xandips

So i decided to get another viper 500... first one crashed on maiden : (

need advice on engine... I wanted a jettsport but will the viper take it??

or an os 50sx or 32 sx

any advice??

thanks

rmenke

My Feedback: (13)

xandips:

The sj 50 or 60 LX is so far above the quality of the OS junk it is unbelieveable. Yes, they are twice as expensive, run and idle at least that much better, and should last you for years, as opposed to the usual one season, if you are lucky, for the OS. Love my little Jett BSE 35, thinks its a hot 46. Has now been running four club racing seasons and just keeps getting stronger. Same for my 50. Go for the Jett 50 LX, the viper constructed and reinforced as recommended in this forum should hold up with no probem. These engines will live when most all others will die under the same conditions. (lean run) Simply well worth their cost. You will be willing to pay more after you have had your first one for a short time. No subsitute for quality and the Jetts are high quality. Period!!!!!!!!!!!!!!!!!!!!!!!!!! Have a experienced pylon pilot maden your next bird. They can get a little tricky until trimed correctly, then a good fun sport airframe. ENJOY

bob27s

My Feedback: (19)

The Viper will fly well with just about any engine bolted on the front.

Ive flown Q-500 aircraft with everything from OS25, ST29, OS32 ----- and all manner of .40 size engines. I seem to recall I even had one years ago with a K&B61 on it.

Standard setup for 424 sport Q500 racing is a Thunder Tiger .40 Pro with a 9x6 prop up front. ..... simple setup, easy 110-120 mph level flight performance. Fast enough for most folks.

So from that perspective, any good .40-.46-50 size engine will get you pleanty of speed. And yes, the plane will fly quite well with an OS32 up front too.

xandips

ok... which wiould be faster... os 50sx with jett pipe or os 32sx with jett pipe???
i just want speed....

bob27s

My Feedback: (19)

OS50SX, jett stream muffler, APC 8.8x8.5 prop

reddikr

My Feedback: (23)

The best bang for the buck is a Thunder Tiger 46 Pro. I think it will be more than adequate for the Viper and will give engines twice the price a run for their money.

freakingfast

My Feedback: (3)

I agree with reddilr. A low ri$k package deal, Thunder Tiger 46 Pro + Ultrathrust muffler + APC 8.75 x 8.75 Run on 15% nitro quality fuel.
I wouldn’t put a high $$ motor on until you clear up the reason for the Viper making a hole in the ground.
The firewall is a weak point. GP puts blocking and fiber glass inside and out now. After installing fuel tank and foam isolation, glue this compartment cover down well (wood to wood) with epoxy. Sorry this cover can't be screwed down (removable) for full fire wall strength. #1 reason for fire wall breakage I’ve seen is bad starting practices from off center starter cones or slamming a weak starter on, to over come compression. You can guess what the others are.

xandips

thanks for the tip... will beef up the firewall area with epoxy... as for the engine.. i might use another 46ax with tuned muffler or the 50 sx... never seen or used a thunder tiger... i'm not that eager to get one... thanks a lot though..

Crazy4Flight

My Feedback: (540)

What engines do you right now? Pick one of those, and keep your cost down until you can handle the Viper at full throttle. The 32SX and a Jettstream muffler is a good starting point. My first ScatCat had a OS .30 MAX, then a ThunerTiger pro.25, next was a K&B.40

xandips

no i have no problem with the speed... im in doubt between 3 engines now... os 32 sx... 46 ax... or 50sx
all three with jett tuned muffler...
fastesT?????

xandips

no i have no problem with the speed... im in doubt between 3 engines now... os 32 sx... 46 ax... or 50sx
all three with jett tuned muffler...
fastesT?????

bob27s

My Feedback: (19)

skip the 46 ax... does not unload in the air well (not like the 46FX or the TT46 was capable of). Good engine, but has to be propped quite differently.

I agree, if you are buying an engine , get the TT46pro and a tuned muffler - best value.

If you have the OS50 already, run that.

TeamMuir1

My Feedback: (-1)

I honestly HAVE THE BEST LUCK with the .52 Evolution.... I have not yet flown it..
but I have one on my Hangar 9 Twist.... IT should be a SCREEMER... lmao.....
Evolution has the best IDLE and off IDLE caracteristics.... I have ever exerianced with a GLOW MOTOR........ this thing had BALLS...... outta be a beast in the air.....

buddude8

My Feedback: (10)

jet 50lx with the black pipe. I have one on mine and the plane holds up fine. Im using a 7.4x8.25 apc carbon prop. Im hitting just over 22,000 on the ground. i will post a small video of it later.

ken

xandips

thanks all.. will look at the evolution 52 and also at a webra 55.. anyone have one???
look forward to seeing the video...
: )

xandips

so Im reading some forums and came across a weston magnum.. never really looked at it cause it has no landing gear... but it really interested me today...
speed wise, is it as fast as the viper (with same powerplant)???
anyone have one??
any tips?
thanks

buddude8

My Feedback: (10)

i didnt post the video on here, i started a new thread on it here it is incase you missed it

http://www.rcuniverse.com/forum/m_5287064/tm.htm

ken

arck

Hi Guys, I bought a Viper 500 last weekend an took me three days to assemble, the maiden was last Sunday and it was a bullet with the tower pro .46 and 10x6 apc,, so fast that I couldn't handled and crashed, the nose was broken and the tip of the right wing too, my question is if you know a thread or review to reassemble and fly in the right manner,,,,,
thanks
wm

daven

My Feedback: (1)

You don't have to fly it at full throttle. Get it in the air, and cut back till the speed is manageable.

buzzingb

My Feedback: (2)

I would recomend the Thunder Tiger 46 with tower muffler ($15) and a 9X7 apc. That setup is pretty impressive and will last for years and years if run just a little rich. TT46 has great idle and transition also. It will pull right close with an OS50sx.

arck

Thanks for your quick response, what do I need to reinforce, I apply two coats of viberglass cloths next to the firewall where the tank is place, and reinforce with the same under the landing gears, the CG is like the instruction's but it needs 3.7 oz lead to reach the right CG and fly stable,,,,is that correct?
wm

freakingfast

My Feedback: (3)

On late model Vipers they have done a fair job of glassing the fire wall, but a little more sure can't hurt. I havn't seen problems were the landing gear mounts. It looks like you still have the stock hard plastic wheels. One may fall off at first takeoff and the other at landing. Jett Engineering and Performance Specialties sell great speed/race wheels.

The weak points of the viper as I see it in order of importance:
# 1 fuslage at the front of the "V' tail mounting block. Use lite weight fiberglass or carbon fiber on sides and bottom and monokote patch.
# 2 the fuslage at the rear servo opening. Glue two strips of 1/8 x 1/4 ply or bass wood on the inside-top edge.
# 3 fuslage under the leading edge of the wing. Use lite weight fiberglass or carbon fiber on sides and and monokote patch.
# 4 more fiberglass on the fire wall, you already did this. Make sure you glue the fuel tank cover down well, don't screw it down.

I put a 5 cell AAA sized nihd battery aft of the rear servos and didn't have to add weight for or aft. I did add 1 oz. in side a wing tip. Is yours nose heavy? Did you use a lot of epoxy on the fire wall?

arck

Thanks, I will reinforce the bird us you say,,,,what about my CG, my viper is tail heavy, so `I put 3.7oz of lead under the tank to balance correctly, it is to much or I miss something, and the rates, I read in the instructions booklet rates high for takeoff and low rates for flight stable, in your experience what is the best recommendations for the rates and how much,,
Thanks
wm

Rudeboy

You should start out at the front CG mark given in the manual... at least!
My Viper is extremely pitch sensitive when balanced at 3" from the leading edge. It's nearly impossible to keep a straight line. Mind you, this is with a QJ500 engine, so the plane is quite a bit faster than a TT46 powered plane, this could have something to do with it.

With the tank on the CG and the battery way back, I needed also needed a big chunk of lead to make it flyable. After the firewall was "removed" by the JETT engine, I moved the engine 3mm forward and put the battery in the tank compartment. It's much better now.

Throws, you can leave the rudder on high all the time, since you only need it for take off and sometimes for landing. It's nice to have good rudder authority during take off.
Aileron and elevator: take off and fly on low, land on high (if the weather is crappy). Adjust the low rates to your own preferences. You do not need 3D deflections on a race plane. Mine does about one 360 degree roll per second, and it has enough elevator to make a very tight turn at number one... any tighter would only mean slowing down or snapping a wing in half, so that's plenty. You do not need much when the plane is at speed.

freakingfast

My Feedback: (3)

On this plane I stay with one rate at all times. The Viper is so smooth and stable that I don't see the need. I use massive throws on the elevator/rudder about 7mm up & down (hence the need for extra reinforcement, you may want less) with 50% expo (JR) on the elevator, no expo on rudder. On the aileron 6mm throws no expo. I had to shim up the rear of the V tail about 1.5mm so the control surface is flush with the stab at level flight. (Less strain on the servo and less battery drain). Would a weighted prop nut (brass) work to fix the CG ? To be honest I didn’t check the CG on this plane, but it's just like the two birds before it. This plane has over 200 flights on it and I pulled the engine because the crank broke. I will CG it when it's together again, you got me wondering.
Some more thoughts: use thin wing saddle foam so the skin of the wing won't get dented and make sure the tank is isolated with foam rubber. Cut some 5mm lengths of fuel line to stretch over the connections inside and outside the tank so the lines don't slip off (it's hard to get at later with the cover glued on)