Decision time 150 vs 160

[Graueradler]

At the risk of repeating (and correcting) myself;

1 HP = 33,000 feet lbs/min so 10 =330,000 f(lbs)pm. Divide that by the max take off weight (in pounds) of the plane you are considering and that should give you the the theoretical limit of the increase in climb rate (about 150 fpm). You aren't going to get that because the prop isn't 100% efficient and the full 10 HP won't be available at the shaft under take off conditions. Maybe good for about 100FPM increase in climb rate.

Very little increase in speed which is mainly determined by airframe aerodynamics.

The increase in take off and climb is very welcome in a plane that is marginal in hot weather at full load.

Airframe aerodynamic mods reduce the HP required to maintain a specific speed. That no longer needed HP for speed becomes available to use in climb.

 

[greghughes]

I have a '75 Warrior (151), with a 160HP upgrade when I had the engine overhauled last year. Since I was overhauling and replacing cylinders/pistons anyhow, the only real additional cost for me was the STC itself - kind of a no-brainer. The parts were no appreciable difference in cost.

I've spoken with the PowrFlow people about the Warrior before, and they told me, "We could make it for your plane, but you'd just be angry with us and we don't like to have anything but happy customers." In a nutshell, there's nothing on my plane exhaust-wise where they could do much improvement. So, the rep at Oshkosh told me, I'd be spending a few grand on a less than 2% power improvement. Better to put that money into laminar flow improvements, etc. he said.

Speaking of which, here's what I've done with my Warrior to pretty substantially improve performance and fly-ability all around:

1. Engine: STC for the engine increased HP to 160 (completed at overhaul)
2. Wings: MicroAerodynamics vortex-generators on wings and tail (the plane already had modified wingtips when I bought it)
3. Ignition: ElectroAir electronic ignition replaced right-side magneto
4. Prop: Dynamic prop balance

Still on the list:

5. Lighting: Remove the tail fin beacon and replace with flush fairing; remove existing recognition/direction/strobe lights and replace with slim-line LED strobes
7. Wings: Gap seals, where applicable, at control surface junctions (the 74-75 Warrior has a different aileron design than others, so those seals don't always fit)
8. Landing gear: Speedpants (eventually maybe - pretty pricey upgrade)

 

[el con]

For equal speed at equal EGT you should also see a fuel savings with the tuned exhaust. The biggest speed and economy boost item per $ you can do to a plane is gap seals for the control surfaces. They can be done as simply as gluing in strips of sail cloth, anything to prevent the flow of air from bottom to top.

Yep, have the Knots-to-You gap seals.

 

[Morgan3820]

All, Thanks for the thoughtful responses. After seeing a price curve of avgas over the last few years, I have concluded that the ability to run mogas is paramount. At my FBO it just went up another nickel to $6.55/gal. Is $7.50 far behind? I like the one with the RAM 160 but I have concluded that it is not practical to install the $3K STC.
I have only one station that has the needed 93 octane and that makes me nervous. Eventually, I need to unmod the engine and put it back to its original configuration so that I can run the 87 octane. What is involved in going back? I called the RAM people and the guy I got was less than knowledgeable. Is it just a matter of just replacing the pistons and a carb jet? Or is it more involved? I have a great ap/ai that works for $30/hr provided that I help.


Black one has 160 hp. 368 SMOH, 5070 total
Green one is 150 hp., 638 SMOH, 7050 total

Both asking $29K, Both need radios, green one is missing wheel pants (~$2K)

Which would you pick? Tell me please

 

[rbridges]

All, Thanks for the thoughtful responses. After seeing a price curve of avgas over the last few years, I have concluded that the ability to run mogas is paramount. At my FBO it just went up another nickel to $6.55/gal. Is $7.50 far behind? I like the one with the RAM 160 but I have concluded that it is not practical to install the $3K STC.
I have only one station that has the needed 93 octane and that makes me nervous. Eventually, I need to unmod the engine and put it back to its original configuration so that I can run the 87 octane. What is involved in going back? I called the RAM people and the guy I got was less than knowledgeable. Is it just a matter of just replacing the pistons and a carb jet? Or is it more involved? I have a great ap/ai that works for $30/hr provided that I help.


Black one has 160 hp. 368 SMOH, 5070 total
Green one is 150 hp., 638 SMOH, 7050 total

Both asking $29K, Both need radios, green one is missing wheel pants (~$2K)

Which would you pick? Tell me please

do you have links to the planes? I have no problems using 100LL, so I'd pick the 160HP/lower TT.