Too much va-va-voom

[Fifth Columnist]

In excess of 1 hour flown at ~3000rpm +18 boost, the manual (As stated on page 108 in the table "Operational limitations of the merlin 25 engine") does not state how long this regime can be sustained, however this is close to the "Operational Necessity" (RPM 300 Boost +25).

I realise the aircraft doesnt fall out of the sky if one of these limits is exceeded, however this seems excessive.

Incidentally I am not sure how I could ever come close to +25 boost, please advise.

Track cannot be uploaded due to size limitations, (76mb) lesser size track would not demonstrate the problem.

Please provide an alterative mechanism to supply the trk file.

Kind Regards

[Terry Dactil]

Read more of the manuals and find the bit about maximum continuous power...

[PawlaczGMD]

If this is correct, 1h+ at WEP is definitely too long. It shouldn't be a hard 5 minutes, but this is basically unlimited usage. I'm just getting started on the Mossie, I will try to test it.

For comparison, the Spitfire has a similar limit and manual wording, and it would definitely get cooked in 10-20 minutes of WEP.

[Skewgear]

The original limits were set to prolong engine time before overhaul (TBO) rather than avoiding catastrophic failure. You won't kill it in DCS as our aircraft are all factory fresh for their 2 hours in existence.

[Fifth Columnist]

3 hours ago, Skewgear said:

The original limits were set to prolong engine time before overhaul (TBO) rather than avoiding catastrophic failure. You won't kill it in DCS as our aircraft are all factory fresh for their 2 hours in existence.

Thats interesting, I was hoping for the equivalent of magic blue smoke is that consistent with other piston AC in DCS? I think I have heard about the p51 and p47 engines giving up in DCS due to abuse.

 

15 hours ago, Terry Dactil said:

Read more of the manuals and find the bit about maximum continuous power...

Thankyou Terry, I am aware of the stated limits are and have been dutifully flying within that regime once in cruise. However I thought I'd just push the handles all the way forward and gun it for paris to see what happened, It looked like I would run out of fuel before anything else happened.

There is a discrepancy within the manual regarding boost, from page 108:

Edited January 22 by Fifth Columnist

[Terry Dactil]

Agree that there is a discrepancy with the boost figures in the  manual..

My post was having a smile at the idea that continuous could meant only after one hour had elapsed. Sorry.

[Nealius]

On 1/23/2025 at 12:57 AM, Skewgear said:

The original limits were set to prolong engine time before overhaul (TBO) rather than avoiding catastrophic failure. You won't kill it in DCS as our aircraft are all factory fresh for their 2 hours in existence.

Not for all of our modeled warbirds, unfortunately. Some of the other warbirds, notably the P-47, are modeled with a differing logic that causes damage or failure with any WEP usage--or even the slightest mistreatment--at all. 

Edited January 25 by Nealius

[Bozon]

On 1/22/2025 at 3:46 AM, Fifth Columnist said:

Incidentally I am not sure how I could ever come close to +25 boost, please advise.

+25 boost was only possible with 150 octane fuel. DCS mosquito is modeled with 130 octane and limited to +18.

150 octane and +25 boost were deemed necessary in order to keep ahead of the Luftwaffe fighters as of mid 1944 (FW190A-8 and late 109G6 or G14 contemporaries). It was initially issued to intruder squadrons and whoever was doing daylight operations. I don’t know how widespread it was by the end of the war.