Mosquito Throttle detent question

[J13 Serenity]

Hi

When throttles are set to the detent, at sea level, you get about +14lb boost
1945 manual states that you should take off and climb at that detent and 2850 RPM
At the same time, the max climb boost is +9 lb
1950 manual states that you should climb at +9lb and 2850 RPM boost specifically

What am I missing here?
Is detent position correct? should it be for +9 at sea level, or is +14LB is a climb power?

Also, for merlin 21 and 23 it mentions +14lb boost as a max takeoff with boost cut-out pulled...

Does anyone knows whats is going on with this detent?
Thank you
 

[grafspee]

There is some inconsistent in those manual, because in warbirds you never take off and climb with same power settings. I would say that detent is to make it easier for pilot to not exceed take off power and climb is done at 2850rpm and 9 boost. To set 2850rpm on the ground you would need to run up engine with rpm lever full forward to 3000rpm then with rpm lever drop it to 2850rpm rather erratic procedure i would say.

Edited September 19, 2023 by grafspee

[Skewgear]

Have you got links to these manuals?

They may have been written for different marks of Mosquito or different engine types. Our one is modelled with Merlin 25 engines so the boost cutout for the M22 and M23 is inoperative.

[J13 Serenity]

Friend gave me that manual, cant find it online quickly
Here are some screenshots from it:
https://app.gemoo.com/share/image-annotation/562805392285552640?codeId=Pa6RjgJ7G3QeN
I missed it somehow, but it specifically mentions "Throttle stops" to be +9 lb bost...

Edited September 19, 2023 by J13 Serenity

[J13 Serenity]

Also this one
https://zenoswarbirdvideos.com/Images/Mosquito/MosquitoFB6Manual.pdf
Page 21
Same +9lb boost at the stops

[grafspee]

DCS mosquito is powered by 2 merlin 25s

So it should give 12lbs at stop and 18 full forward.

 

Edited September 19, 2023 by grafspee

[J13 Serenity]

Any reference for that?
Manuals include Merlin 25 if you read carefully

Also, what is a commons sense for that?
Climb power is +9 and 2850
Max power is +18 3000
What is a name for +14 3000? or +14 and 2850?
Manual says that max for 2850 is +9...
 

[grafspee]

 

From your manual, Merlin 25 engines gives +12lbs boost at stops and +18 lbs when full forward if you read carefully.

Max power 

-Merlin 25- 18lbs at 3000rpm / 12lbs at stop

-Merlin 23- 12lbs at 3000rpm and with boost control cut-out pulled 14lbs Not avaivable in Merlin 25 / 9lbs at stop for take off 3000rpm even at 9lbs boost.

Climb power

+9lbs at 2850 for both engines

Edited September 19, 2023 by grafspee

[J13 Serenity]

Ok
But in DCS we get about +14 boost
How can that be explained?

And what is the purpose of that stop it its +12?
Its not a climb power
Its now a takeoff power
Its no max power
What is it for?

I am not trolling, I just tries to understand the practical reasons behind all this.

Edited September 19, 2023 by J13 Serenity

[grafspee]

It could be that 14lbs max(emergency) power from merlin 23 went to merlin 25 as military power so this stop gate is for to hit that 14lbs, and old 14lbs become 18lbs limit.

But why DCS mosquito is setup like this 14lbs instead 12lbs i am not sure and as far as i checked DCS manual does not mention about this throttle stop and achievable boost at stop.

 

Edited September 19, 2023 by grafspee

[J13 Serenity]

Its a mystery to me 

My speculation, is that it should be at +9
My arguments:
The manuals I've found specify +9 as climbing power
They call this "Throttle stop" as a climbing power
They recommend keeping power at the notch for climb at 2850RPM, that eliminates +14 or even +12lb due to an engine limitation of +9 and 2850RPM max for 1 hour
Takeoff at +9 and 3000rpm is very practical, because takeoff is much smoother and all you need to do after is reduce  the RPM and you are in a climb configuration.
Its the same philosophy as Spitfire, where you takeoff at +7 or +12 3000RPM and only need to reduce RPM afterwards for Cruise or climb engine power.
Less control manipulation, better SA
Makes sense to me
  
But there are evidence for +12 at the notch in the same manual
Here they say "Takeoff at climb power at the notch" and give takeoff safety speeds for either +12 or +18?

And that makes me very confused


null

Edited September 19, 2023 by J13 Serenity

[J13 Serenity]

And yet, they call it a " climb gate"
And we know that climb power is +9lb...

[grafspee]

@J13 Serenity But manual says it clear that in case merlin 25 at stop we should get 12 lbs boost  not 9 lbs.

You may be right that initial "stop" purpose was as you say but in time this could get changed. 

[J13 Serenity]

But here they specify Safety speeds for +9 and +18


But they never mention +14 anywhere
For earlier engines +14 is the max, so why make a notch for max power anyway?null

Haha, but "My" manual says +9?
Is my manual a wrong one?
It says Merlin 25

[grafspee]

@J13 Serenity can you post screen shot of your manual then, because i can't see this in my manuals.  

[J13 Serenity]

There are screenshots in one of my posts above

nullnull

[J13 Serenity]

Hey!
Even more confusion!
HEere is a tactical trials
First past with Merlin 23, apparently, then a little bit with Merlin 25
So now, the +14 and 2850 comes as a "Combat Mode"!
null

 

Edited September 20, 2023 by J13 Serenity

[grafspee]

Now with all that data, my conclusion is as follows. Dcs mosquito has stop at 14lbs for 2850rpm combat mode and range 14-18 lbs require 3000rpm. So you can safely operate engines at 2850rpm. But for take off rpm levers always full on regardless how much boost. Apparently mosquito throttles stop was rigged differently throughout production.

[Holbeach]

4 hours ago, J13 Serenity said:

Hey!
Even more confusion!
HEere is a tactical trials
First past with Merlin 23, apparently, then a little bit with Merlin 25
So now, the +14 and 2850 comes as a "Combat Mode"!
null

 

 

That's for the 23 engines.

Best stick to 25 engines, which we have and save confusion.

..

[J13 Serenity]

That's very helpful
Thanks

[grafspee]

34 minutes ago, J13 Serenity said:

That's very helpful
Thanks

Right now, probably comment from Devs would dispel any doubts.

[J13 Serenity]

Yes, I concur

One of my friend assumed, that, may be, the notch on Merlin 21, 23 and 25 is located on the same physical spot.
But due to Merlin 25 power increase, the notch, consequently, corresponds to more power... 
Also, he mentioned, that due to engine changes and ongoing trials, the manuals had to be rewritten and chaos ensued.

The main question here, is was underlies the DCS developers decision to make Mosquito the way it is. 

[grafspee]

7 hours ago, J13 Serenity said:

Yes, I concur

One of my friend assumed, that, may be, the notch on Merlin 21, 23 and 25 is located on the same physical spot.
But due to Merlin 25 power increase, the notch, consequently, corresponds to more power... 
Also, he mentioned, that due to engine changes and ongoing trials, the manuals had to be rewritten and chaos ensued.

The main question here, is was underlies the DCS developers decision to make Mosquito the way it is. 

Yes, this could be the truth about this stop spot on throttle.

ED usually acquire  maintenance manuals where those information are included.

There is famous topic about P-51 about DCS P-51 thermostats keeping oil and coolant temp too high and some ppl claims that they had to use manual shutter controls to maintain proper temps. But when you look in to P-51's maintenance manual, you can find exact procedure and opening and closing temps for oil/coolant shutter are exact as in game.

So in this case 14/18 lbs setup has to be based on something.

[VampireNZ]

Come across this thread as am setting up throttle detent on the VKB STECS - for what it's worth noting there seems to be be several sources for Merlin 25 engines stating different settings. This one seems the lastest amendment level.

In any case I have set my detent at +12 lbs, as per the asctual aircraft setting and provides a nice reference for 'power' settings at and above it, along with +12 being the required 'clearing' power setting. Just drop below the detent for continual power settings. I might just get in touch with the guys up in Ardmore building the things and ask them.

(I have also added to this post instead of starting a new one, so the above previous info is included for ref - I would be interested to see where ED got +14 from for the stops on the 25?)

EDIT: This also likely to be related to the issues surrounding the boost/throttle position curve etc. Have provided some info in this thread - 

 

 

Edited February 9 by VampireNZ