 5 seconds , has anyone automated engine temp control for water injection now or are the pilots still spending 50% of their time playing with that tweedle valve ?

When I was flying the Mustang, we considered ourselves filthy rich when we could pour some 130 octane in there. Other than that we were restricted down to 55 inches where ADI wasn't needed.
These guys are running ADI at a rate that needs some real fine tuning. The induction temperatures can get away from you fairly fast at the pressures these guys are using.
God, just THINKING about what my wife would have done to me had I been working our Merlin at the cost level these guys are at scares me to death )
The way I understand things, that valve allows the guys to better control their ADI use which for them is critical.
Dudley Henriques

Last edited by Dudley Henriques on Wed Jul 22, 2009 8:11 pm, edited 1 time in total.

[warbirdcrew]

muddyboots
PostPosted: Wed Jul 22, 2009 4:17 pm Post subject:
retroaviation wrote:
aseanaero wrote:
Didn't someone try and put some Learjet wings on a Mustang years ago ?


Yes. It was called Miss Ashley II. Griffon engine with contra rotating props. Disentigrated right in front of our eyes while coming to the home pylon.

http://tbirds.hp.infoseek.co.jp/accid2.jpg

Gary


I hope that is the pilot under a chute ...

He never made it out in time.

[Neal Nurmi]

Dudley -- Back in the 1980s the serious racers ran around 110 to 115 inches of MP at 3500 to 3700 rpm. In the Allison rod era they would use up to 145 inches of MP with up to 3500 rpm, to go around 500 mph on the Reno race course...

That rich enough for you?

[retroaviation]

Yeah, I've had long discussions with one of the former Voodoo pilots who said he'd squeeze 150" of manifold pressure on it coming down the chute to start the race. After that, he'd "pull it back" to 140-145".

Gary

[Kyleb]

Yeah, I've had long discussions with one of the former Voodoo pilots who said he'd squeeze 150" of manifold pressure on it coming down the chute to start the race. After that, he'd "pull it back" to 140-145".

Gary

That'll void your warranty.

[Dudley Henriques]

Dudley -- Back in the 1980s the serious racers ran around 110 to 115 inches of MP at 3500 to 3700 rpm. In the Allison rod era they would use up to 145 inches of MP with up to 3500 rpm, to go around 500 mph on the Reno race course...

That rich enough for you?

Well, I guess that depends. If I had married Guy Lombardo's widow, 145 inches might have been a possibility, but being married to the gal I picked, settling for 61 was enough for me. )
DH

[muddyboots]

muddyboots
PostPosted: Wed Jul 22, 2009 4:17 pm Post subject:
retroaviation wrote:
aseanaero wrote:
Didn't someone try and put some Learjet wings on a Mustang years ago ?


Yes. It was called Miss Ashley II. Griffon engine with contra rotating props. Disentigrated right in front of our eyes while coming to the home pylon.

http://tbirds.hp.infoseek.co.jp/accid2.jpg

Gary


I hope that is the pilot under a chute ...

He never made it out in time.

darn! What a shame.

[Neal Nurmi]

And the pilot is missed very much. Gary was a huge supporter of Warbirds as well as Racing. Over the years he brought his P-38 and at least 4 beautifully done Mustangs to Reno, as well as flying "Miss Ashley II".

[aseanaero]

Why don't you see any P-47s racing ?