BAC 1-11 underpowered/overheating?

[Shaun]

Hi all,
with the upcoming release of FS2020, I am getting back into FSX, and as an old-bird enthusiast, I can't pass up on the DMSim 1-11. Everything is working great, however even with less powerful engines than the Srs 500, the engines actually overheat easier on the Srs 200, meaning I have to pull back on the thrust even more. This results in very long take offs and initial climb rates of only 500ft/m. This is with a payload of about 74,000lbs, so quite heavy. Due to the water methanol running out quickly after lift off, it doesn't help the climb at all. I'm wondering if there is a way to reduce the temperate slightly, as I can't even climb at 94% N1, as recommended, without overheating.

As well as this, I looked at the AIR file, and found that the static thrust of 10,410lbs is only reached at 110 N1, which is never reached. I have to initially takeoff and climb with ~90% N1 to avoid overheating, which on the air file only gives a thrust factor of 0.56, or 5,230lbs. If I could avoid an overheat at 95% N1, I would have a thrust factor of 0.75, or ~7,800lbs at my disposal.

So basically, my question is how do I reduce the heating effect of the engines?

[TSR2]

Switch on Top-Temp

The Air files are dark art. You cant take numbers straight from the real aircraft data and just drop them in. Thats one of the reasons why it was so hard to build models, the air files were made with guess work and experience to try and get them as near to real world performance as possible.

Taken from the manual -

"Water injection
This simulates the system fitted on some Spey 512 engines. Not all One-Elevens had water injection.
Water injection versions of the Spey engine can be identified by a 'W' in the name, e.g. Spey 512-14DW
Used on take-off, the system injects water into the rear of the engine to reduce the temperature. This allows more power to be used for a longer period without overheating.
To operate, simply click the switch. The water injection occurs automatically when the engine RPM goes over 92%.
12 gallons of water is available which is enough for two take-offs. Water level is displayed on the dial above the switch.
In FS the water tank is automatically refilled whenever the aircraft is stationary. A set of lights is also included on the co-pilots panel.
The amber lights show when the system is switched on & the blue show when the water is being injected.
Engine Top Temp
This simulates the top temperature control system on the Rolls Royce Spey.
With Top Temp on, fuel flow to the engine will automatically be reduced if the temperature is approaching the maximum allowed limits."

[Shaun]

It may have been due to a hot OAT... I was taking off from a place that was ~30 degrees Celsius.

[Shaun]

Alright, as an update I've more-or-less fixed the issue. I went into the AIR file and changed table 540's (EGT) scalar from 1 to 0.98. This let me takeoff with 97% N1, without injection. However the airfield I took off from had an OAT of 36 degrees Celsius, so I may change it to 0.99. Atleast I don't have to change thrust scalars and whatnot, but this small change has allowed me to 'safely' climb out now.