Author Topic: Finally! Hvy F-4U Off Cv (Read 2035 times)

Hornet · « **Reply #15 on:** September 01, 2003, 09:07:19 PM »

F4UDOA can you elaborate on the fuel consumption a bit? I spend a good amount of time in the Hellcat but when I do take up either the C/D model Corsair I'm always surprised by how fast it burns through its tanks, particularly if you're on the WEP a lot. Like you said, my understanding was both the Corsair and Hellcat were supposed to have long legs -- but w/o DTs I'm usually frustrated with the "fighting time" the Corsair gives me.

F4UDOA · « **Reply #16 on:** September 02, 2003, 03:31:16 PM »

Hornet,

Sure, I was in a rush during may last post so I didn't make much sense.

First

It is not the duration of the F4U that is porked first of all. At mil power the F4U and Hellcat drink a ton of fuel. Approximately 290 gallons per hour. So the F4U-1D had 237 gallons internal and the Hellcat has 250. So at that power setting it was good for less than an hour. At a 2 to 1 it is good for about 20 + minutes in the MA which is what we have.

So follow this.

All engines have something called an SFC. Specific fuel consumption.

It is how much fuel an engine uses to create 1 horsepower per hour. The R2800's sfc is actually a very efficient engine at it's best SFC rating which as in all engines is in min cruise power setting. This gets much worse when you run at full power. For instance the SFC of the F4U and F6F is .44 at min cruise (best) and .870 at sea level at mil power it's worst SFC.

Here is the porking.

The La-7 has an inferior engine to the R-2800. It is essentially a copy of what went in to the F4F which was a Wright Cyclone 1800 series. It had less cylinders than the R-2800 but produced high HP.

The La-7's engine had about the same SFC as the R2800 at it's best cruise. However in AH that SFC never changes to represent the fuel consumption at mil power or at combat power. And remember the LA-7 carried less than half of the fuel that the F4U/F6F did.

So in AH an A/C that carried 122 gallons of fuel has greater duration than A/C that carried more than twice that amount at the same time the La-7 is generating 75% as much HP as the R2800 at mil power.

So what AH is telling you is that in 1943 the Russians could build an engine that was better than 50% more efficient at producing HP as the R2800 which to this day is the benchmark for Aircooled engines in Aviation.

How does this hurt you.

Well if you want to fight the La-7 on equal terms (duration with 100% fuel) you have to carry in a F6F 1500lbs of fuel and the La-7 732lbs. So you get to carry an extra 700+lbs on your back during combat. Believe me the F6F would fly like the La-7 if it were 700lbs lighter.

I believe this is true for the 109G10 (2000HP and 106 gallons of fuel)as well as other high HP small fuel load A/C in AH.

The answer should be IMHO to correct fuel consumption in all A/C and then probably change the multiplier to 1.5. At 2.0 in reality the La-7 should have a duration of about 10 minutes.

In the end carrying less fuel would help you get off the deck easier as well.

Hornet · « **Reply #17 on:** September 02, 2003, 05:43:41 PM »

I see your point now and that change would definitely affect the MA particularly on the large maps. Thanks for the explanation F4UDOA, great stuff as always.

DamnedRen · « **Reply #18 on:** September 03, 2003, 02:56:19 AM »

F4UDOA,

If your calculations are correct how much flight time would you say an LA-7 should have with a full tank of gas?

Ren

F4UDOA · « **Reply #19 on:** September 03, 2003, 08:59:54 PM »

At a 2 to 1 fuel burn ratio in the MA, about 10 minutes.

DamnedRen · « **Reply #20 on:** September 04, 2003, 04:51:47 AM »

I'm sorry. I think I might have mistated the question. Without a comparison to any other aircraft and using your calculations what flight time should be available to an LA-7 taking off with a full tank of gas?

Thanks
Ren

F4UDOA · « **Reply #21 on:** September 04, 2003, 09:37:31 AM »

Hmm,

I think I got it right.

You are asking what would the flight time be in an La-7 taking off with a full tank of gas in the MA. Porobably about 10 to 15 minutes tops.

This is because if you caompare the amount of fuel required to create 1650HP in real life that would give the pilot about 25 minutes flight time based on research done a few months back. In the MA that would not leave you much time at all.

MoMoney · « **Reply #22 on:** September 04, 2003, 09:55:33 AM »

So what your saying is that the F4u is porked. I agree !! La-7's are overmodeled !! I agree !! YAY YAY !!! ...o time for lunch...

F4UDOA · « **Reply #23 on:** September 04, 2003, 10:13:40 AM »

Half right. The F4U is not porked in the fuel consumption arena.

Yorba · « **Reply #24 on:** September 04, 2003, 12:22:59 PM »

F4,

The key here is flying a full military power. So in AH is there a cruise setting that works well for the D model?, or is that the problem? From what I have seen of people's testing with MAN and RPM settings, it varies alot from plane to plane. I myself prefer flying in blue steel, so what are your recommendations for F4u-1 and D model cruise settings? It would be nice to see those that fly the high RPM, low fuel aircraft to have to smartly allocate their consumption.

F4UDOA · « **Reply #25 on:** September 04, 2003, 01:49:01 PM »

Yorba,

It would not bother me to fly at max continious power or cruise for fuel economy.

It just strikes me odd that so many A/C in here can tool around at full mil power without ever having to worry about fuel.

DamnedRen · « **Reply #26 on:** September 04, 2003, 04:53:02 PM »

Ouch. So you're saying the Russions fielded a plane that could only fly a grand total of 25 minutes, which included take off, climb to the fight (or look for the enemy), dogfight, either limp home fly home and land? And under firewall conditions, around 10-15 minutes. How did they accomplish anything using this plane?

Thanks
Ren

JB73 · « **Reply #27 on:** September 04, 2003, 05:45:20 PM »

Quote

Originally posted by DamnedRen
Ouch. So you're saying the Russions fielded a plane that could only fly a grand total of 25 minutes, which included take off, climb to the fight (or look for the enemy), dogfight, either limp home fly home and land? And under firewall conditions, around 10-15 minutes. How did they accomplish anything using this plane?

Thanks
Ren

just to pop in here .... the La7 didnt have oxygen at all... so it didnt have to climb above 10k (couldnt for pilot would die of asxyphiation)

DamnedRen · « **Reply #28 on:** September 05, 2003, 06:35:34 AM »

Quote

Originally posted by F4UDOA
Yorba,

It would not bother me to fly at max continious power or cruise for fuel economy.

It just strikes me odd that so many A/C in here can tool around at full mil power without ever having to worry about fuel.

Funny thing about that. Your experience within the game shows your comfort level. I have been in an offline conversation concerning fuel burns, etc.
It's interesting to note the newbys take a while to learn fuel management. Not only just having enough to carry so you get home but to carry what you think you need to get the job done. What's easy for us concerning fuel management is a whole new world to them.

What makes it tougher is skill level equals the amount of gas you carry. For example, a newby may take a full tank of gas and die 10 minutes into his flight many times.
Alternatively, a newby may take a full tank of gas and run out of ammo 10 minutes into his flight. Now he has 50 minutes of fuel left and nothing to shoot with.
Or he may take a quarter or even a half tank and run out of gas with half his ammo load still intact.

Ren

F4UDOA · « **Reply #29 on:** September 05, 2003, 02:21:39 PM »

Heya DamnedRen,

I have some documents provided by Tilt that shows very specific flight duration from Soviet test.

There was a very long thread a while back concerning this but I don't have the document handy. But from what I remember the duration at full power was extremely short.

I also read recently that the La-7 WEP could only be used for two minutes at a time.

And yes fuel management is and shoild be a big part of the game. I have brought this up a number of times in different threads. I have a knack for upsetting management in HTC however so I will wait before bringing this one back up.