HPI V2 or SE Heavy Breather compact

[Matty_d]

Looking to get a little more velocity through my SE 58mm TB. Would either of these HPI V2 or SE Heavy Breather compact Air cleaner set ups help with that? 

[kd]

FWIW I have no personal experience with either style breather.  I have however followed several thread discussions in the past and have only opinions based on that to offer.    Both breathers you mention use different methods that IMO can increase velocity and as well have other benefits.

The SE Heavy Breather increases the length of the intake tract considerably which in turn adds volume. The length allows time for the flow to straighten out somewhat and in turn increase speed.  The extra volume softens the adverse effects some cams depart through overlap reversing flow back into the short manifold. These characteristic have a byproduct by increasing velocity.  Some simply like the looks or extra leg room more.

The HPI V2 takes a different approach by installing a velocity stack in the backing plate. Remember that performance through intake design is their business.    The stack gathers intake air from a wider area and therefore has more available to cram into the intake throat. The result is / can be more air and an increase in manifold velocity. This stack also has a minor lengthening of the intake effect.  This (for both styles of breather) is all providing the cam and heads can call for it and the exhaust can move it on properly. It's not so simple as just the breather.

Hopefully a few tuners will add their experience to answer your question.  There is one tuner here that has shared some results and in addition with the Boyesen Power X-Wing device. It has also shown real gains in back to back testing with other breathers in more than just more all out power.  IMO it should not be forgotten.  There also was a couple of members that did flow bench testing on several breather designs which may have dispelled some of the colloquial beliefs about breather performance characteristics.

[misfitJason]

I am not going to speak for the performance aspect of either of them. But I will attest to the differences when I had either of them on my bike.....

The Screamin Eagle heavy breather did its job. However, with mid controls on my Dyna, it was always in the way of my knee. Also the chrome on them kinda gets pitted easily.

The hpi is absolutely well made. It is lighter than the Screamin Eagle but haven't than a standard stage 1 backing plate. I like that you can run external breathers and different covers.

If I was spending the money, I would go HPI all the way

[Thermodyne]

Looking to get a little more velocity through my SE 58mm TB. Would either of these HPI V2 or SE Heavy Breather compact Air cleaner set ups help with that?

What are you running now?  The S&S Stealth works as well as anything I've seen, short of ram air setup and a tune to go with it.

[kd]

I agree that they work well and use one on my built 120.  On a dyno there was no appreciable change when the filter was removed.  How cutting edge do you want?  I have a spare Stealth backing plate that I am working on installing a bell mouth stack from a turbo intake (V2 ish) with an added X-wing type fixture).  I will then pay to dyno it for comparison to the standard Stealth I have.  Those small increases if any are spendy and IMO only worth it if you are into build self satisfaction.

[Matty_d]

Thanks for the info. I think I will stick with the S&S Stealth 1" wider I have for now till I line up a tuner and get recommendation from them.

[kd]

That's the set-up I have been using.