My first mod that I would like to do would be to add the JCW CAI. I like this because it looks stock and I can fly it under my wife's radar. I think I read somewhere that the filters are like 100 beer credits. Are these reusable? how does this compare to the price of the stock filter? How long to then last?

I feel they 100 bucks a pop for a filter is crazy it is is a disposable unit.

 

I think its more like $80. Just order from Classic MINI and get the discount.

Reusable? No.
How long will it last? How dirty is the air around you? It all depends.

Too expensive? Its JCW.

 

The stock replacement is $100 retail, with 10-15% off from some dealers. It is not cleanable and is meant to be thrown away.

There is a washable ITG filter available for the jcw airbox from MYMINI for $80. I installed one about a week ago. I think it's the way to go.

 

Give me a week or two - I've got a JCW intake on the way, and intend to adapt a K&N re-usable cylindrical filter to replace the $90 origami filter.

I'll post K&N P/N and instructions once I've got it done - shouldn't be tough, maybe $50 cost at a guess, and a lot more effective than foam filters.

 

I rec'd the JCW today, and did some measurements. The stock origami filter has an O.D. of 4.5", flange I.D. of 3.375", and length without the flange of 7", not counting the molded support parts on the closed end which serve mainly to get you to pay $90 for the Mini paper filter.

Here is a list of K&N part numbers that would fit - my assumption is that a hose clamp over the K&N flange will be enough to hold the filter in place.

These filters and measurements can be found at http://www.knfilter.com/universal/universal.htm listed as Round Straight or Round Tapered.
RX-4140 cylindrical
RC-2710 cone
RU-2710 cone
RU-3130 cone
These filters are all within 5 sq.in. of the effective surface area of the stock origami filter, and should be far less restrictive, not to mention re-usable.

You can get them from direct from K&N or your local dealer. I ordered an RU-3130 cone, for $36.

This should be a considerable improvement in ability of the JCW airbox to deliver air. I believe that it will allow the JCW to deliver the same additional power as any aftermarket CAI, which it cannot possibly do with the remarkably restrictive stock paper filter.

If a hose clamp on the flange doesn't feel like it will be sturdy enough to hold the filter in place, I'll cut off the plastic support piece from the used paper filter I've got, and graft it onto the end of the K&N.

More later, with pics.

 

Please keep us posted on the results! I have been thinking along those same lines since I learned the astounding price of the replacement JCW filter element.

As an aside, there's no way I'd get the JCW airbox as a standalone item (It came with the JCW Engine kit on mine) Normally I don't slam on JCW, but $80-100 for a replacement filter that isn't meant to be reusable is RIDICULOUS!

Rawhyde

 

What he said... times 2 or 3!

 

I just worked up an adapter to use a K&N in the JCW air box - took about a half-hour total. The idea is to make a metal ring 1/16" thick that goes between a 3-1/2" ID flange of a K&N filter and the 3-3/8" neck of the airbox.

I got 4 ft. of 3/4"x1/16" aluminum from the hardware store for $4.00. Bent it into a 3-3/8" I.D. ring and filed the ends to be a close fit around the neck of the airbox, then epoxied it in place. Once the epoxy set, I took off the hose clamp that had held it in place for gluing, and it all came apart - the airbox plastic won't stick to epoxy or superglue either - must be polycarbonate. Dang - back to the drawing board...

As I was cleaning the epoxy off the aluminum ring, I realized that trying to glue it in place was a complete waste of time. A hose clamp around the filter flange holds the alum. ring in place just fine, so no glue needed.

A couple of tips on making a nice round ring:

- I bent the aluminum around a soup can - about 2-3/4' in diameter. When it springs back into shape, it came out to just about 3-3/8" I.D. A couple of minutes of careful hand-forming, and it fit perfectly.

- Plan to cut off the first inch or so of the ring you are making - it is very difficult to get the bend started near the end. You can cut the alum. easily with tinsnips. Use a hose clamp to hold the ring in place in the airbox, and then mark the end, to fit the two ends butted together.

- To hold the alum. in place while bending, I used a couple of thicknesses of fiber package tape to hold one end of the alum. flat to the soup can, then just rolled the can on my kitchen countertop until it went all the way around plus a couple of inches.

The largest K&N filters that fit the JCW airbox and have a 3-1/2" flange include:

- RX-4140 - cylindrical, 4" O.D., 5-3/4" long, with a flat flower-like filtered end piece - the X-Stream. Kind of pretty, and it has almost as much filter area as the one below.

- RU-3130 - tapered cone, 4-5/8" large end, 3-1/2" small end, 7" long (same as the stock JCW paper filter). I got this one for $36.

By my calculations, the stock origami filter has about 88 sq. in. of effective filter area, the RX-4140 has 79 sq.in., and the RU-3130 has 84 Sq.in. Either of the K&Ns will be far less restrictive than the paper filter and filter better than foam, and are about as large as you will get into the airbox.

 

This project worked out better than I expected. The filter, with adapter ring, is a snug press-fit on the airbox neck, and K&N even supplied a hose clamp for it (band clamp to you Brits).

Pictures attached:

- The K&N RU-3130 compared to the stock JCW air filter. You can see the plastic parts on the top of the stock filter that mate to the plastic hanger bracket in the airbox.

- The adapter ring - 1/16" x 3/4" aluminum bent around a Campbell's soup can.

- The ring inserted into the filter - a perfect fit. To install, I pulled the ring out 1/4" and then slid the filter onto the neck of the airbox, pressing the ring flush with the end of the filter flange.

More pix in next post...

 

More pix:

- The filter and adapter ring, visible inside the airbox neck.

- The filter installed. You can see the angle at which the neck in the airbox points, and all the complicated airbox actuating stuff that keeps you from installing a larger filter or one straight in. You can also see the plastic hanger that holds up the end of the stock filter for want of a hose clamp - I left it there, because the screw would leave a hole into the intake, and to act as a safety stop in case the hose clamp and filter ever came loose (unlikely, IMHO).

This should put the JCW airbox right up there in performance with all of the other CAI's - about 5-7HP, but quieter than any of the aftermarket alternatives. Happy motoring...

 

Awesome work! Are you planning to try the stock paper JCW filter and then swap and try the K&N back to back?

I have the JCW airbox (ordered as new) and inquired about the filter replacement being covered under the MINI 3/36k maintenance - they said it was, but only gets changed at 30k miles. Great I get one free paper JCW replacement filter out of the deal. I'd much rather have a K&N in there. Good work, now go mount that suckar up!

Do we have a hot wire MAF on our Tritec engine or is it something different with the e-throttle? Sometimes, the K&N filter oil ruins hot wire MAFs on Audi S4/S6 and other cars if too much is used. I do need really good filtration here in rallye roaded Vermont, maybe adding the extra slip over cover that K&N offers would be good for me too.

 

another thought on this...

I've only got 438 miles on my 'ess so far and haven't dipped into the 4500 rpm or beyond rev band. So, I have no idea how this little engine goes up top, or for that matter the JCW opening up! The whole e-throttle and supercharger surge yo-yo charateristics are faintly there at around 3,000-3,200 rpms - just slightly - and fully understand why they are there.

On all the cars I've ever fitted K&N filters to and modd'ed up the air box (or cut the whole top off Carrera Cup style on my Porsche 944) the throttle response improved by huge amounts. Every engine revved quicker right off the get go. All good for my driving style.

I wonder how a K&N in the JCW airbox will effect the throttle response and smile factor with the e-throttle, etc.? For the last five years, people have fit almost every imaginable CIA to the Cooper S W11 engine and seems to be all smiles - so, it must be good - right?

 

I have no plans to do a comparo, as I'm not about swap airboxes in and out. The paper filter I got with the used JCW airbox is really dirty, so that wouldn't be a good comparison, and I've been using a K&N flat panel in my stock airbox anyway.

BTW, the stock S airbox panel filter is just about 50 sq.in., so the upgrade to 84 sq.in. of K&N cone should be an improvement all by itself.

I will install the MTH Tuner file I requested for the JCW/K&N change. Between them, I anticipate that the JCW/K&N/MTH combo will open up the engine at the top end a bit, where mine currently has a noticable drop-off in urge above 5000 RPM or so.

 

I've had an inquiry about making the adapter ring available as a product for the JCW airbox - probably as a package with the K&N filter.

Anyone else interested? If so, PM me, and let me know what you would be winning to pay for a kit, keeping in mind that I'd have to make a profit to do it...

 

I'm afraid that I've only had two inquiries for this as a kit, both from the UK. I've had enough experience in shipping overseas to be aware that the export paperwork does not outweigh any potential profits, since I couldn't buy the filters in wholesale quantity, so I won't be offering the filter/adapter kit.

Readers in the UK should be able to find a local K&N retailer here: http://www.knfilter.com/search/dealersearch.aspx , and the instructions should allow you to make an adapter ring quite easily.

 

After a month, how is the K&N working? Any issues with rubbing b/c there is no hanger on the top?

 

The K&N works fine. I suspect that it makes a bit more power than the stock paper filter.

The hose clamp is sufficient to hold the filter in place, but I glued a 1/8" thick piece of plastic on the end of the little hanger triangle that indexes into the stock filter, to give the K&N a stop in case it ever tries to slip - probably a waste of time, but who knows...

 

Hmm, is the cost really that alarming? It doesn't seem like that huge an expense to spend $80 on a maintanence item that does something as important as an air filter every couple of years (once a year I suppose if you drive a lot of miles and/or live in a very dusty/dirty area). Its like motor oil or tires IMHO, important consumables worth the cost for what you get from it. Sure I can see that it seems like a lot for what it is but its not hundreds of dollars and, after all, it is a specialized custom item for an optional add-on created for a limited market. I guess I'm just surprised that considering all the random stuff people spend extra money on I so often see people so outraged over the infrequent 80 bux for the JCW air filter.

Anyway, good job on the K&N, enjoy

 

OldRick - You are the man! Thanks for a great write up along with good research and resoucefulness! This will come in very handy when I order my JCW intake.

BTW - Your username sounds very familiar. Were you ever part of an e-mail list run by Larry W?

 

best prices I"ve found for K&N. Free Shipping as well!

Nice work, OldRick....

And the JCW filter, totally craptastic! Once again!

Matt

 

Has anybody looked to see if Amsoil offers a direct replacement filter?

They're pretty easy on the wallet, cleanable, and, when I had one in my Defender, it seemed to perform better than the K&N.

 

Brilliant, OldRick, simply brilliant! I'd most definately buy the ring from you. PM sent. Thanks for sharing your efforts! Bravo

 

For $29 shipped for that filter and 60% greater surface area? What a deal!! I'd be willing to pay up to $20 for a ring if you'll make me one

 

That shim (or ring) could concievably be made out of rubber no?

 

I need 2!!!!