otterdriver

OK Guys I have tried 3 or 4 different exhaust setups. all pretty loud. I would now like to try a tuned pipe setup for the 80 single maybe one that is a little quieter and hopefully some more power.What is the best RCS or KS or Piffas or Carbons. They are going in a light wight IMAC plane. Thanks. Mark,

rob g

Hi Mark
I assume you mean the twin, as you said pipe's.
I have been running twin KS cannisters on mine for two years, very quiet, with loads of power.
Throttle is instant. Keep the headers short on this engine. Haven't tried any other brand, never had a reason to.
Pulls a 26x10 with ease.

Regards
Rob

rmh

80 single ---responds very well to a full length pipe setup and also responds well to a proper canister tuning-
On full length tuned pipe -it will run with any 100 no tuned . very strong. (I ran the KS 10/80 tuned setup -and Mejzlic 26x10 over 7000)
on a tuned can we consistantly got in mid 6000 range on menzS 26x10. and still got very smooth transitions .
The work in fitting up a pipe properly -is tough on some BARFS-
the best bet is to figure out how to make a trough - open along the belly with the pipe mostly inside . this affords cooling to the system -very important.

DENNIS C

My Feedback: (99)

Hi Dick how loud is the 80 on a tuned pipe like your talking about under the belly

rmh

how loud?
beats me - I never measured it -
it is pleasant tho -

DENNIS C

My Feedback: (99)

LOL

otterdriver

Thanks for the info Dick I am getting the 1080 setup coming and try to hang it on the bottom of my H-9 330s a little whittling but I will make it fit. Thanks again. Mark,

Smokey

My Feedback: (16)

Dick....Will it make a difference in performance if the pipe is just suspended under the belly or inside with a tunnel? Whats the pros and cons?

Thanks
Smokey

rmh

The cooler the pipe -the better .
shoehorning them in a little tunnel is simply a route to disaster - it is awkward- it heats them up - making them actully act shorter ( higher internal pressure )- this is not speculation-- we tested it with engine which had smoke injectors into the system - the addition of the smoke oil cooled the pipes and changed the rpm - noticably --
I always fingd some way to mout the pipes such that muck of them is in a large open area or open to the bottom of the airframe .
In some cases -I redesign the gear mount - to allow the pipes to run in a better path.

Paul Cataldo

My Feedback: (10)

Cubdriver, (Mark)
I am not sure if I asked you by email yet, but when you get the installation of your KS tuned pipe going, would you mind posting some pics, and some info on the install? This would help me decide which exhaust to go with on my new H9 Extra, and ZDZ80. I would LOVE to get the tuned pipe installed in mine, but I'm just not sure if I could produce a clean installation. I've never done a pipe install before. Thanks for any help!

rmh

On my website -in the workshop are some examples
Just look in DOGPILE search - for dhmodels - should be first thing up

DKjens

My Feedback: (50)

I have a header for a zdz80rv that I will not use. This is a Krumscheib flange, 90 degree bend and short extension. It probably makes for the shortest header possible for the 80, which I understand is preferable. If anybody is interested, let me know. Rather than putting a price on it, I'd rather trade for prop(s) or the like.
DKjens

cygnet

My Feedback: (33)

I would be very careful on the header length on you 80. first you have to choose a prop that you want to use and then start to tune from there. I just set up my 80 to day with a 1080 full length pipe 13 1/4 header length was the best turned a bambula 26x10 at 6420. A buddy of mine has same engine and uses a pitts style muffler he gets 5950 on same prop 470 rpm is a lot to pick up. Same header on KS 89 can turns 6250 so the 1080 is the way to go. Just my .02

DENNIS C

My Feedback: (99)

Guys i have a friend that turns a 26-10 menzS @ 6400rpm. with a pitts style muffler. And another with a K&S can and the shortest header possible and he turns 6700RPM. swing the same prop.

So i dont know how good the 1080 is but so far im not impressed at all.
just my 02. cts

luv2flyrc

My Feedback: (6)

Bodyman, I think the Bambula prop is more load than a MenzS, hence the lower #'s

my ZDZ 80 turns a Menz S 26x10 at 6700rpm on a KS 89 canister too.

Mike

aerobear

My Feedback: (4)

Hey cygnet,

I think you may be WAY too long on your header length. About 3 1/2" to long. The chart says for 6500 rpm on the 1080 pipe the total distance from the exhaust port to the band on the pipe should be 750mm. The pipe section of that 750mm is about 500mm, leaving 250mm (9 3/4") for the header length. Cut 3 1/2" off your header and try it again. From what I can tell the KS chart is pretty good and the recommended lengths don't make things peaky. BTW this chart applies to the full length pipes only, not the shorter KS tuned cannisters.

You could try cutting off half the amount first. If you get an improvement you know your are going the right direction.

aerobear

My Feedback: (4)

Don't know where the smiley face came from.

Anyway, with the 1080 pipe and 6500 rpm, your total length should be about 29.5" from exhaust port to the center of the band on the pipe.
I couldn't find the chart on the KS site so here's a pic.

rmh

that chart is a good setup --for KS tuned pipes -and unless you know fo sho how others pipes are made - it is not any good .
Having dropped that caveat --
Never tune for max power - tune for best throttle response
Also a hot setup is effectively shorter than a cold one .
So run in your setup on a bench - play with throttle performance -on the size props you intend to use .
somewhere around 720-750 cm works great on 6000 + rpm setups -on all the ZDZ's we have setup
One more thing - bigger props don't necessarily mean more thrust.
On one recent setup - with the 100NG pulling a 30 lbs wet setup, we found the smaller prop actually pulled harder on a dead vertical -slow speed start.
this engine seems to like to rev- propped at over 6800 for max performance- yet glass smooth transitions
the NG 50 -is the same ( natcherly)
I haven't found the sweet setup for it yet - but I found that by running it a bit rich - it unloaded a bunch on the simple header and paint can I ran!
This means tuning was happening . No low end stumble - just wanted more fuel right at the top end.
when we ran fast glow setups with short tuning - you had to do the same thing - the plane took off rich, then as it gained speed - the tuning would kick in and that required a LOT more fuel to make the jump.
on pattern models -this kind of setup is not desireable-and results in a model that is typically flat in midrange and peaky and all in a all a pain.
The 50 is a runner tho and I am sure that when I find the right prop/pipe combo -it will be a real treat.

cygnet

My Feedback: (33)

OK what would you guys use as a header length on a ZDZ 80 single with a KS 89 can and a bambula 26X10

rmh

still 12" from exhaust flange to connectection of can - and the BEST can is the front in - rear out -also the least expensive

cygnet

My Feedback: (33)

I'm going to try the short header on Sat. Hard to believe one could turn a 26x10 bambula more than 6400 on a ZDZ 80, the thing is. it runs so good on the 131/4 header but I will find out on Sat and post the results.

rmh

if it transitions nicely - leave it alone -

cmitch232-DELETE

My Feedback: (1)

I'm one of the guys running a KS cannister on my ZDZ 80. I have probably the shortest header possible due to space limitations on my 35% Carden CAP, but the engine doesn't seem to care. I'm turning 6700 and change on a Mejzlik 26x10, and considering trying a 27x10 because it's turning so strong. So it's not a fluke that this engine will turn WAY over 6400 with the right cannister/prop combination. Just make sure you have plenty of baffling so the air is channeled directly across the cylinder and keeps the engine running cool. (under 230 degrees) Having a heat gun helps.

rmh

Not a fluke - On that prop on the 10/80 KS pipe -I have seen 7000 rpm . I believe we were set according to the KS chart.
a couple of years back, we noted that the 80 single pulled with and better than some 100's .
It is still in a class by it's self.
This engine setup on a good tuned system is easily the most power you can buy for the money

cygnet

My Feedback: (33)

I agree with Dick. I know I can turn way over 6400 on a 26x10 mejzlik I can turn a 26x10 menz S at 6700, but the whole point of this exercise is to get a quiet set up that pulls hard. Has anyone tried a 28x10 mejzlik? Each prop that I try that turns 6400+ on the ground rips in the air, some worse than others. I think the best IMAC combo is to turn the largest prop you can at around 6000 on the ground(and have good transition) so far the babmula 26x10 on a KS89 can seems to work the best for me and it is very quiet, as always just my .02