ram air boxes

[stevegti2]

hi ive been looking at bike tuning for the last few weeks now and it all seems to come back to one thing with these old bikes. a ram air system was wondering what people are using and the gains they have got from them.

also anyone using the ones on ebay ive noticed two different ones on there one which looks of a very good build quaility and one which looks like something a could make in an hour lol and costs more

cheers steve

[extonyg]

i dont really no much about the ram air boxes, i dont run one. are you looking for one for your road bike?or a track bike?
i think most people dont use airfilters in ram air boxes so might not be best for on the road and also im pretty sure the ram air only works above sort of 70mph or so i might be wrong.

[stevegti2]

yes its for my road bike and yes it does only come into effect at about 60-70mph once wind speed picks up its basically free boost im just intrested in the box designs and power gains etc on these engines


steve

[will#224]

None of the ram air boxes i've seen have the option to run an air filter. I reckon the best engine would gain reckon 8hp tops. With an air filter its probably not even worth the cost. Where would you put the head light? plus you have to modify the radiator.

[stevegti2]

ah ok 8 bhp is alot of power on a 60bhp engine i may just run a thin mesh on the intake of the box or a set of tights lol think i will have to look into making something up

steve

[Davw]

Unless you intend to use it on track then I wouldnt bother. The two differnt "designs" both need mods to the radiator, the holes in the tank plastic then need filled in, the coils need moved as they snag the air intake and carb balancing becomes a pain as the air box blocks the access to the balancing ports. The fuel choke, tickover adjuster, crankcase breather all need accesses into the airbox so depends how you are with DIY. Oh - one final thing - you wil have to ditch the throttle close cable as where it connects on the carbs snags the airbox - or at least it does on the AMS box - not sure about the RMKD design

There is no way that you will get 8bhp from the ram air alone. For that sort of gain you will need engine work (increased compression) and carb mods. To set it up properly you will defo need a run on a dyno.

As you can see - this is a load of dicking about if you intend to use it only on the road.

[jake]

I would't on a roadbike myself mate.
Like said, you dont run a filter, but thats fine on a racebike because they are stripped every year, sometimes more frequent!
A good one gives great power gains when coupled with good bellmouths.

[stuzx4r]

hi, just fitted an AMS airbox and bellmouths, showed a 7 bhp gain on the dyno . thats a big gain for any 400.

however as others have said you do need to move your coils(on l models) and drop the rad down.
its a great mod' for a race bike but is it worth all that work on a road bike? only you can make that call.

Good luck.

[rmkd177]

Good 'sales patter' that stu... 10% increase from an aftermarket airbox ??? Hmmm
Sure that wasnt a bigbore kit you fitted

[jake]

Ive had similar gains with a standardish engine, with similar kit copy airbox and plate bellmouths.
Altho, just about every standrd airbox ive come across has heat deformed bellmouths that no doubt must be a factor.
speaking of bigbores rmkd, its the honda boys on the greybike forum with the +2mm omegas they are buying that need the poke in the eye

[rmkd177]

I hear what your saying...but 'Ram air' boxes dont ADD 7bhp....especially ones that are designed wrong with a large funnel front and then reduce down....that system gives 'high speed' and 'low pressure' (air) when you want the opposite...for the very small 'turbo effect'..........
However....i appreciate that a badly set up bike with a standard air box ect...when removed and a ram air box added and set up correctly could add...well...'how longs a piece of string'
Back to back...a well set up engine and then add a ramair system and set up well again will not gain 7 bhp....3-4 bhp max
and this takes some showing unless you have a Dyno with the full ram air fans...not just cooling fans as most dynos have.
Played around with these things for 10 years now and tried most of them at one stage or another and had the best dyno and dyno man to help develop them...Mark from Hobbsport at Keighley...now retired and cruising round the world in his yatch...an absolute genius.
Jake those honda men can have those 2mm pistons...they need them...when they get them up to 75bhp we might start worrying and may have to push the Kwaks to 85bhp and on standard bores.

[AFM327]

So if one were to be in the process of making an extension from the kawi ram air kit box to the front of the bike should the size be the same front to back, smaller at the mouth getting larger as it connects to the airbox? Enquiring minds want to know.