Jett tuned mufflers used on non Jett engines
 

Hello,
I've been working a finding a tuned muffler for some side exhaust engines that I have. Let me post some rpm's figures first before going into discussion.

All fuel used is a self mix 0% nitro and 20% Omega oil.

Moki 61 LS using a Jett 90 size red tuned muffler and a Jett adapter
APC 11x7, APC 11x8, APC 11x9, APC 11x10, APC 11x11, APC 12x10
13000, 12950, 12200, 11300, 11500, 10600

Moki 61 LS using a Jett 90LX size gold tuned muffler and a Jett adapter (this is about an inch shorter)
APC 11x7, APC 11x8, APC 11x9, APC 11x10, APC 12x10
13700, 13180, 12500, 11800, 9800

Moki 61 LS using a Jett 90LX size gold tuned muffler without Jett adapter
APC 11x7, APC 11x8, APC 11x9, APC 11x10, APC 12x10
14177, 13333, 12733, 12067, 9445

OS 61 FSR using a Jett 90LX size gold tuned muffler and a Jett adapter
APC 11x7, APC 11x8, APC 11x9, APC 11x10
13500, 12900, 12100, 11800
I think increasing the nitro with this engine would add more power as compared to the Moki.
I don't have a way to mount the Jett muffler to this engine without using the Jett adapter.

It looks to me that using the Jett adapter adds more tuned length to the muffler then expected.

I have a Performance Specialties Ultra muffler, but it fits the OS 61 SF only. Later I would like to run this muffler and along with the Jett on this engine (with and without the Jett adaptor).

What I am hoping is there someone that can give an insight to help me with this kind of setup? I would like to stay with a side mount muffler instead of going to a header and tuned pipe.

Is there another Jett muffler that might get me closer to the performance the Moki 61 has using the gold muffler without the Jett adapter?

So far this is just the start. I have a Rossi 60 black head that I am getting ready to run with the gold Jett muffler. In the works is a Enya 60 XF-4 GP.

Thank you for your help,
CM