K&N Filter shape/size question - what's the difference?!?!?

[Robsalvv]

Hiya folks.

I've had quite a play with the seach function but didn't quite find the answer I was looking for. I've got a 2002 ZX9R with a yoshi pipe and stock air filter. Since it runs a little rich when set per the factory manual, I'm thinking a less wheezy air filter might sort things out and maybe make it a bit crisper in the throttle response.

Anyway, I see at the knfilters.com website there are two K&N filters for the '9R.






The only obvious difference I can see between the two is the cross sectional area/shape of the filter (and possibly the filter medium - but nowhere can I see this stipulated). The filter in the top picture (KA-0021) is more expensive than the filter in the lower picture (KA-9098).

Questions:

1. Which is the higher performance filter. The blurbs don't give any kind of clue. ??
2. Does the shape make a big difference?
3. I see in my searches that someone recommended keeping the stocker and removing the mesh - how does this improve the filter?


Appreciate your help, thoughts and/or advice.

Cheers folks.

Rob

[Neka79]

ummm email either k&n or the distributor/retailer??

i'd expect they are for different year bikes??

keep in mind, with a air filter and pipes, it may run lean, so re-jetting may be required....

havent done a filter mod on a 9, so cant answer that one..

[Rossi]

Mate,
the K&N doesn't really do a lot for the 9, just remove the plastic mesh off the standard one to give the best HP gain. If it's running rich after that you gonna have to fettle the carbs

[Robsalvv]

Nah Neka, they're K&N's air filters for the 98 - '03 model ZX9R's. I prolly will shoot K&N an email.

Rossi, I read that about the mesh - never realised that the mesh would have been so restrictive - I think I'll put that in my work list. But let me ask you, is the KSRC conventional wisdom about the stocker related to the cheaper KA-9098 or the more expensive KA-0021?

If I find out the answer before it's posted here, I'll share.


Cheers


Rob

[MadKaw]

Yep as Rossi said the K&N won't breath any better than std.
The best results I got on the dyno was the std filter with the mesh removed..
BTW Its was metal, not plastic on the 98..?.

[Robsalvv]

Well, I have got to say that the Tim at http://www.superbikesupply.com.au" was ultra hot off the mark to respond to my query! Kudos to them.

Here's what i've learned - the Australian importer of K&N, which is Rocket industries, has apparently never imported the KA-0021 (the top picture) into Australia and can't explain why it's different from the OEM replacement filter which is the KA-9098. Short of going to K&N direct (which I probably will because now I have a bee in my bonnet ), any quotes for K&N filters for our beloved 9R's will be for the KA-9098.

Now here's something interesting, Tim's price for the filter is VBG! (i.e., very bloody good). I've been quoted much higher than SBS's listed price! So I give SBS a VBG for service, response time AND pricing.



On the fuel richness question, fuel density is a bit denser in winter than in summer - so the standard mixture settings will result in a noticeably richer running bike in winter than in summer... I had the bike serviced recently and it's been running richer ever since. So far I haven't seen a drop off in performance or fuel economy, but plug fouling potential is in the back of my mind - a more breathy filter might be just the ticket.


I'll let you guys know more when I know more.

Cheers

[Robsalvv]

Well it's taken some perserverence and the answer to the question of which ZX9R K&N filter is the better one is.... drum roll please.... NFI!!!!!!!!

K&N got back to me and gave me a standard "do you want fries with that" answer about the benefit of K&N filters - so I reasked the question and after a few days I got the answer that the KA-9098 is the recommended filter since the other is being discontinued.

So, that's that then.

Hi there K&N, a query from Australia

I'm looking for a K&N filter for my 9R and note that two filters come up as suitable for the 2002 ZX9R F1, namely the KA-0021 and the KA-9098.

There's no information on the site which explains the differences between the two filters.

My question is this: What's the performance difference between the two filters? Rocket Industries weren't able to say. There appears to be a shape and corrugations difference in the filter media - but does that make the KA-0021 the relatively higher performance filter??? It is the higher priced filter.


Any info would be greatly appreciated.


Thanks in advance.

Much obliged.

Dear K&N Customer,



Thank you for your interest in K&N products. On average, our filter will give your vehicle a 2%-3% increase in horsepower. The more restrictive your original filter is, the greater your potential is for a performance increase. We do not perform any dyno testing on our replacement air filters, so we aren’t able to give you an exact horsepower gain.



If you have additional questions, please contact our Customer Support department at 1(800)858-3333.



Thanks for writing,

Hi xxxxx,

Thanks for responding to my query, however I'm writing from Australia so I hope you wont mind saving me an international call to your 1800 number So far, your K&N representatives in Australia have not been able to answer my query.

I appreciate the benefit of K&N filters, my question was specifically regarding the difference between the two filters your website lists as suitable for my F1 2002 ZX9R motorcycle. Namely, the KA-0021 versus the KA-09098.

Can you outline the difference please? It will help me choose a filter.

Much obliged.

Hello Rob,

The Ka-0021 is being discontinued and going over to the new part number KA-9098.



Thank you

Funny huh?!!


Ok, time to decide whether to go with the OEM mod or get a filter with the brake lines from Tim.

[mike-s]

they could always be moving to a newer designed corrugation shape/size, have a look if there are a couple of filters available for a few bike/car models, you may find thats whats up.