Turbo And Turbo Overspeed Light

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alias_unknown_2004
Senior Airman
Posts: 111
Joined: 26 Nov 2004, 17:18

Turbo And Turbo Overspeed Light

Post by alias_unknown_2004 »

"At turbo-speeds around 1500 rpm, this light flickers. That tells you the light is in working order. Then it goes off until your turbo reaches about 18,000 rpm, and then it starts to flicker again. When your turbo gets up to 18,250, the light comes on steady and stays on steady until you reduce turbo speed below critical. The idea in high-altitude flight is to fly with this light flickering." From the Army Training Film: "How to fly the P-47--Pilot Familiarisation" (available from Zeno Warbirds Video Drive-In if anyone's interested.)

From P-47 Pilot Manual: "The supercharger control should be set so that with full throttle, and supercharger control "FULL ON," 52 inches Hg at 2700 rpm is obtained for take-off. When operating at high power above 7000 feet, the throttle should be wide open and should be left there. Adjustments to power should then be made by the supercharger control."


I noticed the boost handle and turbo overspeed light are modelled in the cockpit, naturally, but I'm wondering if they will be fully functional, or purely cosmetic? FS9 seems to be severely limited in some respects...

AU

SD_Research
A2A Major
Posts: 461
Joined: 18 Jan 2005, 11:37

Post by SD_Research »

It's eye candy, but it's good eye candy. The turbo overspeed light in the WoP P-47 will indeed flicker as long as the turbine speed is within limits. If the turbo overspeeds, the light will go solid. This can in fact happen if you use full throttle beyond the critical altitude, so if this light goes solid, you'll need to back out of the throttle to get it to flash again once it comes back in range. This gauge is tied directly to the turbocharger operation in the FS9 FDE so the reading is accurate and does have real meaning. You'll notice that the turbine RPM increases with both throttle position, and most notably, altitude. So while it is not exactly like the real aircraft, it is a close facsimile and does provide real information on what the turbocharger is doing at any given time.

The turbo control handle is automatic and will follow the position of the turbine RPM gauge, it's another example of "good" eye candy. It's realistic in the sense that the turbo control handle will always follow the throttle, but yes, FS9 does not have the sophistication to model the separate supercharger and turbocharger systems on this plane. FS9 models all forms of boost as "turbocharging" and provides a very constant application of boost gain up to critical altitude.

There are ways to create .xml gauges to sort of give the impression that there is a two-stage supercharger, but generally these don't provide satisfactory results and we have steered away from these until such time as they can truly model the results we want. Unfortunately with the FS9 flight dynamics engine as it currently is, this is probably not going to happen. FS9 does give us terrific fidelity in many key areas, which is why it's such a great platform for flight-simming. We are content to live with these limitations because the rest of it is so darn good.

alias_unknown_2004
Senior Airman
Posts: 111
Joined: 26 Nov 2004, 17:18

Post by alias_unknown_2004 »

SD,

It may be eye-candy, but at least it's ACCURATE eye-candy! :D It's this attention to detail that makes WoP the best virtual aircraft available. Can't wait to own it!

AU

sparow
Airman
Posts: 13
Joined: 11 Oct 2005, 07:15

Turbo handle animation .RPM indicator and turbo lt. question

Post by sparow »

According to real flight training manual turbo boost handle under no circumstances supposed to exceed throttle movement in order to prevent turbo damaged due to building up pressures that had no mean of escape.
When the P-47 was serviced with grade 100 fuel,the turbo control could be inter-connected with the throttle by means of a link.This link could be disconnected during starting and at high attitudes with throttle full forward when necessary to pull back on the turbo to avoid overspeeding.
In our flght sim. I noticed specially at high altitudes turbo boost lever exceedes by far throttle handle movement .This situation could provocate serious damage in turbo system of a real plane.Retarding throttle lever down to 7 percent will finally make boost lever to move down from its max. position. At lower altitudes turbo lever moves more realistic.
Is it possible to correct this in the next patch ? :roll:
About overspeed light.It's function is clearly explained in the same manual .The turbo warning light goes on the instant you start the engine.It glows steadily unles you use turbo.In this case ,the light starts to flicker until speed of 22.000 rpm is reached(series D-25 and later) or 18250 rpm(series before D-25) .After those values the light glows steadily again.When this happens,reduce rpm.The turbo is overspeeding.
In sim after engine start the light is out and sometimes at high altitudes at high rpm. :oops:
I simulated engine shut down at high altitude and I noticed turbo boost indicator still showing high rpm (with no exaust gasses any more) :oops: Finally moving throttle back will decrease turbo rpm :?
Last question is about intercooler shutter control indicator, would be nice if you can simulate this too! 8)
brgds sparow

SD_Research
A2A Major
Posts: 461
Joined: 18 Jan 2005, 11:37

Post by SD_Research »

It's not real likely that any of this stuff will be changed, because it's just eye candy. There is no affect on the aircraft from either the turbo handle, overspeed light, or turbo RPM gauge. All of these are connected directly to the turbine wastegate position and they give you an idea of how hard the turbo is working. But they have no real function at all, other than being nice to look at. So it's doubtful this is going to be changed, and if it was, the only thing that would likely change is the turbo handle animation. We could connect it to throttle position rather than the turbo wastegate and have it always be a little behind the throttle. But again this is all just eye candy so it doesn't warrant a patch by itself.

sparow
Airman
Posts: 13
Joined: 11 Oct 2005, 07:15

Post by sparow »

Thanks SD_Research these are of course minor items considering overall complexity of this beautiful historic sim and patch can wait ... but I'm sure you'll do your best when the time comes. 8)
The idea about turbo lever connected to the waste gate is good as it is in reality :)
My suggestion is that above 12000 ft you swap lever functions,in other words make turbo lever active and throttle lever animated and below 12000 ft you leave it as present ,throttle lever-active, turbo-animated. :idea:

sparow

SD_Research
A2A Major
Posts: 461
Joined: 18 Jan 2005, 11:37

Post by SD_Research »

sparow wrote:Thanks SD_Research these are of course minor items considering overall complexity of this beautiful historic sim and patch can wait ... but I'm sure you'll do your best when the time comes. 8)
The idea about turbo lever connected to the waste gate is good as it is in reality :)
My suggestion is that above 12000 ft you swap lever functions,in other words make turbo lever active and throttle lever animated and below 12000 ft you leave it as present ,throttle lever-active, turbo-animated. :idea:

sparow
That may not be possible given the animation tags in the VC but we will look into it!

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