I have de-restricted a Discus BT and a Discus 2cT as described below. The

climb rate definitely improves but not as much as reported - from averaging

timed climbs and post flight analysis of flight recorder data I reckon you
get
about half a knot increase to average of 2.9 knots. Its still a worthwhile

improvement but you have to be aware the regulatory and possible
insurance considerations.

John Galloway



At 23:30 06 March 2015, Charlie Papa wrote:
On Friday, March 6, 2015 at 2:14:12 AM UTC-5,
wrote:
Wondering if anyone has boosted the horsepower of a Solo 2350 turbo
(or
s=
ustainer engine) to get better high and hot performance? If anyone has
don=
e this would like both positive and negative comments as to the work
done,
=
the results and what they did to boost engine performance.

Yes indeed, I have done it. It is not to INCREASE the horsepower so much
a=
s it is to RESTORE the horsepower that the 2350 was originally built to.
I=
t was de-tuned by tack welding a pair of constricting rings into the
exhaus=
t, and then reducing the jet size by one. =20

Mine is installed in a Discus 2cT, and as such, it is a sustainer. That
me=
ans no throttle, no choke, no generator, - just the simplest get-you-home
a=
nd lightest possible. If I understand correctly, the LBA required that
it
=
be able to sustain level flight, presumably in controlled airspace. With
t=
he full 28 HP it was built to, in level flight it would overspeed, which
cu=
ts off the ignition. =20

But using it in controlled space requires the use of headphones; a
non-star=
ter for me. I just stay out of controlled space. However, with the
horsep=
ower estored from the diminished 22 to 28, does it climb better. You
bette=
r believe it.

The restrictor rings are tack welded in and very vulnerable to a Dremmel
to=
ol. Then you must remove the two jets, move the larger one in the rear
(lar=
ger to overcome how much hotter it will run with already heated air from
th=
e front cylinder passing over it) and move it to the front, and then put
th=
e next larger size in the rear. =20

Don't mix up the covers for the pulse diaphragm that 'injects' the
air/fuel=
; the front one should not have the hole that would make it vulnerable to
t=
he prop wash.

The result: MUCH improved climb, - perhaps 300 - 350/fpm vs. ~200.
Hard
to=
be exact as the vibration shakes the hell out of the varios. =20

And in ~1100 hours, there is less than 10 hours on the engine, because it
i=
s just a sustainer, and because I start it right off tow each day
(because
=
it's complicated and it starts faster if it has already run.