I've only ever dealt with carbed bikes in the past because, well, I could fix\tune a carb with a screwdriver, a pair of pliers and a hammer. So my question: gonna buy a set of Yoshi slip-ons and a K&N air filter in the next two weeks. With these additions, is a fuel management module mandatory?

Thanks Folks.

with just those mods ...no its not mandatory, but with a good map it will be a noticeable difference IMO

fyi stock air filter produces more HP than a K&N, Brocks has proved that on the dyno.

* Last updated by: scottjkyl on 3/31/2012 @ 5:47 PM *

You're saying Brock has dynoed an otherwise stock machine and it produced less power after the stock filter was exchanged for a K&N? I've read K&Ns pass more air than stock filters, so possibly it passed enough more to lean the already-lean stock fuel mixture enough to lose some horses.

all I'm saying is he's done a comparo with filters and has proven the stock filter produces higher #'s. But I have heard that K&N is not good if you live in a dusty area I guess cause the finer particles of dirt pass through the filter along with all that extra air lol. I had a K&N in mine and took it out at his recommendation. He makes HP for a living so I took his word for it.

I've spoken with Brock Davidson a number of times back when I was having them drop-ship my CT-Duals to be ceramic coated. He has always given me honest and useful information.

Brock says you are wasting money buying anything but an OEM air filter, because it won't filter better, and it won't make your bike go faster.

Pipercross is ok, it costs a bit more but you wash it and retreat it, so it lasts for years. It won't make your bike go faster.

OEM is the way to go, KHI spent decades of engineering figuring out what works best on their own bikes.

Question :
Does Brock's recommend the use of k&N or BMC aftermarket street or race air filters?

Answer :
Brock’s Performance does not currently recommend or endorse the use of ANY BRAND aftermarket “street” filters. It has been our experience that they do not perform as well as stock and can actually work much worse. The reduced air flow compared to stock; disrupts our known good mapping, decreases fuel mileage, hampers driveability, significantly reduces power levels, fouls plugs, creates excessive soot at the exhaust tip, generates excessive carbon deposits in the intake track etc. When over-oiled we have seen these problems increase dramatically with registered horsepower losses in the vicinity of 10-15+ with greatly increased fuel consumption. You can't go wrong with today’s modern OEM air filters, in regard to engine life and consistent performance.
We have noticed measurable performance gains when using both k&N and BMC aftermarket “race” filters compared to stock, but these filters are for racetrack or low mileage use only since they basically filter out bugs and birds!

fyi stock air filter produces more HP than a K&N, Brocks has proved that on the dyno.

Heard that the difference was not enough to matter. Can use the same map for sotck or BMC and won't amount to much. 2 hp maybe fopr a race filter? If it makes that extra little bit it= is worth the $80 it costs but not wort my peace of mind. I would only run OEM for street riding.

and for that matter, the slipons will only make 6-8 hp more. A map would be best but not going to make too much dif without. Full system, I think you should have a PC and good map.

Just get a full system and be done with it.

* Last updated by: Rook on 3/31/2012 @ 8:46 PM *

Thanks for your replies everybody!

An old dude I know, a factory certified HD restorer explained it to me this way: an internal combustion engine is little more than a big, self-powered air pump (edit: This should read air "compressor", not pump.) The more efficiently you get air in and then out, the better the pump ("compressor") works." This makes sense to me on a basic level, so my aim was not so much to make more power - I mean christ, I made a Wed. night run from San Diego to my living room 90 miles away in an hour, surface streets and signals inclusive, running the 15 from Diego to Temecula (60 mi) at 130 the whole way, with little effort on the bikes part, and at one point 180 +/- by the speedo's reckoning. More power for my simple ass might just be a very, very bad thing. :)

My goal is to make the thing breath easier to increase efficiency and longevity on a budget. Budget with a capital "B". I'm looking at the K&N mostly for it's re-usability factor and only secondly, for it's higher flow rate. The ram air component of the ZX makes the argument against it worth considering to keep the nasties on the outtside of the engine - but at 30 to 40 bucks a pop for OEM, the K&N's re-usability pays for itself pretty quickly. The Pipercross suggested might better suit my needs in this case.

As for the slip-ons, again, budget unfortunately plays the largest role above efficiency with HP increases on the lower end of the scale. I can pick up a set of slip-ons for 500 - 600 bucks as opposed to 1,000 plus for the 4-into-one - I only get a little easier breathing, but some is better than none, I suppose. Also, I've got tires coming up (I got 15,000 per rear on the HD - looks like I might get 5 or 6,000 outa the battlax) and right after that, the dreaded 500 dollar valve adjustment. Dang - fun is expensive, ain't it?

Thank You all again for your excellent help and for kindly dealing with my foolishness - I am certain there will be much more to follow :)

* Last updated by: Hadyomama on 4/1/2012 @ 10:52 AM *

I smell, fobeer bob'd her. YO! We are going to talk about yo momma's legg'inns.

(((Knock-Knock)))

Leggs: Whom be dare?
ATSD: <I'm 'At The Screen Door!

Leggs: Hose say can you see?
ATSD: A little.

Leggs: How many fingers am I holding up?
ATSD: Where is that H-D old guy? WOT finger?

Leggs: Finger pointing down at me legg'inns. Watt can you sea full of?
ATSD: You mean, let more shit in me bike and drop the HP I need more upp'pee'emph out the tire.

Leggs: She EAR... Me leggs are wearing... SHEar... How many pubic hairs you see bouncing out of me legg'inns?
ATSD: Ass (')pposed to you be all naked to see me, tear off them legg'inns and push your pube's thru the door screen?

Leggs: She IT YEah! You she it yet?
ATSD: NOPE!

^ lolz

Wait - What?

:)

* Last updated by: Hadyomama on 4/1/2012 @ 10:32 AM *

Silk screen = Not much debris can fly thru. However, this is slow air, not ideal performance but more for longevity.
Door screen = Lots of larger debris will pass with wider air cleaner pleats. This meets and greets the cylinder walls. WOT happens next are the slight grooves that score down the cylinder wall.

IF = You left it stock, I would not have to shove 220 pea, yes eye said, someone with less mileage than mine, has 180 plus PSI.

IF = You can't see 220 with silk, or 180 psi with a door screen kind of air cleaner, this is for sure, not my bike. My bike reads the higher piss in yo momma's cereal you go and do WOT ever you like...

"Next rookie question..."

* Last updated by: Hub on 4/1/2012 @ 12:16 PM *

^^^^You'll learn. Hubbish

* Last updated by: Rook on 4/1/2012 @ 12:08 PM *

My goal is to make the thing breath easier to increase efficiency and longevity on a budget. Budget with a capital "B".

But yeah, as yu mentioned, "the nasties". If they are let in, that is more likely to amount to a lot more in repair replacement bills down the road if you are running the filter on a daily basis. If a race air filter only makes a small increase in hp, I doubt it really lets all that much extra air in. I haVE one but I never use it.

I have not heard anyone complain that they have seen any signs of engine ware from dust aspiration through a race filter. Go ahead and do it. It's prolly a not unsafe you are not the only one who ever ran a race filter on the street. If for the perfornmance increase, I do not feel it is worth it. You will find people on both sides of the fence on this issue.

130 the whole way, with little effort on the bikes part, and at one point 180 +/- by the speedo's reckoning.

As for the slip-ons, again, budget unfortunately plays the largest role above efficiency with HP increases on the lower end of the scale. I can pick up a set of slip-ons for 500 - 600 bucks as opposed to 1,000 plus for the 4-into-one - I only get a little easier breathing, but some is better than none, I suppose.

hp increase ave cost: ~$100/1 hp increase. <<<<That is why a race filter is a excellent value for the increase i=even if it is a very small increase. You will surely get at least 1 hp for $80 going to a high flow air filter.

A good full system will make +15-18 hp. It also will reduce the weight a lot more than slipons. The stock header is a boat anchor. Strong yes, but HEAVY.

* Last updated by: Rook on 4/1/2012 @ 12:30 PM *

Thanks again, this forum just goes to prove motorcyclists are among the best folks on the planet.

The ZX is my daily driver, 130 miles per day, 5 days a week, rain or shine so I need it to be more of a marathon runner than a rocket, although the rocket part is funnnnn. I just need it to be efficient and to last. I got 218,000 outa the last bike and I aim to see if I can match or do better than that with this one. Again, on a Budget.

Thanks Rook, I won't get busted (knock wood, fingers crossed) and Thank You Hub, I would never, ever piss in me mammy's cereal - I value every bit of knowledge and advice you and the other folks here are kind enough to offer. You so funny. :)