Intake manifold

[278]

Well it was when I was missing the rubber crossover between carbs for the choke so it was running lean on one side and rich on the other. Then I took out the silencer inserts then got the shee running right and didnt put them back in while the motor was in the frame. But I put them back in now

[AKheathen]

the silencers will change the jetting some, too

[06specialedition]

So I take it you shouldn't or can't open the intake manifolds up a little. I haven't ridden mine yet, but when I put my reeds on I dremeled the holes a little bigger.......???!!!??? I started it and it seemed to run good. Did I F things up?

[06specialedition]

I assume i'll be okay....just allows more air to come into the motor....but im no expert.

[AKheathen]

I assume i'll be okay....just allows more air to come into the motor....but im no expert.

if you're talking about porting your reed cages, there is plenty of literature on that if you do a search, mostly this winter that i know. mike is a fanatic on the process, but it is a good thing to do. what were talking about here, is opening aftermarket intakes. a gradual slope would be ok, if there is adequate material to remove, but simply rounding the edges would not be as benificial. either open the whole thing up, install stuffers, or leave it alone. it will work ok no mater what you do, just not as good as it can be when done right.

[06specialedition]

Okay i get it.....You know your stuff AK! Thanks man:)

 

I just put my v force 3's in...im stoked, i havent ridden yet!

[278]

Haha yeah I like to port the cages instead of VF3's simply because VF3's are a top end type mod and the ported cages with right petals will produce the same power unless you have a top end built motor like with a drag port. I think I will port the intakes to get a gradual slope out if I can just to match it to the reeds, which I need to find a stock set so I can port them because I dont like mine, they were the first set I've ever done so the are not as clean as I want them.

 

As far as jetting yeah I know, shit my jetting going to be way different since Im going with 33 PWK's for the 4mil. Im building, plus it's aggressive dune ported instead of trail ported, then Im running pods instead of airbox, different domes, probably 50/50 race gas/premium, and the silencer inserts, it'll be a completely different motor. Im going to get a dial-a-jet though because like we talked about AK the weather up here changes so fast, you can switch jets up to 3 times a day haha... forget that, I'll just turn a screw.

 

[06specialedition]

does the Dial-A-Jet really work? i've seen those around.. you'll have to let us how hey they do!

[FireHead]

are you wondering about making them bigger, or smoothing out the edges to a curve?

obviously, they should be large enough not to cause restriction, but the air will tend to follow any gradual slopes and curves. leaving the sharp edge will allow the incoming air to stay the tract longer. the area with the highest velocity would benefit from an even match to follow, but that usually requires some major machining and/or stuffing. that being said, there is pulses traveling both directions through the reeds which can interfere with the flow more greatly when you spread the incoming charge toward the more indirect flow areas. basically, either maintain higher velocities by using the stuffers, or leave edges that do not draw the charge out of it's path. another factor to think about is the flow delay timing, which, of course will be more conducive to an rpm range.

For the most part, the geometric wizardy in the intakes only support someone stick tell-tales on an intake and sucking through them with a shop vac. If you actually do a little CFD or some math, you suddenly discover most of that stuff people are putting in there is crap.

 

As air speed reaches the speed of sound, the boundary layer increases.......... As an example, the crosshairs in the intake are about 4mm thick, when the air speed iat the speed of sound, the crosshairs are virtually ~10mm thick when it comes to the incoming air's perspective. If you stand back and look at that, then how much air are you actually putting into you engine at high rpm?

 

The basic rule of intakes is that you want all contours to match or flow smoothely together. If you can't necessarily do that then, you can use "stuffing" techniques, but you don't have to do that in today's Banshee aftermarket and you certainly don't ever need a bulls eye in your intake to do it. :geek: