True CAI vs SRI
 

I finally ran my intake into the fender today and made some observations when compared to my SRI

I can datalog intake temps, maf voltage, A/F, etc while driving so I did some comparisons.

SRI: Intake temps: 40-50C when sitting with engine warm (even in 0C weather), 5-15C above ambient when cruising.

CAI: Intake temps: 0-5C above ambient when sitting, 0C above ambient when cruising.

I also made observations on stock ECU timing at various IAT temperatures.

0C IATs and the stock ECU will run 25-27 degrees midrange and 32-34 degrees topend.

50C IATs and the stock ECU will run 18-20 degrees midrange and 25-27 degrees topend.

In the same conditions, that is probably a difference of 20-25hp. It of course varies over these temps.

I setup my UTEC timing tables to run 29-30 degrees midrange and 34-36 degrees topend at 0C, then setup the temperature tables to pull as much as 5 degrees of timing throughout the powerband at higher temps.

When I tuned for the CAI today (when it was tuned for SRI), I had to add fuel throughout (especially lowend/midrange) and MAF voltage increased a good deal in midrange, and even a slight increase in topend. Power delivery also feels more linear than with the SRI.

In addition, the butt dyno says part throttle and low RPM responsiveness and power has increased, ESPECIALLY when starting from a stop when the SRI would heatsoak. Even with the inaccuracy of butt dynos, take my word that low throttle and low RPM power increased, it was a quite noticeable difference.

For now, I am using 3" ID flexible plastic piping (autozone ricer isle special) and sometime in the next few months i will have 3" ID mandrel bent steel pipe used in it's place with a built in MAF adapter and have it powder coated.

One negative is that the sound from the CAI is subdued when compared to the SRI. There was a high pitched wail with the SRI and the CAI still gives a nice roar but it just doesn't sound as good. Maybe with steel piping!

Edit: Reason I say TRUE CAI in title is because "Injen CAI" does not count as a CAI.

Oh, one more thing. This giant, stupidly over sized filter fit into my fender right along with the 6">3" velocity stack... There was about 1" to spare on the bottom.

http://i263.photobucket.com/albums/i...x/DSCF0009.jpg

Did you use the velocity stack with the 'true' cold air intake? You got pics of that there tcai?

BTW, you need more shiny things under the hood. Billet battery tie down?

I haven't taken pics yet, was dark when I finished.

Yes the velocity stack fit perfectly with the filter. I could not use this filter by itself since it's got a 6" outlet, the velocity stack goes from 6">3" and allows the filter to be coupled to my intake.

What filter are you using? I have velocity stack sitting around and a 6" K&N filter, but I prefer to not use an oiled filter with a MAF.

PS, is the .org acting up for anyone else? I need to html to make simple things work.

My filter is an AEM Dry Flow... No oil and easy to clean ftw!!!

Ok I took pictures.

Tools used: 3/8" Drill and holesaw, Dremel with cutting and sanding/grinding wheels. 8mm hand driver, Small flat-head screw driver, 10mm socket and extentions. Jack and 2 jack stands.

http://i263.photobucket.com/albums/i...x/DSCF0036.jpg
Here you can see my scarred and beaten bumper from highway rocks and snow ruts and a peak at the filter. I will be cutting out the foglight backing.
http://i263.photobucket.com/albums/i...x/DSCF0037.jpg
http://i263.photobucket.com/albums/i...x/DSCF0038.jpg
http://i263.photobucket.com/albums/i...x/DSCF0034.jpg

I thought my AEM filter was big...That's a 6" flange but with a 9" long filter body?















































































































































t 9" long body

Yeah it's bigger than I wanted. If I could do it again I'd get a 6"x4"

Pretty hardcore, Sparks. Well done.

What's the plan with the fog light inlet? Are you going to cap it for daily driving, and open it for racing?

Did you have any issues reorienting the battery?

Good work Sparks. The only downfall is having to change the filter. I guess who gives a **** if the results of the the true CAI are better.

I won't have any difficulty. It takes 1 clip and 1 bolt to pull the splash shield down, then I can just pull the filter free. It is also washable in regular water without any need of oil, so I can pull it out and clean it with the hose, then let it dry and reinstall... Not bad!!!

Plans for foglight inlet are to cut out the backing starting about 2" back from the lip of the bumper.

It will remain open during daily driving and at the track. It will probably get dirty quick, but it's easy to clean. I doubt water can make it up the incline into the engine bay. I believe there could actually be some air starvation if the splash guard was left on and the fog light was blocked off or reinstalled (there's room). The part of the fender it's in is completely blocked off.

I may do a headlight-mounted UNFILTERED ram air intake using the headlight hole for the track, something like Aaron's but bigger since I have a bigger headlight hole to work with.

I know that you don't have to remove the foglight....that area is connected to the front radiator inlet and air is in a ram effect already in that area. Cool dense air...Great scientific support of the timing advancement with your SRI Vs CAI...I'll keep my Hybrid SRI and build another heatshield (like on my 3 rd Gen) except it'll have a ram air convergent duct and 4" hose supplying cool air to the Hybrid SRI area...here's my 3rd Gen heatshield I built and it's totally functional with at least an 80 degrees F difference...

http://i406.photobucket.com/albums/p...1256425792.jpg
But for this in my 5.5th Gen
http://i406.photobucket.com/albums/p...rlspics280.jpg

sorry if i missed this.. did you open up/cut out some of the fender shielding on the insidde of the wheel well?

None at all. I didn't even have to touch it. I'd leave that in tact... I throw rubber up in the wheel wells at the track.

Go for black chrome.

I'm wondering if you switched the plastic hose to metal if there would be any other temperature anomalies. Radiant heat? Just trying to think. Definitely will sound brighter with metal.

For the record, im glad someone finally logged the data for the running conditions of a CAI.. I did a ghetto CAI on my 4th Gen down to the Fog light and everyone claimed it would be a waste..

I will say that the way i did it was a waste considering.. but maybe this can be motivation for me to retry my idea more head on.. Oh and where did you route into he Fender well, I just ran through the Relay hole; worked great no cutting or anything..

Although for a 3" Pipe im sure it might need a bit of a hack job, but Not a big deal.

Now if we could just get a dyno of a stock intake Vs this True CAI regardless of the above information and see how the VQ handles the colder air in terms of the modified Torque Curve...

I am tempted to go with stainless steel and have it thermal coated. I could get that done for 100-150 dollars at the mandrel bender/tig welder about 2 hours away. I just need to have a machinist make a MAF adapter block, then drill and tap for the maf bolts and take that to the mandrel bender/welder. Once he's done I'll clean it up, sand it, then have it coated. That way I'll have a 3" maf and a CAI for cold temps all the time. I can also have mounting points in the engine bay for a clean install with no rattles.

I think most of the sound I "lost" from the SRI will be back with stainless steel. With the coating, it'll be at least as good as plastic for heat dispersion.

I am also thinking about getting a water/meth kit before summer. I'll only spray it at WOT when the UTEC takes over timing. I can use the UTEC as the TPS/RPM switch output to the meth kit, so it should be cheap.

I moved my battery and created a large hole (looks like I could fit a 3.5" pipe through it) in the sheet metal between the subframe and under where the battery used to be.

The pipe I am using is 3" ID, about 3.2" OD... It's big, I could barely stretch my coupler over it. So 3" pipe will fit even better!

I'm thinking a true CAI or even a SRI (above 20 mph) would beat the stock airbox for peak power/torque.

The main advantage of the CAI is that you do not have that 50C heatsoak lag after sitting at a stoplight that the SRI is plagued with. I let the stock ECU run my timing below 65% throttle, so it compensates heavily based on IAT. I don't think it will make much difference on the highway, though.

Made a way better video. That one had bad sound.

I'm sure why you think the sound isn't as ferocious, is due to the inlet location down in the wheelwell area not sitting up near the firewall, and the fact that now you have a longer tube to suck thru so the suction has a little bit more resistance...This is what hurt me with the Injen Intake and it's 39" lenght thru a 3" tube where I would have made more power up top with a 3.5" or 3.75" tube. My turbo Mopar will be fed by a 4" tube and transitioned down @ the turbo inlet....the 4" tube will acts as an accumulator as well, reducing inlet suction resistance....

It's not like we don't have a 70mm TB or anything... :rolleyes:

The main reason for the reduction in sound is the plastic. If I use metal piping, especially thin stainless steel, it will be much different.

I'm sure that plastic has sound and heat insulating properties but, If I blown a horn 6" from your head and then blew the same horn 3 ft away in a steel box, it would sound slightly reduced as well....get my point?
How long is your intake now? 30 something including the filter?

GODDDDDDDDD hahahahaha.


Also nice i/m

Total length to the velocity stack is around 28" I will be using 3" ID stainless steel and have a MAF adapter welded in and combine the BB maf mod with a well built CAI.

If I really feel it's choking, there is enough room for 3.5" ID piping, but I'd need to get another velocity stack because my current one takes a 6" filter and mates to 3" ID pipe (will be port matched).

I'm pretty certain 3" piping will flow enough for N/A even with cams at high rpms. I'm also pretty confident this IM will do well. I guess we'll see when I get a clutch and hit a dyno.

Even though the velocity stack is where the air enters I was speaking to the end of the filter...total lenght! My total lenght is 20"

The end of the filter is irrelevant. My filter is 5" longer than yours, to start.

This is the SRI that I went from (which is shorter than yours):
http://i263.photobucket.com/albums/i...x/DSCF0009.jpg

and what I went to:
http://i263.photobucket.com/albums/i...x/DSCF0035.jpg

I did testing with both. That SRI has been on the car for a few months.

I'm pretty certain a 3" tube with 3" maf going into the TB will flow more and colder air than a SRI with the hood closed.

Nice work, thanks for the data comparison. I have a question, what disadvantages if any, do you see with the Injen CAI vs SRI

the injen puts the filter behind the rad, so it is always sucking warm air

precisely. I'm certain it gets just as heatsoaked as a SRI.

The main disadvantage is trying to move a column of air through this 39" long intake at high rpm...it's built for low and midrange rpm...the tube would have to be larger in diameter or shorter in lenght to work at high RPM.

the filter is not directly behind the radiator, but it's down below the shroud almost to the belly splash shields. The intake tube is directly behind the radiator fan and is getting heatsoaked like a MOFO that's why mine was double wrapped with exhaust wrap and an heatshield blanket to reduce any possible radiant overkill...

You're SRI, I can guarantee you,...was no where as hot as an unprotected Injen intake!!! I guarantee you bubba!!!!

I think with the injen it also depends on what filter they give you for the maxima. I know on mine the filter was half the size of a normal filter with a 3" opening and it sat right behind the rad. In my opinion that smaller filter is way too small for a 6 cylinder engine. Might be ok for a 1.5 liter honda.

And I agree that an SRI is not as hot as the injen setup, I have run both and the throttle response of the SRI is much better than the injen.

Probably not. I used to have an injen a couple of years ago btw... got it before I researched :mad:

I built a small heat shield around it but swapped it and sold it after a few months.

http://i263.photobucket.com/albums/i...s03max/008.jpg

Probably not. I used to have an injen a couple of years ago btw... got it before I researched :mad:

I built a small heat shield around it but swapped it and sold it after a few months.


I like how deep you are into the engine parameters...I'm just getting started on some of these high tech tools...but using alot of my aviation knowledge to get by...the best thing out of the Injen Intake was the MAF adapter IMO!!!



http://i406.photobucket.com/albums/p...axtitan043.jpg

http://i406.photobucket.com/albums/p...tures018-2.jpg

Long a$$ MOFO!!!!!

I hated the big intrusions into the injen MAF adapter so I ported it out with a dremel so that the piping ID was maintained.

My SRI setup had the velocity stack+filter assembly port matched to the MAF adapter and MAF, then coupled directly to the TB.

My CAI (when I get the piping done) will be done with the same precision.

http://photos-c.ak.fbcdn.net/hphotos..._7499467_n.jpg
Here's My short ram. stillen pop with knight_yyz's shorty midpipe. Oh yea, its loud.

quick question for sparks03max. does your car run rough at idle, of even stall at a stop? the reason i'm asking is because i had a simular set up with the beather filter. the moment i put it on i ran rough. i would not recommend it. however i love that intake manifold.

Nothing of the such... sorry.

Great info


Did the same thing but with an altima intake.

http://photos-g.ak.fbcdn.net/hphotos..._7790944_n.jpg

True CAI! Works!