Air

[awdsubs]

ok so more specifically this time has anyone used this http://www.roveraccessories.com/airforce1.htm on their disco?

[Adam in NYC USA]

It is a "cold air intake".

If you want to install it you will probably get better breathing and better performance. I find it to be a pricy item.

If you are a tinkerer, you can look around and make one cold intake yourself. I have built two in the past and the only hard part is finding the parts for the intake tubing. I learned from a street racer that clothes dryer exhaust hosing worked for intake, for example. The reason I knew was that he was feeding a huge supercharger under his hood.

For the fitting between the air filter and the tubing, I imporvised and got the 3" rubber coupling used for toilets.

If you are going to install that, you might also want to upgrade your spark plug system and your exhaust headers to complete the package for optimium effect.

What do you say and what do you think?

[Adam in NYC USA]

check your local regulations regarding cold air intakes. In some areas, cold air intakes are considered an improper modification to the vehicle.

Who said? I stated it but knuckleheads like the CHIPS (California Highway Patrol) think they know what and what is not legal for gasoline engines. I wonder what they think of the Toyota Prius.

This heresay has trickled down to some dealers saying that some intakes violate car warranty. That is bunkus, refer them to this "the Magnuson-Moss Warranty Act":

http://www.knfilters.com/warrantyletter.htm

[Disco Mike]

If you look at some of the auto parts stores you will find different brands of intakes that you can buy by the piece, pretty easy to make one and alot less expensive.
Mike

[300bhp/ton]

Originally Posted by awdsubs

ok so more specifically this time has anyone used this http://www.roveraccessories.com/airforce1.htm on their disco?

It's just a filter, aka CAI, althougth it isn't really cold air as there's no ducting for cool air, it just takes it's air from the engine bay as per normal.

Gains will be due to less resistant filter (also less filtering ability) and larger diameter filter.

The stock airbox is designed to protect the filter, has a drain plug for if it gets wet and reduces dust/mud contact. It is also designed to limited induction noise.

If you off road a high rise snorkel is the best bet. And really should have any affect on performance.

This intake will be at more risk when off roading than a stock setup. I also highly doubt their claim of 15bhp increase.

I would expect crisper throttle response and if dirven sensibly better mpg (slightly) but worse mpg when you get on it. A small increase of 5-8bhp would be IMO nearer the mark.

Personally I don't like k&N filters much - SHOCK SHOCK I know - but I'll explain why. And I also respect that k&N have a MASSIVE market share and many will claim to have used their products with great results, although simply claiming great results without comparison is pointless. Or you'll find someone has a dirty clogged stock setup and replaces it with a k&N setup and attributes all the gain to the filter itself as opposed to just have in a clean filter.

Anyhow, back to the K&N issue. Essentially k&N filters are cotton weave, this means they are layered cotton with an oil coating. The oil is there to enhance filtering ability and prevent water ingression.

A clean k&N WILL out flow an OEM stock paper filter. However it will also filter worse, and at the end of the day the whole point of an air filter is too filter the air.

Paper filters also last quite well and as dirt builds up and they clog they will still flow at a similar rate to a clean one, it's only when they get very dirty that they suffer.

Cotton weave filters clog up quicker and very easily will end up flowing far worse than a paper one does. This IMO is reason a lone ont to run one.

This then means you must clean a cotton weave filter more frequently than you would need to change a paper one.

Now this is my real gripe with k&N's and all cotton weave filters. The cleaning solution generally cost about the same or more than a new paper filter does. And it doesn't stop there because once you have cleaned the filter you need to re-oil it as well. Which adds another cost into the bargin, combine this with the high purchase cost of the filter in the first place and it means:-

K&N filters:
-expsnsive to buy
-expensive to maintain correctly
-requires more frequent maintanance
-worse filtering
-if dirty worse flow

And it doesn't stop here. While re-oiling isn't particulary difficult it is suprisingly easy to "over oil" the filter, the oil then gets onto the MAF sensor which causes false readings and poor running, i.e. more cost and hassel.

NOTE: If oiled correctly then there should be no issues with the MAF.

What I would do and will be doing on my brothers 3.9 Vogue Range Rover is make my own CAI.

Foam filters generally appear to be superior to cotton weave, as they are used extensivly in off road motorsports, both bikes and 4x4's. However not ALL foam filters are and there are many which filter particulary poorly.

I have already bought the filter, it's a large foam filter by Piper X and it cost £12.50 all I need to do is remove the stock air box and attach it.

Again personally I wouldn't use metal tubing on a intake as it is prone to heat soak. My preferred choice is a length of silicon hose. You can buy it from many places and it isn't expensive, but it is rigid and suitable (is used for coolant systems and turbo piping).

You can also buy silicon hose in straight lengths, 45 and 90 degree elbows and with reducing sizes from one end to the other.

With a little thought and a little reading you should be able to make your own "better" CAI for around $50-100, I'm aiming at about £30-40 in total to do the one for my brothers Range Rover.

[Adam in NYC USA]

At least we did not start a flamewar on K & N filters.

Quick question: When are you supposed to

1>inspect your air filter and

2>replace your air filter?

Another question: when do you clean your K&N airfilter and when do you have to reoil it, as per manufacturer?

Those who know let the others write in, especially the K&N critic(s).

And those with the books, naughty naughty. But you can try to Google it.

Adam in NYC

[Adam in NYC USA]

From: http://www.washingtonpost.com/wp-dyn...040308127.html

Washington, D.C.: Good Morning Pat,
Great show, I listen every weekend even though it drives my wife nuts.
I'm thinking about switching to a K&N air filter not so much for performance but just so I won't have to buy anymore air filters. I'm thinking of the one that can be cleaned over and over. I plan to keep this car until it dies (2000 Accord). Is this a good product and is it a sound idea?

Thanks

Pat Goss: K&N makes a very high-quality filter. It can be used over and over but does require periodic maintenance. It has to be removed washed and then recoated with a special air filter oil. You have to be very careful not to get too much oil on the filter as this can lead to a failure of the MAF sensor. So BE VERY CAREFUL!

[FelixLockhart]

I did this to my truck, I decided I wanted to get rid of the stock airbox, but I didn't want to spend $100 on an intake pipe. So, here's what I did.

First step, remove the airbox. Leave the hose and MAF in place.

Step two, cut the neck off of the airbox lid, the pipe-looking part that connects to the MAF.

Step three, clamp a 3" diameter rice-boy filter of your choice to the piece that you just cut off

Step four, put everything back together, and voila! A cool-air intake built for the cost of the filter and little else. Now, it'd be a good idea to brace the MAF from vibrations, I used zip ties. Also, if you want to make a snorkel, use the same basic setup and put one of those filters on the external pipe, leaving you lots of space in the engine bay for things like air pumps and MSD boxes.

[apbtpetey]

300bhp/ton is right about this set-up not really being a true Cold Air Intake system.

For it to be a true cold air intake system, you need to box around the filter and run piping from the filter box to a spot where it will draw in cooler outside air instead of drawing in the air from the engine compartment.

For example: It is common to see a cold air intake system set up on a mustang where they have a filter such as the one you linked with a metal box around it. Then coming out of the box is a tube that runs down to where the fog light is on the lower part of the bumper. They remove the fog light and air is draw into the tube through the fog light hole and into the filter box, bringing in cooler outside air.

On a rover when you add a snorkle you are actually pretty much setting up a basic cold air intake system.

Now the other part of this is the size of the tubing you use. The bigger the more cold air you can draw in.

[texasrover]

Question???

How money are you willing to put into these mods when you GEMS will compensate for them?



Am I wrong? I have not really gone knutz in mods to the engine because I always thought the GEMS would cancel out much of the improvement... hmmm

[FrankS]

Originally Posted by FelixLockhart

I did this to my truck, I decided I wanted to get rid of the stock airbox, but I didn't want to spend $100 on an intake pipe. So, here's what I did.

First step, remove the airbox. Leave the hose and MAF in place.

Step two, cut the neck off of the airbox lid, the pipe-looking part that connects to the MAF.

Step three, clamp a 3" diameter rice-boy filter of your choice to the piece that you just cut off

Step four, put everything back together, and voila! A cool-air intake built for the cost of the filter and little else. Now, it'd be a good idea to brace the MAF from vibrations, I used zip ties. Also, if you want to make a snorkel, use the same basic setup and put one of those filters on the external pipe, leaving you lots of space in the engine bay for things like air pumps and MSD boxes.

A "Cold Air" induction system draws air from outside of the vehicle not from the hot box that is the engine bay.
What are you after a couple of short lived extra horsepower, or do you want your engine to breathe Dust-Free air, the standard OEM paper filter will out perform a K&N filter at what they were designed to do and that is Filter out dust (read Grit), what more do you need, there is a post by me on K&N filters with a very interesting comparison test on this Forum, search either "K&N or FrankS, Regards Frank.

[FelixLockhart]

I mostly did this mod so I'd have more room to work in the engine bay, and the stock airbox is ugly. And I didn't use a K&N filter, I've seen MAFs destroyed by them, I got a cone-shaped paper filter.

And I know it's not really a cold-air system, that's just a convenient easy-to-type name for it :-)

I may convert to a snorkel on my next truck, mine is nearing its death (rusting faster than I can repair it), so it's not worth the time/expense until I get another Disco.

[Adam in NYC USA]

Originally Posted by FelixLockhart

..... And I didn't use a K&N filter, I've seen MAFs destroyed by them, I got a cone-shaped paper filter.

AHem. You just stated an opinion , not a fact, based on prejudice.

You did not see any MAFs "destroyed by K&N airfilters".

You have seen MAFs that don't work because the wires were contaminated by the cleaning mineral oil used in the K&N or there was something wrong with the K&N, or the poor MAF just reached the end of its life.

Am I in the minority that a properly cleaned K&N airfilter lasts for quite awhile?

Why is it an axiom of human nature that if some is good, more is better? It does not work for medicine and it dont work for auto mechanics. Try that with motor oil and see where it will get you.

Cleaning and drying a K&N airfilter is not a difficult task but it seems many "intelligent people" can't seem to read the easy instructions and follow them.
If you are in that catagory, well there you are.

I am a happy customer of two K&Ns. They work well and continue to do so. Anybody who says neither does not know the product nor how to use it. Enjoy your paper filter. See if it makes decent coffee.

Adam in NYC (and no I don't own stock in K&N and Lucas, I just believe in something called the scientific method)

[Muddy Oval]

Funny quote from Pat Goss- I know him well... he sells K&N filters and now that his show is owned by advertisers, he won't badmouth anything. He runs K&N on his Corvette, but nothing else.

K&N outflows a stock filter when it's clean, but it only filters as well when it's dirty. I run them on my race car and there is dust inside the ram tubes after a very short amount of time- no way I'd do that to a Rover that I want to keep running for years. Shorty intakes and stuff on a Rover is just silly, to me. But it's your truck- do what makes ya happy.

As for the Magnussen-Moss act and warranty. Stick some silly intake on there and start quoting the Mangussen-Moss act when you have engine trouble and you'll get nowhere. You would have NO case. The aftermarket filters MUST meet OEM specs as per the manual that comes with the truck- and K&N and all those others do not meet that spec...

[FrankS]

Originally Posted by Adam in NYC USA

AHem. You just stated an opinion , not a fact, based on prejudice.

You did not see any MAFs "destroyed by K&N airfilters".

You have seen MAFs that don't work because the wires were contaminated by the cleaning mineral oil used in the K&N or there was something wrong with the K&N, or the poor MAF just reached the end of its life.

Am I in the minority that a properly cleaned K&N airfilter lasts for quite awhile?

Why is it an axiom of human nature that if some is good, more is better? It does not work for medicine and it dont work for auto mechanics. Try that with motor oil and see where it will get you.

Cleaning and drying a K&N airfilter is not a difficult task but it seems many "intelligent people" can't seem to read the easy instructions and follow them.
If you are in that catagory, well there you are.

I am a happy customer of two K&Ns. They work well and continue to do so. Anybody who says neither does not know the product nor how to use it. Enjoy your paper filter. See if it makes decent coffee.

Adam in NYC (and no I don't own stock in K&N and Lucas, I just believe in something called the scientific method)

K&N filters might be OK around NYC but if you tried using one in outback Australia, where roads can have bulldust (like talcum powder) a foot deep, then your K&N would be totally clogged within a few miles, that's after letting in enough dust to do some serious damage. A good quality off-road Paper Air Filter can be blown out, and the Donaldson's on my Mack truck got dry-cleaned once a month and they lasted a couple of years or a million Klms or so. I had A cold air induction on my BA Ford Falcon GT (5.4 quad cam V8 290kw) and a K&N air filter, performance gain with this system was 18kw at the rear wheels extra. The engine was replaced at 15,000klms because of an oil consumption problem. If you could have seen the grit and grime in the plenum and the inlet trumpets, you would not use a K&N, as I don't, Regards Frank.