ram vs. cai

[jmrv705]

I was wondering which performs better and which would be a better choice fpor a '99 mustang. I know the cold air intake would be cheaper and easier to install, but does it outperform a ram air system?? Thanks for any advice.

[BigDanTheMan]

There is a topic of much controversy and debate. My two cents are as follows:
The price of a new hood and a ram air apparatus do not justify the slight performance increase you could expect to receive. The 1971 hemi cuda claimed that it's shaker could suck in 10 more horses just by opening it's vents, but this was a 385 dollar option in 1971 that came with an automatic A/C delete. I know for a fact that the same 10 H.P. on the same engine and car can be reached by slapping on a less restrictive air cleaner and opening up its box a bit more.
On the flip side; the ram air looks tight and acts not only as a slightly better intake system, but adds to the vehicle's aesthetics as well. I'm going ram air when i do the rebuild because i think it'll make up for my lack of interest in dressing up the exterior of my car.

Kits for ram air on your model year rarely go for under 400 bucks.

[351wStang]

You could just get a extended cowl lift off hood and re-route your cai into the high pressure area againt the windsheild.

[Hypsi87]

Its all just a big controvarsy. IMO Ram air does not work. I have posted numbers on this before. do a search and you will find them

s

[StangNut86]

somebody in this forum actually ran some calculations... something like, how fast does air have to go through a 3 inch tube at a certain cfm? it was a high number, like 3 or 4 hundred if memory serves. there result was something like 185 miles/hr. in other words, if you're not going more than 185 mph under identical conditions, your ram air ain't shit. even on top fuel cars... big tunnel rams, right? well, those cars have the largest intake ports you'll ever see (about 3 or 4 inches across, seen them myself) and the blowers push about 40 PSI. no way that ram does anything. all it does is give a mounting location for those massive throttle plates to the best of my knowlege.

i agree totally with hypsi... it's esthetic. my notch may end up with the 'stormin norman' hood from cervinis, but it will be completely non-functional except for esthetcs and a small degree of cooling. even a couple years down the line when i twin turbo it, it'll have 2 filters in the fenderwells, not even messin with complicated ram air plumbing.

[Hypsi87]

Here is the post I put up a long time ago.


Hmmm I was in a coma like state earlier today ( sitting through a four hour training lecture at work). Anyway I was wondering how fast the air in a 3" inlet pipe to the turbo would be traveling if 800 cfm of air was going into the turbo. So when I came up with my answere it woke me up enough to ask my buddies at work to calculate it for them selves and see what they came up with. I didnt tell them how I went about calculating it to avoid getting them started on the wrong foot incase I was wrong. They came up with the same answer as I did. When I asked them how they went about calculating it they had approached it the same way I did.
here is how I did it:
1) I'am going to use standard temp and press for the air

2) area of 3" pipe = pi * radius squared
3.14 * 1.5in * 1.5in = 7.07 in2

3) Inside volume of pipe = area * length
I wanted to know how long a piece of 3" pipe had to be to half an internal volume of 1 cubic foot. I rearanged the equation:
length = volume / area
length = 1 ft3/ 7.07 in2 = 1 ft3 * 144in2 / 7.07in2 = 20.4 ft

4) OK now I know that 1 ft3 is the volume of a 20.4 ft long piece of 3" pipe. I also know that Iam looking for 800 ft3/min. so this is next:
Speed of the air in the pipe (mph) = (800 * 20.4 * 60) / 5280
800 is cfm (ft3/min)
20.4 (ft of pipe for one cfm)
60 (convert from minutes to hours)
5280 (convert from feet to miles)

ANSWER: 185.45 mph!!! Air speed in a 3" pipe with 800 cfm of air moving through it. Makes me shake my head but it appears to be right. I also calculated for a 4" pipe and the speed dropped to 104 mph.

There is no intended point of this. I was just kind of suprized by my answere and thought I would pass it along. BUT....it does make me wonder how much ram effect some of these late model cars get at 60 mph or even 80 mph with the little factory snorkels. Maybe they're just fancy looking cold air induction set ups?

[HiFlow5 0]

LOL, I remember that post hypsi!

OK, now heres my 2 cents worth. CAI and ramair are pointless for performance, but definitely look nice. Quick info about my experience, I have a CAI (for looks not performance reasons) that runs into the fenderwell. So at the track last year, I made to runs. One in stock form, the other with my marker light removed. Now removing the marker light allows a ram air effect directly into the air filter in the fender well. I noticed no gains what so ever as result of my ghetto made ram air set up.

[BigDanTheMan]

yo -
ram air is not a forced induction thing what so ever, but it does increase airflow by being far less restrictive than the fender wall. also the idea is to grab colder, more dense air - air speed isn't the point. the performance increase might be marginal at best and is defiantly uneconomical, but if the benefits are fruitless how do you explain the introduction of ram air in the 60s and it's rebirth in the late 90s?

[DDMTK421DS]

Originally Posted by BigDanTheMan

yo -
how do you explain the introduction of ram air in the 60s and it's rebirth in the late 90s?

$$$$$$$$$$$ People will pay Top $ for anything they think will help them gain Hp wether it does or not.

Every shop I have been to says the same thing. "Neither will help much with Hp", it just looks nice and makes you feel like you've accomplished something under the hood cause it looks cool or is shiny. lol

A better investment would be a Bigger Throttle Body, mass sensor and a new Boot. Then a K&N Filter charger. (Same as CIA but less expensive)
Adding A filter charger to a stock car alone will increase HP more than Ram air or CIA.

BTW CIA is not Cold air, It is just more expensive Hot air from ur fender...lol

SO I saved and got a (1998 GT) Vortec Supercharger.....Worth every penny......

[GTStang]

I had a ram-air hood set-up and a CAI niether one I got performance I consider them both dress-up. I like Ram-AIR just cause of the hoods look nice and worth the extra cost.

[vortec4_2001]

My thought as well on ram air. BLAH. Looks and that's it. Don't go buying those hoods and FUNCTIONAL ram air kits. WHATEVER. lol Any, I'm actually selling my K & N Kit for a BBK Polished kit, for looks basically. So anyone want to buy mine, give me a holler.

[vortec4_2001]

My thought as well on ram air. BLAH. Looks and that's it. Don't go buying those hoods and FUNCTIONAL ram air kits. WHATEVER. lol Anyway, I'm actually selling my K & N Kit for a BBK Polished kit, for looks basically. So anyone want to buy mine, give me a holler.