I am looking into an air intake for my STS 91 Civic Si and was wondering if it is worth the extra money to get the cold air intake over the short ram. I was plannig on getting an AEM unit, as they are CARB certified.

Does the CAI make more power?

Anyone with dyno results on each?

Are there any other brands of intakes out there with CARB approval and reasonably priced?

Jeff

 

Tires and suspension first, then worry about freeing up 3hp. So long as it filters aire coming into the motor its fine, though I've always prefered a "short ram" style intake since the filter stays far away from puddles and throttle response is better imo. Get whichever one makes you happy in the pants, because its not something thats really going to affet how well the car does.

Being a longtime lurker, I dont see this thread ending well...

 

Suspension, wheels and rear sway bar were first on my list, but I have those now

GC 450/500, yellow koni's, GC raised top hats, 15x7.5" SSR's, Azenis, Suspension Tecnique rear sway bar, DC Sports header, new brakes F/R, new clutch, new axles, Mugen trailing arm bushings, CRX HF front bar, removed the A/C, New timing belt, new water pump, Unorthodox Pulley is on the way.

I also have 2 16x7" Volk TE37's with new 215 Azenis to try out

Now it is time to find more power.

I have already removed 143lbs, and I still have things to do to remove more.

Jeff

 

I believe AEM claims something like 7 - 10 hp with their CAI (not short ram) intake. I'm sure that depends a lot on the environmental factors, but when I put one in my integra I felt (and heard) a noticeable difference. I like the CAI over the short ram because the short ram has a high-flow filter, but is still sucking in the hot, hot engine bay air. The CAI actually dips out of the wheel well (at least in the teg and crx) and picks up the much cooler ambient air. The only concern there is water injestion. I used the AEM bypass valve and didn't have any problems. The race car doesn't have a bypass valve, but I don't have to worry about puddles on the track here in AZ very often. There are other brands out there (K&N, Injen, etc), just do a search and you're bound to come up with some.

HTH,
Scott

 

get a SR and then make a heatshield for it. that way you get the best of CAI and SR. that's what i did and it works. i get the cold air since the heatshield blocks a lot of the heat from getting near the filter. and i also get the throttle response.

 

SR for the throttle response

 

we dyno tested an AEM cai against a Jay's Racing short ram and found that the Jay's produced about the same horsepower but what was significantly different was the smoothness of the power band. It was no where near as choppy and overall it was slightly higher than the AEM. The throttle response was better also. The larger tube serves as a good resevoir of air for off and on throttle use.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by joeysol &raquo;</TD></TR><TR><TD CLASS="quote">we dyno tested an AEM cai against a Jay's Racing short ram and found that the Jay's produced about the same horsepower but what was significantly different was the smoothness of the power band. It was no where near as choppy and overall it was slightly higher than the AEM. The throttle response was better also. The larger tube serves as a good resevoir of air for off and on throttle use.</TD></TR></TABLE>
AFAIK, the J's Racing intake will not work in an EF without relocating the battery.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by joeysol &raquo;</TD></TR><TR><TD CLASS="quote">we dyno tested an AEM cai against a Jay's Racing short ram and found that the Jay's produced about the same horsepower but what was significantly different was the smoothness of the power band. It was no where near as choppy and overall it was slightly higher than the AEM. The throttle response was better also. The larger tube serves as a good resevoir of air for off and on throttle use.</TD></TR></TABLE>

Did you dyno-test with the hood open or closed?

There's a really good set of tests on these described in "How to Build Honda Horespower" by Richard Holdener. Every article in that book is a dyno session, with very good procedures for isolating the test variables. In short, his take is that a short ram will typically make more power on the dyno, but only if the hood remains open. The true CAI works better when the hood is closed since the cold air benefit is larger than that of the shorter intake tract length. And since we don't race with our hoods open, the choice becomes clear.

You also need to look carefully at the area under the torque curve. That's what works for you, not peak hp. Intake tract length is a wave-tuned runner. Longer builds torque lower in the RPM range. Shorter builds it up high. Torque x higher RPM = more hp. But area under the torque curve is what makes you accelerate faster (until wind resistance becomes a factor).

The author above describes a "best of both worlds" approach where by a shorter tube length is used and the filter is then sealed into a plenum that is vented to outside air. Comptech sells something like this off-the-shelf for newer cars.

Another good place to get info on this is the AEM site where they discuss the new V2 intakes. That's another approach to spreading out the wave tuning (two concentric pipes).

HTH,

--Andy

 

At one time I had AEM CAI's on all of my autox cars, but after some testing--I ended up liking the short ram intakes the best. Throttle response is sooo much better.

About the hot air suck thing...for autox...I really think it is a moot point. You warm the car up with the hood up, then when you are ready to pull to the line, you shut the hood (or have someone do it for you), take your ~60 sec run, pull back in the pits and water everything down.

For street driving or roadcourse I can see the benefot of the CAI, but for autox I really don't think there is any. What also scared me a few years back is when I was at Grissom (Peru) with a CAI and we were running through huge puddles and heavy rains. I was somewhat scared I'd hydrolock the car with the CAI.

 

Regarding intake temps…

Back when I had an OBD2 scanner, I did some testing between a CAI and a SRI intake temps on my old car using a stock IAT sensor readings with the scanner. The CAI was run into the fenderwell, the SRI in its usual location under the hood in the direct path of the radiator fans. At idle, the CAI did pull noticeably cooler air, however past 30-35mph the difference was nill. Turns out that a LOT of air gets moving through the engine bay at speed and it doesn’t stay around long enough to get that hot. Between that, cheaper price, the better throttle response and the all-weather-ness of a SRI, I’d just go with one of those.

 

One of my concerns of the CAI, besides higher price, was the wet weather issues. We have been getting a lot more rain the usual here in SD and I can almost guarantee rain for the SD Tour. Who was here a couple of years ago for the "Monsoon Tour?" I was, have you ever seen a Viper float around a course before

I was also thinking about enclosing the short ram to help shield from the heat. I follow Andy's logic as well, the longer tube should be more torque, which is what we need the most.

So many options and variables to sift through.

Jeff

 

CAI + 3" deep puddle that I hit IN NEUTRAL





FWIW, there was no fender liner.

 

OUCH!!!

You just made my mind up for me, short ram it is. I will just make a shield for it when I get the chance. Motonishi's Civic has a short ram, and it is damn fast.

Jeff

 

I am running an AEM cai and I couldn't ask for better throttle response. I guess it depends on the car set up, but with my fadanza flywheel and hasport motor mounts it is great. The throttle response would just be stupid if any better.

The hp gain is greater with the cai. As mentioned above a back to back dyno will not show a difference if the hood is opem. I sure as heck know my engine bay is dang hot while on track, I would like to see what type of hp #'s you could generate if you were able to replicate them on a dyno. Is there anything in the CR about running with no hood?

 

I have the best of both worlds. I started off with a Injen 3" short ram but later ordered up the cold air extension, takes 5 minutes to change between the two. Wrap the intake if you need to. for me there is a noticable difference between the two, SR it feels like it's choking the top end, Cold Air and it pulls nicely to 8k but then again it could do with me running a JRSC.

 

I just looked at the injen SRI, and now I'm wondering if anyone has figured out if there is a difference between SRIs with 2/5" vs. 3" tubing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fireant &raquo;</TD></TR><TR><TD CLASS="quote">I just looked at the injen SRI, and now I'm wondering if anyone has figured out if there is a difference between SRIs with 2/5" vs. 3" tubing. </TD></TR></TABLE>

The larger piping should generally move up your powerband a few hundred rpms. I'm sure this doesn't apply to every motor setup but it is common.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by n1div &raquo;</TD></TR><TR><TD CLASS="quote">The larger piping should generally move up your powerband a few hundred rpms. I'm sure this doesn't apply to every motor setup but it is common.</TD></TR></TABLE>

hmmm...interesting, thanks!

 

I personally have an AEM cai, WITH a bypass valve. If you get a cai, get a bypass valve, it has actually saved my car TWICE from water injestion, they work as advertised. I have no worries of going over puddles.

In the colder winter months I notice a gain in power (colder outside air tem). That would not be as much so with a short ram unless you have a heat shield. And IMO the heat shield still does not work as well as just plain moving it away from the heat all together. And the trottle response is very good, just as good as my friends with an AEM short ram.

 

I personally conducted a test that measured intake air temps right at the filter and noticed that with the short ram(j's style intake in my case), the temps rose between 20-30 degrees when the vehicle was moving and 30-50 degrees when the car was standing still versus the outside ambient temps(winter around me was typically 25-35 deg). This was with a cardboard heatshield ghettofabbed to isolate the short ram somewhat.

I'm currently using an AEM style ~2.5" CAI that I recently switched to based on my findings. For me, throttle response still seems the same. This could be due to my smaller 1.6L of displacement though...

Just my $.02

 

MAD THROTTLE RESPONSE Y0!

I really don't see how higher temperature intake temps IE air that is increasingly volumous or the opposite of dense - could in a motor that is NA or operating under pumping loses could have a greater throttle response than an intake of cooler air - it can't

+ 0~30mph is a pretty big area that the CAI has a big advantage in then at least

HOWEVER

You don't tune your car in a wind tunnel on a rolling road dyno so what happens @ 80mph is without really expensive equipment to make the measurements accurate easy to prove or ever tune for. So some people have figure out that dyno testing with the hood open and a large fan is close enough

in that case the CAI still reigns suppreme but is still second to the new V2 if applicable which uses velocity tuning and sound waves and other mumbo jumbo

: the last post was purposely jumbled a bit so as to be more easily understood by the i - generation of youths :

 

I would recommend the iceman,WAY less heat soak then an aluminum intake tube because it is basically a dura-plastic ceramic coated material....you can use the cai extension or keep it short ram like i did,damn good throttle response and overall smooth power.....I LIKES IT ALOT!

 

I've had a couple of D16Z6 cars dynoed with AEM and Iceman intakes. Basically, the Iceman in short and long configurations were better than the AEM.

AEM lost power 3500rpm and below, and only had a peak gain of 2hp, which was also the peak power over stock.

The Iceman in short mode was about the same as stock until over 5000rpm or so, where the peak gain of 3hp was also the peak hp over stock.

The Iceman in long/CAI mode did not raise the peak hp. It was still 3hp over stock at about the same point as the short mode. HOWEVER, the peak gain was 6hp at 4400rpm. There was no power loss throughout the powerband.

I do think you can lower your time by improving your technique. Taking an autocross school will probably do more for your than an intake.

 

I will look into the Iceman intake system. Being able to switch between the short ram and CAI sounds like a great compromise.

Thanks for the tip, Outrun.

I will also look into some driving schools

Jeff &lt;----- 17 year Solo II veteran