SL top speed issue

Just realized the same issue is present with the P-51, the rads here also do not close again unless you reduce throttle, regardless of wether coolant temperature as dropped below the 115 deg limit.

Is this really supposed to work like this?

Could this be because the intercooler on the Spit and Mustang perhaps? Is it on a separate coolant fluid cycle I wonder...?

So eventhough I am no fan of DCS propjobs I decided to buy the Spitfire Mk.IX (in conjunction with the F/A-18 ) anyway as I do love the jets and want to support ED as much as I can.

 

However having now flown the Spitfire IX for a while I cannot achieve the real life top SL speed of the aircraft, maxing out at 520-522 km/h at SL, instead of the real life 537 km/h.

 

Ran at +18 lbs/sq.in. and 3,000 rpm, but no luck.

 

Engine also seems quite fragile seizing rather quickly during combat if run at full boost. Definitely can't seem to make it last the 5 min limit.

Close enough, don't be so picky.

In real life, no two aircraft have exactly the same shape, exact same dry weight, exactly the same engine power etc. etc. etc... It boils down to manufacturing tolerances. No two handle and perform identically, and the differences probably become greater the older the aircraft are.

Specifying max speed to within 1 km/h is pretty funny, I'm surprised it was ever done like that.

AD

Close enough, don't be so picky.

etc. etc. etc...

Wow . . :music_whistling:

You didn't read what I wrote, the rads DON'T close when temperature drops below 115 deg, once open they ONLY close if you reduce the throttle. In other words after the first turn at full boost the rads will open and once I level out the temperature drops steadily to 95 deg, but the rads stay open and the only way to get them to close again is to cut the throttle.

 

In short the automatic radiator system only seems to react to an increase in temperature and not any decrease.

Did you read in my post when I said "P.S. I am still on 1.5 release version, so have no experience of later versions/patches."?

Thing is, the rads on my Spit are working fine and dandy. I have just watched them open and close 4 times over with no problem, just as they should.

I have just tested them using the Instant Action, Free Flight mission for the Spit in the 1.5 release version.

If you have a different version then that might be the key to the issue you have raised.

What version of DCS are you using?

P.S. I only mentioned throttling back in a previous post because that is what I sometimes do in combat if there is a break in action, to get the rads closed again as soon as possible.

Happy landings,

Talisman

Did you read in my post when I said "P.S. I am still on 1.5 release version, so have no experience of later versions/patches."?

Thing is, the rads on my Spit are working fine and dandy. I have just watched them open and close 4 times over with no problem, just as they should.

I have just tested them using the Instant Action, Free Flight mission for the Spit in the 1.5 release version.

If you have a different version then that might be the key to the issue you have raised.

What version of DCS are you using?

 

P.S. I only mentioned throttling back in a previous post because that is what I sometimes do in combat if there is a break in action, to get the rads closed again as soon as possible.

Happy landings,

 

Talisman

Ok, so in 1.5 the rads close again after they've been open purely due to temperature drop via increased speed, i. e. without you touching the throttle and staying at full boost?

Cause thats the problem atm with the Spit & P51, the rads won't close again when still running at full boost regardless of temp, you have to reduce throttle.

The 109's rads, whilst they actually do close a little after gaining speed, also don't seem to close as much as they should as temp drops. But the issue is most severe with Spit & P51.

Why is this important? Because it severely reduces achievable top speed after a few turns unless you reduce throttle for a period after.

Ok, so in 1.5 the rads close again after they've been open purely due to temperature drop via increased speed, i. e. without you touching the throttle and staying at full boost?

 

Cause thats the problem atm with the Spit & P51, the rads won't close again when still running at full boost regardless of temp, you have to reduce throttle.

 

The 109's rads, whilst they actually do close a little after gaining speed, also don't seem to close as much as they should as temp drops. But the issue is most severe with Spit & P51.

 

Why is this important? Because it severely reduces achievable top speed after a few turns unless you reduce throttle for a period after.

If you are running a version other than 1.5 release version, then it looks like you might have found a bug worth reporting. I don't have time to check the P51D at the moment.

Sorry if I missed it, but what version of DCS are you using?

P.S. I agree with you that it is important that the rads close as they should.

Happy landings,

Talisman

If you are running a version other than 1.5 release version, then it looks like you might have found a bug worth reporting. I don't have time to check the P51D at the moment.

 

Sorry if I missed it, but what version of DCS are you using?

 

P.S. I agree with you that it is important that the rads close as they should.

 

Happy landings,

 

Talisman

No problem. I'm running 2.5, so if you say it's not doing this in 1.5 then it has to be a bug.

Wow . . :music_whistling:

That's what I thought, hence my reply :)

One brand-new Spitfire IX went 525 1/2 km/h, another one went 532 5/8 km/h, another went 529 11/16 km/h, then there was that "magic" one that went 541 km/h and maybe a little more on a good day. In actual combat, it made no difference whatsoever--what the real pilots often noticed was the slight difference in handling qualities between one airplane and another of the exact same make, model and variant--even when they were new. The differences probably increased with the number of hours put on each airframe and engine combination.

If the OP squeezed about 520-522 out of 'er near sea level, that's about right. It's within 1% of the official max speed of the real aircraft, and those same real aircraft probably varied quite a bit more than that 1%. If the DCS Spit went 540 km/h, nobody would have brought it up. :)

Just like overclocking CPUs, or GPUs, or memory, everything is manufactured to a tolerance--including aircraft.

AD

Dumb question: sensitivity of these tests to fuel/weapon loadout? Weight and drag may be the factor here. Was max SL speed without the hispanos?

Drag? yes, it would. Weight? not really. Weight or actually mass would increase the inertia of your aircraft, in other words, how long it takes to reach 530km/h (just an example).

One little detail though, heavier the aircraft, more lift you need in order to maintain a constant altitude, and you would do that with AoA, and higher the AoA, more induced drag you would have (drag due to lift).

But in this case, I don't think it's a big deal.

Hummingbird said he was using operational loadouts anyway.