HMF BB sig.series or Regular one???

[TRX450R014]

I am looking to buy a hmf pipe (slip-on) but i want to know if the bb sig.series makes more power than the regular one.
Also,is it as loud or quieter.Which is best?

[dn1911]

don't know about the other ones but i love my Ballance Pro
but i also got the full system without the quite core. its loud but i like it for know maybe later i'll add the insert