carcraze

I am looking to get into a new jet and have been doing some reading and it seems to point to a Flash as the best option for what I want. I have been looking at either a used C Flash or U Flash new or used but I have been pondering power choices.

At this point it will be either a 100 or 140 and I was leaning to a 100 to keep it light and would like to try and get the fuel usage down for longer flight times and keep residual thrust down for landings.

Is there options for additional fuel over that of the wing tank?

I have also heard that the 100 is marginal for that bird as I don't want an under powered jet either. Operation will be off of grass fields.

Any thoughts?

AFTERBURNER1

My Feedback: (80)

JETCAT p140 fully bypassed is a great combo..

PaulD

My Feedback: (39)

Check out what Peter Ayache has done with his UF. He put a BF100 in his which is more comact than a P120 but puts out similar thrust @ 27 lbs. I also think he sells the engine for about 2500 so a pretty good value. I have seen/flown Dean W's fly with a P100 JetCat and it has really good performance. The UF is a lot slipperier than the Classic.

I flew my Classic Flash with a Merlin 160 and it was ballistic but was a real handfull and was really tough to land until I put crow set-up in with the flaps. (Too much residual thrust)

Carf sells a sadlle tank kit in place of the wing tank that adds lots of capacity:

http://carf-models.com/public_carf/p...ory&proId=2772

Cheers,

PaulD

RCISFUN

My Feedback: (44)

I a have a Classic Flash and originally I had a Jet Central Rabbit rated at 19 Lbs, it flew great with that Turbine, when it came time to send in the motor for its 25 hour service interval I decided to bolt in my Jet Central Cheetah, all I can say is WOW, at 31 Lbs this thing is a rocket ship. I usually fly around at less than half throttle. The landing characteristics changed also because of the residual thrust.

I would not hesitate to put the Rabbit back in when I need the Cheetah for another project.

So what I am trying to say is pick a turbine that you feel will fit your long term flying goals, a larger thrust motor that is compact will not be a disadvantage as far as weight and fuel consumption because you probably would not be flying around at full throttle. Then is is good if you need it for a larger airframe, if you have no plans to go bigger then the New Rabbit 100 would be perfect at 22 Lbs of thrust.


Good luck, no matter what you get you will like the Flash!

indubitably

My Feedback: (14)

P 100 RX will push it past 200 mph

luv2flyrc

My Feedback: (6)

Yep, I agree. I have a Classic that originally had my Rabbit 100 in it, flew great, nice and light, easy to land, actually had to drag it in with some power on. Put my Cheetah in it to use the Rabbit elsewhere. Gained 11oz's overall in weight with the additional 2oz's upfront to balance, about 70km/hr faster...mind you the Rabbit 100/ flash would still do 290KM/hr but, feels heavier, more of a straightline speed plane now if that's what you're looking for.

I actually prefer it with the Rabbit 100 and may put it back in over the winter. It's lighter, more agile has lots of speed. It still has unlimited vertical if you go into it with some speed. The only thing it won't do is go unlimited vertical, fully loaded from takeoff. So, for the way I like to fly it, 22lbs is perfect.

Mike

carcraze

Currently I have Rookie 1 with a super eagle and I am going to keep it around. With the Eagle it can be a pain to land in our short field as well I get 7 min flights.

I was hoping to get into a flash with either motor but want to try to get 10 min, should require about 4L and want it tame on the landings hence the 100 statement.

Just looking at options so I do it once.

carcraze

Don't want a brand X war but I had a look at the B100F mentioned above which is impressive with a 120N thrust and low weight.

Also saw the Merlin 140 which looked impressive with regards to weight, pricing seems decent as well.

Even more confusion.

Edgar Perez

My Feedback: (13)

Cheetah due to thrust and weight

RCISFUN

My Feedback: (44)

+1

Merlin 140 is basically the same as the Cheetah; however the Cheetah has the lifetime warranty

Both are excellent Turbines, you would be happy with either.

http://dreamworksrc.com/catalog/jetc...ah-p-1911.html

http://dreamworksrc.com/catalog/merlin-m140-p-1929.html

PHIL GREENO

I have a J-Munts Merlin 140 in my Ultra Flash and it suits it just fine.With 31.5 lbs of trust it will do 250mph as wedo not have any speed limit here in the UK.

But thats not the mainreason for using the M-140.This turbine is very well constructed and is smaller in diameter and weighs less than a JC 140. I have no nose weight to get the balance correct.It is also very economical and 8-9 minutes is easy with variable throttle use and the using the main and wing tank. Gaspar is also a very helpfull guy and gives excellent service.

Phil.

Jetpilot24

My Feedback: (21)

Don't forget to look at the Kingtech K-100 and K-140. I own a K-80 and a K-140 and both engines are putting out more thrust then advertised. I love these engines very reliable and if you were to actually need service, Barry and Dirk from www.kingtechusa.com are located in California.

Joe Lewis
Kingtech
K-80 and K-140
Owner

carcraze

I was actually looking at the 100g and the 140 which is what promoted the original post.

I have really thinking about weight though as well and there seems to be a lot of units in the 120 140 area now with much smaller cans, I must say though the Kingtech price seems attractive.

Trying to sort it out before I make a very much thinner wallet [:@]

Any idea now the blue angels scheme shows up in the sky as I am getting old these days?

PaulD

My Feedback: (39)

The Merlin 140 definitely wins in in the mid size power to weight ratio IMO. The Kingtech 140 is a tank^2 - it puts it strong thrust but is the same size as a 160 turbine. It will fit but it's too heavy....

It's ok to get old as long as you don't complain it's too loud!

PaulD

Ramz

Sounds like a good 100 would be the proper choice. If landing, fuel consumption and lightweight are of concern, any modern 100 would be perfect. I have a K170F in mine. GPS'd at 276 mph. For me, it is perfect but most people would be perfectly happy with a 120 or 140. I definately notice the residual thrust on landing but it is still a ***** cat to land. Just takes a bit more time to slow down.

Dave Wilshere

I built one last year with a P-80SE just to prove to the powerheads it would work well. Think there is a video on the UF thread somewhere. Enough for a rolling loop....
Partner Claire's UF will have a P90RXi in it and that will have a little more go than the P80SE.
I've flown UF's with P100RX, P-80SE, my 2 year old UF loads with a P-120SX. Friends with EvoJet 90, P-140RX, Hawk 100R. Great model what ever you power it with. Flights from grass with most of those too.

Dw

Jamie C

[youtube]http://www.youtube.com/watch?v=w7DaBv8474A[/youtube]

basimpsn

My Feedback: (5)

Mine flys very well with the k170, At Hamburg jet rally everybody thought I have a P-120 because I was just cruisin around the skies, I wasn't pushing it too much. I also had the best landing

Ramz

Yeah I hear ya. It is always fun to do a low, slow dirty pass, pour on the coals and accelerate vertically. A buddy of mine has a UF on order and he is going with a K140F. We probably won't be able to tell much difference straight and level. A truly great airframe.

Wayne22

My Feedback: (2)

watch this video....and look what power they used (at the end of the video..) You have lots of options...[youtube]http://www.youtube.com/watch?v=-aJsU42W6Rw[/youtube]

Jame

I think your definitely on the right track with either the 100 / 120 / 140 size turbines, I wouldnt be tempted to fit anything larger than this, we have a Merlin 140 in our UF and it feels so well balanced compared to my 160 powered Classic Flash, I had a Wren SS in mine originally and while it was nice to fly it always felt like it was cruising round with no option to go any quicker, now Ive fitted the 160, while its absolutely balistic and fun when its flat out, its hard to find a point on the Throttle position where its not at least 50 - 60mph faster than it used to be, I know some guys will say they are sure Idle would cure this but flying an aerobatic routine with the throttle set at partial settings I find a little awkward.

I had a flight with two 140 powered UF's last weekend and just thought they seemed alot nicer to fly, maybe its just me, I dont know, they just felt alot smoother and easier to fly due to the slightly lower top speed and what seemed like a more linear throttle curve.

Theres also been a few of the our club members that have dealt with Gaspar and couldnt speak highly enough of him.

PaulD

My Feedback: (39)

The other thing to consider with the big blocks is unless you have the will and airspace to be flying around at 200 mph all the time, you will spend most of your flights in the lower end of the throttle curve - right where most turbines have crappy throttle response.

PaulD

Dave Wilshere

Jamie

Yep! That was the one I thought about. P-80SE...plenty

Dave

VF84sluggo

My Feedback: (55)

Excellent point!!

This is exactly my concern over putting a pre-SE/SX P-120 in an Elan I'm getting. Sure, I'll have a great punch into the vertical, but the rest of the time I'd in this rpm range. And then on landing, with this older -120 with the slow spool-up time (but fast compared to my P-70) , I'll for sure be back in this rpm range.

Sluggo

Jack28

My Feedback: (19)

I had a Classic Flash with a Jet Cental Falcon 23lbs thrust flew great. I built an Ultra this year with a Jet Central Cheetah (31 lbs thrust) it was way over powered for my flying field. Unfortunately I lost it last week due to a radio issue. Most of the fields I fly at and the jet meets I attend monitor speed with a radar gun. If i were to build another Ultra I definately would put my Rabbit 100 (22.5 lbs thrust ) in it. Plenty fast , longer flight times, lighter wieght, and less residual thrust for landing. Hope to try this combo out someday when i can fund another jet.