CAI vs Short Ram...an un-scientific approach...

*sam o nela* · 10-05-07, 07:31 PM

Cold Air Intake and Short Ram Intake....

Which is better? Cold air or more air? The answer is "both." You want to have more filter area, but you also want to be bringing in cool air from outside of the engine bay. How much cooler? Well, see for yourself.

In all of the following pictures, the fender well where the air filter is housed is represented by the Temp Gauge on the left while the engine bay's temperature is represented on the right.

I warmed up the car to normal operating temperature (allowed the fans to come on twice) and then drove around for a while before officially starting to record the temperatures. Outside ambient temperature during the test was about 60 degrees F (it was much more chilly today than it's been for a while).

First: Allowed to idle for 5 minutes

The underhood temperature fluctuated between 130 and 135 which coincided with the fans coming on. It was definitely interesting to watch

Second: Cruise for 7-10 minutes at 45 mph

Both temperatures dropped significantly. The fender temp went as low as 65. But they both leveled off around these temps (67 and 89) before I finally took the pic.

Third: Cruise at lower, neighborhood speeds. 30 mph for about 10 minutes.

Engine bay temp rose back up though it was still quite cooler than at idle. The fender temp rose, at most, a mere 5 degrees.

UPDATE
Took a trip to Simi Valley today. 70-80 mph the whole way (30 minutes on the highway) at 75 degrees ambient temperature.

Cruise at Highway Speeds for 30 minutes

The temp leveled off and stayed at this temp even as the outside temperature rose from the beach to the valley. It also stayed fairly steady while the engine was under load while going up a steep 3-mile grade...

Heat Soak Max

After a 30 minute highway run and sitting outside in 75 degree weather, this was the max temp reached in the fender well and under the hood...

Night time cruise home on Highway (30 minutes, same route)

Temperature was about 60 degrees at 70-80 mph the whole way.

Now for my setup:

C25a Manual Tranny with Homemade CAI:

Cold Air Intake is built from 4 90 degree elbows of PVC

Now for some Mythbusting:
It has been debated on many a car forum whether PVC is suitable for intake construction. It's a well known fact that when heated, PVC can melt, deform, and (worst of all) start to release fumes that can be toxic to both engine and occupant. Some say it WILL AND DOES happen, while others argue that the engine bay just doesn't get hot enough.

Well I decided to go straight to the horse's mouth. I asked a contractor what the temp rating of this PVC was. He was stumped. He called the manufacturer and we were informed that this particular PVC is rated up to 180 degrees for safe use. At 210+ degrees it will start to release the fumes. As the temps continue to rise, it will start to lose its shape and eventually start to melt.

One thing that I found interesting was that the company also produces ABS and stated that although it has a higher temperature rating, once it DOES begin to melt is releases fumes that are FAR MORE TOXIC than those released by PVC. Hmmmm.....

So if your car ever catches fire, head for the hills...or at least inform the fire department of the health hazard.

Anyhow, this material will only be temporary for me as I have something better waiting in the wings. But I digress...

I have another part to this un-scientific experiment that I will have to add to this thread at a later time. In short, I will be adding cold air to the stock air box in an attempt to stop biting my nails thinking about hydrolock come the first heavy rain storm.

For now, though, it looks like CAI > SRI (but I didn't have to tell you that now did I?)

Beeze · 10-05-07, 07:46 PM

Very Nice write up Gabe,
this is similar to the CAI I am in the planning stages of...except mine involves a short ram straight to a 90 degree coupler by the batt connecting to a 90 degree pipe to the fender well...again thanx for this experiment very informational...

GrtOutdoorsAZ · 10-05-07, 08:53 PM

yea that was awesome to see the actual temps...thanks for the write-up

very curious to see what I'm reading out here in sunny AZ...I bet my under hood is like 150 when it's 100 outside! where's a Rangerjoe CAI when you need one! guess I dont have to worry about hydrolock too much!

Xcaliber003 · 10-06-07, 02:17 AM

Nice writeup. IMHO it should be a sticky.

Quote:

Originally Posted by sam o nela

........In short, I will be adding cold air to the stock air box in an attempt to stop biting my nails thinking about hydrolock come the first heavy rain storm.

That's what I have on mine. I bought an OEM K&N filter and decided I still wanted some of the benefits of CAI.

BTW I know this is way off topic but do you have a write up or parts list for an auto trans to man trans swap?

Ken · 10-06-07, 03:13 AM

lol and I just put my stock resonator and last section of the stock intake back on like 5 mins ago. oh well, ive been through 4 intake setups before.

Jay P · 10-06-07, 03:59 AM

Hey nice, I vote keep the PVC, those elbows are pleasing, kinda doubt it will deform due to heat. When bending PVC electrical conduit one has to heat the crap out of it.

Do you worry about rain with cai? It pisses here in the winter.

Does it prolong engine warm up in cold weather? My car does 80miles/week of short trips in the burbs, I'd rather it warm up sooner rather than later.

What filter to use? I thought K&Ns are the way to go, better filtration and flow than paper.

I was once told the best is a conical filter crammed into the stock box, I fail to see how that would be better than a drop in K&N.

Any thought on the above?

cheers, Jay

music2bmurderedby · 10-06-07, 05:33 AM

yes my front bumper is in need of paint --- but besides that ... k&n drop in in the stock airbox with cold air coming straight into it via the front of vehicle (rammed air so to speak), & a friend of mine with an injen air intake would always beat me by about 1/4 to 1/2 a car b4 i did this ... i shit you not it is now the other way around. he paid $180.00 to get under the hood air, i paid $40.00 for the k&n & less than 10 for the aluminum 3" dryer hookup pipe & used a plastic piece from my yard blower that i will never use anyway. cheap or whatever you may call it, the power increase IS noticable & proven & it DOES give off a nice growl under the hood

Ken · 10-06-07, 06:09 AM

Quote:

Originally Posted by Jay P

What filter to use? I thought K&Ns are the way to go, better filtration and flow than paper.

Its actually less filtration and better flow. Can't have the good without the bad ya kno?

awelliott · 10-06-07, 10:49 AM

Nice writeup. Couple of questions: first, exactly where does your CAI end? Second, what are you using for filtration? Thanks...

*sam o nela* · 10-06-07, 11:55 AM

Quote:

Originally Posted by Xcaliber003

BTW I know this is way off topic but do you have a write up or parts list for an auto trans to man trans swap?

Hmmm...I believe there is an informal tranny swap post by Legend_Master in the FAQ....if not I will add it right now....but I'm pretty sure its there...

Quote:

Originally Posted by Jay P

Do you worry about rain with cai? It pisses here in the winter.

Does it prolong engine warm up in cold weather?

What filter to use? I thought K&Ns are the way to go, better filtration and flow than paper.

I was once told the best is a conical filter crammed into the stock box, I fail to see how that would be better than a drop in K&N.

Any thought on the above?

cheers, Jay

~I do worry about rain because there are some places in my area that are notorious for flooding come the first heavy rain. I know for a fact that my CAI will only be protected for so long by the splash shield and I've seen way too many horror stories on car forums...I know I could get a bypass valve, but I'd rather be safe than sorry...my next experiment will test the air temp difference between the CAI and cold air routed into the stock air box.

~I think that ambient temperature would affect your warm up time more than the CAI. I've had this intake on for over a week now and yesterday was the first day I noticed a longer time to warm up...but it was 60 degrees out when for the past few months it's been in the mid 70s every single day...

~Yeah I am using a regular paper air filter for a 91 Prelude...I trust the paper much more and I knew this setup would only be temporary. And regarding the Conical shoved into the stock airbox. Nikhai has this setup on his coupe and it does work, the only problem is though that I believe the stock filter or the drop in has more filtration area...either way I've just never been a fan of oiled-gauze filters...like Ken said, its a trade off...more flow with less filtration

Quote:

Originally Posted by music2bmurderedby

k&n drop in in the stock airbox with cold air coming straight into it via the front of vehicle (rammed air so to speak), & a friend of mine with an injen air intake would always beat me by about 1/4 to 1/2 a car b4 i did this ... i shit you not it is now the other way around. he paid $180.00 to get under the hood air, i paid $40.00 for the k&n & less than 10 for the aluminum 3" dryer hookup pipe & used a plastic piece from my yard blower that i will never use anyway. cheap or whatever you may call it, the power increase IS noticable & proven & it DOES give off a nice growl under the hood

Yes this is the California CAI that Erik (body9599) did way back when...this is kind of what I am planning to do, but minus the hose in the fender well...if one ever has to go through a deep enough puddle, that hose might become a straw

Quote:

Originally Posted by awelliott

Nice writeup. Couple of questions: first, exactly where does your CAI end? Second, what are you using for filtration? Thanks...

My setup ends as most peoples'...in the fender well with the resonator removed (been removed for quite a while actually hahaha) and protected from the elements by the splash shield. Also I am using this paper filter....

Stock Filter for a 91 Honda Prelude

Its a great paper filter...like I said I'm not much into oiled-gauze and I've had this filter on the intake for my wife's Infiniti for a long time now and its still going strong...plus I have no gripes about paying $6.99 every other oil change to change it out rather than having to clean and re-oil....

Thanks for all the great comments guys!

l4zy415 · 10-06-07, 12:44 PM

great write up gabe i mean teacher lol

my filter is foam, is that a good thing to use. plus its pretty easy to clean it up.

*sam o nela* · 10-06-07, 12:49 PM

Hate to tell you this man, but I have read in the past that foam is probably the worst in terms of filtration....

l4zy415 · 10-06-07, 12:59 PM

Quote:

Originally Posted by sam o nela

Hate to tell you this man, but I have read in the past that foam is probably the worst in terms of filtration....

damn well thats a kick on the nuts

Beeze · 10-06-07, 01:24 PM

What is the diameter of those PVC elbows, what size are those couplers, and where did you get them?

*sam o nela* · 10-06-07, 02:02 PM

3" 90 degree turns, 3" couplers, bought everything at Ace for about $20

10-05-07, 07:31 PM	#1 (permalink)
sam o nela His name is Robert Palson Join Date: Aug 2003 Location: SoCal Posts: 8,265 Car 1: '87L, 5 speed Sedan Car 2: '71 Datsun PL521 iTrader: (10)	CAI vs Short Ram...an un-scientific approach... Cold Air Intake and Short Ram Intake.... Which is better? Cold air or more air? The answer is "both." You want to have more filter area, but you also want to be bringing in cool air from outside of the engine bay. How much cooler? Well, see for yourself. In all of the following pictures, the fender well where the air filter is housed is represented by the Temp Gauge on the left while the engine bay's temperature is represented on the right. I warmed up the car to normal operating temperature (allowed the fans to come on twice) and then drove around for a while before officially starting to record the temperatures. Outside ambient temperature during the test was about 60 degrees F (it was much more chilly today than it's been for a while). First: Allowed to idle for 5 minutes The underhood temperature fluctuated between 130 and 135 which coincided with the fans coming on. It was definitely interesting to watch Second: Cruise for 7-10 minutes at 45 mph Both temperatures dropped significantly. The fender temp went as low as 65. But they both leveled off around these temps (67 and 89) before I finally took the pic. Third: Cruise at lower, neighborhood speeds. 30 mph for about 10 minutes. Engine bay temp rose back up though it was still quite cooler than at idle. The fender temp rose, at most, a mere 5 degrees. UPDATE Took a trip to Simi Valley today. 70-80 mph the whole way (30 minutes on the highway) at 75 degrees ambient temperature. Cruise at Highway Speeds for 30 minutes The temp leveled off and stayed at this temp even as the outside temperature rose from the beach to the valley. It also stayed fairly steady while the engine was under load while going up a steep 3-mile grade... Heat Soak Max After a 30 minute highway run and sitting outside in 75 degree weather, this was the max temp reached in the fender well and under the hood... Night time cruise home on Highway (30 minutes, same route) Temperature was about 60 degrees at 70-80 mph the whole way. Now for my setup: C25a Manual Tranny with Homemade CAI: Cold Air Intake is built from 4 90 degree elbows of PVC Now for some Mythbusting: It has been debated on many a car forum whether PVC is suitable for intake construction. It's a well known fact that when heated, PVC can melt, deform, and (worst of all) start to release fumes that can be toxic to both engine and occupant. Some say it WILL AND DOES happen, while others argue that the engine bay just doesn't get hot enough. Well I decided to go straight to the horse's mouth. I asked a contractor what the temp rating of this PVC was. He was stumped. He called the manufacturer and we were informed that this particular PVC is rated up to 180 degrees for safe use. At 210+ degrees it will start to release the fumes. As the temps continue to rise, it will start to lose its shape and eventually start to melt. One thing that I found interesting was that the company also produces ABS and stated that although it has a higher temperature rating, once it DOES begin to melt is releases fumes that are FAR MORE TOXIC than those released by PVC. Hmmmm..... So if your car ever catches fire, head for the hills...or at least inform the fire department of the health hazard. Anyhow, this material will only be temporary for me as I have something better waiting in the wings. But I digress... I have another part to this un-scientific experiment that I will have to add to this thread at a later time. In short, I will be adding cold air to the stock air box in an attempt to stop biting my nails thinking about hydrolock come the first heavy rain storm. For now, though, it looks like CAI > SRI (but I didn't have to tell you that now did I?) __________________ <Monocolor Paint Scheme> <JDM Clear Corners> <Cleared out Rear Turn Signals> <Acura Caliper Grill Emblem> <Independent Yellow Fog Mod> <15% Tint> <Iggee Seat Covers> <EL Reverse Glow Gauges> <Dimmer Mod> <Ford Taurus Cupholder Mod> <CC Tunk Light Mod> <Fut Short Throw Shifter> <Custom CAI> <AEM Bypass Valve> <OBX Headers> <Magnaflow High Flow Cat> <Dynomax Super Turbo Muffler> <Drilled/Slotted Rotors> <Painted Calipers> <Axxis Metal Master Pads> Last edited by sam o nela : 10-07-07 at 02:55 AM.

10-05-07, 07:46 PM	#2 (permalink)
Beeze Me & Nomuken(Monkey) Join Date: Jul 2007 Location: SoCal Posts: 765 Car 1: 1989 Acura Legend L Sedan iTrader: (7)	Very Nice write up Gabe, this is similar to the CAI I am in the planning stages of...except mine involves a short ram straight to a 90 degree coupler by the batt connecting to a 90 degree pipe to the fender well...again thanx for this experiment very informational... __________________ HOME DEPOT Tuning!

10-05-07, 08:53 PM	#3 (permalink)
GrtOutdoorsAZ Well Wisher Join Date: Apr 2005 Location: Casa Grande, AZ Posts: 2,107 Car 1: '94 GS sedan 6MT Car 2: '91 L sedan 4AT iTrader: (14)	yea that was awesome to see the actual temps...thanks for the write-up very curious to see what I'm reading out here in sunny AZ...I bet my under hood is like 150 when it's 100 outside! where's a Rangerjoe CAI when you need one! guess I dont have to worry about hydrolock too much! __________________ '94 GS 6MT Exterior: jdm headlights <> paint job <> retro '91-'93 OEM fogs & bumper <> 17" Konigs Performance: tuned Apexi SAFCII <> Sr5Guy chipped ECU <> Blackend engine damper <> MLS strut bar <> sr79labrat pulleys <> OBX headers <> Custom Y-pipe, Magnaflow Cat & Resonator, Stromung B-pipe & Muffler (All 2.5") <> TB Bypass <> RJ CAI w/ AEM bypass valve <> cross drilled/slotted rotors <> RJ short shifter <> ground wires Interior: Kenwood DDX6019 w/ NAV & Ipod, 2-tone leather

10-06-07, 03:13 AM	#5 (permalink)
Ken aka desired_speeds Join Date: Sep 2002 Location: The Hella Part of Cali Posts: 7,053 Car 1: 93 Honda Legend (LS) Car 2: 87 Honda Legend 2.5L Car 3: 96 Honda Inspire 32V iTrader: (2)	lol and I just put my stock resonator and last section of the stock intake back on like 5 mins ago. oh well, ive been through 4 intake setups before. __________________ . k e n

10-06-07, 03:59 AM	#6 (permalink)
Jay P Registered User Join Date: Jan 2005 Location: canada Posts: 158 Car 1: 1988 legend iTrader: (0)	lookin cool Hey nice, I vote keep the PVC, those elbows are pleasing, kinda doubt it will deform due to heat. When bending PVC electrical conduit one has to heat the crap out of it. Do you worry about rain with cai? It pisses here in the winter. Does it prolong engine warm up in cold weather? My car does 80miles/week of short trips in the burbs, I'd rather it warm up sooner rather than later. What filter to use? I thought K&Ns are the way to go, better filtration and flow than paper. I was once told the best is a conical filter crammed into the stock box, I fail to see how that would be better than a drop in K&N. Any thought on the above? cheers, Jay

Remove Advertisements Sponsored Links
The Acura Legend & Acura RL Forum Advertisement

10-06-07, 05:33 AM	#7 (permalink)
music2bmurderedby absconds using pump gas Join Date: Sep 2007 Location: stockton, ca Posts: 478 Car 1: 91' legend ls sedan Car 2: 2000 odyssey van Car 3: 96' rl iTrader: (0)	yes my front bumper is in need of paint --- but besides that ... k&n drop in in the stock airbox with cold air coming straight into it via the front of vehicle (rammed air so to speak), & a friend of mine with an injen air intake would always beat me by about 1/4 to 1/2 a car b4 i did this ... i shit you not it is now the other way around. he paid $180.00 to get under the hood air, i paid $40.00 for the k&n & less than 10 for the aluminum 3" dryer hookup pipe & used a plastic piece from my yard blower that i will never use anyway. cheap or whatever you may call it, the power increase IS noticable & proven & it DOES give off a nice growl under the hood

10-06-07, 10:49 AM	#9 (permalink)
awelliott Registered User Join Date: Jan 2007 Location: Helena, AL Posts: 570 Car 1: 1987 Legend L Coupe Car 2: 03 Honda Odyssey EX Car 3: 93 Dodge Dakota LS iTrader: (6)	Nice writeup. Couple of questions: first, exactly where does your CAI end? Second, what are you using for filtration? Thanks...

10-06-07, 12:44 PM	#11 (permalink)
l4zy415 FRISCO LEGEND BABY!!!! Join Date: Jun 2007 Location: Frisco Cali Posts: 2,117 Car 1: 1988 Acura Legend 4 Door iTrader: (4)	great write up gabe i mean teacher lol my filter is foam, is that a good thing to use. plus its pretty easy to clean it up. __________________ My Legend Is Rising Back From Hell!!!! BEWARE. 18" Limited 341 Chrome Rims Candy Red Paint Weapon R - Secret Weapon Intake LED Bright White Dash Lights/Floor Kenwood KDC-X590 Excelon Mp3 Deck Ford Taurus Coin/Cup Holder 2 12" Kickers 1200 Watt Sony XM-2200GTX 2-Channel Xplode Amp 2 Rockford fosgate Capacitor Power Acoustic Capacitor Clear Rear Turn Signal More to come...............

10-06-07, 12:49 PM	#12 (permalink)
sam o nela His name is Robert Palson Join Date: Aug 2003 Location: SoCal Posts: 8,265 Car 1: '87L, 5 speed Sedan Car 2: '71 Datsun PL521 iTrader: (10)	Hate to tell you this man, but I have read in the past that foam is probably the worst in terms of filtration.... __________________ <Monocolor Paint Scheme> <JDM Clear Corners> <Cleared out Rear Turn Signals> <Acura Caliper Grill Emblem> <Independent Yellow Fog Mod> <15% Tint> <Iggee Seat Covers> <EL Reverse Glow Gauges> <Dimmer Mod> <Ford Taurus Cupholder Mod> <CC Tunk Light Mod> <Fut Short Throw Shifter> <Custom CAI> <AEM Bypass Valve> <OBX Headers> <Magnaflow High Flow Cat> <Dynomax Super Turbo Muffler> <Drilled/Slotted Rotors> <Painted Calipers> <Axxis Metal Master Pads>

10-06-07, 01:24 PM	#14 (permalink)
Beeze Me & Nomuken(Monkey) Join Date: Jul 2007 Location: SoCal Posts: 765 Car 1: 1989 Acura Legend L Sedan iTrader: (7)	What is the diameter of those PVC elbows, what size are those couplers, and where did you get them? __________________ HOME DEPOT Tuning!

10-06-07, 02:02 PM	#15 (permalink)
sam o nela His name is Robert Palson Join Date: Aug 2003 Location: SoCal Posts: 8,265 Car 1: '87L, 5 speed Sedan Car 2: '71 Datsun PL521 iTrader: (10)	3" 90 degree turns, 3" couplers, bought everything at Ace for about $20 __________________ <Monocolor Paint Scheme> <JDM Clear Corners> <Cleared out Rear Turn Signals> <Acura Caliper Grill Emblem> <Independent Yellow Fog Mod> <15% Tint> <Iggee Seat Covers> <EL Reverse Glow Gauges> <Dimmer Mod> <Ford Taurus Cupholder Mod> <CC Tunk Light Mod> <Fut Short Throw Shifter> <Custom CAI> <AEM Bypass Valve> <OBX Headers> <Magnaflow High Flow Cat> <Dynomax Super Turbo Muffler> <Drilled/Slotted Rotors> <Painted Calipers> <Axxis Metal Master Pads>