.12 NR and Macs 2.5 pipe length

[tmunn]

I am planning my pipe mount location and need to know aprox distance straight back to the wide part of the macs 2.5 pipe when using the .12 Nr and 50-65% nitro.

I would also take the distance from the glow plug around the header and to the wide spot on the pipe but from the center of the combustion chamber back to wide spot on the pipe would be prefered.

Thanks

 

[Zach Davis]

Terry,

7.25 " worked well for me.

Zach

 

[tmunn]

he bud what ya been up to...let me guess rigga's is that measured from the back of the header or the glow plug then forward following the cl of header.I forget where you started... B)

 

[Zach Davis]

he bud what ya been up to...let me guess rigga's is that measured from the back of the header or the glow plug then forward following the cl of header.I forget where you started...

That is from the plug. I tried 7" but it was to short for me. I know some get down even a little shorter.

Life is good. Crazy busy. Talk with ya soon.

Zach

 

[Ron Olson]

Wow, I've got some more hacking to do! Mine's at 8-1/2" right now and there isn't a whole lot left to cut off. The GS Racing "J" pipe coupler does help to get it down.

I guesstimated mine at first by looking at the shots of Rod's boat and comparing it to where it's near the bulkhead.

 

[shoboat]

Guys,

Glenn's pipe at 6.5" to start with.

You will have to fine tune the propellers of course.

Happy Holidays,

Mark Sholund

 

[gooycheese]

Hi Terry,

I know a few people running the macs pipe, I am pretty sure they are running it at about 7.5" - 7.625". I runn a AB15N Pipe and I think my pipe is around 6.625". Ohhh I dont run the muffler any more.

Paul

 

[MattHench]

When runnin the mac on the NR 5port does thier need to be a reducer put in the exit/stinger on the pipe?

 

[Neil LaGarry]

matt420 ,The IMPBA has a noise requiremerts I think 92 des.

 

[Ron Olson]

Right now I've got 3 Mac pipes, one stock except of course cut down to length, one with an internal stinger and the 3rd with one of David Preusse's muffler. What works and what doesn't will be part of the testing. A fourth pipe is Glenn's Texan .12.

 

[Rick Sowell]

Ron: I think you will be very suprised when you get to run Glenn's pipe, I have it on a jae 12 with the NR 12 and the air cooled head. running a back cut 1440 with extra pitch in it, and it still needs more prop, testing is fun, this thing is a rocket. Rick

 

[Ron Olson]

Yeah, it's gonna be fun! Seeing how I've got 2 JAE .12's I can play with a lot of things at once from props to pipes and beyond. One is already air-cooled and the other will be water cooled.

I've got a Radio Shack dB meter to check the noise and Waltr's got a Stalker so we can check the speeds. Side-by-side will be easy also as my son will drive the other. The problem will be getting it back from him!

 

[top fuel 1]

Yeah, it's gonna be fun! Seeing how I've got 2 JAE .12's I can play with a lot of things at once from props to pipes and beyond. One is already air-cooled and the other will be water cooled.

I've got a Radio Shack dB meter to check the noise and Waltr's got a Stalker so we can check the speeds. Side-by-side will be easy also as my son will drive the other. The problem will be getting it back from him!

ron, make that 3 jae .12 at the pond this year, i am building one right now should be a blast at the pond this year.

brian

 

[Ron Olson]

Maybe we can get Randy interested in one. I know that he's got a .12 laying around.

 

[Rick Sowell]

Ron: my JAE 12 didn't need any stinger or muffler, just the little bit of stinger that Glenn has installed is plenty quiet for Namba, don't think IMPBA is any different. these pipes are very good, and the boat is just plane fun to drive. Rick

 

[Ron Olson]

I'm just trying different things to see what does and doesn't work. I sure don't want ot get into the mess of muffled and unmuffled pipes and the dB limit. The internal stinger like what Glenn is using is considered a muffling device so I tried one on a Mac pipe just for the heck of it. I'm out less than a buck if it doesn't work on a Mac.