Ok.. I was looking through towers site and seen these and was wondering if anyone has used them and if they work.. http://www3.towerhobbies.com/cgi-bin...?&I=LXD636&P=0 heres the site... they're the Dubro exhaust deflector.....

Yes they do work. I have seen them on airplanes and rc cars/trucks

Indeed so, they help keep a bunch of gunk off your plane. I use them and it helps keep cleaning time down.

Thanks guys... I was hopeing to hear that... I'm going to get some today.......

But beware, they can also reduce your RPM.

I used one once, and it DID keep the airplane clean, but the engine performance was so poor that I removed it after one flight

Absolutely, they work great. Order as many as you can afford as I never seem to have enough around here!!!! They are great.

Ken

That's interesting, Mike. I have them on my OS 1.20's and... well, I guess I ought to clarify that. I have never run the engines without deflectors so I don't know if there would be a decrease in power. But, the planes seem to have pretty much unlimited vertical with those engines, so I would say that they work ok with the deflectors.

Now..can you imagine the Protege with OS 75 AX without exhaust deflector.. if indeed they do rob power? WOW!!

Did the deflector seem to change the tune point? Require more lean/rich mixture?

Dick.

Depends on the exhaust port of the engine, but they do work. Sometimes they're hard to keep on.

If they are falling off one can use a small zip tie and clip the excess off. This works well.

Another idea you might look at is clear plastic tubing. I buy it for .22-.25 cents a foot .. Most any hardware store carries it. It comes in thick or thin wall(what I use) in the 3/8 I.D. size. It will harden with the heat and may fall off once in a while but I usually secure mine so that it stays on. I keep a length in my accessory box I take to the field. If it falls off the plane it's no big deal. If the factory made deflector falls off you have lost $3.
Fred

I didn't have any mixture issues, it just wouldn't come up to full RPM no matter what I did with the needle.

Now, maybe others are not having this issue, but I did, and I know of several others who did.

Haven't tried them since - and that was about 15 years ago

I use em they work pretty good,on 2stroke engines as well as 4st with no perceptable power loss.
if you have a muffler that has a lip on the exhaust pipe they stay on pretty good, but with no ridge to grab onto they tend to slide off even when you crank the zip ties down tightly.
I haven't done this myself but I have read that JB Weld sticks to muffler pipes,and you can build up a small lip on the end of the pipe then the deflector will hold on alot better.

I had mixture issues with my GMS .76 and the Hobbico exhaust deflector. When I put it on, the engine was slobering rich (4 stroking)and wouldn't lean up much. Take it off, everything is fine. Now it just takes up space in the field box.

I use'em on my la.25 and my ax 46 with no problems. No effect on RPM's for either engine. They are quite alot larger than the id of the muffler outlet. Cuts down on slime by 80% I'd guess.

I've used a file to make a small groove on the exhaust where none was provided to prevent slippage.

J

I have a deflector on an ASP .61 two stroke. I bought the biggest size that Tower sells, not sure if it is Hobbico or Dubro. To keep it on I just drilled a 1/16 hole through the deflector and muffler, then ran safety wire through the hole and twisted the ends.

I find on my planes that putting the deflector on only means the oil collects further back on the fuselage. I personnaly don't use them.

Brad

I use them on planes that the exhaust directly hits the wing yes the residue hits further back but without it still hits further back AND further forward, definitely less to wipe down.
I also use them when needed to clear a cowl.

Ive used them on tons of cars and trucks and they do their job just fine.

I've seen the same effects Minniflyer has, reduced RPM, on some of the models it was used on.

I dislike them intensely. I've tried both Dubro and Hobbico ones, and they rob top-end power, make the engine harder to tune, and increase engine temperature. However, if you get a Pitts muffler and have too much flow (so you don't have backpressure at idle to keep the tank pumped up) they are great. Looks better than pinching off an exhaust stack with pliers.

I have used them and also got the reduced rpm's. I was using it on an os la 46 (needs all the power it can get) and lost a ton of rpm's. I took out the muffler baffle and it raised about 250 rpm's. Although I still don't use it because it didn't really do much for deflecting the gunk. Now I have the .46 with no deflector and no baffle.

Austin

I use [link=http://www.aerotrend.com/shop_cat.php?cat=6]aerotrend[/link] tubing. I cut it to the length I need and wire tie it to the landing gear. Hardly any mess on my plane.

Minn
The size and length will change the tuning of any engine 2st are the worst. Like a motorcycle or aircraft tuned pipe you change the back presure and air flow to get peak power when you need or want it.

I got my first one today and used it. It worked great. no problem with loss of rpms, I did have to do some clean up on the horizontal stab but that was it. It deflected about 80% of the oil.... I will be buying more of these very soon.....

I tie mine on with a piece of braided Dacron fishing line (or very thin wire) and tie it to the exhaust screw....never lost one.