Yeah I know this is hotly debated. I'll just share my experience because I finally got my fat internet pipe back up so hopefully you guys will be seeing longer posts of mine . But anyway...

Back in Austin some of you may remember that wreck I got into with the VW girl...I got a new intake and bumper and fog lights. Worked out rather nicely. Well my CAI got smashed...the lower portion. So we fitted the filter (undamaged) to the upper portion and in effect made a short ram. So I basically got to test cold air, short ram, then cold air again. And here's what I found.

-For the first maybe...3-4 minutes...the two felt the exact same, the short ram even felt better.
-In standard low speed conditions, the CAI prevailed
-In moderate/high speed conditions...the two felt the exact same.
-The short ram was throatier

So I can reason this out. For the first few minutes the engine bay is warming up from a cold start...the air inside the engine bay isn't particularly hot...but more importantly the surrounding metal pieces aren't particularly hot. And the short ram doesn't make the air travel as far up a 3" tube (for my TL-S) as the CAI does.

In standard low speed conditions the CAI sucks the air from under the bumper instead of hot engine bay air...as said in many other posts...and thus prevails.

In moderate/high speed conditions quite a bit of air is being forced into the engine bay...so the temperatures by the bumper and at the short ram are relatively the same...thus no difference.

The short ram was throatier because of being higher in the engine bay (duh).

Just wanted to post my thoughts

Austin519

 

good deal...

I wouldn't have expected any different results than you got.

In effect, the short ram and CAI should do the same thing. And like you mentioned, the only difference that should be noticeable is when the engine bay is hot and there is no circulation.

 

agreed and agreed.

Good info Austin. I think what you typed is what everyone suspected, but it's good someone was able to verify it.

 

So wait, for all practical purposes....it makes no difference? Is that what you guys are saying? It doesn't matter if it's hot when your are idiling. And, when accelerating from a stop the short intake might me be better? is their a signifigant price difference b/w the two?

 

i don't agree IMO...we've discussed this issue going back to when i first joined A-CL a year ago, and the consensus was there was a CLEAR difference between the regular CAI and short-RAM...CAI gave u more HP and pleasant roar, while the S-R gave u more sound and no HP

 

chikai and juniorbean:
Yeah me too.

Loseit:
Not at all. There is a difference. From a cold start for the first few minutes these two are the exact same...the short ram actually felt better. After warming up (a few minutes) the cold air is the better of the two for all speeds up to I'd say 30 mph or so...it's really hard to put a defining line...which is why I said moderate/high speeds. There is a gradual decrease in the difference in gain between the two and when you get to highway speeds...say 60, and you gun it...there is no difference. So it depends on the range. But understand that both are an improvement over stock. And yeah there is a price difference...off the top of my head I don't know how much...I never bought a short ram. I want to say it's about $50 or so?

Scooter:
Nah I can't see how anyone would say short ram gives you no HP. I don't see how we can say short ram in our cases because I seriously doubt you're getting any added psi from it...only a scoop would do that. Both both intakes use a higher flow filter and smoother intake path (in terms of what the air would see) so both will show an improvement. I think my results follow what the natural laws of physics would dictate...it's just nice to see that's the actual results...

Austin519

 

assuming both pipings for the CAI and SR are 3" and they both use the same filter, I don't see how they can vary in HP in the same temperature setting.

The volume of air being sucked in should be the same.

 

A looooong time ago I did a little semi scientific testing with a radio shack indoor/outdoor thermometer. I placed the outdoor sensor in the engine bay directly next to the air filter.

I waited for the temperature readings to stabilze (it was about 70 degrees) and then I started my car. After about 2-3 minutes of idling the underhood temps were up to about 90 degrees. I then got in my car and started driving around with the temp display inside my car. Going a slow steady 30mph was fast enough to force outside air into my engine bay and drop the temp reading back down to 72 degrees! I then parked at Taco Bell ran inside to get some food and when I came back out the underhood temp was in the low 100's. No sooner than my car started moving the temps quickly started dropping. Doing a steady 40mph on my return trip the outside and underhood temps were EXACTLY the same. Everytime I got to a stoplight where I had to sit for a minute or so the temps would slowly creep up into the 80's.

When I my testing I used a piece of styrfoam to mount and insulate the thermometer sensor from any direct heat transfer with the car frame or any other parts under the hood.

 

Thanks Austin!

 

I'm proud to be a member of this board because of ppl like BNut. Always engineering, testing, and proving theories in an objective manor.

So I'm guessing your Taco Bell excursion proves:
1) during normal driving speeds CAI and SR should not be any different
2) at red lights and short stops CAI will have the advantage because of where the air is sucked in from.
3) Taco Bell uses grade D meat

 

BNut

did you take temperatures from both where the CAI filter is situated and where a short ram filter would be.

Basically either next to the battery or under it?


I'm not convinced that hot air isnt hovering around in the lower extremities of the car as well.

 

Loseit:
Np

BNut:
Exactly. I totally agree.

chikai:
He prove the last one later that night

soopa:
I dunno adam...hot air rises dictates that that won't happen...and that's in a totally still environment...our engine bays get a lot of air...so I'd think that any pockets would be dispersed pretty quickly maybe?

Austin519

 

Heres the solution...........Get a CAI with the bypass valve, when you want a short ram, take of the bypass and put the filter where the bypass is

 

Next time I dyno I plan on doing exactly what you described above.

 

Simple solution to a simple debate

 

Nicky Pass:
That's exactly what I did. The lower portion of the tube was crushed at the bypass...so we just removed it and re-attached the filter.

Austin519

 

I loved my CAI until the first time I washed my car with it on. My filter was drenched. I was not to crazy about that. I borrowed a pipe cutter from work, made a few mwasurements, and ended up with a SRI. I will post a pick later of my creation.

 

juice:
Then why didn't you buy one to begin with?!? It's cheaper. And your filter may get wet...which isn't a big deal.

Austin519

 

I only took temp readings with the sensor situated next to the battery.

It would be an interesting test though to see if/how much the temperature would rise at the CAI filter location when stopped at a light.