Optimizing flight/speed with CEM

[prophet106]

Hello all. Another newbie here . . .

I took the plunge a couple of days ago and decided to start playing the sim properly with CEM turned on. I'm looking for a few pointers with regards to optimizing my flight. I've done lots of reading (especially here - http://www.2gvsap.org/flea/OP2GvSAPINST_3710.1A.pdf) and watched a fair few vids on youtube for pointers. Of course a have a couple of questions

Firstly my start-up/take-off procedure with the MKI spit looks like this (keeping in mind i'm new to this game)

- Fuel on
- Megnetos on
- Airscrew fully fine
- Mixture rich
- flaps normal
- Start engine

Wait for a little while for her to warm up

- Full throttle and adjust for swing/torque
- Tail up (50ish MPH). Nose up (100ish MPH)
- Wheels up
- throttle back to about 80%
- Rate 1/2 climb

This is when the problems start

Firstly my exhausts smoke a little. I assumed it was the rich mixture so i set it to weak (with my current controls mixture is either 'yes' or 'no'). Still smoking. Interestingly enough if i switch to auto-pilot the smoking immediately stops and performance improves. What the hell is 'he' doing that i'm missing ?

Next is with regards to prop pitch. I was under the impression that once we are in general flight we should switch to course pitch. When i do the oil temp and revs drop but so does the speed. Anything more than a rate 1 climb and you are loosing speed. Trying to catch up to a bomber formation above is a right ball-ache (without blowing the engine by flogging it to death)

So smoking exhausts (viewed with cockpit off, until my trackir gets here !) and lacking power. Any hints/tips would be greatly appreciated

Many thanks
James

[Bulau]

Well, I've read that there is a mixture bug that affects the Hurricanes, perhaps also the Spits, wherein the mixture control is bass-ackwards. So you might try setting mixture to RICH and see if that actually gets you LEAN.

My understanding of coarse pitch is that it's for cruising economy. If you're trying to catch up, use fine pitch.

[Vengeanze]

Guess you opened up radiators. Otherwise that will overheat your engine and break it a couple of minutes after take off.

Otherwise your to procedure looks ok.
You could add like 20 clicks on nosedown trim to get your aft up faster.


Edit: Actually no need to switch on Magnetos in CloD. Just the fuel cock and 15% throttle and hit I. After that u can run through the check list while the engine warms up.

[prophet106]

Thanks for the replies chaps (and that lengthy one Woarmonger, excellent).

Yes i open the radiator fully for take off/landing and keep it at about halfway during flight. i'm still slightly at a loss as to the exhaust though. i haven't even contemplated playing it online yet. just working my way through the campaign (hence having to use the spit). i'll try doing as you say with regards to keeping low after takeoff and building up airspeed before climbing.

yes the first couple times i took off for an interecption i keep climbing in fine pitch on full power. It either pops the piston head or blows the carb.

Thanks again. more innane questions to follow im sure !

[Blackdog_kt]

Whoarmonger got most of it and you seem to have a good grasp on things, so i'll only add two things:

Mixture: Not all people agree it's a bug, because it was reversed in the real aircraft too. This is a carry-over from manual mixture systems, so that by pulling the throttle back the detent on the throttle lever will also pull the mixture back into rich to prevent fuel starvation.

Try to think in terms of what you see the controls doing in the cockpit and not what your key bindings are titled and you'll be fine: auto-rich mixture is with the lever fully back and auto-lean with the lever fully forward.

Prop pitch: Think of it like gears in a car. The two-stage prop only gives you two gears (fine and coarse pitch) so it's like you only have 1st and 4th gear, but they do have a pretty wide power band. In fact i find these Spits pretty easy to manage compared to a 109 which has fully adjustable but still manual pitch.

Use fine pitch just like you would use 1st gear in your car: Slow climbs, low speeds, to limit your speed in a dive (just throttle back a bit to avoid over-revving it), when you want faster response to throttle changes (both decrease and increase) like for example when taking off/landing. It's good to have it on fine for the landing approach in case you need to go around too.

Use fine pitch like a 4th gear: Fuel economy during cruise, attaining your top speed, accelerating in the dive and climbing while at high speed (switching to fine for every climb is like driving on the highway at 140km/h and downshifting to 2nd gear whenever you see a small upwards slope on the road: the torque sure is enough to climb it, but you are bleeding off speed like crazy).

Keep in mind that changing the pitch will also affect manifold pressure, even more so with these props because the pitch change and resulting torque change is quite big: boost will rise when setting coarse pitch so you might need to throttle back a bit, in a similar fashion it will drop when going to fine pitch and you might need to throttle up a bit.

As you can see, it's mostly situational and there's not a hard and fast rule. In fact, there are cases when flying at fine pitch all the time severely limits your performance, like for example trying to catch a 109 in a dive: fine pitch will not only cause the RPMs to pick up and force you to throttle back, it also gets to a point during the dive that the prop creates considerable drag, due to the prop blades being almost face-on to the incoming airflow. It's like having a disc-shaped airbrake in front of you.

Switching to coarse pitch in such a case presents a smaller "head-on" cross section of prop blades in regards to oncoming airflow and lets you pick up more speed.

[EZ1]

You may want to keep that radiator open a bit more in flight--85% maybe. I just closed mine to 50% and it blew a gasket in about a minute. LOOK at the temp guage.

[whoarmongar]

Congrats on tackling CEM it can be daunting at first but is probably the most satisfying aspect of this sim.

For a self confessed newbie you seem to be doing fine and have the basics sorted.

The Mk1 isnt easy to fly becouse of that horrible prop, the frustration you have with the Spits Mk1 performance is shared by all. However if you want to fly a spit online your stuck with the Mk1 and Mk1a coz most servers dont allow the MkII due to its performance advantages. Its due to this that many online RAF fliers now use the Rotol Hurricane just to get the more efficient prop/engine management and better rate of climb.

If you do use the Spit I am by no means an expert but I can pass on a few ideas that I have found to work for me

Flaps are only used for landing with the spit not for takeoff

Warm your engine before taking off this is essential

Set your compass and course setter whilst waiting for your engines to warm, its very easy to get lost on a realistic setting server with no map help.

In theory its rich mix for takeoff and lean at height and for cruising, but its a bit bugged and seems to change with various patches to be honest i havnt got a clue what is rich and what is lean anymore I just use whatever the engine seems to prefer, its certainly less critical than it was before all the patches so just experiment, its a bit like setting a carb up in real life, if the revs pick up the engine likes that mix, if it coughs splutters or farts it dont.
Open your cockpit canopy for better view.

Open your Rad for takeoff, but once up and flying close it to 50% ish and just watch your temps and open and close accordingly.

After takeoff Dont try to climb immediatly, set course pitch stay low and get some speed up, the engine revs will drop, but you will eventually go faster. You will find that with coursepitch in level flight you will only get anywhere near max revs @ about 16000 ft, this is due to air density. Its very easy to over rev in a dive, so coursepitch throttle back.

If your engine starts to "bog down" and you cant get any revs switch to fine pitch and climb a bit or keep in course pitch and dive a bit, obviously not at low alttitude

Really the only way you will blow your engine is by overeving it 2850 is my max revs for safety, or overheating it so watch your temps, to be honest I have never killed an engine by overboosting it but then again i have never "gone thru the gate"

If you have to climb hard, set fine pitch and rev that engine, For some reason I find it better to climb in "steps" rather than a constant climb, I dont know if this is real or just my perception but it seems to work for me, so I climb hard fine pitch, level out coursepitch, pick some speed up then climb hard again and this for me works when chasing high bombers, it also avoids arriving at the bombers from below whilst climbing
slowly in full view of them rear gunners, instead I do a final claw for height behind them then attack at speed then after the attack convert that speed back into height ready for another go.

The rotol is so much easier to use, basics are you set your throttle and use your prop pitch to keep the engine in the sweet spot, after that horrible prop in the Mk1 its a total joy to use.

hope this helps

BTW im a terrible pilot and even worse shot, in truth I prefer bombers (lets not go there with Clod) so I just play with fighters to give others some target practice, im just happy to survive a mission.

Have fun

In time this is going to be a great game

If it can just survive its difficult birth.