Extreme Speed Prop Planes Discuss the need for speed with fast prop planes (Screamin Demon, Diamond Dust, Shrikes or any REAL sound breakin'''' plane)

Viper Help

Reply

Old 11-08-2004, 10:43 PM
  #1  
freebird1
Senior Member
Thread Starter
 
Join Date: Apr 2004
Location: Coalmont, TN
Posts: 598
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Viper Help

Hi

I was at a club this week and took my Patriot 40 ARF with a 45 Rossi. It was challenged, but was the victor in raw speed. One member had a Viper with a 32 OS. I loved how the plane flew. It would turn on a dime. A super fun plane to fly. I bought one at a deal, and now setting the Viper up. This is my set up. Please let me know if it will be OK or anything you might change. I know that will not be a racer, but any advice is greatful to make it as safe and fast as possible.

600 Mah Futaba Battery Nicad
7 channel receiver
Futaba 3004 for ailerons and rudder
Futaba 3003 for throttle
Expert Hi-torque for V tail
40 Rossi Pylon engine Older model with low time
APC 9x7

Any help is greatly appreciated.

Freebird
freebird1 is offline  
Reply With Quote
Old 11-08-2004, 11:35 PM
  #2  
Razor-RCU
Senior Member
My Feedback: (50)
 
Razor-RCU's Avatar
 
Join Date: Mar 2002
Location: Mira Mesa, CA
Posts: 5,405
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

The Patriot was faster than the Viper/OS-32 combo?

I never use the 600MAH packs because they do not last long enough-
The 9x7 may be a good lace to start but a pylon prop (what like 8.75x9W? Daven???) will be much more efficient and faster-
Is the Rossi a rear exhaust?

SOunds fun- keep us posted
Razor-RCU is offline  
Reply With Quote
Old 11-09-2004, 12:08 AM
  #3  
daven
Senior Member
My Feedback: (1)
 
Join Date: Dec 2001
Location: Waseca, MN
Posts: 8,455
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

The 600 mah pack is fine if you don't plan on flying 5+ times per day.

Servos seem fine, although a little on the heavy side. I don't know the Rossi .40 well, but would figure the lighter plyon props would be ok.

I'd try the following:

APC 8.8x8.5
APC 8.75 x 8.5W
APC 8.75 x 8.75 W
APC 9.5 x 7.5

That should be a good start for the viper. My biggest issue with the viper is the heavy wing tips. Cut them off and go with a basic razor style tip.
daven is offline  
Reply With Quote
Old 11-09-2004, 01:07 AM
  #4  
Flyboy Dave
My Feedback: (21)
 
Join Date: Mar 2002
Location: Pinon Hills, CA
Posts: 13,775
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

Your plan sounds good. [8D] I have a very similar plan with a Viper, and
either a K&B .40 pylon motor (FIRE) or a .45 Rossi (FIRE) just for grins.

I want to make up the streamlined part over the engine and pipe, like those
speed planes, just use one aileron, pylon style landing gear, and see what she'll do.

FBD.
Flyboy Dave is offline  
Reply With Quote
Old 11-09-2004, 02:27 PM
  #5  
NitroWoman
Senior Member
 
NitroWoman's Avatar
 
Join Date: Jun 2002
Location: Venus
Posts: 347
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

REINFORCE THE FIREWALL!!!!!!
NitroWoman is offline  
Reply With Quote
Old 11-09-2004, 03:02 PM
  #6  
Razor-RCU
Senior Member
My Feedback: (50)
 
Razor-RCU's Avatar
 
Join Date: Mar 2002
Location: Mira Mesa, CA
Posts: 5,405
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

One aileron? Which side do y'all use?

I figured if I got a Viper I would use my Webra-50 only because it is the lightest of the engines I have, and I do NOT have any fancy Pylon engines around---

I sold both a MVVS Grrt-40, K&B 7.5CC [:@]
Razor-RCU is offline  
Reply With Quote
Old 11-09-2004, 03:26 PM
  #7  
daven
Senior Member
My Feedback: (1)
 
Join Date: Dec 2001
Location: Waseca, MN
Posts: 8,455
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

Doesn't really matter what side you put the single aileron on. I would put it on the left side to help offset the head and muffler weight.

On the viper, I'd stick with two ailerons, they are relatively small and you need them both for control on takeoff at slower speeds.
daven is offline  
Reply With Quote
Old 11-09-2004, 04:00 PM
  #8  
bob27s
My Feedback: (19)
 
bob27s's Avatar
 
Join Date: Apr 2002
Location: Cleveland, OH
Posts: 5,576
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

On some of the older F-1 and QM aircraft we had single ailerons...... if I recall it was on the right wing panel. This was mainly to turn left. I seem to recall my old wood Dara had one aileron. God forbid you had a crosswind at landing

As Dave noted, stick with two surfaces. The drag and/or weight reduction is not all that impressive when you get down to it.

Freebird..... 16,500 to 17,000 RPM on the ground with that Rossi. Select prop accordingly. The 9.5x7 was pretty good on that engine. The 8.75x8N is not too bad either. When I raced Rossi engines, we used 8.75x7 and 7.25 revup wood props. The APC props became legal about when most of us transitioned to the Webra .40 engine.
bob27s is offline  
Reply With Quote
Old 11-09-2004, 08:22 PM
  #9  
garys
Senior Member
 
Join Date: Jan 2002
Location: Stansbury Park, UT
Posts: 937
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

I remember some guys trying a single aileron with Q500's in the late 80's. Most ended up cutting a second aileron into their airplanes anyways. It seemed like they tended to have quite a bit of adverse yaw when rolling, which would slow the airplane down a lot more than any possible increase from drag reduction of only having one aileron to begin with (because during the adverse yaw, the whole airplane is effectively flying sideways).
GS
garys is offline  
Reply With Quote
Old 11-09-2004, 08:56 PM
  #10  
Q-Ball
Senior Member
My Feedback: (1)
 
Join Date: Jan 2002
Location: Beaumont, TX
Posts: 554
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

I agree with it all....LOL.
My Viper with Jet 50 is a screamer with the 8.75X9.Rite now I'm running 8.75X8.Maybe just my eyes but it seems faster with the 9 pitch.I haven't tack it with the 8.
I've never used just one aileron.But another guy has and his scat cat does fine.It's not as fast as my Viper flat out,but does turn tighter.But the Viper does not have great handling trying to go slow and after it touches down,most control is lost.

Razor: The Webra would work really well on the Viper.

I'm using a 270 battery pack.It fits just rite.Not much room in there.

You can't do anything about it till it breaks but the fuse rite in front of the tail feathers is very weak and one hard knock and it breaks.The fireall does need extra help after some age on it.

I don't see how any Patriot could outrun a Viper with the rite engine setup.I'm not a rocket scientist but I just can't see it. I have a Patriot with a MVVS 49 and pipe and no way could it keep up with the Viper.Lota difference in weight and drag.

Later
Walt
Q-Ball is offline  
Reply With Quote
Old 11-09-2004, 11:31 PM
  #11  
freebird1
Senior Member
Thread Starter
 
Join Date: Apr 2004
Location: Coalmont, TN
Posts: 598
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

Thanks

I will try the 9x7 till I get the fill of the plane, Then I will lower to get the SPEED. I will go over ever inch of her to reinforce anything that may be needed. The aileron servos is in the middle of the wing. I may be missing something with the right and left placement. bob27s, I have been looking at the Webra 40. Are they a better engine for the Viper than the older Rossi.

OK, let me get the facts straight. The plane was a Lanier Predator OS 32. Both of these planes (viper) look the same(sorry). There where also a sky dancer and another type of pylon plane. Of course the other planes could turn on a dime, but believe it or not on the straights the Patriot ran off from the planes. We flew in a flat circle 600 feet wide and about 800 long. I could not believe the Patriot beat the planes on the straights, but I had 3 other members of my club that where there as well with me. The plane gained in the turns, but the Patriot pulled away in the straights. As the laps mounted so was the lead of the Patriot. Here is the kicker the Rossi was leaning out bad and was not at full performance. The patriot won by almost a full straight. Nothing special just a Rossi 45 with a Minn tune pipe with an APC 9x8 prop on a Patriot 40 ARF. !QUOT! That is the truth and the whole truth.!QUOT!

Maybe I just need to put a V tail on my Patriot

Placement of the friendly race

1. Patriot
2. Sky dancer
3. Predator
4. The other plane
freebird1 is offline  
Reply With Quote
Old 11-10-2004, 01:05 PM
  #12  
bob27s
My Feedback: (19)
 
bob27s's Avatar
 
Join Date: Apr 2002
Location: Cleveland, OH
Posts: 5,576
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

Just for a quick reference.......

A properly built and balanced Q-500 (Predetor, Viper, or any of the typical, current wood designs) fly at about 120mph with a 424 engine up front........ the Thunder Tiger .40 is sorta the standard.... with an APC 9x6 turning about 16K rpm on the ground. A Q-500 legal for AMA type racing weights no less than 3.5 lbs.

On a good day on the race course, these TT40 powered Q-500 planes can fly the 2 mile course in 1:20. Typical average is 1:25. Pretty darn good.

Fifteen years ago, we were flying 1:15 - 1:25 range with the Rossi .40 - 130 mph range (yes, we are now with the TT40 where we were with the original Rossi .40 - apc prop and improved q-500 designs helped...but that TT40 engine is pretty good).

Ten years ago, SEMPRA was running the Webra Q-500 .40 engine. We could get those down into the 1:09 -1:19 range consistantly. 140 mph range.

Eight years ago SEMPRA Q-500 ran the SS-40 Jett sport engine. Times on 2 mile course with those got down into 1:03-1:13 consistantly. 150 mph range. Same engine on the long 2.5 mile course up in Ohio with the CAPS circuit was approaching 1:20.

A current, 428 engine powered Q-500 (even properly prepared ARF kits) can fly 1:09 to 1:15 EASILY on the 2.5 mile course. 160+ mph range.

The best Patriots I have seen, with Jett-50 power, have typically flown in the 130-140 mph range in level flight. In a turn or tight mauvering, they rapidly lose a great deal of speed and energy.... and since its much heavier (5-6 lbs), it take a while for it to accelerate back up to speed.

Considering this, a 3.5 lb Q-500 with a good performing OS32, (figure 90-100 mph - about what we got with Webra 28 engines) would very likely stay with, and probably outperform even the best performing Patriot, on an actual 3-pylon racing course.

It is worth noting...... when flying any aircraft on a race course, aircraft setup (CG, trim) and pilot skill is critical. Timing, smoothness all relate to speed. Every time you touch a control, you essentially 'put on the brakes'. Having to correct for mistakes or for a poorly trimmed aircraft , or simply over-flying the aircraft, can absoultely destroy speed and lap times.

Just for pondering and such. Your milage and speed will vary. Please, no wagering
bob27s is offline  
Reply With Quote
Old 11-10-2004, 04:43 PM
  #13  
freebird1
Senior Member
Thread Starter
 
Join Date: Apr 2004
Location: Coalmont, TN
Posts: 598
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

I can not get any of my battery packs to fit where the instruction put it on the viper. where have the rest of you put the battery..

The guy with the predator stated he was running around 100mph. I did my Patriot by distance and time the day after to get 123.36 MPH. I do not claim to be a stats man, but that was a difference of around 23 MPH of top speed. I brought the Patriot down to the deck and let the nitro burn.[>:] I did lose speed in the turns, but again, I pulled away in the straight to smoke the predator. The sky dancer was faster than the predator. The sky dancer had me worried. Stayed close to me the whole race. Maybe it was the engine; I do not know. I am not going to sell the Patriot short regardless what paper states. I was where the wheels met the runway, and the paper (stats) are back at the shop. So, with that I am going to drop the friendly race where the Patriot out speeded a predator. I do have some fishing stories too.

V tail Patriot
freebird1 is offline  
Reply With Quote
Old 11-10-2004, 04:59 PM
  #14  
bob27s
My Feedback: (19)
 
bob27s's Avatar
 
Join Date: Apr 2002
Location: Cleveland, OH
Posts: 5,576
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

what battery are you using ??

Normally you can fit anything from a 250 to a 600 mah nicad pack anywhere within the wing saddle in a Q-500.

Usually I end up putting my battery behind the wing, just forward of the servos (sometimes behind the servos). Typcially 350mah sanyo 4 cell pack. Its pretty small.

I just looked at the Viper instructions PDF.

From the Viper instructions, you should be able to get a 250-350 mah pack where they show you. If you have a std 500-600 mah pack, install it just forward of the aft bulkhead, wrap in a bit of foam and keep it in position with a pop-stick and some zap.

(good lord, is that REALLY how they show you to install a RX in a Q-500 airframe ????? I wouldnt care if it had an LA.25 up front.....YIKES!!!)

I can't imagine that this thing comes out that nose heavy that you would need all of the radio gear back there..... but I have not built one.
bob27s is offline  
Reply With Quote
Old 11-10-2004, 08:29 PM
  #15  
freebird1
Senior Member
Thread Starter
 
Join Date: Apr 2004
Location: Coalmont, TN
Posts: 598
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

Thanks

That is just where I installed it before checking the post( makes me fell better). I have everthing finished on the viper except the muffler. I have no muffler for my engine, so I said what the heck and called Dub Jett for a pipe. I CG her with every thing except the muffler, and she was a bit tail heavy(not bad). I hope the weight of the pipe will make it just right. Again, I am new to the Q-500 planes, but the 40 Rossi pylon engine seem to me it will ripe the plane apart. What kind of speed can I expect with the viper with the rossi and Jett pipe? I am hopeing ALOT!!!

I have 3 battery packs. Which is the best for the viper mounted where you stated?

Futaba 600 square
Futaba 600 flat
Cermark 700 flat

Thanks
Freebird
freebird1 is offline  
Reply With Quote
Old 11-11-2004, 09:08 AM
  #16  
bob27s
My Feedback: (19)
 
bob27s's Avatar
 
Join Date: Apr 2002
Location: Cleveland, OH
Posts: 5,576
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

Did you order a full pipe or the Jett-Stream muffler from Dub?

The 600/700 flat packs would be prefered. Install them just above the aft wing hold-down bolt blocks up against the bulkhead. Make sure the resulting installation does on interfere with or get hung up on the aileron torque rods and pushrods when the wing is installed.

Your CG should be just about right when you install the exhaust system. Balance the plane at 2.750" - 2.875" for the first flight (dry). Aft of that back to around 3" is ok....... not suggested for the first few flights.
bob27s is offline  
Reply With Quote
Old 11-11-2004, 12:04 PM
  #17  
AdamB
Senior Member
My Feedback: (9)
 
Join Date: Jan 2003
Location: Reading, PA
Posts: 454
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

I recently assembled a Viper 500. I have a Jett 50 with mufler up front. I found that to balance it at 3", I placed my 600 mah flat under the throttle servo, resting against the landing gear support.

I too was having a problem attempting to find a battery small enough to mount in the back. Before I got too crazy, I just CG'ed it and discovered it was tail heavy.

I have only flown this plane 1 day, about 10 flights. The engine is new to me as well as the plane. I didn't use the included pylon wheels as the bushings kept falling out, so I used a regular set of wheels (until I get better wheels) and the only prop I had on hand (APC 9X8) which turned 17400 on the ground.

Must say the Viper and Jett 50 were breath takingly fast. Can't wait to get better prop and wheels...
AdamB is offline  
Reply With Quote
Old 11-11-2004, 11:25 PM
  #18  
freebird1
Senior Member
Thread Starter
 
Join Date: Apr 2004
Location: Coalmont, TN
Posts: 598
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

Thanks for the info!

I got the Jett-Stream muffler. I have two types of fuel on hand to use with this engine. One is 15% Bryons and the other is 20% blue thunder. What is the best fuel to run in the rossi. It is the older one (black head) with less than 3 tanks under its belt. I am going to lock tight the wheels. bob27s, that is where I have the pack as of now. I was thinking if I should CG her a little nose heavy at first. Any help on the fuel issue is greatful.

Anyone what to guss the speed. I do not have a gun, but can do it by math and get close. (5-10 MPH)

Freebird
freebird1 is offline  
Reply With Quote
Old 11-11-2004, 11:31 PM
  #19  
bob27s
My Feedback: (19)
 
bob27s's Avatar
 
Join Date: Apr 2002
Location: Cleveland, OH
Posts: 5,576
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

Any fuel will work in the engine....... 5-15% nitro. I would not suggest using more nitro. If its relatively new, make sure which ever fuel has at least some castor oil in it (most of the byron sport fuels are blend of synth and castor... thats fine).
bob27s is offline  
Reply With Quote
Old 11-11-2004, 11:33 PM
  #20  
freebird1
Senior Member
Thread Starter
 
Join Date: Apr 2004
Location: Coalmont, TN
Posts: 598
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

Adamb

I would love to see the viper in the air, sound awesome. I am using an APC 9x7. I do not know what the RPM will be but I will post it. After I get use to the plane I think I will try a APC 8.75x8.75. Seems small, but I am new to the pylon planes.

Freebird
freebird1 is offline  
Reply With Quote
Old 11-12-2004, 07:44 AM
  #21  
Ed Smith
Senior Member
 
Join Date: Dec 2001
Location: Brantford, ON, CANADA
Posts: 3,305
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

Freebird,

I am using an APC 9x7. I do not know what the RPM will be but I will post it.
A few words of caution here. If the rpm is reaching the upper teens then be careful about using ANY of the "Plastic" props available. Use only the APC props with the mark "D-1" on the hub. Go to the APC site and read about this. I mention this so that you do not end up with half a prop sticking out of your ear!!

Ed S
Ed Smith is offline  
Reply With Quote
Old 11-12-2004, 08:04 AM
  #22  
NitroWoman
Senior Member
 
NitroWoman's Avatar
 
Join Date: Jun 2002
Location: Venus
Posts: 347
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

The Battery I like in Quickies. Fits Fine.[sm=thumbup.gif][link=http://www.servocity.com/html/4_8v_750mah_nimh_battery.html]Battery[/link]
NitroWoman is offline  
Reply With Quote
Old 11-12-2004, 11:50 AM
  #23  
AdamB
Senior Member
My Feedback: (9)
 
Join Date: Jan 2003
Location: Reading, PA
Posts: 454
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

I usually use 15% coolpower in 2 strokes, Byrons 15% in 4 strokes and 30% Coolpower in heli's. However, I ran the Jett 50 on Byron's 15% since it is not fully synthetic... The Jett ran awesome.

I've been reading some other posts on here about the Viper regarding motor incidence, I checked mine against the wing and the motor is -2 degrees... supposed to be 0 degrees all around. This is probably why I had to dial in up trim to keep her level in flight. Guess I'll fix that and then pin the firewall on too while I'm at it.

I glued the bushing in the Viper wheels and just used a regular axle to hold it on (haven't flown it yet to test).

Ed Smith, thanks for the info on the D-1 APC props, I too am new to running motors that'll spin so fast.

Any prop recommendation for the Jett 50 and Viper combo... I was thinking about trying a 8.75X8.75 or higher pitch and go from there...

PS I plan on adding color to the all white wing so I can see it better in the air... And the Jett 50 sounds awesome as it's unloading in the air!!
AdamB is offline  
Reply With Quote
Old 11-12-2004, 01:59 PM
  #24  
Ed Smith
Senior Member
 
Join Date: Dec 2001
Location: Brantford, ON, CANADA
Posts: 3,305
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

I was thinking about trying a 8.75X8.75 or higher pitch
Use a higher pitch than 8.75. there are two Pylon props listed on the APC site that would be more suitable. 8.75 x 9.25 and 8.75 x 9.5.

Ed S
Ed Smith is offline  
Reply With Quote
Old 11-12-2004, 02:09 PM
  #25  
AdamB
Senior Member
My Feedback: (9)
 
Join Date: Jan 2003
Location: Reading, PA
Posts: 454
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Viper Help

Will do, thanks for the input.


ORIGINAL: Ed Smith

I was thinking about trying a 8.75X8.75 or higher pitch
Use a higher pitch than 8.75. there are two Pylon props listed on the APC site that would be more suitable. 8.75 x 9.25 and 8.75 x 9.5.

Ed S
AdamB is offline  
Reply With Quote

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service