Russ Posted July 17, 2013 Posted July 17, 2013 which one and why.......... maybe "pros and cons" for each machine might be more betterer ( smirk )
keith.b Posted July 17, 2013 Posted July 17, 2013 Hi, I'll start this off for you, I only have about 80 hours total time, all in Jabs. I prefer the 170 over the 160, to me seems to fly better with the bigger wing. Landing can be more challenging with the 170, it can float along way if you round out too high..... Regards keith
JabSP6 Posted July 17, 2013 Posted July 17, 2013 Russ The J160 was nicknamed the fatboy and was produced to accommodate comfortable flying for the bigger people like myself at 6ft and 100kgs. The cockpit is slightly wider than the J170 so if you are after room then the J160 is the pick. The empy weight of the J160 is around 320kgs and the MTOW is 540kg. The J170 is slightly narrower in the cockpit and has longer wings as Keith has mentioned which can be a little tricky in windy conditions but if you get the approach speed right use the correct technique you will be ok. Both models have 135ltr fuel capacity but the J170 is around 340kgs with an MTOW OF 600kg. So if you are after extra take off capacity then the J170 is the choice. The cruise speed of both models is 100kts and both use around 15lt/hr and 2850rpm with the 4cyl 2200 motor. Both Models are great so it is up to you want you need in a plane. Good luck mate. Safe Flying JabSP6
Gnarly Gnu Posted July 17, 2013 Posted July 17, 2013 Yeah, 170 is better overall IMO - with a couple of hefty Gnu's on a warm day the extra climb rate of the longer wing is nice & there doesn't seem to be much if any trade off in cruise speed.
nong Posted July 17, 2013 Posted July 17, 2013 RussThe J160 was nicknamed the fatboy and was produced to accommodate comfortable flying for the bigger people like myself at 6ft and 100kgs. The cockpit is slightly wider than the J170 so if you are after room then the J160 is the pick. The empy weight of the J160 is around 320kgs and the MTOW is 540kg. The J170 is slightly narrower in the cockpit and has longer wings as Keith has mentioned which can be a little tricky in windy conditions but if you get the approach speed right use the correct technique you will be ok. Both models have 135ltr fuel capacity but the J170 is around 340kgs with an MTOW OF 600kg. So if you are after extra take off capacity then the J170 is the choice. The cruise speed of both models is 100kts and both use around 15lt/hr and 2850rpm with the 4cyl 2200 motor. Both Models are great so it is up to you want you need in a plane. Good luck mate. Safe Flying JabSP6 I reckon the cockpit is the same width. Prior to the J170D upgrade, the fuselage for both types is the same part number, from memory. Those short wings on the 160 are much more useful hangarage-wise. 1 1
jetjr Posted July 18, 2013 Posted July 18, 2013 Id argue short wings are a little quicker, and they are WAY easier to live with hanger wise. Wings are much shorter. The MTOW has nil to do with wings or climb rate as far as I know, one just climbs at more AOA
facthunter Posted July 18, 2013 Posted July 18, 2013 Bigger span wings would have to affect the cruise speed. ( less effect when you are heavy) Getting out of short strips on a hot day would be better though. Nev.
Acky Posted July 18, 2013 Posted July 18, 2013 170 wins in my book. Identical fuselage to the j160, but longer wings. Better short field performance, much better usable load, however, it will float along the runway a bit if you're a few kts too fast on shirt final though. From the 160's and 170's I've flown the 170 seems to be 4 or 5 knots slower. 1
jetjr Posted July 18, 2013 Posted July 18, 2013 I think the wings on J160 are the same as J200 and J400, approved to 700kg in Experimental. 125kts with 3300 and decent prop @ 2850rpm, easy cruise 128+ with a few more rpm Longer wing was to decrease stall 45kts @ 600kg "clean" for over seas markets. However short wing stalls @ 48kts with 700kg with flaps so SFA difference under local rules. Jab believe they didnt loose much cruise with longer wing - different profile altogether. Was some strut problems though and max manouver speed dropped a lot. 1
facthunter Posted July 18, 2013 Posted July 18, 2013 You will certainly float if the speed is too fast. The plane would probably be more gust sensitive too as there is always more lift available quickly with a bigger wing. Might be slightly less easy to manage in a crosswind also. Nev 1
AVOCET Posted July 18, 2013 Posted July 18, 2013 I think the wings on J160 are the same as J200 and J400, approved to 700kg in Experimental.125kts with 3300 and decent prop @ 2850rpm, easy cruise 128+ with a few more rpm Longer wing was to decrease stall 45kts @ 600kg "clean" for over seas markets. However short wing stalls @ 48kts with 700kg with flaps so SFA difference under local rules. Jab believe they didnt loose much cruise with longer wing - different profile altogether. Was some strut problems though and max manouver speed dropped a lot. Pretty sure the wing profile is NACA 4412 on all jab wings . The 230 and 250 wing are 4ft overall longer than the 200 wing . 1 mtr cord including flap for the 230 & 200 4ft cord for the 250 wing The 230 has longer flap & aileron The 250 has same length as 230 but is proportionally wider . 250 wing is not an option on j160/170. Cheers . Cheers
Thirsty Posted July 18, 2013 Posted July 18, 2013 Our 160 weighs 304 kg according the the placard in the cockpit. I notice the jab web site says its 320 now with the 170 20kg heavier. At 304 kg we have 236kg useful load with the 170 getting 260kg so not a huge difference.
Keenaviator Posted July 18, 2013 Posted July 18, 2013 Bigger span wings would have to affect the cruise speed. ( less effect when you are heavy) Getting out of short strips on a hot day would be better though. Nev. Depends on the relationship of parasitic drag to induced drag. At any given speed and load a long wing will have less induced drag than a shorter wing but more parasitic drag and vice versa. Laurie
facthunter Posted July 18, 2013 Posted July 18, 2013 Most planes IN CRUISE unless they are very high ( near service/absolute ceiling,) have surplus wing capacity and more drag than if the wing was smaller. The higher aspect ratio is more efficient, all other things being equal, but washout helps the shorter ones. Nev
Keenaviator Posted July 18, 2013 Posted July 18, 2013 No discernible washout in my UL450's wings. Just that introduced by recommended rigging of flaps and ailerons.
biggles Posted July 18, 2013 Posted July 18, 2013 With the shorter wings the 160 has a higher wing loading ,giving a less bumpy ride compared to 170. As previously stated , the 160 and 170 fuselages are identical . Bob
Russ Posted July 18, 2013 Author Posted July 18, 2013 Ok........good read here further matters........the 4 cyl engine, mods..........replace valves and guides with different type/brand, cut end off muffler, remove some baffleing ( more free flow ), reweld up, revamp air flow into/out of engine compartment.... hanger goss is telling me that these mods do wundrous things to the engine ...........and use a different engine oil other than that jab recommended, ( one in particular to use, but changing to it, is not a matter of just pouring it into the engine )......which oil ???
fly_tornado Posted July 19, 2013 Posted July 19, 2013 There are a heap of 160s and 170s for sale on the RAA market. You can get into a Jab from just $5k
AVOCET Posted July 19, 2013 Posted July 19, 2013 Ok........good read herefurther matters........the 4 cyl engine, mods..........replace valves and guides with different type/brand, cut end off muffler, remove some baffleing ( more free flow ), reweld up, revamp air flow into/out of engine compartment.... hanger goss is telling me that these mods do wundrous things to the engine ...........and use a different engine oil other than that jab recommended, ( one in particular to use, but changing to it, is not a matter of just pouring it into the engine )......which oil ??? I think unless your in a position to make a decision yourself , these "so called "mods ,it's all going to end in tears , and acute wallet drain ! Danger Will Robinson Beware of hanger talk . Cheers Mike 2
Russ Posted July 19, 2013 Author Posted July 19, 2013 Just tossing it out there guys......... How about jabs on mogas now, as "Ok'd" by jab
Thirsty Posted July 19, 2013 Posted July 19, 2013 We went from avgas to mogas in our 160. We were getting lots of rubbish buildup on our pistons after only a few hours from new and we were often getting crap under the exhaust valve meaning bad leak down figures. After going to mogas no more problems, good leakdowns and no more issues though it is harder to start and the cabin now smells of fuel! We run our engine at 2900 most ofthe time and have since new so we don't baby it. I won't be going back to avgas. Also on wing loading, the wing loading depends on the weight of the aircraft vs the wing area. With the 170's higher mtow the wing loading between the 160 and 170 probably isn't that different at mtow. 1
facthunter Posted July 20, 2013 Posted July 20, 2013 912' get valve sealing problems with avgas, because they run too cold in the head area for the tet lead to work properly. I can't see why there would be more build up on the pistons with avgas. I have used it in aviation motorcycle and car racing and the fuel seemed to burn cleanly with few deposits. Other things like dust and lube oil, deposits on the combustion chamber surfaces, sometimes. Mogas has certain quality control problems that bulk avgas doesn't and as explained recently on this forum is much lower in real octane values. Nev
Thirsty Posted July 20, 2013 Posted July 20, 2013 Yep understood about the quality control issues etc but we just never had much success with avgas. After going to mogas all our leakdowns problems went away so take from that what you will. It's definately more convenient using avgas though. Where we are avgas is about 60 cents per litre dearer as well which helps offset the hassle of using mogas :)
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