Settings for best low level performance.

[Drakeshoot]

Hi All,

 

I’m having a lovely time with the Mossie (insert Lord Flasheart reference about machinegunning my number into her bedroom wall here) but am wondering how best to squeeze performance out of the bird in at her preferred altitude (1-30ft…). I’ve been running around at 2950rpm with +9lb boost and she tends to sit around the 270-280MPH mark which is fine but I’ve just seen a video of a guy screaming along at a lower RPM, 2700ish but at higher boost, 16-18lb and he had a solid 300-320 out of her. Is this sustainable?

What settings are you guys using for the various phases of a strike? Also, cowl flaps, do they make a huge difference in speed and temp? Edumacate me!

[grafspee]

16-18lbs is definitely a bit too much for 2700rpm.

I would go with 12lbs and 2850 rpm for longer use and 14-16 for short burst at 2850rpm.

Edited September 21, 2021 by grafspee

[DD_Fenrir]

From the Pilot's Notes:

 

Quote

PART III

 

LIMITATIONS

 

51. Engine data Merlin 23 and 25

 

The principal engine limitations are as follows :-

 

Merlin 25

 

	Supercharger gear	R.P.M	Boost lb./sq. in.	Temp °C Coolant	Temp °C Oil
MAX. TAKE-OFF	Low	3,000	+18*
INTERMEDIATE 1 HR. LIMIT	Low / High	2,850	+9	125	90
MAXIMUM CONTINUOUS	Low / High	2,650	+7	105 (115)t	90
OPERATIONAL NECESSITY 5 MINS. LIMIT	Low / High	3,000	+18*	135	105

 

*May not be used at r.p.m. below 2,850.

t The temperature shown in brackets may be used if necessary for short periods only.

 

 

 

 

[Nealius]

I've been using +12/3000 and barely getting 270 myself. 

[DD_Fenrir]

Radiators closed or open?

 

[Nealius]

12 minutes ago, DD_Fenrir said:

Radiators closed or open?

 

 

Open. One of my engines (usually starboard) smokes if I close the rad flaps. 

[DD_Fenrir]

Getting the smoke myself if I don't get to the runway promptly enough but it doesn't seem to correlate well with maximum allowed coolant temps so it may be a bug....