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What's up with P-40 and carb temp? At 15 deg C ambient air, the carb temp is 9 deg C. I push in the carb heat, it rises to 12 deg C but soon drop back to 9. I pull out carb heat, it RISES again to 12 deg C but drops to 9.

How come both enabling and disabling carb heat:
A) only has only a temporary effect?
B) has the SAME direction of effect?

Note: applies only to using carb heat while warm-up. In-flight it works as always. And seems that boost increases carb heat as supposed (but wasn't implemented in previous Accusim). I'm still curious why applying carb heat on cold engine (which means carb heat doesn't actually do much anything since there's nothing to draw the heat from) temporarily rises the temp and lets it drop again.

EDIT: while it appeared to work properly after take-off, the problem re-appeared. I fly at 13000 feet, -10 deg C at that altitude, full throttle (around 41", rpm lever full forward). Carb air was around 0 deg C. I press the carb heat, it jumps to around +10...15 deg C and returns back to 0 deg C. I pull the lever out to get cold air back and the temperature rises again to 10...15 and goes back to zero. The manifold pressure goes up with added heat (prior to update MP went down with added heat).

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Another observation, this time regarding engine power output or prop characteristics:

Previously you needed 25...26 inches to reach 2200rpm for mag test. Now you can achieve it with 21 inches in P-40.

In Spit, I used to need -1 psi in summer (-2 psi in winter) to reach 2000rpm. Now I need only -3...-4 to achieve the same rpm. What has changed? Prop stalling characteristics? Calculated engine power output on partial throttle? I can now also cruise MkI with full coarse at rather low altitude without rpm dropping dangerously low and/or needing to raise MP dangerously high to sustain rpm (which kinda makes sense as these props were designed to be two speed instead of continuously variable, and not being able to cruise at low altitudes would make flying them very much pain in the posterior).

I also had that.

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I can confirm that issue.

Further i would be interested in a feedback from an A2A staff member about my lost P40 aircraft states and flight hours as written before. My "through" the world trip with only one engine is over after a couple of month flying and no kind of reaction until now how to get back that hours prior core update 1.3 and 1.3.1 ?

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FSX SP2 DX9.Addons:FSG2010,REX OD, AS2012, PMDG, DA Do27, Dodosim, A2A accusim all, Katana4X,Coolsky DC9 Classic, Swiss Pro,ORBX all, Fly Tampa, DRZEWIECKI DESIGN, FS Dreamteam, FranceVFR Haute Normandie 3D...

It's always been with updates that the counters are reset since the engine itself may require a reset with completely swapped modules. Old condition of certain engine parts might not be convertible to new modeling. You could make a back-up of the old state but transferring it to the updated plane might cause glitches or corruption if save state files are parsed differently. It might require manual work, and partial copying of several parts of save state even if you had the old file backed up. ...and the .DAT files aren't plaintext so you can't just use Wordpad for it.

Basically: the old state is lost.


The only question is, if the update self-extractor should give a warning about lost plane state and hour counters followed by a YES/NO prompt. If you choose YES, then obviously it's your choice.

I'm glad the developers don't insist on retaining compatibility to old save states because doing so would prevent many improvements to the systems, especially when durability of parts is concerned.

You are right,

i understand that saved states of old core modules doesn´t fit to new core updates, but we need a solution for that.
No readme, no core update tread and even the installer did not warn or informed me about old states get lost.

At every core update hours gets lost, does anyone can fly until TBO intervals to really enjoy accusim to see if do a good job at the controls? If i had known that before i never had started that challange around the world spending hours of free time, accusim addons is the reason i decided to fly it..

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FSX SP2 DX9.Addons:FSG2010,REX OD, AS2012, PMDG, DA Do27, Dodosim, A2A accusim all, Katana4X,Coolsky DC9 Classic, Swiss Pro,ORBX all, Fly Tampa, DRZEWIECKI DESIGN, FS Dreamteam, FranceVFR Haute Normandie 3D...

Nico081,

We should have put a disclaimer about hours being lost when doing major upgrades. We are sorry for that.

whiic,

Yes, I see what is happening in our P-40. The new system with the P-51 has affected the P-40's carb heat. In the P-51, you have to have ram off for the carb heat to work, and somehow this was reversed. We'll fix this in the P-40 for the next update. However, keep it in RAM for now.

Regarding the cooling of the CAT temp, this is accusim simulating the cooling in the venturi, which we fed to the CAT gauge a while ago so we could see it easily during testing, but actually, should not be showing on the gauge. We'll sort this in the next update, that won't be long.

Scott.

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A2A Simulations Inc.

I started writing this before Scott posted the last message. I'll post it anyway even though it was partially answered already. The partial throttle power output difference is still an unanswered question.


Good to know it's now solved and waiting for the next bundled update. Just don't release it too quick to get in all sorts of bug fixes that are likely to pop-up with all the changes made.

For example, power output on partial throttle has increased noticeably (both Spit and P-40): I can notice it on taxi, during engine run-up tests, low-power take-off from longer runways, cruise at low altitude and approach - whenever I'm using reduced throttle. 20 inches is enough to launch P-40 into air as if it was strapped into a rocket booster. MP required to obtain textbook rpm for mag checks is much lower than before. It might be intentional (especially if the old performance figures were off), I don't know.

And that odd [carb temp / carb temp gauge / carb heat ] thing with P-40. Since the temperature is less than ambient when idling on the ground, I presume the sensor for carb temp is between throttle plate and supercharger or at the venturi. Anyway, if temperature drop is in any way unintentional, it could also solve why the engine seems to produce more power at same manifold pressure (air being thicker).

Anyway, it all looks logical for the carb temp to drop below ambient on partial throttle but there's still the partial throttle power difference between Accusim versions. Maybe the system was calibrated to obtain natural values with inaccurate carb heat modeling, and when latter was fixed, the engine started to produce too much power. That... or the power on partial throttle was off before, and is now closer to reality.

ah, ok, we'll check the power outputs. Scott.

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A2A Simulations Inc.

Yeah I've noticed coolant temps generally lower now in the P-40 too.

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"The knack of flying is learning how to throw yourself at the ground and miss." - Douglas Adams

Also, the cool down ticks and tacks are noisier than engine backfire. They could be toned down quite a bit, yet still remain audible, since the effect is played only after engine shutdown when there's typically little noise. Backfire pops on the other hand can barely be noticed over the engine rumble.

Also the period of cool down sounds could be limited to a few minutes after shutdown. If you shut down the engine at 120 deg C coolant, it's not likely to continue making ticking sounds until it has cooled below 80 deg C. After all, the ticking sounds come from hotter parts' (like exhaust stack) contraction to match the temperature of the engine block - not necessarily requiring for the engine block itself to cool down at all for the noise to disappear.

I did a test: I ran the P-40 standing on the pavement to 120 deg C coolant, then shut it off. It took around 20 minutes to stop making the noise.

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There's misinformation on P-40 in-game pilots notes regarding priming:

page 1 (quick reference notes):
priming strokes: 3@30 deg, 5@15 deg, 12@0 deg
(note: this is probably direct copy-paste from Spitfire's pilot's notes because it is letter by letter identical to the first line of quick reference page of Spitfire)

page 3 (engine start-up):
prime engine with 2-4 strokes
(note: this is what I've always used and 4 seems to be enough even for sub-zero start-ups (works even after the update))

How can I verify which AccuSim Core version iam currently running
I installed the P51 with Accusim yesterday evening do I need to upgrade the AccuSim Core or did it come with the latest version?

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< Slow - Fast >

Bert, if you don't have either the Spitfire or P-40 then you shouldn't need the Core update yet. If you have either of these planes then install the update as the last item.

When the next update comes out, (version 1.4?) that's the first one you'll want for your Mustang, if you have only the Mustang.

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I like Thunderbolts! (Link to MySpace tribute page)


120th Fighter Wing, Montana Air National Guard

Thanks Skycat. Currently I only have the P-51 (besides the great Accusim PiperJ3 )

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< Slow - Fast >

I just did a few hours in the P40 and Spit. I didn't notice any thing wrong with the power. 20MP in the P40 didn't launch me in the air like a rocket. Maybe something went wrong with your installs? or mine? dont know.

Oh I did notice it was easier to keep the Spit cool using proper heat management techniques. Nothing noticed with coolant in the P40

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This sounds about right. You don't usually notice these cracks as there's always a lot of noise on the runway, and yes, they are louder than in the real aircraft, but then again, your speakers are not able to produce anything close to the volumes in the real plane, so we do compress all sounds. We may tone the volume down in a future update, but enjoy them as they are being generated from the physical engine cooling (not just a looped recording sound, they are physically created on the fly).

Scott.

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A2A Simulations Inc.