ORIGINAL: cmoulder
ORIGINAL: tele1974
I looked back through the thread but I didn't find the information on the turbo hose.
Can you post a link for your source of turbo hose and/ or specs?
Thanks
Direct link: [link=http://www.siliconehose.com/commerce/ccp11370-870id4-ply-silicone-saej20-compliantgl-c40-087.htm]Silicone Turbo Hose[/link] Look under the ''Categories'' list on the left, at the bottom is ''silicone turbo hose''. Get the .870'' inside diameter stuff, which sells for 83 cents per inch.
Also search this thread for posts about the JB Weld lip I made for the pipe, and also Matt's posts on the button-head screws for the header, which all keep the hose from slipping.
[link=http://www.rcuniverse.com/forum/fb.asp?m=9623509]JB Weld Lip[/link] on the ES 30G pipe (Hmm... I posted it only on the Sport thread)
[link=http://www.rcuniverse.com/forum/fb.asp?m=9645509]Matt's button head screws[/link] on the header.
Although the turbo hose holds up to heat fairly well, it will likely greatly extend its life if it is shielded as much as possible from direct exhaust gases. I am using an [link=http://www.rcuniverse.com/forum/fb.asp?m=9687199]aluminum spacer[/link] made from a 1-inch length of .875'' OD wing tube, inserted into the turbo hose before installing. Using this, the exposed area of the turbo hose is very small, no more than 1/32'' total.
Matt can update you on his results with the [link=http://www.rcuniverse.com/forum/fb.asp?m=9694367]Teflon PTFE coupler[/link] he is using now. For me, the silicone turbo hose is working extremely well, but it requires doing it the way we've figured out by trial-and-error.
If you figure out another way to do it or another coupler material, it's always nice to add to the database!
As Bob suggested, here's an update on the Teflon coupler.
It is holding up well so far after 15 tankfuls (1 gallon). I originally also used an ally spacer under the PTFE, as Bob uses under the turbo hose. It turned out that this spacer just couldn't be held tightly enough under the PTFE and slid back, making a racket during flying (hit against the pipe stem). After the first day of flying I removed the spacer and have flown without it ever since. I left the 1" separation space between the pipe and header tho. No problems after about a dozen or so flights.
I am sure that eventually the teflon will burn through...it is rated for 500F continuous service and I am sure the exhaust gas is hotter than that. But it is fully exposed to cooling air so it may be fine for quite some time.
Minimally, there are two coupler solutions as indicated. It's a good idea to use the ally spacer under the turbo hose. Silicone rubber holds it in place fine. It may not be as good an idea to use it under the teflon...it's impractical, noisy. If you decide on the teflon, get the 1/16" wall material X 7/8" ID. Must use some type of bump on both the header and the pipe stem to keep it from sliding apart. The button heads work well and the 20 awg stainless wire holds great and is light.
If you have clamps of the correct size use those. I don't reccommend worm gear clamps... one could easily overtorque the pipe and destroy it. Use spring types