I have repped of the forst part of the tube. I saw some improvement on thretle response. Then I thought a 4cm hole seems kind of small for a 2lit engine, so I drill a 8cm hole ( its a speaker's bass reflex tube) and saw some more (small) improvment, then, reading a post on snorkels and how cool intake air is goor I added the aluminium tube wich is 10cm diameter ( 10 cm is the "flange" of the bass tube) so here are some picks.
Evaluation? Hmmm not much at low thow it seems to rev a little faster, notisable from 3,500. I think that all you with KN filters you may see more improvment.
Here are some photos



Its not over yet since I have to relocate the radiator expansion bottle because now the alu tube is severely bented to pass and not at fuul diameter

and if you see any possible improvements ( note: I dont know to weld)

how about this: instead of running it out right nesxt to the hot radiator where there is very little room, why not turn 90* and run the tube out through the inner fender into the wheel well. may require some snipping of tin.

What has happend to your fuel mileage?? I would love the power increase but can't bear the loss of too much fuel mileage. Right now I manage to squeeze about 280 to 300 miles per full tank. This lets me get back and forth to work on two tanks a week, and I need to keep it that way.

Would something like this be ok to make out of PVC pipe?? I'm pretty good with working on that stuff.

I've heard that PVC melts with the heat. I dunno if it's true or not though. I've also heard of ABS pipe. Anyone know what that is?

Chris,

I would suspect no change in MPG unless you put your foot into it more often. <img src="/forums/images/graemlins/wink.gif" alt="" />

In general, anything that you do to the intake side of a fuel injected engine, especially before the butterfly, will effect power, not fuel economy.

A more free flowing exhaust will improve both power and fuel economy due to less pumping losses.

I did pretty much the same mod a month or so ago and my mileage increased a bit. My mod was more simplistic, though, and did not require any cotting of the air box, which can be very useful, so you can just keep the stock intake and plug it back into the air box if needed.

I meant to do a write up on it. I have some pictures to post up. <img src="/forums/images/graemlins/kewl.gif" alt="" />

ABS Pipe is pretty much the same thing as pvc and it looks the same also. I think it just has a colored strip on it or something. But anyway, The ABS pipe will last forever while the pvc pipe, over time will just deteriorate and get a little bit brittle. I have no clue what heat does to it though!!

PVC is susceptible to a slow collapse while clamped down with something. not sure if it has to do with heat or not, but my air-tube has done this. next time i clean my filter (this weekend), i'll get a shot or 2.

My intake's all metal ( and it's flexible) - no welding necessary. <img src="/forums/images/graemlins/kewl.gif" alt="" />