Effect of Ram Air Induction on Carbs?

Pipes are mostly for show

Originally Posted by Owenski

You're correct.
If you adjust the air intake, you'll need to adjust the fuel as well to maintain the fuel/air balanace.
This mixture takes place in the carb and would need to be perfected by dyno runs and jet/needle swaps - fail to get this right and the bike will run either lean or rich depending on which (air or fuel) you deprive it mostly of.
NB: IT WILL RUN< IT JUST WONT RUN WELL (as well as it otherwise could).

if you ensure the flow rate through your new airbox is the same as the standard then you wont have a problem... but that does sort of over write of the benifit of the project some what. All the best and keep us updated.

i wouldnt have thought it would have much difference to the mixture on a carbed bike as the more air that is going through the carbs the more fuel it will pull through the jets,this type off mod is as old as the hills and can also be achieved by useing a fan to stop negative pressure in the air box,husqvarna have been useing a fan to up the hp on there chainsaws for years with out any carb modifications

Any images, diagrams or sketches of this fan badger?

What course you doing at what uni Chris? Im doing Motorsport Technology BSc at Oxford Brookes. What year project is this? Looks like fun!

I'm doing BEng Motorcycle Engineering at Swansea Met...

I'm on the foundation year at the moment as I didn't go to college so we're not really being taught anything about bike this year. Just concentrating on Maths, Physics and project work, which is what this is. So at the moment I know rod all and I'm just running at it blindfolded.

How far through your degree are you?

I'm on a BEng Mech + Auto eng course right now and from my understanding You and Owenski sum
it up pretty well. How are you finding the motorcycle eng? That was my second choice in UCAS.

Not bad so far. Because I'm on the foundation year at them moment, I haven't touched any actual motorcycle engineering yet. I think they're just trying get us up to an A-level standard in Maths and Engineering Science. Recently started calculus, moments and stress and strain among other things. It's safe to say my brain is dribbling out my ear...

RAMair does make a difference to the fueling, if the jet size isn't big enough to compensate for the RAM effect it will not be able to deliver the correct amount of fuel to keep up the burn rate and the engine will lean to a point where it will start to misfiredown the straights.

[ogden]

The hoover pipes on a ZXR400 don't go anywhere, they're purely cosmetic and just clip on to the tank, rather than passing through to the airbox. They're only there to mimic the look of its larger brother, the ZXR750 , which did (I think) have a pressurised airbox.

If you want to get your hands on a bike that does this for real, your cheapest option is probably an old ZX7R. There's loads about and they're dirt cheap, especially if you don't mind it being a bit knackered. Most big sports bikes in the last ten years have used it to a degree though - it's rare to find one that doesn't have a duct directly from the nose to the airbox.

You'll need to consider the AF ratios, and consider the area in which the fuel curve peaks to ensure you don't run it too lean (as said above) at high rpm. In fact, focusing on the nominal ratio in peak performance at the cost of running rich outside of it.

What level are you looking at this, just theoretically? I'm on my phone sorry