The Ultimate Mustang?

[RobertLawson]

Okay, I admit this probably belongs to the Design forum, but its so dead there and I've gotten such limited responses there in the past. I thought I'd try my luck here. I hope thetas all right.

This is a subject I've thought long and hard about. I've looked over the various Mustangs from over the years, studying all of the modifications that've been made over the years, but it left me with one question.. What would be the ultimate Mustang Racer? I know if Money wasn't a problem, you'd probably be better off designing a Racer from scratch, but for the moment.. Lets discuss what modifications would make for the ultimate Mustang.

How about the Boil off system used on Stiletto? I know there were some quirks, but would it be possible to work them out and make such a setup be a real winner? Or would it be better to just go with a lowprofile scoop like on Miss Ashley II? And one question I've really wondered about is.. How much of an advantage did the learjet wings offer on Vendetta and Miss Ashely II? I've heard some people suggest they offered for flying the speeds and race courses, is this true? Would it really offer any advantage if someone used such a wing on another Mustang? And as a side note, If it wasn't that good for pylon racing, Would it be better for say trying to set a closed course speed record?

What about Power plants? I know the Griffon has some serious draw backs, but could it or other maybe.. more obscure
power plants be of advantage?

And, Are there other ideas out there that've been discussed but never implemented? Or do some of our brilliant members have ideas of their own?

I'm most curious about this, because I like to think up dream unlimited racers and tinker with the ideas. The last one I've toyed with was a P-51 based Racer, but more along the lines of the Cameron Aircraft composite P-51s, extremely light weight, all of of the standard race modifications.. with two versions, One with a Boil off system ((which made it look quite a bit like a spitfire!)) and a low profile scoop, both painted black and green and dubbed Black Beauty, A very attractive scheme I tell
you. But I'm not quite satisfied and would enjoy some input, so I could tinker with it further.

Anyway, I hope this sparks a good discussion on this because I'm curious. :P

But anyway, Thanks for your time.

[Blue Foam]

Re: The Ultimate Mustang?

Everyone will expect me to bite on this, so I won't disappoint.

Given the $$$ that it would take to do what is proposed, I would advocate a new aircraft. Smaller, higher power density, higher wetted aspect ratio. That said...

Wing: The P-51 wing is superior in all aspects to the Lear wing except Mmo (Mach, max operating) and Reno race conditions are far from the Lear Mmo. Stick with the stock wing. I will go so far as to say don't clip it. The minor decrease in wetted area the clip provides is more than offset by increased induced drag of the lower aspect ratio. This trick worked back when Mustangs were clocking 350-400 mph laps, not 500+. IM<HO, Dago and Strega would be slower in a straight line, but faster on course with stock wings. Given a willingness to throw $$$ at the engine, I would stick with the stock wing and some better wing tips.

On the engine, the Griffon is a lot heavier than the Merlin and this offsets the displacement advantage. That said, the Griffon counter-rotating set up has enormous potential.

If we stick with the "Merlin size" engine, the hydroplane racers have definitively proven that the turbocharged Allison is superior in all aspects to the two stage supercharged Merlin. I highly advocate an Allison with an equal length header, collector exhaust turbo'd over the -7 and -9 Merlins. There is a reliable 500 to 800 HP advantage. This is not speculation, it has been proven by over a decade of racing.

Where to hide the exhaust? Go to a P-38 style nacelle, wider forward of the wing where the area rule will benefit. The turbo outlets can be aligned for maximum thrust recovery which the current Merlins are far from (~30 degrees mis-aligned to the local flow). Of course, this would cook the aft canopies of stock Mustangs, so this is limited to the ones with turtledeck fairings. A couple of stainless panels and we're fine. After all, this is a pure racer.

Go CR. Period. There is a 20 to 40% thrust advantage at the current record speeds for couter-rotating props vs. singles. Yes, it would require adapting the -84 Griffon gearbox design to the Allison, but it's worth over 50 mph! What's that worth???

If it's a pure racer, then boil off is a given. Strip the scoop completely and stack a multi-stage boil-off radiator in the tail. Have a large scoop open for ferry flights and when the boil off fails.

The tail is just fine. Let's stick with the P-51H tail that has been dive tested to over 650 mph TAS.

All of this leads to a 4000 HP, 560 mph level, 530 mph lap (Reno) Mustang. Give us a few million and we'll make it happen.

I will now take slings and arrows from the gallery.

[Wild Bill Kelso]

Re: The Ultimate Mustang?

I would say a H model with a race style canopy. Some work around the scoop to make the profile a bit smaller. Then use a CO2 spraybar instead of water in front of the radiator(I've been looking into this ). I think you would have a very light airframe with the latest developed P-51 airframe ever made. I think that would be a good start. I think most of my budget would be spent on warding off the angry hord for cutting up an H model on the other hand.

[Peashooter]

Re: The Ultimate Mustang?

Hello, Gerry Beck & Allison Competition Engines? Great post, Foam.

[Unregistered]

Re: The Ultimate Mustang?

Eric,

Prior to the turbine era of unlimited hydroplanes (and over several decades, not just one) the Merlin proved far superior to the Allison in all aspects. As one who grew up in Seattle with my father involved in unlimited hydroplane racing I would point to the multitudes of winning boats that used Merlins and not Allisons:

Miss Budweiser
Atlas Van Lines
Miss Bardahl
Pay-N-Pak
Miss U.S.
Miss Thriftway
Circus Circus
Squire Shop
Notre Dame
...and many more

In fact, prior to the turbine era, the last unlimited hydroplane with an Allison to win a National Championship was 1957.


Also, doesn't the increased weight of the counterotating gearbox offset the thrust advantage which is also debatable (we'll get to that later)?

[speeddemon]

Re: The Ultimate Mustang?

Wing: The P-51 wing is superior in all aspects to the Lear wing except Mmo (Mach, max operating) and Reno race conditions are far from the Lear Mmo.

John Dilley might disagree with you on this.

P.M. me, Eric...I have something you might enjoy giving a once-over.

[Jay]

Re: The Ultimate Mustang?

How about using the P-51H's thinner laminar wing, full span, & a new technology prop, like the 5 Blade on the PC-21.

If it is Griffon powered, Propfans like the AN-70, with different number of blades front & rear, and make the rear prop smaller diameter so it does not operate in the front propfan tip vortices.

[John]

Re: The Ultimate Mustang?

My vote is for a modified (scratch built) P-51H also. NACA pilots found the "H" handled higher dive speeds better than the "D". ...I believe around .80 Mach. With the right mods, propeller and power, no telling what a race P-51H could do.

[AirDOGGe]

Re: The Ultimate Mustang?

A thinner "H" wing and boil-off system sound like the best suggestions yet. Anything to reduce frontal drag without affect lift in the turns (just an observation, but I think the unlimited planes spend more time making turns than going straight).

The exception to a boil-off system would be a coolant scoop/ejector design that can produce enough thrust to counter all the drag it induces (essentially, like a jet engine). That may not work, as I don't think a WWII V-12 produces enough waste heat to do this (unless prehaps someone figures out a way to add engine exhaust heat to that produced by the radiator(s)).

I won't suggest a smaller/narrower home-built fuselage, as I feel that would be traveling too far from the topic of creating a faster P-51. "Tsunami" was never considered a Mustang.

If costs-be-damned, then you could probably make a Merlin, Griffon or Allison nearly bulletproof using modern Indy, Nascar and/or NHRA technology....

.... or even design a whole new V-12, but it would be VERY expensive to do so, possibly in the tens or hundreds of millions of $$ to develop and test it properly (judging by the money spent to develop new auto engines by GM and Ford). You'd have to REALLY want to win, BADLY...


I doubt that a swept version of the P-51 wing would matter much at Reno race speeds..... Have there been any reports of compressibility problems or shockwaves forming on the airfoils yet?

Maybe if they start approaching 600 mph someday it might. Swept wing technology is mainly for aircraft that approach or surpass near-transonic speeds as far as I know, with the exception being the use of forward or aft-swept wings to assist the CG balance of certain designs (like the long-EZ) or to provide more cabin space (like Hansa's model 320 business jet).

.

And so, my best choice would be a counter-rotating Griffon (IF you can build it reliable enough), the "H" model's thinner wing and taller tail (the tail to handle reduced stability from the twin-prop) , a boil-off coolant system, MAYBE an NACA-style low drag airscoop to feed the engine's lungs...........And some form of lightweight ejection seat system, because that is gonna be ONE FAST pony to escape from if everything goes south ....

.

[RobertLawson]

Re: The Ultimate Mustang?

Wow,

I was kind of afraid that this topic wouldn't really take off, but the response has been most excellent! I admit, it's taken a little time for all of the ideas to sink in, but by God.. Intelligent people discussing such subjects makes me all warm and fuzzy inside I swear. :P But more seriously, The ideas are really intriguing and I've been trying to visualize and apply some of the ideas to my race drawing, with mixed success I suppose. I've mainly been trying to visualize the turbo exhaust outlets and their exact positions on the airframe, I've drawn it up and its kind of convincing I suppose but maybe not exactly right.. Hopefully I'll figure it out. :P Next I need to draw up a CR. Hub, which I actually already have done with another racer I drew up, I jut need to modify a few things to make it all fit nicely.

And a cost be damned modernized V12 has been a fantasy dream of mine sometimes, Oh if I only had Howard Hughes Money to burn.. I'd inject some new life into Air racing I tell ya! Actually, building up a modern version of the Crecy would be really awesome.. meh, if I had the money? I'd develop the new inlines, then sell them at a loss. Talk about an expensive hobby.

Then on the NACA intake scoops, Thats almost become a given for me.. every P-51 based racer I've played with has a NACA scoop lol. Between that and the removal of the belly scoop? Dang thing looks like a Spitfire. :P

But thanks guys, really.. Its fasinating to a guy like me, and I hope we get some more posts going.. and actually, I have a few more thread ideas.

[h34race]

Re: The Ultimate Mustang?

Guys thay need to solve the engine bearing problem first I was sick to see all the needless engine problems at 1 million a shot,I realy wanted to see P51s racing not sitting on the ground with the engines off,Cadillac has a real nice v12 out 1000hp unsupercharged injected

[AirDOGGe]

Re: The Ultimate Mustang?

Guys thay need to solve the engine bearing problem first I was sick to see all the needless engine problems at 1 million a shot,I realy wanted to see P51s racing not sitting on the ground with the engines off

I believe that was due to a bad batch of bearings, not an on-going Merlin problem. At least I think that was what was discussed here last year.

Cadillac has a real nice v12 out 1000hp unsupercharged injected

If you are referring to the XV-16 (not a V-12), it's just a prototype engine used for a Cadillac concept showcar. It never went into production and is not available to the public.

I'm familiar with the this amazing mill only because I built a 3D model of the XV-16 for a popular video racing game, and I did a lot of researching of it beforehand for the project.





I guessing this is the engine you mean, because this engine was tested to 1000 hp normally-aspirated on a dyno.

They DID make a V-12 too (XV-12), but it's only rated at 750 hp.

http://www.autointell.com/News-2001/August-2001/August-2001-4/August-22-01-p3.htm

Either engine is too small & underpowered for a Mustang swap, but it might make a good Sport class motor IF you could make it bulletproof enough to handle aviation-related stresses and forces.

.

[Warren_C]

Re: The Ultimate Mustang?

Isn't that the one Heidi Klum buys for you...oh I'm sorry thats fantasy mustang.

The other kind of ultimate/fantasy Mustang, is not a NAA product. It would be the Piper Enforcer, before you roll your eyes, the PA-48 was an airframe designed to handle 5000 shp all day long. One only needs to compare longerons with the "D" to know this was the Ultimate variant

[h34race]

Re: The Ultimate Mustang?

Yes I was thinking of the V16 sorry for the mistake,I just hope they sovled the bearing problem we really need some mustang growl in the air sounds so cool,the caddy motor looks like a falconer nock off with GM backing.just to ask a dumb question because I don't know, you need 3,000HP to 5,000HP for a race motor ???

[SCEPTER]

Re: The Ultimate Mustang?

race 38 with a sparrow built merlin and cr props