[Wayne22]

I didn't say that, did I?? The P80 would probably work well in the Tutor, the only concern would be whether it physically fits or not...and that is easy to figure out by comparing the diameters of the recommended engines with the P-80.....(4.4")

[Guest]

Originally Posted by johnld

If you goto
http://www.altecare.com/tutor.htm
you will find a tutor that takes a 17 to 20lb thrust turbine!

Yeah, I saw that one, talked to Peter about it too, I've been waiting quite a while to hear of anything happening with that one....... So far nothing.....
Jet Legend had one the same size too that never made production, the horizontal stab failed on the prototypes. I asked Peter about the tutor a few months ago and never heard back so I assume it still isn't ready. Time will tell....

As far as thrust goes, keep this in mind, while having lots of thrust is great, it was only a few short years ago that we were flying jets the size of that tutor with a single ducted fan producing 12lbs of thrust on a good day, oh, and did I mention that the 12lbs of thrust was dynamic, in other words it was only 12lbs once at a good clip of speed? static thrust was somewhere closer to 8lbs or so. We are all so used to excess power now that we forget what it really takes to safely fly these models. I have almost 30lbs of thrust in my kingcat and over 30lbs of thrust for my super bandit, yet having flown my kingcat you could safely fly that jet with 18lbs, might not be really jet like or exciting, but you could safely do that, the super bandit, well, the original bandits were hitting 200mph with 14lbs of thrust, yet guys are putting 30+lbs in them all the time.
Same with servo's, it's unlikely that any of the jets we fly truly require 300oz of torque, but that's what we put in there

What I'm trying to say is, if you already have a baby boomerang, buy an engine that will work correctly in THAT aircraft. A P70 will be plenty, it will also work fantastic in that tutor, and truthfully, if you decide you want more thrust, a P70 will not be hard to sell in order to upgrade to a P80 down the road. The weight and balance is so important but even more important will be your residual thrust at idle, the baby boomer floats like crazy, couple that with to high of a residual thrust for landing = a difficult jet.

Just my 2 cents

[johnld]

LGM. I understand what what you are saying(imagine that ) . The more I read and listen to you guy's the more I realize more power is not really what it's about in a jet .It more to do with the right combination of power and plane. I'm used to gas engine planes where bigger is not usually a problem and would probably get you out of trouble more then it would get you into it. Thanks for the response I appreciate it. Havent bought the engine yet but when I hear from the plane designer that will probably sway me one way or the other. You guy's make a good case for caution.

LGM Guitars you live in Abbotsford B.C. and I live in Langley B.C. maybe we'll run into each other in Princeton rally end of May.

[Ted Anton]

Hi Guys
Since were all throwing in our " loose change " here's my 2 cents ( again )
If your considering a P 70 and want to upgrade to a P80, I think the digfferance in thrust performance considering the extra weight penalty would be nominal at best
I would go with a P120 instead of a P80. It is the same size and weight as a P80 with about 8 lb of more thrust, not for the Intro but I'll bet it would open a few more doors as far as suitable airframes available.
What ever you choose good luck

Ted

[johnld]

Ted I think your going to give Wayne22 a heart attack hehe.Seriously size and weight are definately similar though there is a slight weight difference But theres a big cost difference. The P60 ,70,and 80 are the same price which makes the 80 more desirable to me as far as usefulness is concerned in thrust and cost. All this info is great so keep it comin ; I'm gettin closer to an engine decission all the time!

[Wayne22]

Actually, I wasn't going to go down that road, but since Ted opened the door.....

any jet that a P-80 will fit in, a Titan or P-120 will fit just as well since the physical sizes are almost identical...that's what most guys do....

And just beneath the P-80, a lot of smaller, lighter and more fuel efficient turbines are nipping at it in the thrust department..

That just leaves a tiny window that the P-80 will fit in which may limit its' appeal if you ever try to sell one....

[reo]

[
That just leaves a tiny window that the P-80 will fit in which may limit its' appeal if you ever try to sell one....[/quote]

I agree totally with this statement. The P-80 is a bit of a 'mister in between' here. Too big and heavy for the smaller jets and not enough power for the larger airframes.

Resale interest on a P-80 would certainly not be up there with the P-70 and the '120s and Titans for these reasons and others mentioned in this thread.

But then, in the end to each his own.

Ron

[RC_MAN]

Check the residual thrust at idle. That may make up your mind.

Peter

[johnld]

Well I've talked to the designer Alan Cardash and Ali Machinchy regarding the p80 baby boomer combo. Now Ali M. sells this as a combo and well over a 100 flights no problems I might expect him to be biased as he sells this combo but Alan Cardash the designer has experimented extensively and has an updated on how to install the P80 and tells me that this is a very good combo and when done right works well. Now I cannot argue with the designer. They do talk about residual thrust and suggest extending the flap by about half an inch for landing purpose's.
I think they idea of putting in a P120 because the physical size is the same as the P80 would be a dangerous and certainly more expesive move. The P80 may be older technology but is a proven design that has been improved over the years.
Ali M. did say that they experimented with a wren 18 Lb thrust jet and he loved that setup but for price versus technology and thrust he beleives the P80 is an excellent combo.
I have listened and had lots of input which is what I was looking for and this is not a mind set decission but now an informed one because of all the help I've received on this site and from Alan Cardash. and Ali Machinchy and JetCat USA re there engine I have no hesitation in purchasing the P80 for this installation!
Thanks Everyone for your input..
John Dycke

[Steve N.]

Hmmmmm,,,

Now that we've got that all sorted out and John appears to have made a decision,,, I'll just give him a quick call so he'll know what he should do here

Stevo