Air filters

[Red SLR]

I have noticed that my supelight has a foam air filter. Does anyone know if K&N make a replacement for this filter?

 

Also does anyone recomend putting cool air induction pipes in to provide some fresh air into the inlet? (as it is facing backwards)

 

Ta

 

Simon.

 

X777CAT

[Red SLR]

This post is sinking faster than the Titanic - come on guys!

 

X777CAT

[elie boone]

Dear Simon,

Saving the Titanic is a little difficult as i can not hold my breath long enuf to go 2.5 miles onder sea level.Cool air is more dense than hot air, so it is surely not a bad thing to get some cooler air in to the motor.But if the air has to come in a tube from the front of the radiator up to the filter you will lose a lot of the effect you are aming for.Best is to make a box withs match one of the louverbloks in the bonnet as it is done for the heater.

 

 

[Red SLR]

Has anyone dont this to a superlight - does it offer any benifits???? Thanks simon.

 

X777CAT

[old captain slow]

You want MORE power?

[Pierre Gillet]

Simon,

I would have thought that a foam air filter is more "free" than a K&N. So, I would probably keep it unless the reason to go for a K&N is less maintenance or better filtration efficiency.

As for cold air, it should be good to be able to bring some to the filter, but I imagine it would not be so easy to do so without making a kind of air box, and benefiting also of some ram effect.

Pierre

[SLR No.77]

My 1400 Supersport (supplied as a C-Class racer, 1995) already has the throttle body and K&N filter facing forwards from the plenum chamber, unlike most other supersports I've seen which have everything up at the scuttle end. Maybe this was true to all 1400s, I'm not sure.

 

Looking at the plenum chamber it appears to be double ended, and could be assembled with the throttle body at either end - this assumes the plenum in question is the large bore aluminium type as opposed to the newer plastic ones? I assume the plastic ones are a standard Rover part (less cost than aluminium) and therefore there would be no choice as to the location of the body & filter?

 

 

Stu.

[Red SLR]

The reason why I like K&N is becuase I have seen them perform much better than all foam filters - but I think I will leave the foam one in place for now but run in some cool air pipes.

 

Ta.

 

Simon.

 

X777CAT

[Peter Carmichael]

If you are wondering what extra performance you might get from a filter change...

 

One trackday at Goodwood I failed to realise until I got there that the previous night's maintenance activities had left the filter on a bench in the garage. I can honestly say that it made stuff all difference.

[elie boone]

Dear Simon,

You need to clean a K&N as often as say a Pipercross foam filter.

 

 

[Red SLR]

I think everyone has got a bit confused.

 

I am not looking for a performance increase... I just like K&N filters.... I like the fact that I can oil them etc myself thus I know my engine is protected.

 

Also the reason why I asked about fitting induction pipes is because a K&N57i kit should not be fitted without them - which I why I had asked about them - as the inlet faces backwards.

 

Any way I will keep hold of my foam filter for now but I will no doubt replace it wil a K&N.... with induction pipes of course!

 

As for performance increase - on an engine which is designed for quiet running dropping the origional filter box and tubes and going to the induciton kit can add upto 20bhp (Jeep Cherokee V8) but on an engine in a 7 there is not much to be had - under 1bhp. But K&N filters offer far better filtration properties than paper or foam.

 

Simon.

 

X777CAT

[Peter Carmichael]

Whose marketing material have you been reading?

 

smile.gif

[Red SLR]

I can vouch for the gain on the Jeep Cherokee.. it was 23 Bhp at the wheels.

 

Most cars will see 2bhp - 10 bhp at the wheels from ditching their air box and going to K&N.

 

I think the Jeep was a record for a std K&N filter gain.

 

Simon.

 

X777CAT

[Andrew Russell]

I recall reading an article in Racecar magazine which did a back to back test of air filters on a Vauxhall engined 7 racecar, comparing the standard K.N. filters with foam Ram Air filters.

 

The improvement shown by the change to foam was quite impressive as I recall, but as Peter has said, whose publicity do you believe?

 

Personally I like the classic look of the K.N.'s but also think that the large foam types also have a certain appeal, be they ITG or RamAir, or whatever. There are problems with fitting the single large foam filters in the standard bonnet aperture for side draught carbs but this has been discussed previously in this forum.

 

As usual, horses for courses, personal taste, size of wallet and so on are all factors!

 

Andrew

[Pierre Gillet]

Relative to K&N cleaning, what is your experience?

K&N claims that you can use them without cleaning them for almost ever!

Cheers,

Pierre

[CHRIS CLARK]

Stuart F.

 

For your info, my '93 1400 SS has the fwd. facing filter whereas I believe the std. 1400 has a rear facer.Due I'm sure to the plenum chamber alterations. Anyone confirm?

[Red SLR]

I would say a K&N filter should be cleaned every 10K. I do my road car one ever 3K.

 

Even after 3k there is a good handfull of cr*p gets washed out.

 

Have you got a K&N cleaning kit?

 

X777CAT

[SLR No.77]

Chris,

 

I've seen newer 1800K Supersports with plastic inlets and the filter facing backwards. Just makes me realise how superior the 1400K Supersport is!

 

Stu.

[Pierre Gillet]

Simon,

yes, I have what I believe is the K&N kit: that is the detergent and the oil.

I shall take into account your experience and clean the filter let's say every 5,000 km when I change the oil.

Cheers,

Pierre

[Red SLR]

I would say that is a good idea.

 

Cheers

 

Simon.

 

X777CAT

[EFA]

On sidedraughts (carbs or throttle bodies) the ram pipe length is critcal to the combustion process, hence many of these reviews have got this length closer to optimum hence the big power hike.

 

I guess this is of less consequence in a single venturi throttle system like on the Vx injection and K series (except VHPD and R500).

 

If anybody out there has some interest on using ram air induction let me know - this is one of the faetures I may add to my engine soon, as its rebuild and rebore will mean remapping.....

[Peter Carmichael]

So Arnie, are you going to revert to carbs? Why do I ask, when I am sure you have a plan?

 

First off, when people start talking about ram pipes they are usually referring to the flared trumpets that go on the induction system. The tuned length is the length from the back of the inlet valve to the flare. When the valve opens, a low pressure sound wave (essentially a sound wave) travels back along the inlet tract at a speed determined solely by the temperature of the air in the tract according to some magical formula which I keep in my sock drawer. When the rarefaction wave reaches the change in cross-section at the rampipe, a high pressure reflection heads back down to the port. The length of the inlet tract determines the overall time taken and hence the rpm at which this causes the greatest boost to cylinder filling - i.e. pulse tuned inlet. My new engine will peak at between 7500 and 8600 rpm - Mike Bees has a longer inlet tract, so the peak will be a bit lower.

 

Arnie, I think you are talking about something else: using stagnation pressure to produce a measure of forced induction in a well-designed airbox. The difficulty with this comes when trying to map the fuelling in a throttle body implementation. The airbox obviously is subject to pressure pulses and fluctuations so you need a filtered measure of the airbox pressure feeding a correction to the basic map. Either that or carbs which would self-adjust to an extent.

[Nick]

A friend has just sent me this URL

www.itgairfilters.com - means nothing to me!

[Graham Sewell]

My understanding was that K&N filters worked better once they had collected some rubbish - but that airflow was not diminished for close-on 50,000 miles smile.gif .

 

Therefore, cleaning the filter every 3,000 miles puts the engine at risk sad.gif .

 

Cheers,

 

Graham

[Dartmoor7]

Don't clean K&N too often. See below:

 

1. SERVICE INTERVAL

In normal, on-road applications, service your K&N Filter every 50,000 miles. A certain amount of dirt build-up will actually work for you. It does not degrade performance and helps filter the air.

 

Service the filter more frequently if it is subjected to frequent or heavy dust. Regular operation in a fine dust environment, such as what would be present for agricultural, construction or off-road use, will cause oil loss from the element. Frequent re-oiling of the element's clean side may be required.

 

Service K&N Filters only with K&N Air Filter Cleaner and K&N Air Filter Oil.

 

2. PRE-CLEANING

Tap the K&N Filter gently on a hard surface to dislodge loose dirt. Tap the base of a round filter. Tap a panel filter dirt side down. Do not tap any filter on its edges. Remember to tap gently. Next, gently brush the dirt side of filter with a soft bristle brush. A old tooth brush works well.

 

3. CLEANING PRECAUTIONS

Use only K&N Filter Cleaner. It is available in either spray-on or liquid form. Do not clean K&N Filters with gasoline, solvents, parts cleaners, strong detergents or caustic cleaning solutions. Do not steam clean or use high pressure car washes to clean a K&N Filter. Any of those processes will damage filter media and/or the rubber base, top or end caps.

4. SPRAY CLEANING

Spray K&N Air Filter Cleaner liberally onto the entire element. Let the Cleaner soak into the filter media for 10 minutes.

 

5. PAN CLEANING

Most larger K&N Filters are easier to clean in a pan. Best to use for larger round filters is a bread pan of adequate width and depth such that a section of the filter can be dipped in the Cleaner. Fill the pan with K&N Air Filter Cleaner to a level where the filter media is just barely submerged. Rotate the filter once so all parts of it go through the Cleaner. Do not agitate the filter in the Cleaner as dirt removed from the dirty side may be redeposited on the clean side. Remove the filter from the pan and set it aside. let the Cleaner soak into the filter media for 10 minutes.

 

 

Panel filters are easier to clean in a roasting or turkey pan, such as the disposable aluminum units found in grocery or cooking supply stores. Place the filter in the pan and pour in the Cleaner to a level where the filter media is just barely submerged. Do not agitate the filter in the Cleaner. Remove the filter from the pan and set it aside. Let the Cleaner soak into the filter media for 10 minutes.

 

6. RINSE

After the Cleaner soaks for 10 minutes, rinse the filter with low pressure water. Water out of a household faucet is best. Always flush opposite the direction of air flow ie: from the clean side to the dirty side. This removes the dirt and does not drive it further into the filter media.

 

7. DRYING

After rinsing, shake off the excess water and let the element dry at room or outside air temperature. Many people hang filters on a clothes line to dry. Do not use compressed air because it will damage the filter media. Do not use heat from any source to dry a K&N Filter. Heat will shrink the filter media and may damage the rubber base, top or end caps.

8. OILING PRECAUTIONS

Never put a K&N Filter in service without oiling it. The filter will not function properly without being oiled. Use only K&N Filter Oil or the filter will not function properly. K&N Filter Oil is a unique blend of mineral and organic oil base stocks and special polymers that form a very efficient “tack barrier.†Red dye is added to show areas of oil application. Eventually, the dye fades but the oil remains to filter the air. Do not use automatic transmission fluid, any kind of motor oil or diesel fuel to oil a K&N Filter. Do not use “WD-40â€, “LPS†or any othertype of light-weight spray lubricants to oil a K&N Filter. Any of those products will damage the filter or degrade its filtering ability. A K&N Filter used on an engine that is regularly operated in a fine dust environment will require frequent re-oiling of the filter’s clean side in between cleanings.

9. SPRAY OILING

Spray K&N Air Filter Oil from a distance of about 10 inches onto a group of pleats. Spray each group of pleats only once. Spray oil onto the filter media such it becomes reddish in color. Let the filter sit for 10 minutes then respray any areas that are still white.

 

10. SQUEEZE BOTTLE OR TUBE OILING

Squeeze K&N Air Filter Oil onto each pleat. Let the filter sit for 20 minutes as the oil “wicks†into the surrounding filter media. Apply more Filter Oil to areas that are still white

 

11. REINSTALL

Re-install your K&N Air Filter with care. In some applications, especially off-road use, it may be necessary to use K&N Sealing Grease on rubber base, top or end caps of the filter. Make sure the element seats properly in the filter housing. Install the cover and tighten all the nuts, bolts, screws or clips to the manufacturer’s specifications.

 

12. DO NOT DISCARD WARNING

Apply the "Do Not Discard" sticker, included with every K&N Filter, to the filter housing. Place the sticker in a visible position to alert service technicians to the existence of a K&N Filter on your engine.