Soon2BMaxed

ok everyone's theory on why top end sucks with a CAI seems to be that the tubing is just too long so i got an idea. after looking at my friends PR cai in his spec-v sentra i noticed that his filter sits RIGHT underneath the hole we had to cut. on my maxima the piping sat a few inches below the hole (almost low enough for the filter to touch my splash guard) so what if i was to cut a few inches off the end of the pipe? has anyone tried this? i could make it quite a bit shorter so it sat just under the hole like my friend's does. whats everyone's thoughts on this? i might try it later today.


Trevor

BBaker025

iTrader: (1)

Try it!

Mishmosh

iTrader: (3)

On my PRCAI, there is probably no more than 2 inches of pipe into the fender well... Not worth ruining your piping. Just try midpipe hybrid to see if you like that better.

Chebosto

iTrader: (1)

its not really how long the tubing is, is the way the tubing is shaped.

think of air like water flow. it's curving up the pipe to get to the TB..

obviously if it was a straighter path, air could accelerate faster than curving all over the damn place.


having the fiter up higher the hole wont help.

its about eliminating that particular bend from PR's cai lower piece...



no way really around it, unless your air from the TB goes straight down into that hole where 5speed have all that space to put a longer straighter piping and just have a bend at the TB, but eeven then, you would want your air to be as straight as possible BEFORE the TB so that the air doesnt have to bend/loss velocity.

gtr_rider

iTrader: (50)

get a supercharger..

Street Reeper

Triming a little off your pipe might help a little. I think that if you can find a way to straighten the CAI a little more, rather than the 90 degree bend at the fender, that this would pay off even more.

As far as the hybrid set up, this is just a short ram intake. These intakes where replaced by pop chargers because if your getting hot air from the engine bay you might as well not have any restricitive piping, they were also replaced by CAI to get cooler denser air. These hybrid intakes seem to only be a hybrid of the negative properties of pop chargers and CAI, which are heat from the engine, and extra piping. Also the midpipe used for these hybrid intakes was designed to be a part of the CAI, it has not been R&D for use by itself. A true hybrid would be a pop charger fed with outside air from a fabricated feed pipe. Keep working with the CAI.

Soon2BMaxed

bah! i agree with cheston. and just looked at my pipe again and realized that there was less piping there than i thought so cutting it wouldn't have done anything for sure anyways. oh well, my hybrid works fine, i was just bored and looking for something to do. this is the first night this week that i dont have a paper to write.

Trevor


p.s. i did finally make a template for a heatshield though.

Street Reeper

I agree as well as stated in my post. However instead of a bend at the throttle body (like most short ram intakes) I was thinking about a very gradual bend that extended from the throttle body to the fender well. There is a company in Dallas that makes carbon fiber intakes, after I get the diminsions I hope to have one fabricated. But i would really like a real hybrid intake (you know how I feel about the current ones) with the popcharger and fabricated feed pipe, but the dimensions may be just too large for the feed pipe to to not be restricitve, and provide only cool air.
However, if their are any engineers, how big would the pipe have to be to not be restrictive for the stock throttle body, I would think that a throttle body can only suck so much air, so i would want this air to be as dense as possible, as in a CAI with piping large enough to comfortably feed the dimesions of the throttle body. Any thoughts?

Nismo

iTrader: (18)

not shure if this applys to intakes as it does exhausts but would having a larger diameter pipe decrease air velocity? If theres a way to tune the piping to a certain size to maximize the velocity and also reduce air turbulance.

Nismo87SE

Try running a 4in pipe instead of 3in, that should increase topend power but lower low-midrange gain.

Street Reeper

What about a resevoir in the pipe. Comptech or Mugen makes an intake for the s2000 with this design. It was a 3 inch pipe with a resevoir (bubble) close to the part that conects to the throttle body. This I would think would act as a velocity stack, but i wonder what it's characteristics would be like on the dyno, any thoughts?

poorcollegeboy

if you cut the tube, you'll lose a little of the low end...

intake performances throughout the rpm band depends on the tube length. yes, the temperature is a factor (somehting like for every 10 degrees cooler is 1% gain in hp), but tube length is the ultamite factor. cai suffer in the high end b/c of the air whipping around the corners of the tubing -> turbulence. pop chargers suffers in the low end b/c there isn't enough tubing for the air to be readily (unrestrictively) "stored" and also to gain velocity into the manifold. that's why frankencar has the best design (for now..... no, there is nothing up my sleeve). long straight tube.... that's all it is. nothing special (sorry steve).

no i did not pull this out of my *ss. there is fluid mechanics analysis behind this... but if you want to try something out in your homes... just take a long hose around the house blow into it...now blow into the same tube with the same bend with something like a leaf blower.... you WILL feel the decrease in air flow coming out the other end. peace.

T-bone

iTrader: (1)

has anyone figured out a way to get a thermometer in where the intake meets the throttle body to see check air temps of the various intakes (at different speeds)?

Nismo

iTrader: (18)

I think radio shack has this digital one that has a wire connecting to a probe that you can stick in places.

Mizeree_X

iTrader: (9)

Being an engineer, I was thinking about a plan similar to the VI manifolds -- have a CAI with a hole cut in the side of the pipe. Put a Pop charger there. Have a piece of metal on a track slide the hole open and closed, rigged to an RPM dependent switch. Mad $$, but would probly look cool, anyway

Shannon and Ian

iTrader: (1)

We have a few threads about this on the SR20DEforum too!

http://www.sr20deforum.com/showthrea...threadid=26568

Nismo

iTrader: (18)

I had the same idea once only It was a manual version with a pull rod that controls the cut out valve welded on the top of the pipe.