I had previously removed my entire stock air intake system including the piping behind the bumper and below the headlight. I'm not sure if this unit will fit without removing the stock equipment. The hole I cut in the fender is 4" but it could be smaller. I used a hole saw and the metal wasn't too thick so it cut relatively easy.

If you jack up the driver front of the car and unbolt the inner fender well you could install the air filter that way. I didn't have my jack with me while doing this so I was able to remove 3 screws in the front portion of the plastic under the air filter location and pull back the plastic and get it in from there. I did have to push pretty hard to get that plastic down far enough to get the air filter in.

I only have the prototype completed now. Anyone whos interested in one let me know. Since I was going to build one for me anyway I just ordered parts to make a few. First come first serve. Don't know if I will make more or not, depends on interest I guess. When I sell the prototype it will obviously be cheaper than the next two as I will be sending them out for welding so they will look a little nicer.

Here's the photos of the unit and the install.

Before cutting

4" hole for down pipe.

4" hole 2nd view

Test fit

Bottom view of down pipe

Bottom view with air filter installed

Top view after CAI was finished with 80 grit glass bead

CAI before bead blasting

CAI after bead blasting

CAI after bead blasting view #2

CAI closeup after bead blasting



Modified by qsiguy at 10:09 PM 4/27/2007

Changing things can affect the tuning and accuracy of the MAF. This might be negative or positive and vary in small rpm increments. You would need to flow bench the entire system to see any improvemnts or problem caused by resonation.

The oem air filter being close to the MAF straightening screen help dampen the acoustic reflections that occur in any round tube.
Base on years of experiments the best restriction improvement will be 4" H2O................as the oem only has 6.5" H20 restriction at 6500 rpm and it is not measureable below 4,000 rpm

At speed the oem system can make the convoluted ducts and passages almost transparent to restriction due to the pressure build up infront of condenser/radiator......................why the inlet horn was placed where it was.

Anyway oem restrictions only occur from 5,500 rpm up due to the low air flow rate.

The engineers tuned the oem system to also help 55 mph MPG.

Think twice before you second guess a Million dollars worth of engineering effort since this was a one of a kind design and no parts were cross used on any other Nissan.

Nice metal work job!

If you examine the MAF voltage output [with an oscilloscope] you will see the actual gulps of air transformed into a voltage...........^^^^^^^^^^^^^^^^^^^^^^. whose sine wave shape mimics the intake cam lobe shape and air flow since each flow is 90 degrees apart and 248 degrees of flow occurs you have acoustic over lap.

at 600 rpm =20Hz [600/2=300 x4cyl=1200/60=20] and 6000 rpm 200Hz.

The design of the resonance chambers and the OEM inability to flood may well be lost, and fo what gain, if any? Would have to have back to back dynamometer runs and accelleration runs to accurately assess performance.

Nice metal work, but seal the cut out before it starts corroding.

Discover the power of the button!

Not intending to start up another debate as to the functionality of the "CAI". It sounds good and is better then the MAF adapters that put the air filter in the engine bay, which is what was on my car before. Not sure why you assume the air filter is in a low pressure area as there is an opening in the front bumper that sends ram air directly to the air filter. I know how some of you feel about modifying the stock airbox but there are many who are doing it just the same. I'm sure the stock airbox is perfectly functional but rarely is performance the SOLE goal in designing parts for a vehicle. They have to concider economy, sound volume, and many other issues. Now I got going on the debate!

Anyhow, if anyone wants one let me know, if not I'll stick them on e-bay. Just sharing the info and my project. Thanks for the compiments on the workmanship.

If anything this might help out the turbo guys.

Very nice! I think you need to give yourself more credit. You did a real nice job. Now go bolt that turbo on and never mind the critics!

6 DAYS TILL CARLISLE!

So this is all an exercise to increase intake noise?

As far as performance, I experimented a while back with a long tube that moved my Stillen filter into the same spot as QSI's design. It worked. The longer tube did affect my torque band a bit but it didn't hurt performance compared to the stock setup. Of course, my design was not anywhere near as professional as what we see here.

A nice semi exhaust stack sticking up 10 feet would ingest cooler air.

Cold air is relative compared to the air in engine bay after flowing thru radiator and radiantly heated by engine.

A simple sensor inside the flex hose feeding TB after MAF or better inside plenum might be very instructive.

Ever notice the inside center vent on fresh air is 10F warmer than ambient?

With so many spending on sound system I've wonder why someone doesn't create one for underhood sounds.

See:
http://www.aempower.com/ViewCa...ID=20

That will put it in almost the same place as my air filter but mine is about 10-15" further back than the headlight. We don't get rain all that much and I don't drive it daily so it's not as big of a concern for me. The only other water safegaurd I will be doing is putting a filter sock on it which repels water and larger garbage. K&N makes some and I'm sure some other companies have them as well.

This system will only be on my car for a short time as I'm in the process of installing a turbo on it so I will be using pretty much the same intake pipe for my compressor plumbing. If you guys think this filter location is asking for trouble the flood gates will open when you find out that my air filter will be under the rear of the car after the turbo is installed! It's not for everyone and to each their own!

By the way, I have parts for a couple more CAI's and until I make them there are some options on how it's put together. For instance if you want it to turn go and forward behind the headlight and have the air filter installed somewhere behind or under the headlight I can do that too. So if you are interested and have the cash let me know and I can put together a custom setup for you. I'm not going into business doing this so first come first serve and I don't know if I'll ever do any more. Something more involved won't be cheap so be prepared to spend some cash. I already have quite a bit of cash in the stainless and the flange cutting and for something more complex the labor will be higher. If no one speaks up I am just going to copy what I've done and put them up on E-bay and try and get some of my cash back.

Before some of you start debating the necessity or functionality of a custom "CAI" again, don't bother. You are beating a dead horse, so to speak. Everyone's heard it a thousand times. You've stated your opinions now let the people that are interested discuss the options. I would appreciated it. Thx I don't make any performance promises, I'm just saying here it is if you are interested. Also, some can use my design and modify it and make their own to suit their preferences.

This is a car that you can get relatively inexpensively and for me it's a good platform for a project or "toy" that I can modify and not feel guilty about it. It's been paid for for years and now I am fixing it up the way I see fit. Whats the fun in leaving it stock?

There are a few others like him on the board but most are satisfied with doing safe things with their cars like new rims, aftermarket radios and muffler deletes. Those things are okay but if you want more power you have to go out and get it. No one is supporting the Q in the aftermarket. We, the owners have to do it ourselves.

Especially since the cost is less than the usual $100 per HP.

I doubt you will be able to put one of these in without at least a little cutting. I'm using 3.5" tubing to keep it the same diameter as the MAF opening and the OEM opening behind the headlight is more of an oval shape. I could get you a filter sock or find one of those water baffle devices talked about above. I think the filter socks are more than adequate as they are used all the time for filters that are subject to direct spashing. As long as you don't submerge the filter you shouldn't have any trouble if you have a sock on it.

Also, I need to know what design you are interested in, one like the one shown that I already have designed or a more custom one. I'll email you and we can discuss what you want.

No other company has ever spent the time or money [and never will again] to achieve so close to perfection.

It should be on display in every museum on Earth. School children should be taught that this is one of the highest achievements of mankind.

does it makes sense or senseless?

You could do it like PopPop did and just put the air filter in front of the OEM opening but you'll never get as cold of air as you'll get where I put mine. If you want that for simplicity that is no problem to make. I just removed my old one that left the air filter in the engine bay right there and I could always tell a power difference after the car warmed up and engine temps were high.

my father did it to one of his cars and made it look much nicer. it will seal up that gap a little more too.

nice job and effort.

So if you reduce the resistance in front of MAF by 4 or 5" H2O you reduce the lower pressure to the fuel dampener............fooling the dampener into thinking your flow is lower [lower rpm].

Never actually measured the fuel rail pressure waves but obviously Nissan would not have included a damper system if it wasn't needed to optimize something.

The air flow is not comtinuous but in pulses as each cylinder opens.

The dampener is their to help control the rail pressure drop at high flow rates when an injector opens then flows.

There are always consequences in any modification.

Visualize as the TB is opened the plenum [vacuum goes away] which closes the fuel pressure regulator in the return line and as the rpm reachs torque peak the pressure dampener opens allowing more fuel into rail.