Analysis of real life 109E performance for CloD

[camber]

Originally Posted by Crumpp

The equations in the sim should be the same.

One certainly might hope so but perhaps not count on it

Originally Posted by Crumpp

What were your other settings? Radiators and how did you treat the engine before hand?

Radiators fully open, I polished the engine and swapped the rubber hoses for braided stainless steel

Originally Posted by Crumpp

What rating did you climb and did you allow the temperature to recover after climbing?

Climbing is the hardest thing you do to an airplane engine.

Climbed from sea level to FTH at 140mph IAS, full throttle, 6.2psi, 2700rpm. Full fuel and normal ammunition load. FTH@2700rpm detected via onset of boost drop from 6.2psi. Aircraft allowed to settle at close as possible to FTH@2700rpm and 0 fpm. Speed taken from guage in no cockpit view.

Your point is correct that cooling the engine (e.g by throttling back at FTH to give say 150mph IAS for a while, then accellerating to maximum speed) might make it possible to stay on 3000rpm for longer without engine failure. But 2700rpm to 3000 rpm at FTH gave no hint of speed increase prior to the engine failure.


Cheers, camber

[Robo.]

Originally Posted by Crumpp

285 mph at 2700 vs 315mph at 3000rpm....

My suggestion would be to learn about how aircraft perform and put your pointy tin foil hat aside.

Crumpp please have a go yourself, I am looking forward for your tests at FTH at full power.

[Crumpp]

Climbed from sea level to FTH at 140mph IAS, full throttle, 6.2psi, 2700rpm

That looks like a problem. According to the Operating Notes, Vy for the Spitfire Mk I is 185mph ASI below 12,000 feet, 179 mph ASI to 15,000 feet, and 169 mph ASI to 20,000 feet.

Climbing at such a reduced airspeed will limit the cooling of the engine at a very high manifold pressure and rpm.

If your oil temperature and coolant temperatures are high, you won't last as long at any overboosted condition.

Try climbing at the faster speed. You should get to altitude quicker and have a cooler engine.

But 2700rpm to 3000 rpm at FTH gave no hint of speed increase prior to the engine failure.

In reality it won't either so that actually sounds realistic. In fact, on a summer day, the aircraft will slow down instead of speeding up. That is why I was saying many folks will be mad if they realistically model density altitude effects.

Once the propeller tips begin to approach their mach limits, the ability of the propeller to make thrust diminishes. So you get less thrust the faster your propeller turns at high density altitudes.

[camber]

Originally Posted by Crumpp

That looks like a problem. According to the Operating Notes, Vy for the Spitfire Mk I is 185mph ASI below 12,000 feet, 179 mph ASI to 15,000 feet, and 169 mph ASI to 20,000 feet.

Climbing at such a reduced airspeed will limit the cooling of the engine at a very high manifold pressure and rpm.

If your oil temperature and coolant temperatures are high, you won't last as long at any overboosted condition.

Try climbing at the faster speed. You should get to altitude quicker and have a cooler engine.

True for a real MkI, but remember we are talking about a CloD Spitfire with modelling issues.

I tried climbing at 170mph IAS to 16500ft, +6.2psi 2700 rpm
Oil temp at 16500 feet 93'C, coolant 107'C
Itunes playlist: Kim Wilde 1980's pop diva
Throttle back to +2psi 5 mins for cooling, Oil 91'C, coolant 100'C
Then 3000rpm +6.2psi for max speed test.
Itunes Song: Kim Wilde "Kids in America"

What do you get under similar conditions? I don't want to give away all the flight tests, we need to encourage a cadre of high alt flight testers for CloD to get some data variability

Cheers, camber

[Crumpp]

we need to encourage a cadre of high alt flight testers

When am I supposed to fit that in?

[fruitbat]

Originally Posted by camber

True for a real MkI, but remember we are talking about a CloD Spitfire with modelling issues.

I tried climbing at 170mph IAS to 16500ft, +6.2psi 2700 rpm
Oil temp at 16500 feet 93'C, coolant 107'C
Itunes playlist: Kim Wilde 1980's pop diva
Throttle back to +2psi 5 mins for cooling, Oil 91'C, coolant 100'C
Then 3000rpm +6.2psi for max speed test.
Itunes Song: Kim Wilde "Kids in America"

What do you get under similar conditions? I don't want to give away all the flight tests, we need to encourage a cadre of high alt flight testers for CloD to get some data variability

Cheers, camber

Camber I see your problem.

Its a well known fact you will climb better with Elton John - Rocket Man.

Of course, you will bleed from your ears.....

[bongodriver]

Of course, you will bleed from your ears.....

And other places if Elton has his way......

[Crumpp]

rubber hoses for braided stainless steel

Bad idea in an airplane....

I have experienced a cut oil return line (low pressure thankfully) and had a hole in the intake manifold cut by braided stainless steel lines.

I got rid of every one. Braided stainless steel and airplane engines do not mix very well.

[5./JG27.Farber]

Hang on a minute... Was this thread not about the 109?

[notafinger!]

Originally Posted by 5./JG27.Farber

Hang on a minute... Was this thread not about the 109?

No, these are the 100 octane forums.