Matt's Volvo Blog, $25 Cold Air Intake :: Discussion Area ::

Post by **matthew1** » 08 Dec 2009, 14:42

My much-delayed $25 Cold Air Intake blog post I finally finished last night. Basically, this Matt's Volvo Blog Issue #2 is all Cold Air Intake. It's about what I did, how, why and what my impressions are after 6 months about a few thousand miles.

>>> Here's the writeup Cold Air Intake Tutorial <<<

This very post is where you may discuss it, ask me questions, tell me I'm an idiot, etc.

Sample:

Before we start, I’d like to warn you about something. This mod does one big no-no, and that is exposing the engine to a greater risk of ingesting pollutants like dust, water, sand, grit or other debris. Volvo engineers have been working for decades to keep this stuff away from the engine, and by doing this you’re removing a big safeguard they designed: the position of the air intake.

To judge the degree of risk, a proper test of several (dozens? hundreds?) of 5-cyl turbo Volvos would be in order. Of course this has not and will not ever happen, so you must decide for yourself how much the extra power/efficiency is worth to you. SO FAR, my engine is fine.

If you absolutely must not take any chances with your Volvo, don’t perform this modification. Put in a K&N filter and call it a day.
Want more power?

I’ve had a bug in my head to do this ever since Pete in Australia posted his cold air intake modification years ago. Mine is really no different. Just better documented . Want more power, more efficiency? Don’t mind getting your hands dirty? Don’t mind checking on your work every month or two? Have $25?

Then this mod is for you. You’ll need

1 plastic funnel, $5

1-2 yards of 3-inch diameter dryer ducting tube, $10

High heat duct tape, $5

Duct tape, $3

Lock ties, $2

>>> Here's the writeup Cold Air Intake Tutorial <<<

C@lvin · Post by **C@lvin** » 09 Dec 2009, 09:24

Matt, I find this very interesting.

I did the 960 throttle plate and the air box hot air flap mods on my N/A 98 S70 (188K) and found no change in MPG but my perception is that it resulted in a very pleasant improvement in throttle response.

I keep tank by tank MPG so I can easily document whether something has affected MPG (still not completely scientific because all contributing factors cannot be controlled - but good enough for me).

It would be interesting to know if the effect of these modifications (other than MPG) could be physically measured in some way (without a gajillion dollar's worth of equipment), but in the end perception counts as much or more than proof.

I am adding a K&N filter to the mix this week and look forward both to measuring whether it effects MPG and to whether there are any perceived enhancements in response and acceleration. When I added a K&N to my wife's 00 Honda Odyssey (6 cyl.) I didn't really "feel" any difference. But when I put one in my 94 Toyota Previa (4 cyl.) I "felt" a significant improvement in acceleration.

The $25 cold air intake "experiment" may not be too far down the road

for my S70. For $25 (or less, since I might find most of this stuff lurking in my cluttered basement) and a few minutes of tinkering it may, at a minumum, enhance my perception and thereby boost my already elevated Volvo driving pleasure quotient.

Halo affect, you say? Who cares.....

Post by **matthew1** » 09 Dec 2009, 11:07

Calvin,

I agree, the biggest downside of this is not knowing how much better, if any, the performance and fuel economy is with the mod. Barring going to a track, or knowing a friend with a dynamometer, the only truly feasible test that would satisfy my curiosity would be long-term fuel economy test. Even then, you'd preferably want to test it on the same drive, say the route to work every day, with and without the mod alternating every day or every week.

You could run some repeated highway on-ramp tests late at night using a passenger with a stopwatch, or a performance tester, but you'd want to test, remove the mod, test, put the mod back on, test, etc.

You'd have to be pretty dedicated toward knowing if this cold air intake added 1hp or 2hp

.

Whatever. It's fun, and it's fun to point down to the odd red thing in the spoiler and say "I made my own ram air intake." Then see friends and family roll thier eyes.

Let us know how your K&N testing goes, and your cold air intake, if you do it.

C@lvin · Post by **C@lvin** » 09 Dec 2009, 11:50

This made me think of the Myth Busters episode where they tested the effect on MPG of having golf ball dimples on the surface of the car. Now those guys really know how to have fun (and not to mention seem to have an unlimited budget)!!!!

http://green.autoblog.com/2009/10/22/vi ... on-fuel-e/

Post by **RobTheModd** » 09 Dec 2009, 19:59

Ive noticed a 2-3 mpg increase, and its still rising after 1,000 miles of driving after doing the airbox mod.

Matt, Wouldnt Widening the air incoming area, and perhaps enlarging the hose do essentually the same thing as lowering it? And provide less worry, *puddles/snow*

Lets say your intake is this big
[__(_)__]
If you increased the intake to this
[______(_)__]
The (_)is the hose area
You would be increasing the area of intake. Thus pulling in more air.
If I can find a way to make something like that... Possibly with a trip to walmart for a large rectangluar tupperware container...

This way you are only Widening the side towards the pass side. since the radiator top is next to the intake opening. You would be leaving the hose in the same area just simply because of where the radiator is.

Post by **jtp** » 10 Dec 2009, 06:32

matthew1 wrote: To judge the degree of risk, a proper test of several (dozens? hundreds?) of 5-cyl turbo Volvos would be in order. Of course this has not and will not ever happen, so you must decide for yourself how much the extra power/efficiency is worth to you. SO FAR, my engine is fine.

This mod is on my list of to dos, as is an oil testing at 1k miles after an oil change. I'll try to get a test done at 1k w/out this mod, and another done at 1k miles with the mod, which might give a pretty good idea of what sort of pollutants are allowed in the engine by the lower intake position. In the mean time I'm still trying to put together a low psi smoke machine...

Post by **RobTheModd** » 10 Dec 2009, 09:13

jtp wrote: In the mean time I'm still trying to put together a low psi smoke machine...

or for under 50$ you could do it this way...
fog machine
http://www.hollywoodtoysandcostumes.com ... ap=1019100

power inverter...
http://www.codemicro.com/store/product/ ... efurbished

HAHA!

Post by **jmmxc** » 31 Dec 2009, 10:02

Matt:
This may not be entirely related to the mod you describe but it is closely related and you sure got some good insight on this: After reading this mod over and over and other related materials on the subject, I decided to take a look at my air cleaner box and found out that that the flap is stuck on Hot Air In position. Took it out and tried the refrigerator trick as described somewhere else (wife was not home to see this in the frozen chicken section of the frig). Sure enough the thermostat is not working. This thing never budged cold or warm condition. So I decided to stick a piece of wood behind the thermostat pushing and keeping the flap in the "cold air in" position. I have not modified the original air duct except to tape couple of layer of gauze material on the front of the CAI port to catch some potential debris...I also keep the same filter etc...
(a)_ I notice when I gun the engine and accelerate, it sounds different. A more "mature" sound.
(b)_The car responses rather quicker upon acceleration and up goes the sound of the engine as well, not too loud but different.
(c) _The rpm on idle did not change ~900.
(d)_ The engine initial warm up to temperature is faster. And when I am cruising...55~60, the engine tends to cool down slightly (not the usual 3 o'clock position of the needle, more between 3 to 4 o'clock). Note that outside air temp is about 28 to 30 degrees F now.
(e) I have not been driving it long enough to notice any mileage gain (or loss). Besides, my odo is not working. I will have to sort of rely on the gas tank meter and distance used to travel to give me an idea. (Not too scientific at all, being an engineer!)

Here are the questions and concerns: (1) Given that the air cleaner thermostat has not been working probably for quite a while now...does it make a difference whether the flap was stuck on HAI all this while as far the engine is concerned. I have not had any trouble codes related the air cleaner and components over the years...
(2) Is it safe, long term, for the engine to leave the flap in the CAI position from now on. I understand I have to watch the filter more often now...
(3) If I need to replace the thermostat how do I take out that piece from the air cleaner box. I do not seem to be able to wiggle the plastic (cai and hai) piece from the side of the bottom cleaner box. These 2 tabs that I pressed down...they are about to break... no movement of that plastic. So can the spring/thermostat mechanism be removed from the inside,looking at the back?

This is a long message but so much good stuff to talk about.
Thanks for your answers in advance.
jmmxc
Volvo 850GLT ,1996

Post by **matthew1** » 31 Dec 2009, 11:58

jmmxc, I can't speak to airbox thermostats. I can say that if the position of the deflector has been stuck for years and it didn't set off a code or cause a drop in fuel economy, I wouldn't worry about it. The computer corrects rich or lean conditions on its own, to a degree. No pun intended.

If it was too rich you would have seen a code and you'd have needed new O2 sensors long ago.

Post by **jmmxc** » 31 Dec 2009, 15:22

So either way I should not matter, based on what you are saying.
With the flap in cold air in position I should worry about debris and a dirtier filter.

I will give it a try as is, until I replace the thermostat.

Thanks and Have a great New Year 2010.
jmmxc