Turbojet Engine Tweaking. Looking for Help

[Jetblst 23]

I noticed my N1 and N2 fan speeds are OFF THE CHARTS and the model is too overpowered.  I tried to adjust it via FSUIPC calibration with my controller levers to no avail.

 

Where can I go to adjust the parameters.  I fly the jet RW so I simply would like the engines to behave a little more realistically.

 

Thanks.

[charliearon 3,023]

Look in your aircraft.cfg file for:

 

[jet_engine]
thrust_scalar = 1.0

 

Depending on the aircraft and it's developer, you may want to lower the number.

[Bjoern 1,157]

Making a plane fly by the numbers, even just by N1 and N2 is an endeavour in blood, sweat, tears and urges to kill someone.

 

Unless you are willing to sink hundreds of hours to get acquainted with the basics of FDE engineering for FSX, jet engines and aerodynamics in general, just follow Charlie's advice and lower the thrust scalar. Then throw away the charts.

[Jetblst 23]

Great points guys.  Thanks.

 

Im not looking for chart realism, I just want to tone it down a little.  Right now the RW published N1 limitation is 104% and the N2 is 96%  In FSX no matter the calibration, max lever throw gives me 111.8 N1 and N2 of the same.  

 

So scalar it is.  and No I don't wish to become a programmer just yet.  LOL

 

Question

 

What about Engine Inlet Paramaters or any others?

 

IS there a way to simply limit N1 and N2 to some value slightly over the above limitations?  

 

If not thanks for answering my questions guys.

[Bjoern 1,157]

Nope. N1 and N2 values are always an .air file related issue. Same as EPR and EGT, but these are borked even when the rest of the numbers is accurate.

 

 

The inlet_area in the aircraft.cfg just changes ouput power and ram drag.

[Jetblst 23]

Well had some success with scalar.  However I had the most success with fuel flow gain verses the other parameters.  I am actually very close to the feel anyway of how the engines behave.

 

Usually in the aircraft we hit slightly over N1 of 104% on our takeoff runs.  I have it where in the sim I hit 104.8 at present time.  The best parameters to tweak so far are scalar and ffgain.

 

http://www.mudpond.org/jet_flow_chart.pdf

[Jetblst 23]

Interesting update.

 

I found out that the guy who did the programming for the BeechJet also flew the Beechjet.  What is really interesting is that I took a look at the RAT, SAT, and ISA that I was getting on the climbouts and developed a hunch. 

 

FSX Weather engine DOES in fact leave a lot to be desired...  So I fired up Active Sky, and used the High Altitude Mode.  Funny how the engines now behave almost EXACTLY like in the aircraft.

 

The only problem is the the fuel flows on the fuel FLOW gauge are way off.  I haven't flown long enough yet to determine if it is a gauge thing or if I am actually getting those burns. 

 

(Posted just incase anyone is follwing this)

[stans 702]

If it is just the fuel flow/burn rate that is now off, adjusting the fuel flow scalar entry in the aircraft cfg file might get you some realistic burn rates.

[Jetblst 23]

If it is just the fuel flow/burn rate that is now off, adjusting the fuel flow scalar entry in the aircraft cfg file might get you some realistic burn rates.

 

 

Thanks for the tip Stans.  All I had to do was to adjust the fuel flow scalar from 1.0 to 1.2, use Active Sky and that did the trick.

 

We rule of thumb plan fuel at 1500 lbs first hour 1200 there after and we are good for realistically a 3.5 hour trip max.

 

Well first hour fuel was 1525.  I have the RW charts and Simuflite Manual, so the performance programming is spot on.

 

I grabbed a copy of AirWrench and I am learning how to use it.  Funny how it turns out that all I needed was a realistic weather generator.

[Bjoern 1,157]

MSFS' default amospheric modeling is rather simple and it makes for quite a bit of a headache when hacking in engine-related numbers.

[Jetblst 23]

MSFS' default amospheric modeling is rather simple and it makes for quite a bit of a headache when hacking in engine-related numbers.

That and it made and makes the flying part a lot less real as well.  So Active Sky for now.  Not sold on Next.

 

Using Active Sky I am amazed at how close to real world things are.