Jammin JP-6?
 

What do you think about this pipe?

I own one.
It's the newer EFRA pipes 3XXX line.
It's supposed to minimize noise.
People who have compared it with other pipes said that offers a bit more bottom end than the 2047 but not as good top end although i haven't notice any low top end power on my case.
Fuel consumption though gets better...around 30-50 sec better runtimes compared to 2047.

I run this pipe on my RB .21 Killer 9. I find it similar to the JP4 pipe but gets nearly a minute more run time. The exhaust note its a lot lower than any pipe I have used but don't let it fool you. Out of all the pipes I have used and tested I put down the fastest lap times with the JP6 in my buggy and truggy. Maybe it fits my driving style better....what works for me may not work for the next guy.