no bug Supercharger switch not working

[Nealius]

While flying between 14,000 and 16,000 I was maxed out at 44" full throttle, so I attempted to manually engage the supercharger. Clicking on the guard opened the guard. Clicking on the switch resulted in no response. Left click, right click, either way the switch remained in the down position.

[grafspee]

You need to click area near the switch which corresponds to auto/high or low position, clicking switch alone do nothing.

There is no need to switch supercharger High gear manually, automatic switch will do it for you in proper time.

Doing it too early you will lose power.

Low blower 61"/3000rpm 1600hp, 52"/3000rpm 1380hp ideal switch point for this rpm.

High blower 61"/3000rpm 1380hp

Edited April 15, 2021 by grafspee

[Nealius]

Yeah it looks like I misunderstood when the supercharger engages. I'm aslo confused about throttle/RPM usage around 12,000~14,000ft before the supercharger kicks in. I can't maintain max cont. in the climb without advancing the throttle well past the RPM lever, which going by the "prop on top" rule always makes me a bit uncomfortable. Even 36/2400 isn't maintainable without throttle above RPM lever. 

[grafspee]

1 hour ago, Nealius said:

Yeah it looks like I misunderstood when the supercharger engages. I'm aslo confused about throttle/RPM usage around 12,000~14,000ft before the supercharger kicks in. I can't maintain max cont. in the climb without advancing the throttle well past the RPM lever, which going by the "prop on top" rule always makes me a bit uncomfortable. Even 36/2400 isn't maintainable without throttle above RPM lever. 

This rule apply only when you are flying below critical alt, at higher alt you can do that.

I dont know what version are you running now, but P-51 in  2.7 has smal bug that you cant move cold air lever to ram position and this strips P-51 out of RAM effect. Only way to do it is to assign cold air lever in axis tab than you can move it to ram position, but actual lever in cockpit remains stationary. So it makes a lot of confusion. 

 

[-0303-]

On 4/18/2021 at 8:46 AM, Nealius said:

I'm aslo confused about throttle/RPM usage around 12,000~14,000ft before the supercharger kicks in. I can't maintain max cont. in the climb without advancing the throttle well past the RPM lever

I've been wondering about this behavior. Stumbled over this just now.

http://www.aviation-history.com/engines/merlin.htm

Quote

There was no doubt when the supercharger cut into the high-blower position on the P-51 Mustang. The aircraft shuddered violently and pilots had to learn to anticipate the cut-in and reduce throttle. When descending, the change to low-blower took place at about 14,500 feet, and the only indication of the event was a drop in manifold pressure.

 

[Nealius]

The supercharger behavior in general is confusing to me. My hi-blower will kick in at 14,100 in one mission, and in another mission it won't even come on at 18,000. 

Edited May 9, 2021 by Nealius

[grafspee]

On 5/9/2021 at 5:21 AM, Nealius said:

The supercharger behavior in general is confusing to me. My hi-blower will kick in at 14,100 in one mission, and in another mission it won't even come on at 18,000. 

 

It depends on your power settings and IAS. If you climb at slow speed high power setting(61" 3000rpm) , high blower speed will kick in early, if you climb at shallow angle with low power setting (40" 2700rpm) you will see switch happen at higher alt.

After first 2.7 release, P-51 suffer from inability to set your ram air handle in ram air position, so you may have been flying w/o ram air, this also would lower switch altitude for supercharger speed switch point.

I think now it is partially fixed.

Edited May 10, 2021 by grafspee

[virgo47]

Without the explanation in the first answer, I'd have no idea how to operate this without bindings just with the mouse clicking. There is a green cue when you go around it, but I'd not figure it out on my own and there is nothing in the manual about how to click-operate it. The switch is distinct from the cover when you open it, but clicking it does nothing (or toggles the cover instead) and the tooltip doesn't help you at all, so from purely UX perspective it is quote poor. You have to know somehow.

There is a benefit, of course, it is easy to click on what you want.

The cover acts a bit strange in Auto position though, if you click at the upper part where the pin is - it toggles between the closed position for Auto and Normal (different "depth" of the closed state).

[=475FG= Dawger]

The physical position of the throttle and propeller levers in relation to each other is never relevant. 
 

The relationship to watch is manifold pressure and RPM. More specifically, avoid high MP and low RPM. 
 

Prop forward before throttle, throttle back before prop.