There is a lot of discussion on this site and others about LOP operation with TAT converted 520 and 550 engines, but not so much information about LOP operations with factory turbo 520UBs.
The aftermarket conversions are all turbonormalizing, rather than tubrocharging and this leads me to have a few questions that have so far been unanswered.
First of all, deakin and others say (basically), run the throttle wide open and use mixture to set the power.
Well, that doesn't work in the TSIO520UB where the MP boosts to 36", so does that mean pull MP to 29"? actually, it seems like 31" is a more "standard MP" for the TSIO520UB since that is the max cruise value ? maybe?
Either way I'd like to see if any of you are running LOP with this engine, and what your experiences are.
Here are my numbers.
First of all, yes I installed GAMIs and worked with GAMI tuning the injectors to get it just right, those guys are great BTW, can't recommend them highly enough.
secondly, I had new spark plugs, and had the mags overhauled and got everything just right, this took a few months tweaking here and there.
I also have a JPI700.
All these things are required before you can get anywhere LOP with this engine.
Running ROP basically uses huge amounts with this engine, to keep the cylinders cool (380F max)
I see fuel flows of 22gph at max cruise: 31" 2400rpm 11500' 10C OAT
Getting LOP to run smooth only works well for a few power settings, the best I have got so far is 29" 2350rpm 11500' 10C OAT 15.1gph
the 15.1gph using the (13.9 * ff) / 280 formula gives 75% HP
this runs pretty smooth most of the time and gives me about 165kts at 11500'
CHTs are all around 360 to 380, TIT about 1600F (50 < than the 1650 redlne)
that's about 10 to 15kts slower than I could get ROP at max power, but is 7gph less !
How do these numbers compare to others?
Anyone else out there running this engine LOP ?