Powernow carb mod

[vmxrider]

Just heard about this thing today, seems to have some merit in reducing 4 stroke cough off idle and some gian in low end on 2 strokes, looks easy enough to make one to try, but probably not era legal for VMX.
http://www.scaryfastracing.net/

[mx250]

Who's gunna know?

(Lozza or someone else might like to tell us if the performance is as good as the promise  )

[mx250]

BTW it looks like BS to me but I would love someone to buy it and prove me wrong.

Why BS? Because it does nothing (I can see) to speed up air flow through the venturi. In fact I would suss it to slow down air movement. If there was a enormous and obvious advantage it would come from increased turbulence or something else equally hit or miss.

But hey, prove me wrong .

[firko]

There was an almost identical gizmo produced by Skunk Works back in the early seventies. It worked in conjunction with their vortex inlet manifold of which I have fitted to my RT1 engine. Methinks it's a load of shit but I'd be prepared to give it a shot if someone bought me one.

[cappra]

I don't know if this gizmo works, but I know for a fact that these work.

http://www.thunderproducts.com/u_f_o.htm

Been using them for over five years with excellent results.

[Mike52]

BTW it looks like BS to me but I would love someone to buy it and prove me wrong.

Why BS? Because it does nothing (I can see) to speed up air flow through the venturi. In fact I would suss it to slow down air movement. If there was a enormous and obvious advantage it would come from increased turbulence or something else equally hit or miss.
But hey, prove me wrong .

Another intelligent observation MX.
 All those bike makers were so Dumb that they missed this free HP boost.

[firko]

I know one gizmo that definitely works.
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=160372062329&ssPageName=STRK:MEWNX:IT#ht_3604wt_1059

[Mike52]

I know one gizmo that definitely works.
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=160372062329&ssPageName=STRK:MEWNX:IT#ht_3604wt_1059

They put them on those little pocket bikes Firko, can you imagine?

[mx250]

I don't know if this gizmo works, but I know for a fact that these work.

http://www.thunderproducts.com/u_f_o.htm

Been using them for over five years with excellent results.

I haven't tried them but have been thinking of it (or D.I.Y.).

I would suss to actually work because see why in principle that they work - improved, smoothed, air flow through the venturi.

[VMX60]

Cappra

Most people laugh at the UFO once you have the jetting sorted which can take a while there a good unit
Brought my first one over 8 years ago
I am a believer

[tony27]

I can understand the theory behind the powernow, by using a blade that comes as far forward as the slide it possibly fools the carb into acting as though it is smaller diameter. No idea if it actually works

[mx250]

I can understand the theory behind the powernow, by using a blade that comes as far forward as the slide it possibly fools the carb into acting as though it is smaller diameter. No idea if it actually works

That what the slide does  .

The only way that the Powernow will improve power is if the 'channeled' air speeds up or smooths the air flow to such a degree that it improves efficiency of the venturi to more accurately mix the air/fuel or if in some way it improves atomising of the fuel. And the effect would have to be dramatic to have a noticeable effect to power.

The only way there is going to be more power is by more air/fuel been feed to the engine, or, what air is been feed in is more efficient by means of atomizing.

The other contradiction that has more BS metre atingling is the improved top end performance.

I'm not saying it doesn't - they are offering dyno sheets - but there's no stand out reason as a basis of their claims. I'm a 'doubting Thomas' waiting for someone to whack me between the eyes with the bleeting obvious.

[Mike52]

Sorta like that Aluminium whirley thingy advertised on telly.
Saves you fuel AND gives you more HP.
Whatever you do never let the maths get in the road of a good scam.
As for the twirley bit mixing the fuel better I thought the angle built into the inlet port did exactly that.
From the factory no less.
And what about the spark booster thing that used to be sold at the shows.
Cost about $80 but never open one or you will be real pissed.
By putting a gap in the spark lead you can increase the spark voltage.
So you paid $80 for a gap.

[sudman]

I had a Gasgas 200 with one on it when I purchased the bike, tried it with & without as far as I could tell it did nothink at all.

[Toolboy]

I had the powernow fitted in my 07 RM250 and it defiently made a difference to the mid range, i also had to go leaner in the jetting.

I would like to try on my 79 RM400

Tim