Drum Charger

Dogbreath · 29 Nov 2016 at 21:35

The Drum Charger is an interesting development by Alterego Hardware that uses exhaust pressure pulses to provide inexpensive low pressure supercharging to small bike engines.

Very simple in concept and design, but requires one charger per cylinder, so limited to singles or twins in practice.

IC3 · 29 Nov 2016 at 21:41

So that little thing would boost my power from 69bhp to around 86bhp? How much does it cost?!

Dogbreath · 29 Nov 2016 at 22:05

IC3 said:
So that little thing would boost my power from 69bhp to around 86bhp? How much does it cost?!

It's literally just been announced so probably no availability right now and I;ve not seen any pricing hints yet. Obviously should be vastly cheaper than a turbo or supercharger.

If you download the PDF from the website the main downside is the physical size of the device, it's not so little! For up to 400cc cylinder the diaphragm diameter is 270mm (so overall would be a little larger) and you'd need two of those for a twin. Could be tricky to mount unobtrusively on most bikes, but manufacture is envisaging motorcycle manufacturers building the design into the airbox.

TallPaul_S · 29 Nov 2016 at 22:47

IC3 said:
So that little thing would boost my power from 69bhp to around 86bhp? How much does it cost?!

Yeah... ok then.

I'd be HIGHLY suspicious of their claims. The dyno chart shows about a 5bhp gain on an RC390, so maybe 10BHP on a 80bhp bike, in return for having 2 nearly 300cm flying saucers attached to your bike

You'd probably get the same BHP gain by having it set up with a power commander and decent exhaust.

IC3 · 29 Nov 2016 at 23:24

TallPaul_S said:
Yeah... ok then.

I'd be HIGHLY suspicious of their claims. The dyno chart shows about a 5bhp gain on an RC390, so maybe 10BHP on a 80bhp bike, in return for having 2 nearly 300cm flying saucers attached to your bike

You'd probably get the same BHP gain by having it set up with a power commander and decent exhaust.

I was sarcastic there...

No more money is going towards the SV apart from normal maintenance.

Shimmy · 29 Nov 2016 at 23:36

Sounds really interesting, shame it's quite a lump and not very practical for after market.

MowyTone · 30 Nov 2016 at 07:56

I'm already thinking up ways this can be put onto the CBR. At 150cc a cylinder that means I only need the 220mm drums. If mounted like below it might get somewhere (excuse the crude drawing)

Diddums · 30 Nov 2016 at 10:00

I can't see this taking off tbh. It's great as a tech experiment but who is honestly going to have four of those stupid looking things stuck to their pride and joy for a 10% boost in power? And I suspect that four of them with all the necessary plumbing and tweaking is probably going to get very close to turbo territory cost wise. It's also a massive billboard which effectively says "I can't afford a turbo". I hope they develop it further but as is it just doesn't add up.

MowyTone · 30 Nov 2016 at 10:57

In it's current form it might not be the best....However I wonder if this tech will get bought up by the manufacturers and progressed further. A factory fitted 15-20% gain must be something they would be interested in

Dogbreath · 30 Nov 2016 at 17:10

Button Pushed said:
I can't see this taking off tbh. It's great as a tech experiment but who is honestly going to have four of those stupid looking things stuck to their pride and joy for a 10% boost in power?

As the manufacturer states, it's primarily suited to single or twin cylinder machines, and it could be build into the airbox rather than an add-on design.

TallPaul_S said:
You'd probably get the same BHP gain by having it set up with a power commander and decent exhaust.

But then you could add one of these and make even more power, just as you could with a turbo or supercharger so I don't really see how your argument works.

The big question is whether the device meets the actual claims made for it.