I do a carbon airbox - check this thread
is it possible to get the ram air effect with an airbox ducted from nose cone. have seen a nice one on the bay and was wondering if it would work on the mnr.his ebay name is qbert_10
Ram air works well above about 150mph. Unfortunately most sevens reach their terminal velocity well before then!!! LOL...
was meaning more like an extra bit of forced induction from ducted nose cone.
I read somewhere (can't remember where or when) that an engine can easily 'suck in' more air than you can force in just by driving into the air. Unless you are going at 'silly' speeds, ie over what the car can drive at. So the ram effect doesn't actually exist in normal conditions. What you can do though, is channel as much cold air to the inlet as possible, therefore giving the engine the air feed that it can suck in.
With a good airbox/intake arrangement you will get an improvement - but the most pressure you can get will be between a quarter and a half a PSI .
The biggest gain will be from giving the engine cold , dense air - rather than the loss from feeding it hot or low pressure air .
thanks claire. the one i have seen looks nice and is small and light(c/f) he is also selling some nice carbs which may be an option.
Small isnt allways best - but light is good
I do a carbon airbox - check this thread
Ram air does work quite well, used it on the old cortina. If you use a carb it must have a float chamber that is pressure balanced from the Ventura and not the external atmosphere, otherwise the petrol will be blown out. Don't underestimate the pressure, hold your hand out the window at 70mph, it’s quite a force, especially at the front of the car
quote:
Originally posted by Mr Whippy
Don't underestimate the pressure, hold your hand out the window at 70mph, it’s quite a force, especially at the front of the car
quote:
Originally posted by daniel mason
is it possible to get the ram air effect with an airbox ducted from nose cone. have seen a nice one on the bay and was wondering if it would work on the mnr.his ebay name is qbert_10
What about these electric "superchargers" advertised on fleabay and t'interweb. I know they cant actually supercharge but perhaps they
might give a similar effect to ram-air. Anyone tried one?
Tech info link here
[Edited on 12/5/09 by sucksqueezebangblow]
Ram air can work, and does, very effectively on bikes. Might be an idea to search on the systems employed there rather than on cars.
Basically you need a large reservoir (air-box) fed through a narrow tube which is fed from a scoop. The carbs/throttle-bodies, all their breather
pipes, etc need to be contained within the pressurised chamber or they won't work.
The scoop doesn't need to be that big (look at ones on bikes) and neither does the feed pipe.
I believe airbox on the CBR is 18 litres so is quite a lot bigger than the engine capacity (600ml) - but at 9000RPM the engine is trying to consume 45
litres of air per second.
I spole to Andy Bates abput airboxes yesterday. He said you need at least 8 litres of volume ona BEC.
The ram effect isn't really worth bothering about unless you're at very high speed for any sustained period.
Intake air temperature is vastly more important though, and some 'ram' intakes may often get most of their apparent benefit not from air
pressure but simply from sourcing 'fresher' air from colder locations.
To compare, the ram effect at 150mph is loosely equivalent to an 8 degree difference in intake air temperature.
Have a read of the Kawasaki Ram Air box. I've talked about this before on other car forums. Simply channelling air towards your filter, does
not increase air pressure in the manifold.
So summarise the link, they got a 20 millibar (0.28 PSI) increase at 150mph through the ram air box. This 20 millibar increase came out to 4% engine
power increase.
I think 150mph in a kit car is unlikely, and frankly the extra 4% HP isn't going to help much against the enormous drag.
Kawasaki Ram Air trials