Hi All, 

Ryno , basically , if when u open it up wide and give the motor a rev out under load. if you hear strong sucking from air cleaner, well thats a restriction as the air is being drawn from out side air cleaner you want in all inside so no restriction. but impossible with these set ups and a bit of restriction ok. increase air space inside air cleaner or increase air space inside manifold if you can & that helps, the foot ball cover restricts some out side air flow too.

When I crack it wide I hear  deep roar from the filter area, I think I'll just put on a different cover instead of the football. Thanks Krash. 

Try running it without any cover at all, that’s how mine is but mine is 60mm TB and larger AC filter to suit it

Yeah was thinking of that or one of the cover that just cover the screw hole. Would it affect the tune much? I wouldnt think it would be drastic enough to need a retune.

Depends how much you are chasing. The tune is made using the parts in there at the time. If I recall correctly, your tune was questionable anyway with that pretty big torque dip.. that shouldn’t happen. I know 2 into 1’s are known for it but a decent tuner should be able to get rid of it unless the components are very very not compatible with each other (which is the key, the parts have to suit each other)

Yeah Ive looked into that pipe and it well and truely known for a dip below 2750 and bit makes up for it past that. It's something that you need to live with with the pipe I guess. 

I would get a better pipe not live with it lol 

If I could afford it I would consider it, but I do love the sound. It was either this for $500 then I could get cams aswell, or just a rhinehart 2 into 1, which at $1500 is alot and which still wouldnt have stopped the bike pinging like it used to. Plus I was under the impression any 2 into 1 is better than the short shots I had. Also the thunderheader is meant to be a good performing pipe, some setups just get the dip, unfortunately I'm one of them. I still have over 80 ft pound at worst which is good enough for putting around town most the time. I'm just looking for air cleaner covers now to freshen up the look. Just wasnt sure if the stock cleaner and case would have exagerated the dip or been known as a shortfall in my setup. I daily ride so I've never been chasing numbers just a reliable bike.Thanks for the advice, it all helps me get a better bike in the end.