Air box question

[RoadDogma]

I like the tunability aspect of your inlet port. As far as I'm concerned more detailed info is a good thing. Hearing the results of your trials is informative and provides further discussion. Good job.

[FZRRDRZ]

Thanks.

I know most of this info is specific to my layout but I figured it might be useful to anyone trying to wrap their mind around systems like this-- I experimented with, and learned a lot of general info messing around this week.

And here’s one more thing (actually related to the reasons I started thinking about all of this)— my bike cools better.

It now heats up a little slower (which is great in itself) but what it profoundly does since the duct inlet relocated is cool down faster. When hot (at a stop light for instance) I basically had to open the bike up to air-cool it down. This meant, quickly find a good stretch to break the speed limit and wait for the temp to drop.

Now temp. red line starts to drop in maybe 200 yards at “normal” speeds.

These 400s are like little heat factories—they make it, then eat it, then make it, etc.

[FZRRDRZ]

I want to button up this thread a little ‘cause it drives me crazy when I’m reading forums that go on for pages then drop dead a post before the “answer”.

The U.S. 400’s box volume is a shave under 6,500cc (w/ filter).

I have a different filter set up from stock now, running a single UNI (UP-6245ST) in the same location as the old that displaces my box volume by 513cc. This is less then the standard K+N replacement I pulled out of there by, maybe, around 200cc, but it’s all pretty close.

For comparison sake the 2009 GSXR1000 air box holds 8500cc-- and this was referred to as “massive” a few years ago. As a compared number to the 400’s however, in engine displacement to box volume ratio, that GSXR system is pretty "small".

The GSXr ratio is about 1:8, the FZR4 is near 1:16. So, in effect, the 400 box is twice the size as the Suzuki.

Kind of amazing how ahead of the curve these 400’s are proving themselves to be.

I know how all my intake stuff is gonna run now (after a few weeks of some stupid/ dangerous experimenting) and I’ll post some photos after it’s all built.

John

[Kurlon]

The BDK snorkel needs the radiator to be notched or dropped down, BDK do a specific rad for this and racing so it's bigger volume too.

The 600's cam cover sits higher than the 400 so you can't get the snorkel in. You can cut a hole in the bottom headstock bracing though (this 3TJ frame) and strengthen around it then put in a little quarter turn scoop. You probably wouldn't need it to come any further forward than the bottom yoke, you can bastardise the snorkel with an airbox or fibreglass a base to seal to the tank or airbox cavity and keep the carbs and coils inside the box.

I don't suppose you've got pics of a 3TJ that's been modded like that? I'd love to get a ram air setup going on my machine but it's the limited room for the snorkel that's stopped me.

[Evilchicken0]

Um ... Not me. Have a look on the BDK website it shows all the bits maybe not on the same page though