Awesome!Bob, I'd forgot to reply beforehand on some of the isues I had found earlier. You mentioned the cockpit lights could be actuated from the center pedestal, but in my panel, they only light the center pedestal itself and not the whole panel. I have not been able to get an acceptable panel layout since I don't have any decent bitmaps. I may be able to do something with another photoeditor though..regards,Macs :)

>Gustavo;>> Have you done a curve-fit on the N1 vs EGT plot? If so,>that would be useful for writing some updated gauge>internals.Bob, If you send me the data, I can do that for you.regards,Macs :)

bob, did you tested the EPR formula for the JT8D-17?regards

Gustavo, Here is a compilation of the linear approcsimations of EPR vs. N1, N2 and EGT from the tables that you provided. I am not sure if this is what you are looking for , but I have typed your table in Eccel, so I can provide any format you need. I would dare to predict that FS uses linear approcsimations :)http://forums.avsim.net/user_files/148953.jpghttp://forums.avsim.net/user_files/148954.jpgregards,Macs :)

A minor correction: N1, N2 and EGT are the dependent variables or Y. Sorry,http://forums.avsim.net/user_files/148956.jpghttp://forums.avsim.net/user_files/148954.jpgRegards,Macs :)

Hi,Actually, FS internally plots "SAT normalized" engine data, called "Corrected Nx" (CN1,CN2) as to avoid changes in readings because of pressure/temperature differences (TAT).So a single plot of EPR/N1/N2 can be done by converting nominal (instrument) readings to its Corrected version.For example:EPR ref: 2.15TAT -40C N1= 87.1 N2= 84.9 CN1=96.84 CN2=94.39TAT 10C N1=96 N2= 93.6 CN1=96.84 CN2=94.39TAT 15C N1=CN1= 96.84 N2=CN2= 94.39Then you can plot EPR=2.15 = CN1= 96.84 = CN2= 94.39 and so on for each file in the table.As FS handles CN1 and CN2, I think you should make EPR the Y value for the calcs.Just my two cents :-)Tom

Hi Tom,I already made a formula to fits the EPR due CN1 for the jt8d-17.also, I had remade the 1502 from my airfile 1.5 (beta) to fit with the values from table....but I guess that need more work to fits 99.99..%I can post here the formula only to the -17... is a polinomial formula with R^2 of 0.99 (I guess that this is good enought...)regards,Gustavo

Tom, I am not doing the modeling for this project, but am only providing the formatted data. Nevertheless, I would like to learn about it. I can do an EPR as the dependent variable correlation, but am not sure how you arrived to the corrected N values. Juat curious,Thanks,Regards,Macs :)

>but am not sure how you arrived to the corrected>N values. Juat curious,Convert Nx to CNx:CNx = Nx/Sqrt((TAT

I recall Ron Freimuth did a fit of EPR vs CN1 for a 727 engine, also a JT8D if I'm right. I for one did a plot of EPR vs CN2 for a RB211 535E4 engine, the one used in 757s. Ron and I discussed the different advantadges/disadvantages of using either of the spools (LP or CN1/HP or CN2). After a couple of months doing tests, I opted for the CN2 variable, which in fact was a bit more complex to plot, because I needed to know the proper EPR for a given throttle position (RB211 Commanded EPR gauge) and throttle is linked to CN2 (tables 1503 and 1504). Tom

Yes, the 727 uses JT8D.but the logic of ron for the JT8D is valid... I don't know how works EPR in the RR engines...but the best way to check the epr is via N1. all charts in QRH and for TO planning gives only your EPR, your N1 and the correction for a bleeds off for take-off...

As I am not familiar with the air file intricacies, this is a bit above my head. I can provide any correlations for the data provided though. Not to say I am not interested in learning though.. :)regards,Macs :)

>Yes, the 727 uses JT8D.>>but the logic of ron for the JT8D is valid... I don't know how>works EPR in the RR engines...>>EPR principle of functioning is the same for every engine model, although figures are quite different. Big turbofan engines like PW use a lower scale (1.0-1.80) while older types like JT8D measure higher values (1.0-2.20) being RR in the middle.>but the best way to check the epr is via N1. all charts in QRH>and for TO planning gives only your EPR, your N1 and the>correction for a bleeds off for take-off...I would say the easiest way, but there are others as well :-) And CNx must be used if one wants to plot only one curve for Nx to EPR. This is easy to do in a spreadsheet, through the conversion formula I posted before on this thread. A bit of work though, but worth the effort.Tom

The air conditioning panel was completed and integrated this evening. That was the last subpanel left to code in the TinMouse II overhead panel. I have also rewritten the engine instruments to work with the B732 FDE written by Gustavo (Omykron), using polynomial and fractal functions which get the EPR-N1-EGT relationships correct to within a few percentage points.We're definitely getting close to a beta release. I will have to put the project on the back burner for a few weeks due to other priorities.RegardsBob ScottATP IMEL Gulfstream II-III-IV-V L-300Santiago de Chile

Cooool! Can't wait Scott! :)regards,Macs :)