Fuel economy better with an exhaust?

**ducatilover** · 17th May 2011, 14:24

Originally Posted by bogan

but I reckon solenoid controlled intake valves with exhaust ports at the bottom of the stroke, and a supercharger

They are doing good things with multipoint injection and stratified charge ultra lean burn I hear.

Can the engine block be matt black?

**aprilia_RS250** · 17th May 2011, 14:30

Originally Posted by superman

Something like a turbo for example increases efficiency with no detriment to fuel economy.

Hahaha, stick with your 20hp ninja my man.

**superman** · 17th May 2011, 16:13

Originally Posted by aprilia_RS250

Hahaha, stick with your 20hp ninja my man.

Only 1.5 years till I'm allowed my dreeeeam bike

**tigertim20** · 18th May 2011, 00:59

Originally Posted by racefactory

I can't quite get my head around if carburettor bikes are better on fuel with standard exhausts or after-market ones. Who knows for sure?

Of course there is a weight saving from removing the stock item but in terms of flow they are very restrictive and would hamper efficiency right? Less efficiency means more fuel consumption? If a free flowing can is put on it should make the engine more efficient but then again you have to jet slightly richer making the bike use more.... so I'm confused.

'Who knows for sure?'
Well each bike is different. But generally, if you are replacing the exhaust to get more horsepower, usually more horsepower means more fuel, so good chance your economy is going to go down. Not always, but good chance.

In terms of increasing flow, more air will also mean more fuel, unless you forget to rejet your carbs to match the new exhaust, in which case, youve probably just wasted a bunch of time and effort anyway