Macchi C.202 performance

[Pyro]

I think most of you have looked past my explanation and are trying to attribute it to things in our flight model or the way data is interpreted.  It's not a matter of prototype vs production, it's a matter of what is physically possible.  V-Twin, if you saw specs on a car that had 80HP and weighed 1000 kg yet claimed it could accelerate to 100 km/h in 4 seconds, what would you think?

In the case of prototype vs production, it really doesn't matter here.  Both are beyond what is possible and the prototype data is even worse.

At a test weight of 6206 lbs, the 202 prototype specs allege a time to climb to 3280 feet of 34 seconds.  An average climb rate of 5788 feet per minute.  

One horsepower is defined as 550 foot-pounds of work per second, or viewed another way, the amount of work it takes to raise 33,000 lbs one foot in one minute.  Therefore, to raise 6206 pounds at 5788 feet per minute would take 1088 horsepower.  (6206*5788/33000)  Even without considering the power losses due to the propeller and the power required to fly at climb speed, both of which are very significant, this is an impossibility for a 1075 HP engine.  

It's not a matter of interpretation because that data is not even in the ballpark.  It's not even in the same sport as Jules would say.  

If anyone can mathematically show how a machine can output more work than its input, not only will they convince me of my error, they'll win the Nobel prize for physics and provide the world with a clean unlimited power supply.



------------------
Doug "Pyro" Balmos
HiTech Creations

The road to hell is paved with good intentions.

[funked]

Pyro I think it has one of those "Mr. Fusion" devices from "Back to the Future"...

[Vermillion]

 

In the case of prototype vs production...

Pyro, I can guarantee that the C.202 was not the focus of my other topic I started.  

I honestly know nothing on this aircraft, and have been trying to stay outta this one  

Mr Fusion... hehehe I like that  

------------------
Vermillion
**MOL**, Men of Leisure
Carpe Jugulum
"Real Men fly Radials, Nancy Boys fly Spitfires"

[funked]

JULES
E**** a b**** out, and givin' a b**** a foot massage ain't even the same f***** thing.

VINCENT
Not the same thing, the same ballpark.

JULES
It ain't no ballpark either.  Look
maybe your method of massage
differs from mine, but touchin' his
lady's feet, and stickin' your
tongue in her holiest of holies,
ain't the same ballpark, ain't the
same league, ain't even the same
f***** sport.  Foot massages don't mean s***.


[This message has been edited by funked (edited 04-24-2000).]

[VISCONTI]

Hi all,

was not my intention to participate in this tread cause i'm working (whit some friends) in the researc of data about the Italian WW2 aircraft and our work is not finished.

I read the post of Pyro and i think that the data about the 3280ft/34sec. is refered to a c202 whit the Daimler-Benz DB-601E-1 1350 HP.

I know that in a c202 Serie XII (MM.91831) in summer 1944 was installed a DB-601E-1, i dont know if this is the only c202 whit the "new" engine but probably that can give us an answer.

The c202 (MM.91831) whit the DB-601E-1 crashed 21 January 1946.


Anyway the data about the "Alfa Romeo RA.1000 RC.41I Monsone" (standard engine on the c202) are:

0m 2500rpm for 1' 1175HP <take off>
0m 2400rpm for 5' 1015HP <climb power>
0m 2300rpm for 30' 950HP <normal power>
0m 2200rpm for unlimited 860HP <cruising power>
3700m 2400rpm for 5' 1100HP <max power>
3700m 2250rpm for unlimited 970HP <cruising power>
4100m 2400rpm for 30' 1050HP <normal power>
4500m 2400rpm for unlimited 1000HP <cruising power>

We can see that for about 1 min the c202 is capable to perform 1175HP that give at the plane the possibility to climb at 3280ft in 34sec.

This is only my opinion, hope to see more input in the following days.

Regards VISCONTI


[This message has been edited by VISCONTI (edited 04-24-2000).]

[wells]

Visconti,

I agree, I think that the data with 601E would make alot more sense.  1175 hp still isn't enough though...

[Kieren]

YEAH! WHAT FUN  ked   s a i d....

*what the heck DID funked say?*

 

[funked]

Kieren, I couldn't resist posting the conversation in Pulp Fiction that Pyro alluded to.  

[gatt]

Sorry for some of you, but data of the official manual are NOT from a DB601E powered C.202. They are from a Series IV-VIII model. That means from November 1941 to July 1942. So, it was probably a light C.202 with only the 2x12,7mm (as most of the C.202 were till the end of the war).

Again, if you take a look at the table you can see that up to 5,000mt (16,400ft) the average climb rate is 3,519ft/min and up to 6,000mt (19,700ft) is 3,280ft/min.

The AcesHigh C.202 has an average climb rate up to 6,000mt of 2,720ft/min (with WEP). I find very strange the 1,075hp shown on the table, whereas the same engine on the 109E-3 shows 1,175hp and the same Alfa-Romeo license built engine of the Re-2001 shows again 1,175hp for t/o power (PYRO has that Re-2001 power table). How 100hp+ as t/o power could help to understand those data?

Moreover the offical Re-2001 performance data show that the kite got to 19,700ft in 6'30". Her t/o weight was 3,240Kg (some 310Kg more than the C.202).

Do I have to think that the C.202 didnt climb to altitude with a 109E-3 or an Hurricane I or II? From all the books I have red about North African and Malta theatres I know she was superior to those 2 fighters and pretty similar to the Spit MkV (probably with Vokes filters).
 
Anyway, no flames from me here. I just wont fly that Macchi, even if I am a dedicated Macchi driver. Well, not really a big issue ... hummm


[This message has been edited by gatt (edited 04-25-2000).]

[VISCONTI]

Gatt have right, the data are from an Alfa Romeo RA.1000 RC.41I Monsone and not from a German build engine.

We have found some data about the c202 whit the 1075HP engine:

5000m <16404ft> 5'30"
6000m <19685ft> 6'10"
7000m <22966ft> 8'16"
8000m <26247ft> 9'54"

These data regard the c202 before serie IV i think.

We are still working on these data to have a confirmation.

Anyway i agree whit Gatt when he say that the actual AH c202 performance are undermodelled, i think that the turn rate of the c202 is a little overmodelled but we dont have data till now. We hare working on his turn performance too but is a long job.

[Dnil]

But pyro and wells saying that its physically not possible to match those numbers, why not address that issue first.  If the numbers cant possibly match those given from the "official" source then the source needs to be questioned, think thats the whole point.

------------------
Dnil
JG-2
Part time aircraft restorer. www.kingwoodcable.com/jheuer

[Dinger]

Well, Dnil, as I see them, the arguments are these:

A. The manual gives an obviously impossible figure for the initial climb to 1000 meters.  Therefore, they are entirely unreliable and should be discarded.

B. The manual gives a figure for the climb to 6000 meters that is not implausible, and is considerably better than the one the currently modelled 202 has.

The question is: how big is the corruption of the data?  How did that figure for A. get in there?

Now Visconti comes along and posts some different numbers.  It might help the case if he could post his source.

[Dnil]

I agree, an interesting subject.  I would love to know why the different numbers and if AH is way off which I suspect it might be a little then lets fix it, but only after we have definite proof that confines to the laws of physics    

p.s. I fly the 202 and love it, even though it has a weak punch.

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Dnil
JG-2
Part time aircraft restorer. www.kingwoodcable.com/jheuer

[Citabria]

whats wrong with the 202?


(ducks,runs, slips and falls)  

[gatt]

 LOL Citabria ...