Mac or Jet Tuned pipe
07-05-2009, 02:00 AM
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RE: Mac or Jet Tuned pipe
i meant the long aluminum one that goes down the fuselage. such as [link=http://www.macspro.com/tunedpipes.asp]This[/link]
07-05-2009, 05:43 AM
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RE: Mac or Jet Tuned pipe
I am glad you started this thread as I am considering the same project with some other engines. The MAC pretuned for the 61 FX seems an easy way to go as you do not have to R&D the tuning of the pipe. I would call at talk to both JETT and MAC before I made the decision and possibly buy both if I could afford them and do my own independent comparison and then I would know which one performed the best. Just because one gives better numbers on the ground doesn't mean it will perform better in the air. I have a .61 FX and wait your decision and results.
07-05-2009, 04:39 PM
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RE: Mac or Jet Tuned pipe
k well i think im going to go with the mac for now just because its is lighter that the jet in total weight and i like the look
07-20-2009, 11:27 PM
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RE: Mac or Jet Tuned pipe
I am not very experienced with the long tuned pipes, but I have been around a little bit and will tell you the difference between these and the short ones that Jett and Nelson sells (or Nelson use to sell) as I know them.
The long tuned pipe is the original. It was modeled somewhat off of what the Japenese were doing with their 2 stroke motorcylcles 30+ years ago. The advantage of using this type of pipe is that you pick the prop you want to run and tune the pipe in to that prop. In other words, you have to keep cutting the header pipe down an 1/8" at at time until you peak on RPM and the next 1/8" you cut, you lose a little. Then you just lengthen back out to the optimum with the coupler.
Sounds like a lot of work, and it is. Also instrumental in this type of pipe is to put the fuel pressure fitting at the fat part of the pipe, not at the header manifold. Jett explains this on his website.
What happened years ago (about 20 years back), a discovery was made to make a "folded" tuned pipe to compete in Quickie 500 racing. The rules stated in Quickee 500 that the muffler could only be so big and long. Nelson came out with the idea of puting a stinger inside the allowed dimensions of the canister muffer. This tricked the exhaust into "thinking" that it was going thru a long tuned pipe. This stinger pipe was tuned to a specific prop that worked well. This is true with all of Jetts and Nelsons bolt on folded tuned pipe mufflers. They are pretuned to a specific prop, and where you want the peak RPMs at.
Advantage to this, is you don't have to tune them. These "folded" pipe mufflers are done for you. Disadvantage is that you need to size the prop to the muffler instead of the other way around as described above, which I don't consider to be a problem at all.
Anyway, I prefer the short folded pipe. It is a lot easier to manage and in a lot of cases will out perform the long one.
Don't get me wrong, the long one is cool, but its tecnology is somewhat archaic compared to what Jett offers and Nelson used to offer.
If you are insistent on the long one, Dub Jett can still help you out and perhaps even sell you one pretuned. You just have to ask.
Mike Walther
The long tuned pipe is the original. It was modeled somewhat off of what the Japenese were doing with their 2 stroke motorcylcles 30+ years ago. The advantage of using this type of pipe is that you pick the prop you want to run and tune the pipe in to that prop. In other words, you have to keep cutting the header pipe down an 1/8" at at time until you peak on RPM and the next 1/8" you cut, you lose a little. Then you just lengthen back out to the optimum with the coupler.
Sounds like a lot of work, and it is. Also instrumental in this type of pipe is to put the fuel pressure fitting at the fat part of the pipe, not at the header manifold. Jett explains this on his website.
What happened years ago (about 20 years back), a discovery was made to make a "folded" tuned pipe to compete in Quickie 500 racing. The rules stated in Quickee 500 that the muffler could only be so big and long. Nelson came out with the idea of puting a stinger inside the allowed dimensions of the canister muffer. This tricked the exhaust into "thinking" that it was going thru a long tuned pipe. This stinger pipe was tuned to a specific prop that worked well. This is true with all of Jetts and Nelsons bolt on folded tuned pipe mufflers. They are pretuned to a specific prop, and where you want the peak RPMs at.
Advantage to this, is you don't have to tune them. These "folded" pipe mufflers are done for you. Disadvantage is that you need to size the prop to the muffler instead of the other way around as described above, which I don't consider to be a problem at all.
Anyway, I prefer the short folded pipe. It is a lot easier to manage and in a lot of cases will out perform the long one.
Don't get me wrong, the long one is cool, but its tecnology is somewhat archaic compared to what Jett offers and Nelson used to offer.
If you are insistent on the long one, Dub Jett can still help you out and perhaps even sell you one pretuned. You just have to ask.
Mike Walther
07-21-2009, 05:05 AM
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RE: Mac or Jet Tuned pipe
The prop depends on what you want to do with it, which air frame you want to put it in, how clean the airframe is. Give some of those parameters and we can make some recomendations. I have a Phoenix Models "Strega" P-51 that I put a PRO .61 with and Ultra Thust pipe and It runs with an 11X6 or 11X7 depending on the wind conditions.
