Spit Mk1 Boost?

[SEE]

I can't seem to see or get any noticeable performance change with 'boost cut off' enabled or disabled.

I have been testing it at various altitudes climbing/level flight/throttle variables, etc. I would be grateful if someone could offer their results.

[Ze-Jamz]

~S~ m8

Are you getting yer 110% out the throttle too?

[Plt Off JRB Meaker]

Are you flying with 'Complex engine management'?,this would be important to establish.

[superman]

I had problem with this too, till i ffigured out what the "cutout" does.

Boost cut out is a little lever that prevents the throttle from going all the way forward (in the "red")

If you disable cutoff,you will be able to move throttle a little bit extra.

But if you already have your throttle at 100% you won´t be able to push it further so you have to move it back a bit to "reset". and then you can get that extra 10% (or whatever). You will hear sound effects warning you that its not a good idea to leave it for long

But the cutoff itself does nothing to your power. Look closely at the throttle and you will figure it out.

[ATAG_Snapper]

Originally Posted by superman

I had problem with this too, till i ffigured out what the "cutout" does.

Boost cut out is a little lever that prevents the throttle from going all the way forward (in the "red")

If you disable cutoff,you will be able to move throttle a little bit extra.

But if you already have your throttle at 100% you won´t be able to push it further so you have to move it back a bit to "reset". and then you can get that extra 10% (or whatever). You will hear sound effects warning you that its not a good idea to leave it for long

But the cutoff itself does nothing to your power. Look closely at the throttle and you will figure it out.

Good post. "Boost cutout" is a bit of an obtuse label. It should've been "Throttle Gate" which could be toggled open or closed. At least with this beta we can now close the gate after going full boost if we want to. I believe in the real Spits there was a bit of wire that would be cut if full boost was used to clue in the ground crew that further engine checks were in order.

[Plt Off JRB Meaker]

Yes spot on Snapper it's the smallest little 'gate' in red with 'PUSH' on it positioned at the front of the throttle,and just allows you to move the throttle about another 10% as Ze-Jamz and Superman have already informed us.

The new patch now allows us to switch this off,which as Superman points out is important,as you don't want this on for long periods.

[SEE]

Thanks guys, I know how to use it but has anyone tested to see what performance increase they are actually seeing in flight with it enabled?

[Das Attorney]

Hi See,

I posted the following up in the ATAG thread: This is taken from the game data using kegetys.dll. These are pre_beta so not sure if it's changed since. Basically, the MkI and Ia have 0.002 lbs/sq in extra boost (ie nothing)

You need to look at the NominalPressure entry for normal max manifold pressure, and the WEPPressure entry for boost cut out.

The Mark I and Ia are modelled up to 6.25 lbs/sq in. Boost is 6.252 lbs/sq in. Yes, that's an increase of 0.002 lbs/sq in when boost is engaged.

Check the MerlinIII entry in the engine.fmd file:

Supercharger SingleStageSupercharger Efficiency 0.5 LimiterInput Manifold NominalPressure +6.25 lbsqin ContinuousPressure +4.5 lbsqin WEPPressure +6.252 lbsqin NominalAltitude 16250 feet
Valvetrain Generic SlowRunningEfficiency 0.9
FuelPump Pushrod NominalPressure 9 lbsqin at 500 RPM
Carburettor RollsRoyceFloat DiffuserBore 6.1 cm OrificeSlowFast 1.0 sec Heater AutoEngineOil Altimetric DensityRatio Dresser BoostDriven Input +4.5 lbsqin to +6.25 lbsqin Output 1.0 to 1.01

The Spit IIa has +9 lbs/sq in boost.

From the MerlinXII entry:

Supercharger SingleStageSupercharger Efficiency 0.5 LimiterInput Manifold NominalPressure +6.25 lbsqin ContinuousPressure +4.5 lbsqin WEPPressure +9.0 lbsqin NominalAltitude 13500 feet
Valvetrain Generic SlowRunningEfficiency 0.9
FuelPump Pushrod NominalPressure 9 lbsqin at 500 RPM
Carburettor RollsRoyceFloat DiffuserBore 6.1 cm OrificeSlowFast 1.0 sec Heater AutoEngineOil Altimetric DensityRatio Dresser BoostDriven Input +4.5 lbsqin to +6.25 lbsqin Output 1.0 to 1.01

Cheers

EDIT: Don't forget that you need to jiggle the throttle a little after engaging the boost otherwise it won't 'take'.

[=XIII=Wedge]

Isn't that because all you are doing is overriding the automatic boost control system.

With an engine modification to the Merlin III and the use of 100 octane fuel it was possible to to override the automatic boost control system and get up to + 12 lbs boost although this is considered an overload condition.

With the automatic boost control engaged the boost is limitied to + 6.25 lbs.

Unfortunately we do not have this in the game currently - e.g unmodified Merlin III engine using 87 octane fuel.

[SEE]

Originally Posted by Das Attorney

Hi See,

I posted the following up in the ATAG thread: This is taken from the game data using kegetys.dll. These are pre_beta so not sure if it's changed since. Basically, the MkI and Ia have 0.002 lbs/sq in extra boost (ie nothing)

That explains why I am not seeing any worthwhile gain but risk manfold pressure failure if enabled for too long. Best ignore it on those figures.

Cheers Das.