Originally Posted by scunna

No mods to ducting. fan is suspended where it is supposed to be. I think the awesome sound comes from the fact that the plane is designed to run 90mm fan so the 70mm fan has lots of free air( not starved)

I wonder if the exhaust pipe of the stock 90mm mirage way too big for 70mm fan?
much bigger than 100% FSA of the 10 blade 70mm fan

the stock exhaust pipe of the 90mm mirages is way to big for even a 90mm fan. I am sure scuna is using a thrust tube on the 70mm fan for the 70mm fan.

No thrust tube ! The exit is huge, i considered one but i have fitted lander 90 mm afterburner ring looks and sounds great. When i built the model i made a removable hatch, slicing through the bottom half of rear tailpipe. I installed 2 beams for cs10 to fasten to them. It was only a test really to see if 70mm fan worked, if it was no good i was going to install a cs12 fan and motor, but it has worked well.Model is light and powerful, and has a lighter wing loading, bonus all round i would say.

And is it the stock plastic CS housing or an alloy housing your using?

Originally Posted by scunna

.... I installed 2 beams for cs10 to fasten to them. It was only a test really to see if 70mm fan worked, ....

Did you have to seal around the 70mm so that there is no airflow escaping to the front?

If it has the full exhaust side, that is probably so free of restriction that no air would even try to go back forwards!! LOL
(But I do expect he filled around the fan!)

I installed 2 beams for cs10 to fasten to them. It was only a test really to see if 70mm fan worked, if it was no good i was going to install a cs12 fan and motor, but it has worked well.Model is light and powerful, and has a lighter wing loading, bonus all round i would say.

For 3 yrs, I flew an RBC Panther on a 70mm Minifan. First with a 4s ARC 28-48-1 system for 1400W, 4s-4000 Zippy and 4.3#. Thats about 2# lighter than the 90mm versions.

Later, I switched to an ARC 28-48-1.5, 5s Zippy 3000, for 1200W and 4#. Even better performance and an amp draw of 60A vs 105A.

Now I'm looking for another kit for the CS rotor and alloy shroud with BL32 on 5s-6s. There are many 90mm designs that will fly just as good or better than the intended 90mm, due to less AUW and sometimes higher watts and efflux than the original was designed.

Fuzz

Originally Posted by PAPE

And is it the stock plastic CS housing or an alloy housing your using?

stock plastic housing with intake lip.

Originally Posted by anlucas

Did you have to seal around the 70mm so that there is no airflow escaping to the front?

No filling round fan. there is a 3mm gap round bellmouth on fan. It just sits there where the 90mm fan should sit but smaller of course, maybe thats how it gives a throaty roar, honestly i have had turbine models years ago but it sounds just like one

Just ordered lx F-117 gonna run it on same setup. As far as twins go 5s is the better setup less amp draw on single 8000 ma lipo. Also just bought a-rc 70mm hornet gonna give that a try on same setup as mirage.

The 90mm fans sound really good aswell have a listen of this

Hobby topgun L-39 DPS -12 changesun (lander) fan 10 s 4400 65-130 c nanotech 1kv motor (3 min 23 sec)

That model is currenly 9.5 pounds Listen at the end of video it sounds really good like a tubine. 10 years ago i had a avonds f-15 full scale job i used to fly it at shows etc the model weighed close to 30 pound, model cost me 4000 pounds it was awesome but to be truthfull i used to soil myself everytime i flew it. It had over 300 flights. But these new fans are the way to go cheap powerful sounding good, and your not breaking the bank if you stuff it in. Since may this year i have puchased the following models

sebart mig 29
freewing su-35
fly fly mirage x2
fly fly l-39
hobbyking l-59
lx raptor 70mm
lx raptor twin 70mm
lx a-10
lx F-117
a-rc hornet
lander f-16

all These models in total were cheaper than my turbine model. Deffo the way to go. Never had as much fun LOL.

Originally Posted by scunna

The 90mm fans sound really good aswell have a listen of this

The L-39 does sound great with the CS12 but the Mirage 2000 is not as good.

Your effort with the 70mm CS10 is better sounding.

Here is a couple more running on 5s with stock cs-10

Lander F-16 cs10 fan bl-32 motor 5s fitted with afterburner Who needs a turbine (4 min 10 sec)

Lx F-22 Raptor changesun 10 blade 70mm fan Bl-32 motor 5s 4000 45-90c 4 mins wot (4 min 53 sec)

The trick to get the good sound is the balancing, the last 2 videos you can here the whine. Get it balanced perfectly then Whooooooooosh Lol