Parts bought + Price-From Home Depot

1-7ft 2 1/2" shopvac hose. $16.96
1-Flex Coupler-3" to 2" conversion $7.48
1-Util Nozzel $5.96
1-Flex Clamp $0.69

Total: $33.58 with NY state Tax at $0.008

What I did was cut the shop vac to 15" while putting the rough edge in the air box.

I then put the hose end on the extension part(I'll have pics tomorrow. looks perty good) to create like a scoop somwhat like I saw.. hmm i think it was umd's site?? Anyway someone did.. Well I cut a hole out of the splash guard. sniffle sniffle.. but it was the only way to do it right.. I then put the extension through the hole and the flex clamp around it.. Then fitting the hose into it.. Can barley see it..I then screwed it to the Guard so it would stay up..Can't even see it..

Pics coming soon

 

do you feel the increase hp?

 

Hard to tell ya know?? I would have to say yes. I think my amsoil filter is restricting to much.. Im wondering... what if you had a high powed fan taking air in?? would that be better? Also.. do I have to worry about things flying up?? I def. Know Im going to radio shak tomorrow to get some plastic so I can cut a cover out for the nozzel.. I dunno Ill have pics tomorrow.. you tell me if it looks queer

 

a high power fan will make you loose power. It creates a turbulence affect. Just like Tornado air. This is bad and is not recommended. Also, having the the Vac tube pointing to the front of the car will also increase turbulence, reduing power.

I might be wrong. Anyone can correct me.

 

??? arggg so what shall I do? I saw some other cut a hole for it.. So I was thinking why not gather more air with the scoop? Damn now I cut that hole... What shall I do? cover up the hole and route it just poitning down?

 

cool stuff I think it was Paul2kGXE's site that you saw the OSCAI with the hole in the splash guard. I have heard that the Amsoil filter is a bit more restrictive than the K&N. So, maybe if you get the K&N, you will have better results..

 

Isn't the ram-air concept based on aiming the intake towards the front?

 

Roger that.

 

You raise an interesting question, Green_2. Follow along with me here, everybody. And understand that I'm not an engineer. I'm just trying to think this through logically.

The idea behind ram-air, it strikes me, is to increase the air velocity in the intake tube, thus making more air available to the engine. First of all, in order to have any effect at all, the vehicle would have to be moving pretty fast. In addition, you wouldn't want to introduce any restrictions in the air flow. So you'd want the direction of the air traveling in the ram-air tube to be as straight as possible from the point of entry to the throttle body. How am I doing so far?

Now if you have a tube that is running perpendicular to the air flow as in the case of the OSCAI, introducing a ram-air system becomes something of an impossibility. Even if you install a scoop pointing in the general direction of the air stream, all you're really doing is creating a lot of air turbulence at the point of entry. The air will want to travel in one direction (front to back) but the tube will try to force it into going another (bottom to top). So it seems to me that putting a scoop on the end of an OSCAI actually interferes with the velocity of the air in the tube, thereby reducing the OSCAI's effectiveness. (OMG! He's lost his mind!!! )

My contention, and I have absolutely no evidence to back this up, is that you're better off keeping the OSCAI out of the air stream entirely. I've got mine sitting on the inside of the splash guard for that very reason. By doing that, I believe I'm minimizing the amount of air turbulence at the point of entry and, if I'm correct, increasing the velocity of air in the tube as a result.

Does that make sense to anyone besides me? Or have I been smoking too much bamboo again?

 

Well, It think ram-air is not about velocity...it's about air pressure. The idea is for the force of air (while traveling at high speeds) to pressureize the air that is going in...and thus it would be acting as a mini-super/turbo charger.

As for turbulance, whatever turbulance in the air I would presume would "calmed down" once it passes through the air filter. Further more, more turbulanave would equal better mix of fule and air...which would also help with performance.

Any engine/performance experts want to comment on this??

 

Good points. So I guess the question becomes whether introducing a scoop on the end of the OSCAI increases, decreases, or has no effect on the amount of air pressure in the OSCAI tube when the vehicle is in motion.

I'd also like to hear from engine/performance experts because it's pretty clear I don't know what I'm talking about.

 

I think the main thing to consider as far as building a beneficial intake is to create positive boost with minimal turbulence - I'm not an engineer either (although I do have almost 3 yrs of electrical and mechanical engineering course work)- but I think intuitively this makes sense. The motor is sucking air in, exactly like a vacuum, so if you have more air readily available at the point of intake (readily available meaning with minimal turbulence) by way of positive boost, or positive pressure, then it's going be easier for it to suck in more air. Check out the link in this thread - It's long but it explains this point very, very, well:
http://216.122.219.59/forums/showthr...threadid=35172

With this in mind - creating positive boost or pressure while minimizing turbulence - I came up with yet another variation on the OSCAI theme. I'd previously tried the shop vac intake route where you cut hole in the splashguard and have a shop vac scoop sticking out and pointing directly forward. Although it did work and resulted in better acceleration, the car at times was herky-jerky and not accelerating as smooth as it did before. So here's what I tried next and have been very happy with the results:

http://images.cardomain.com/installs...07_19_full.jpg

The screen not only protects from leaves ect but it straightens out the airflow and creates a small amount of positive pressure as well. You can see that the screen members are tall and narrow, if you look at it head-on from the front of the car it looks almost like a solid piece of metal. Anyway, I think this creates a small amount of positive pressure similar somewhat to the way a spoiler, by resisting airflow and thus creating positive pressure above the car, provides a small amount of downward force. I also didn't attach the OSCAI directly to the screen but let it hang a couple of inches above it - I think this further serves to minimize turbulence. I hope this makes sense but bottom line I now have the same or better acceleration, and much more smoothly delivered.

 

The car has ram air and cold air intake in stock form. The problem is that the intake tract is restricted where it passes over the radiator so under very high demand conditions there is probably a vacuum behind the restriction. OSCAI or any other cai removes or bypasses this restriction so WOT high rpm performance will be better unless the air taken in is hot (like from inside the engine compartment). BUT - most of these systems will not give the positive pressure of the stock system, adversely affecting tip-in behavior, and possibly top end power at speed. Turbulence at the intake is much less an issue than pressure. Maximum air to the airbox is the goal. A scoop facing into the airstream would be the most effective overall, the trick is finding a good place in the airstream to put the scoop.

wdave

 

After Driving my car for 2 days now I def. think i found a sweet spot with my scoop.. my scoop is very small, So I think it minimizes turb. The tube to the intake is straight also. I def notice an increase in power. Wish there was a way to dyno.. I dunno I'm leaving mine on.. Though I am going to radio shack today to see if I can make a remote controled cover for it. If I cant I'm just going to make a removable cover for it.

Im just very worried about water right now..

 

wadve- with Oscai we still have the stock scoop in addition to the OSCAI so I don't think there's any loss in positive pressure. I do think that turbulence is more of an issue because you have two airstreams meeting within the airscoop close to the airbox. You have an airstream from the scoop opening itself and another stream from the OSCAI. I did some basic testing with a homemade manometer when I first installed my OSCAI. I hooked up the airbox side of the scoop to a vacuum cleaner and insereted the manometer sensor where the air temp sensor opening is since this is close to where air enters the airbox. There is quite a bit of turbulance, meaning constant pressure variations at this point, when both streams of air are available (scoop opening and OSCAI) as compared to having just the scoop opening. With the just the scoop opening as the single intake source the turblence is very minimal but the vacuum is greater (the water rose in the manometer). Meaning you have less air going in, but it's flowing smoothly. With both intake openings available you have more air but flowing less smoothly - so minimizing turbulence at the OSCAI source takes on greater importance.

But in "real world" terms the differences in driveabilty regardless of where you have the OSCAI scoop located are not that noticeable - I just happen to be a somewhat touchy about having as smoothly accelerating a car as possible and think for me, I've found a good combination of driveability and acceleration with my variation.

 

So do you have yours right on the splash guard? I like that Idea because then I wouldnt have to mess around for the scoop cover.. but then again... If you have the scoop sitting on the splash guard where are you getting the air from? Will it really work that good just sitting there? I would think it would need air rushing in it.. Keep in mind.. Where I might be somewhat of an expert with computers.. I am new to cars... I would think keeping the tube right there would pick up engine heat..

Thanks!

 

What about experimenting with a "turning vane" to direct the air flow coming up through the CAI to be parallel to the air flow entering through the stock scoop? I'd expect that such a mod to the interior of the ducting would cut down on the turbulence and reduce the losses involved in getting the CAI air to make that 90* turn at the tee junction before entering the filter box (they are used in building HVAC system elbows for a reason). You might have to relocate the IAT sensor.

Norm

 

You have to remember flow losses too...the more tubbing you run, the longer the distance the air will need to travel...

 

There's plenty of air flow around the splash guard and the tube is low enough and near enough the front of the vehicle that it shouldn't pick up engine heat. The splash guard itself should act as a windbreak, thereby minimizing turbulence and helping to prevent foreign material from entering the tube opening.

All in all, I'm still not convinced that there's anything to be gained by placing the OSCAI tube opening outside the splash guard, particularly in light of sleepermax's revelations.

 

Here is my version of the OSCAI. 4" aluminum dryer ducting with a 4" aluminum "L" bracket and a rubber 3"-4" adapter with metal tightners. The "scoop" / intake is sticking out of the splase guard about 1". It goes straight up into the bottom of the stock intake with the help of the 3"-4" adapter. I really niticed a difference performance, both low end and high. As for water, I have now driven thru a couple of Houston "monsoon" rain storms over the last 2 weeks and have checked for water after each one. The air filter was not even damp. More dirt, but no dampness. I figure I will tap out the dirt on my air filter every time I wash her, just to be on the safe side. Even if I was (never in a million) to drive thru standing water deep enough to cover the OSCAI intake, there is no way the engine would create enought of a vacume to suck any amount of water up a 4" conduit, especially with the original intake intact. Even at 65-70mph in the rain, the air filter was not even damp. I will have pictures as soon as they are developed.

 

DeaZal - The Oscai scoop is about two inches right above the screen.

Norm - I thought about that but it's tough to come up with a functional and beneficial homemade version of what you're suggesting. The ideal thing would be for NISSAN to just make a much wider stock scoop opening. Because, given it's position pointing directly forward and just above the top front grill opening, there is a ram air effect taking place at the mouth of the stock scoop and since the air is really almost entirely coming from outside the engine compartment, heat is not much of an issue. I think the 2K2's may come with a wider scoop, check out the first line in the fifth paragraph of this link ("2002 Maxima's exterior has been enhanced with a new front grille and aggressive front fascia with large air intake"):
http://www.nissannews.com/cgi/frames...727162526.html

So if this is the case I may try swapping out the scoop with a 2002 as long as it fits.

 

With all this concern over the turbulence at the air intake source for the tube, doesn't the shopvac tube create additional air turbulence going to the airbox because of it's 'ribbing'?

I figured if the tube is, say a PVC pipe, it may perhaps make a difference

 

Did anybody ever think about putting OSCAI pipes instead of the fogs...that would be the coolest setup but you are loosing the fog lights...but then it will be a good ram air right?

 

Here's your ram air


The air flow is smoothed out by the filter and MAF tube. The 2nd source of air helps. My track testing has proved it. I think the cone style intakes help more though. I can't determine if CAI or cone is better though. Cone seems to dyno higher. The CAI may lose it's advantage after the car is moving. Further testing at a nearby track is coming soon.

 

Do you have more closer closeups of your ram air?

 

Sure do...

http://paulwendy.com/maxima/svcai.htm

 

The link is dead

 

Sorry about that.

I mistyped it.

http://paulwendy.com/maxima/svcai.htm

 

Hehe...awsome!

Like I said, you shouldn't worry about turbulent flow inside of the tube...unles you have a very long tube. But what most people worried about is the turbulance at the tip, which they think will create a pressure drop at the tip and thus less air will flow inwards.

I just don't know...

I knew I shouldn't have slept through my fluid dynamics class!

Green

 

Hey, you are just right Watson. Oh BTW, about smoking Bamboo, it increase intelligence and creativity not to all but for most who enjoy it. he he he ( if you have a chance someday try the Quebec Gold, awesome he he he ).

Cheers

double A

 

yeah - I definitely agree. There's no question the scoop sticking out forward through the splashguard definitely works best, no questions at all. This will get you the best acceleration especially for track purposes. My point was that for everyday driving, not for track purposes, I experienced smoother acceleration with very little tradeoff as far as diminished acceleration with my set-up - having the Oscai scoop inside the splash guard a couple of inches above the screen as shown in the picture. My goal was to create an Oscai that I didn't have to mess with and that provided smooth, strong accelaration with little to no trade-off when compared to having the scoop sticking out (which in my experinece at least, resulted in herky-jerky acceleration at times during everday driving).

The ideal intake would be a much wide stock scoop. It's only about 7-8 inches wide, is almost ideally positioned and provides a very aerodynamically efficent and straight path to the air filter box. Think how much better it would be if it was 16 - 20 or more inches wide. We wouldn't have to mess with any CAI kits, OSCAI or anything else for that matter! But I think the reason it's not any wider and somewhat restrictive is to keep noise levels down. There's just so many compromises engineers have to make on a "family sedan".

 

Woh! Hang on... just saw your sig. You are ordering S-03's. Let me know how you like them.

 

I've got to update my sig! Actually I had them for about a week then returned them to the Tire Rack (unlike most other tires these come with a 30 "tryout"). Got the Kumho's now.
Don't get me wrong the SO-3's are awesome tires. They do everything great - they stick very well, brake well, and break-away well, have excellent high speed stability, very little sidewall flex on hard cornering, comfortable ride, low noise levels, and stick really, really well. I didn't have a chance to see how they are in the rain but have no doubt they'd perform great as well.

The problem was I plus sized to 225/55/16 from the the stock size of 215/55/16. This turned out to be a mistake because it seemed to slow the car down a bit. This size is about 4% wider and about 1/2" bigger in diameter. So I decided to get the Kumho's instead at 215/55/16 because I was originally undecided between these two. Where the SO-3's do everything great the Kumho's do everything very well but at $75 vs $190. I had just spent so much on mods over the last couple of months I decided to "take it easy" this time. I'm very pleased with the Kumho's - can't go wrong with either tire with all things considered. The Kumho's are a surprisingly well performing tire and not much of a drop-off from the SO-3's at all, but I'll probably get the SO-3's (at the right size!) next time I need tires though.

 

Shweet testing settup! How did you make your manometer?(wanna try it).

If Burnulli's principle (roughly.....narrow volume area to travel=increased velocity and decreased pressure...going to a larger volume area (airbox)velocity decreases and air pressure increases)is applied for a ram air intake, then a scoop then a scoop facing forward should add a bit of pressure to the intake and increased the velocity of the air on the way to the airbox where it slows down in the greater volume area, increasing the air pressure. Turbulence at the scoop shouldn't be a concern do to the filter evening things out in the end, so long as there is just more air. Fluctuations in the system while moving should only be due to how much your engine is needing.

May want to test the airpressure while in the wheelwell while moving. Odds are that there will be a slight vacuum in there due to the airflow over the body of the car.

Of course, it's entirely possible that I'm quite hidiously insane....I think I'll eat some cheese now.

 

where did you get yours? Ill post pics of mine today...

I almost wonder if it is making my car slower?? I dunno the spot where the air box connects seems to be loose? anyone else have this problem?

 

Mine is a shop vac attachment. I went shop vac the whole way. tubing and scoop. High class all the way.

 

Mind if I join you?

 

The turbulence to be concerned with will be where the two airflow streams merge rather than at the inlets. And that represents a restriction that still adds to the rest of the pressure drop through the intake system. What happens at the scoop entrances we're pretty much stuck with based on the local aerodynamics of the rest of the car.

Particularly since the OSCAI airflow is perpendicular to the stock scoop airflow in an otherwise unmodified intake tract there will be turbulence introduced when both inlets are in use. This can be expected to generate a restriction that will vary in intensity as a function of vehicle speed due to the airflow differences between the two air ducts. That's why I previously suggested adding a turning vane mod (just a curved piece of flexible plastic or sheet metal or something similar) to the duct at the junction between the OSCAI and stock inlet flows to get the OSCAI airflow turned parallel to the stock scoop airflow before allowing the two flows to mix.

Norm