Cold air intake Project/ DIY

I drive an automatic.

You don't have to worry about water in it unless it's fully submerged. Some engines(turbos) have water sprayers that will actually spray water into the intake to cool down the turbo. Your main concern will be keeping the filter clean during rainy season. Good luck with that! =D Just makes sure not to drive thu any 2 foot deep puddles. For filth issues, you may think about some sort of splash guard, but that will probably be some custom fabricating tho.

Did you find a way to fasten this system to the wheel well? You might run into rub issues in the future where your extension thru the hole will rub/bounce against the edges. It may be an issue for you, and it may not. Personal preference.

On my taco project, I have a blitz bumper on it, and I will connect the piping off my injen intake to the hole on the passenger side once I finish up the bumper. That'll give me a pretty awesome ram air intake.

A CAI should improve bottom, not top. A header will help with top end.

CAI-top end
SRI-bottom end

i know its a integra but all cai and sri work the same
http://www.honda-tech.com/zerothread?id=2361487&postid=35049515

AEM Cold Air Intake Review
http://www.streetracersonline.com/articles/aem/

No. You've got it mixed up. A CAI will net you low to mid range power, while the WAI(warm air intake. ) will net you top end power. The CAI supplies colder air to the motor immediately aiding in throttle response and low to mid range power. Power drops off as restriction from the long piping starts to take effect on the volumetric filling efficiency. The WAI gains top end since at high RPM's the motor needs for air for combustion. Air is immediately available due to a short distance tube and faster filling volumetric efficiency. However, due to heat soak, power gains become less and only apparent at high RPM's where air flow surpasses in order of importance rather than air temperature. There is still some controversy about all this, but keep in mind that different motors will react differently to each intake. I did some in depth research and uncovered this article to explain it all in detail.

Quote: from Automotivetech.org's "Intake Tech" Article
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A. Short Ram vs CAI


When hooked up to a single stage runner intake manifold, the old AEM CAI (single chamber design) provides some gains in the upper rpms and an increase in power from 4000-5000 rpm ( known as the " AEM hump" where it was first seen. I guess since the Injen CAI has a very similar design to the AEM, we can now also call it the " Injen hump").

However, does a CAI make more power than a short ram with the same diameter and filter material? For folks with single stage runner intake manifolds and mega cams that can rev up to 9000 rpm or more, the AEM/Injen- style CAI actually stops making more power after 8000-8300 rpm . The gain in power for AEM that is quoted in the ads occur at the famous "AEM hump" and not in the upper rpms after 7000 rpm.

Believe it or not, a short ram with the same diameter does pretty well in the upper rpm range from 7000-9000 rpm ! Is it just about getting "colder air" that makes the CAI appear to be better? What role does the intake tube's length play in making big all motor power? Is having a constant diameter different from having a tapered tube?

You may not have noticed this isolated gain from 4000-5000 rpm before on the AEM CAI's and single stage manifolds but look at any Integra LS, Type R, or Civic B16a dyno with an AEM CAI and there it is sticking out like a sore thumb by itself....this is what most people "feel" as a noticeable gain on the butt dyno after installing one of these. The more relevant gains at the upper rpms where the truly faster cars (with proven timeslips) make power are not "felt" by the butt dyno.

Sakai's Intake in his 2000 Championship N/A Daily Driven ITR :



In the 2000 NIRA Comp4 all motor championship final, Stephen Sakai ran his 1997 ITR to a high 12 sec et beating Jeff Taylor's B18C5-powered GSR using a homemade 3 in. diameter short ram intake with a K&N RU3130 filter. Jeff's car had an AEM CAI (see dyno below).

http://sgt.b16a.com/tuning.html

Here's a dyno of Jeff's and Stephen's cars back then before the finals:




Quote: Originally posted by Jeff Taylor 1999 and 2001 NIRA Comp 4 Champion
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basically you can see from these (dyno) plots why Steve just killed me on top end and my car was being held back by the jdm 4-1 that I modified. It's actually very interesting. It also shows that blast of power the aem gives you (only) from 4-5k rpms...lol. yup...thats about all it does. This is where they can make crazy hp statements....they aren't really fibbing...look at the HP increase at a given rpm...Steve was telling me it was the short ram intake....but that damn aem had me fooled until I did this comparison and saw for myself. He gets the credit for it.

I'm not saying that ram air isn't better...I'm saying that short ram in my opinion seems (remember I said "seems") to be fine. Look at the (aem) plot...its nothing more then a power spike. I'm sure it's useful but once you get past it, its very difficult to tell if its beneficial to any degree
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Here's Val's comparison of a 3 in. diameter short ram and a 3 in. diameter AEM CAI on his B20 nonVTEC with Crower 62404 cams, a JDM 4-1 and 2.36 in. exhaust. The short ram version was not tuned to it's potential either. Remember this is a comparison of the 2 intakes on the same engine. The only thing that has changed is the intake.





When the diameters of the intakes are identical, there is virtually no difference between the 2 intakes after 5700 rpm to the redline. The CAI is superior only at the AEM hump.

Now some of you CAI people may argue that a chassis dyno does not take advantage of the colder air, since the car is stationary and in a moving vehicle, cold air feeds the CAI. That test, comparing a CAI with a fan blowing air to the fenderwell to a short ram (with the same diameter and filter material), on the same car may show a difference, since the temperature differential may be greater than on a typical chassis dyno pull...or will it?

The temperature differential between the outside ambient temp. and engine bay temp. under the hood at the short ram intake opening has been measured while an Integra is travelling at speed. There is virtually no difference. We can expect the temp/ effect between short ram vs. CAI to be not as big as people think.

In Formula car single plenum intake manifold testing, we see that the same rule is consistently seen, when it comes to relating intake length and the location of maximal volumetic efficiency (cylinder filling) along the rpm range (ie. shorter length shifts the maximal filling efficiency higher up the rpm range). Here is the graph showing volumetic efficiency vs. rpm for different length intake tubes in a single plenum, single stage runner IM ( from http://www.eng.ed.ac.uk/~jchick/Y5/t...nt/public_html):

Longer pipes shift the max. filling efficiency to a lower rpm and shorter pipes or no pipe shifts the maximum filling efficiency to the upper rpm's.




Some short ram people would say that bigger VTEC race cams would really show how good a short ram can be above 6500 rpm.

For now, Steven Sakai's performance at the 2000 final and Val's dyno (the only one comparing the same diameter) basically says there is no difference, as long as you get the diameter right (i.e. more than 3 in. ID in a single chamber design).

It makes scientific sense from a fluid dynamics point of view :

A bigger diameter tube allows more air to go in but at a slower speed (more cross sectional area). The air flow speed needed to make peak volumetric efficiency occurs at a higher rpm compared to a smaller diameter tube.

A longer tube creates faster air flow compared to a short tube (i.e. more pressure differential from the opening to the TB end) and peak volumetric efficiency will occur at an earlier (i.e. lower) rpm. This is why a longer CAI has an advantage in the midrange over a short ram, regardless of intake temperature differences.

Some people prefer short rams and need their powerband to be higher with bigger cams. They get around the temperature controversy by building their own short ram heat shield.



For those on a budget and who intend to upgrade to big cams, big compression, and a big header, a 3 in. ID short ram with a homemade heatshield may be all you need. For people who want some midrange along with some upper rpm gains, the CAI ensures that butt dyno gets what it expects.

B. Is the AEM CAI Still the King?

The AEM CAI (single chamber design) won the 1996 Sport Compact Car Magazine Intake Comparison in a Civic b16a powered EG hatchback with headers and exhaust by gaining more power and higher top speed . Ambient, intake filter opening, and underhood temperatures were measured in the intake test. The AEM ran much cooler than it's competition at the time which were all short underhood intakes (2nd place went to RS Akimoto Ram 1 ).

Since 1996, AEM has been the undisputed gold standard at the top. The latest innovation to this aging design is the bypass valve for people who get hydrolock anxiety when it rains. There has been one recall already related to a fastening problem with the bypass valve and the valve got sucked into the TB causing engine damage. A new clip has cured this problem. It is noteworthy that the bypass valve lowers power by 2-3whp across the entire rpm range but you can sleep at night.

When you're at the top, the competition shoots for you. People always try to build a better mouse trap. Injen was formed by an ex-AEM employee and it's 2 piece CAI is essentially an AEM design with the ability to convert to a short ram. They now have a 1 piece CAI that looks identical to the AEM. Comptech has their own CAI but it is composed of a short ram with cold air being drawn into a pressurized box much like the stock intake and the Mugen intake. The other more well known CAI's on the US market are: the Iceman 2 piece CAI made by Knight Engineering (Knight7254@aol.com) (not to be confused with the Comptech Icebox) and the Canadian PRM CAI. Neither of these were in the 1996 SCC magazine test and came out just after that test was done: they have been around awhile before the newer Injen and Comptech CAI's.



Based on this dyno comparison done at Comptech's dyno facility (test was independent from Comptech) on an ITR with just header and exhaust, the Injen & Icebox make more power from the ITRs at 5600 rpm up to 7500 rpm. All 3 have essentially the same peak whp. Notice the hump in the AEM (red) and Injen (blue) at 4000-4500 rpm.

There is no independent head to head, independent, published dyno comparison on the same car between the Iceman, PRM, ARC, or Mugen CAI versus the AEM single chamber design CAI, to my knowledge.

I have to disagree with you in the theory of "warm air intake." The fact is intake air temperature between a CAI and SRI is negligible while the vehicle is in motion and heat soak doesn't happen unless you are idling for a long period of time. The whole "cold" air intake thing is more of a marketing ploy developed by the marketing department of AEM (coming from an engineering standpoint).

But you are correct in that the length of the intake pipe that plays a role in optimizing volumetric efficiency. The air density differential between the underhood area and the fender area is not great enough to make a difference in the power band. The variable to focus on is intake air velocity under naturally aspirated vacumm. Like you said, a longer pipe would help speed up air intake velocity at lower RPMs but could potentially starve the engine at higher RPMs where air is needed to fill the cylinders at a faster rate.

This is where cross-sectional area comes into play. While length is largely governed by the engine bay area one has to work with, diameter is.. less so. If you observe AEM, they employ different pipe diameters which is determined by the car's redline. ie. the Integra lineup LS: 2.5", GSR: 2.75", Type-R 3". This is done to help optimize volumetric efficiency across the entire power band... increase intake air velocity without starving the engine.

Furthermore, even though the filter is located in the fender area with a CAI, it is still essentially a long aluminum pipe. which have a low specific heat capacity. So heat from the engine bay would be transfered into the intake air anyways.. Cold air intake.. nice try, AEM marketing department.


[edit]

Actually what I just said about air temperature not making any difference is stated and proven by the article you posted up..=P

You are absolutely right though. AEM designed each intake individually to match each motor best according to volumetric volume efficiency. Now that I re-examine this, I also agree that when in motion, the CAI and WAI/SAI/SRI are almost negligible in difference due to the minor air temperature differences since there is no such thing as cold air, merely "cooler" air. This may only differ by a few degrees when the car is in motion. LOL I suppose the CAI is better for a car that may sit in traffic where the underhood temperatures would be a key factor in heat soak. The difference in CAI and SRI are even less since the metal composition of the intake would induce heat soak nevertheless in both. The only major factor is due to the differences in volumetric efficiency and air velocity due to the different lengths and diameter of the tubing, which you stated. The best design would be of a variable design where the intake incorporates both SRI and CAI like in some racing applications that I've seen. I recall some racing BMW's utilizing these 2 stage intakes which act as a SRI at low RPM's and as a CAI at high RPM's. Perhaps I can start to engineer and build one? haha I doubt I'll have the time and resources, though for such a low power increasing yield in our application, it's just not worth the time. A CAI will suffice. LOL

Honda owners use something called a Tsuchinoko chamber. It is essentially a SRI made of composite or a polymer to prevent heat soak plus a large internal chamber/reservoir of air to aid in initial throttle response.

Since the shop I work at sells these I took one out to see if it'll fit my 7th gen with battery relocation and it did.. but i'm not keeping the engine anyways so meh.


But yea I agree you should just stick with the ELP CAI. The engine bay layout of the 8th gen + doesn't allow for anything better... except maybe ITB + forward pointing velocity stacks

haha Very true, but even velocity stacks would be a waste of money at this point. I'm looking to get an AW11 as a project car which I can really play around with. Then those velocity stacks will be useful. hehe

Bump: first post updated and tweaked a little.

Maybe we could get this moved to the DIY forum, i dont know why i posted in the general.

Cold air intakes are too long if you want low end torque. You need a Ram air, but you will lose High RPM gains.

Yes, that's right, you will LOSE more than stock, as in, it will lower it below whatever it was before in mid - high rpms, but you will gain more low end torque/horsepower, mostly torque though.

That's why most professional racers prefer CAI, because you don't lose anything, but gain something.

You have it backwards. It comes down to volumetric efficiency. A CAI will gain you low and mid end due to the immediate air available and the longer tube(more volume), hence throttle response improvement. A RAI will gain you top end since at higher RPM's, air is more readily available since it doesn't have to travel down a long length of tube to get to the throttle. They're also typically a wider diameter. Read the in depth discussion several posts back between me and Jspex. Professionals use a hybrid system. Racing BMW's use a variable CARAI where the tube is split into two and a plate opens and closes the two according to RPM's and throttle pressure. Best of both worlds.

The design of the intake also plays a major role. If you take a look at Iceman intakes, the tubes aren't a consistent size. They're designed to have the smoothest and most efficient flow. AEM recently has a version 2 of their CAI for the same reason. A section of the pipe is larger to retain more volume, which is better for top end, before it narrows down toward the throttle. It's all fluid dynamics.

btw, the temperature of the air has no effect on horsepower whatsoever as explained from before.

Apparently i ditched one of my air dynamics classes, :lol

well it does, but when the car is in motion the temperature differential between underhood and outside ambient are negligible.

/thread


nice write up though.

Right, so unless you do a lot of stop and go, you won't really notice.

Wrong! you'll notice the noise though...

lol

Scratch that.

It is for a Corolla T-Sport (Euro model) that has the 2ZZ-GE motor. (Though from the pictures it almost looks like it could work on a 1ZZ-FE)

so what do you have holding your battery down? from the lokks of the pic you had to remove the stock harness?

nothing holding down the battery, its wedged in pretty tight.

did you have the MAF sensor attached to your CAI
i bought a SRI and it only had two holes to show, did you know how to put that MAF sensor in without doing custom?

there were 2 cables that i attached to the intake, i custom made fitments for.

Hummer's got a 99, so there's no MAF. MAF started in 2000