As we know the F5C has been the centre of deep discussion for various reasons (Spammed, ahistorical flares & hard to lock)
After a short bit of digging, i’ve found that a NASA test (pdf linked below) with the J85-21, the engine produced an exhaust gas temperature of 1000 degrees Kelvin (727 Celcius) which is hotter than the F5C produces in game, at both 100%, & during WEP.
However, the issue im having, before submitting a bug report is finding proper documentation of the exhaust gas temperature when in WEP/Afterburner.
I have found two tables, which come from from a paper published by the Azad University - Iran, However im not 100% these tables will be accepted by Gaijin.
As we know, the Iranians took the J85-21, studied it and reverse engineered it, so these temperatures may very well be accurate.
At Sea Level
At 11,000 Meters
Does anybody have data on afterburner temperature for the F5C, so I can make a bug report for its low heat signature?
Maybe a Tech Mod could add their piece to see if its worth reporting with current data?
This is part of a wider problem with how engine temperature is measured in game. Gaijin model engine temperature according to what is displayed to the pilot on the engine temperature gauge in cockpit. This makes sense from a flight simulation point of view - being a flight simulator you want the number displayed to the “pilot” (us) to be the same as what a real pilot would have seen.
The issue is that gaijin appear to be using this number as the basis for how hot an aircraft appears to IR missiles. This is a flawed approach as the cockpit engine temperature dial means different things in different aircraft (some aircraft use turbine blade temperature, some use turbine inlet temperature, some use other values). The different types of temperature measurement can vary by hundreds or even a over thousand degrees for the same engine (turbine inlet temperature is always hotter than turbine blade temperature for example).
So really we need to get Gaijin to model the exhaust temperature for every aircraft in the game separately to the current engine temperature reading. Then they can use exhaust temperature to put all engines on a level playing field against IR missiles, while keeping the engine temperature reading of the engine correct in the cockpit.
The problem is that finding the exhaust temperature for every aircraft in the game will be a very time consuming process for them (as you’re finding out). That is probably why they are using the current system.
I agree the system needs an overhaul for IR signatures based on Exhaust Gas Temperature.
Talking of Turbine inlet temp, Wiki has the J85-21 TIT as 980c, so I’m still wondering where gaijin has got the current F5C temperatures from.
The F5 is the only jet in game that IR missiles struggle to lock.
From my experience with the 9L, I have to be within 1.5-2.0 Miles, in the rear aspect, for it to lock an afterburning F5, whereas I can lock an A6E around 4+Mi from the side.
But do we think the current data I have above, is enough for a bug report?
Looks like we’re not going to get an IR overhaul of any sorts, and they’ll just continue to use max engine temp as the limiting factor…not the reheat plume.
Which means, as we know, aircraft like the harrier, have a higher IR signature then an afterburner F5, which is hugely incorrect.
