Ram air on the road

[Drunkn Munky]

Some interesting thoughts there, My NC is by no means going to be a commuter bike, Sunday scratching and trackday tool is the plan. Its currently a trackbike with mild porting but i miss riding the RVF on the road so its getting lights, a mot and some fancy bits while im at it. I just like the idea of ram air and as its been knocking about on the V4 scene for some time now some people must be running it on the road with good results. Im not dependant on the NC so i can afford play about with it getting it setup id just like to know im not heading down a dead end with trying to get it working well on the road.
I think a chat with chris at dynopro is my next port of call.

[CMSMJ1]

You are closer to Mike @ BMC mate.... His setup works and I guess both Simon_ed, me and Leon would vouch for it being the mutts danglers..

Whitchurch is not too far away compared to Runcorn!

Mike is on here as rvfhonda...PM him, he is a top bloke

[Drunkn Munky]

Cheers Mark,

I've been checking out there website and theres a few bits on the shopping list i'll be getting from there for my little project.

[Morespeedvicar]

Hiya, the size of the scoop doesnt matter, as long as its bigger than the area of a carb then your on a winner, engines only breath through on cylinder at once ish( unless it a new R1, i cant remember if a V4 would over lap much), the pressure in a ram airbox is totally speed dependant (think its sumat to do with energy in gas been related to pressure, velocity, temp and i cant remember the name of it tho).
You wont get more airbox pressure by having a bigger scoop any excess air just tumbles over the entrance if its not got anywere to flow to ( small scoop on a F1 car has to flow 800BHP of air).
i dunno why you'd need a fuel pump if could vent the petrol tank breather to the air box (nc30 have a handy vent for doing this), it would equalise the pressure.
Cheers
Ian

[Neosophist]

The New ZX10R's are an awesome machine (and a good example of Ram Air on road bike)

Kwak quote 184bhp without Ram Air, 200bhp with Ram Air (I think I read somewhere that it kicks in over 130mph)

Anyway, back to the VFR's.

I think to benefit fully from a Ram Air system you'd need a good fuel injection system, with the addition of a Manifold Air sensor you could map the ECU to give out appropriate fuel depending on how much air you have.

With the stock NC system you'd need to calculate how much extra air the Ram air is providing at different speeds then pick an optimum speed to tune the carbs / jets / needles to. The downside of this is that theres going to be a sweetspot for the ram air and anything over / under isn't going to be as good, on a track this wouldn't be too much of a problem as you'd have it somewhere near the top end speed but road riding varys so much I dont' think you'd get the most of it.

However, if somone knows of a better way to tune a road bike for ram air without FI then go for it :-)

[tk400]

Works well on ZXR400's the main thing to remember is that there are three functions of the ram air box all aimed at increasing air density.
1. Cool air ( obviously )
2. Utilizing head pressure from front of the bike ( Ram air) pitot tube style
3. Helm Holtz resonance

One is obviously beneficial over the entire RPM range
two is beneficial in an exponential relation to speed
three is beneficial at a particular frequency and its octaves

Most people understand one and two ( to a lesser extent), But Helm holtz effects are much greater in percentage at a particular RPM than ram air can ever be. This is particularly true at Low RPM, Fortunately most ram air boxes work out at very roadable frequencies. In fact it is very difficult to get most airboxes to resonate at High RPM and hence the greatest gains of a good airbox are actually only able to be utilized on the road..........

Thats my 2 cents...LOL

cheers

REgards TK400