KR-1S.co.uk Forum

So most of you will know bought some TZ bodywork some time ago for my latest project.

Now I want to develop a pressuirised airbox with this bike, but the fairing has two feed options for me.

What I want to know is, which one should I use?

I am leaning towards blanking the one in the nose off and routing the one from the side.

Here are the pictures, just let me know what you think.

Cheers, Ben

Side would probably be easier as routing through the hedstock can be a problem, although, the side may be more prone to damage though if you drop it

my humble opinion -not that you'll listen : don't waste time and energy on presurised airboxes, they are not worth the effort.

only above 200km/h they start to give measurable advantage, and how many times per lap do you run those speeds on a non-prodie 250

on the downside : you add more weight, make the bike a lot more complicated, more possible problems (with the need to preasure the float bowls), a lot harder to work on, especially when jetting and make it more difficult to find the correct jetting.

I would just make an as big as possible airbox and make sure it gets cold air.

I appreciate what you''re saying and might take your advice Jan. I am still wanting to run a cool front air feed to the carbs though.

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ducting airflow from the backside of your radiator is probably more a concern

if you were starting from scratch youd put a hole through the frame from the side one

the top one isnt really a good shape for catching air from the point of the fairing - but would be easiest to get a duct into the front of your dummy tank and to the top of the airbox - but your steering damper is on that side (currently) - however a single scoop asymetric design might have jetting consequences banked over left or right (high speed)

my previous thoughts were - single heads (due to thermostat) and two radiators (vertical V) with a central duct above the mudguard straight between the cylinders into the airbox

I'm with KR-1R on this one so far. I wouldn't bother with the pressurised airbox personally, but I do like the idea of a cold air feed.
Aesthetically speaking, I prefer the side duct though. Perhaps if you put a nice large and smooth radius on the left side of the opening of the top feed (looking from the front), it would be more effective at picking up air.

KR-1R wrote:if you were starting from scratch youd put a hole through the frame from the side one

That's the thing Danny, I am starting from scratch and that is exactly what I was thinking.

This is why I brought this subject up now, because I need to get any and all the fabrication work on the frame done first

I'm going to throw a spanner in the works here ben and suggest that you will get the highest static airbox pressure by designing a duct that takes its supply from smack bang in the middle of the top fairing. This would also give the most 'still' air too.

This might not be possible though with your frame/rad set-up.

There are some very in detailed threads on the rgv forum discussing pressurised airboxes. I believe they are the way to go and i would like to design one for the 3xv one day too

Dan

Do you have a link to the thread? I have an RGV forum account.

I also didn't fancy going through the head stock.

This one has alot of info in:

http://www.rgv250.co.uk/forums/index.ph ... msearch__1

Also check out barry b's building f250 thread in the f250 section.

Dan

Thanks Dan

Having read all that, I will not be making a fully pressurised airbox on this bike.

I do still intend on using the side feed to route cool air into the airbox though.

you could make an air tray like my old h***a rs 125 had and my nsr has mate

Post some pics please Si

sorry its a bit late,i wasnt near a computer yesterday mate,this is mine