It was not an easy search, but Internet friends, Hanns Lim, and Tze-Law Chan, not to mention Dave Lockhart all gave their input. And gave a "thumbs up" to the Bolly units. I didn't want a "pipe" sort of setup, so I opted for a 2 stroke Muffler.

Bolly designates these as MF, then the length of the unit in mm. On their home page (see link on this home page) is a VERY detailed "Bolly Book", which told me more about pipes and mufflers than I thought I'd find in one source. They also provide a lot of technical details which were helpful in determining the modifications necessary to my EMC.  The Bolly MF 590R is a 7 chamber muffler, measures 23 1/2" long, and 1 3/4" diameter.  Makes for a LOOOONGGG setup.

Modifications consisted of lengthening and slightly widening the existing glass tunnel. I did this by dremel cutting the fuse bottom as far back as I needed, then cutting a cardboard Christmas wrap tube of 2" diameter, made a "tunnel" to glue into the opening. Coated this with thinned epoxy, and painted the mess, and you almost can't tell that it wasn't the original stuff. (Ply plates are the external repairs where the fuse bottom was rebuilt after the September crashes, and reinstallation of Supras in the wings.)

Had to come up with a lightweight and foolproof way to anchor the new Bolly MF590 muffler, so Wayne Powell at Falcon Hobbies (see link on this home page) was quick to provide some ideas. I modified his, and came up with this: Yes, it is CRUDE, but the pipe is held onto this platform using TWO black nylon "tie wraps". They are installed on the legs of the platform, around the pipe, then snugged down. This seems to really work quite well thus far. The platform is held with a pan phillips screw into a 6-32 rubber well nut mounted to the fuse bottom in the tunnel. It works!!!

Pipe Mount Platform	Pipe Retainer	Belly Pan mods

BOLLY PERFORMANCE - This is the great news....all of my sources were correct with their recommendations....the MF 590R sounded smooth. Almost sort of BMW-like...Anyway, my APC 17 x 12N turned 7500 rpm, not lean, and measured per the FAI measurement standard, read 92 db. Yes, that sure worked. And airborne, downwind, the only way I knew the engine was still running was the smoke trail. Very silent. The other MAJOR benefit was the improved linearity of the throttle response. It was EXACTLY as the "Bolly Book" outlined.

So - noise problem solved. Power still outstanding. Throttle transition better than ever, and no tendency at all to lean out.

My thanks to Bolly, Wayne Powell, Dave Lockhart, and Fred Burgdorf at APC !!!

Last spring, at the opening of the season, Dick Hanson sent me an email about a "new" Supertigre engine which he had been "playing" with...at the time, as a Die-Hard YS user, I was mildly interested, but didn't really want to "take a chance", running something that "no one else has run"...Boy, was I mistaken...

Later in the year, as I contemplated changing to a fixed gear EMC 2, I really began thinking about the viability of the larger two stroke for my style of flying, and usable in FAI. Had to be as reliable as the YS, and have a considerable power advantage. Dick's preliminary information was that the Supertigre had both. AND the added benefit of NOT REQUIRING A TUNED PIPE !!! Now, I was looking hard.

Last September, at North Dallas, I installed and ran the Supertigre 2300 for the first time using a Cline regulator unit. Kept the tank on the CG, fueled, fired up, off we go. Not so good. Forgot that two strokes need to be a little richer, and when new, can't be too loaded (duh!!)...so the first tests were cut short by the late-season hurricane which cancelled the North Dallas event, and I went home to ponder the choices for the fall.

*** During the fall of 1998, I wanted to run the ST, and had to solve the muffler situation. The stock one worked well, but I had to invert the motor hanging the muffler out the side. Worked fine, but aesthetics were bothersome. So I decided to rotate the motor. Dick Hanson suggested I start about 7:30...and that allowed me to install the STOCK muffler in the centerline of the belly pan, plenty of room to spare. Ran a long extension tube out the rear of the pan, and I was in business!!! Had a very interesting quiet tone to the exhaust. And passed noise using the APC 17 x 12N, turning 7800.

But I had not yet discovered the real "secret" of the motor's performance. Although Dick had told me about the benefit and ease of using just muffler pressure and moving the tank forward, I was hesitant to do so. Had this phobia about moving the CG forward so much...What would happen to pitch trim?

In the meantime, Mac's started producing three versions of headers, all with 7/8" tubes, specifically designed for the ST 2300. Hanson came up with a muffler, so NOW I had to give the muffler-pressure configuration a real test. Results were amazing.

Most important, the motor ran superbly and continues to the present. I've run a very wide assortment of props searching for the perfect match, and the only thing I have POSTIVELY learned is that this motor will turn just about anything. And not need a lot of nitro to do it. For a variety of reasons, it seems the 17 x 10N is the best all around at this point. Who knows about next week??

The motor weighs about the same as the YS 1.4 FZ. The Hanson muffler and Mac header ends up slightly less. Mounting width and hole dimensions are the same as the YS, except that the stock YS holes ends up putting the spinner backplate 3/16" further forward. I didn't want to do that, so I redrilled my homemade imitation rotational damping motor mount. No problem. Also the nose ring was no big deal to change.

I can tell you that there was very little noticeable trim change with the forward shift of CG moving the tank to the firewall made. It ended up about one turn "up"of my 2-56 clevis on the elevator servo. Lots of advantages to the shift...spin entry, snap exit, line "lock on", and a significant improvement in the "solid" feel of the plane. Also reduced knife edge mix needs by about half.

Many folks have seen mine and Doug Matthews EMC's flying with the Supertigre. It works. It is easy, inexpensive, reliable, and FUN...to have the power to perform knife-edge Cuban 8's and do things with a pattern plane that only TOC birds can do....well, it's a "cheap thrill"....Until something better comes along, I'll be running this setup.

Bob Pastorello