Just picked up a new Z400. I have a few questions.

How many of you are running with your air box lids off? I am trail riding for the most part. Should I get a Uni or K&N?
Also, I want to add a pipe. Are the slip ons effective or do I have to replace the whole exhaust?
Does anyone have expierence with the Power Now product from Scary Fast? Does it work?

Do I need to replace the stock skid plate? I saw the new product in Dirt Wheels from Nurkle. It looks nice nut it is expensive.

So far I love this thing. Very predictable and fast too. Thanks for the help.

 

you can buy a lid from outerwears that has a screen in the center and will repell water and dirt pretty good, i still gotta pick one up myself, i've heard they work good

get the full system on the pipe, slipons dont give that good a power gain really and full system on my bike feels like a different bike now.

Im going to replace atleast the swingarm skid on mine because the plastic one seems to flex to much and the brake caliper is eatting through it.


i'd atleast drive the bike stock for one summer, enjoy it for what it is, then the next summer add a bunch of mods and you got a differnet bike! lol

 

If money is an issue, get a slip-on White Bros. E-Series or a Pro-Circuit T-4. If money is no object then I'd agree on a full system.

I have got a Power Now valve on/in my Z-400. They are worth every penny!!! Yes, expensive for a little piece of metal, but the throttle response & power gains far outweigh the cost. I'll agree with DVXDUDE about leaving it stock for the time being, OTHER than get a Power Now valve. You won't be disappointed.

 

I know a few guys who race XC, and they originally went with the full systems, but later went back to the stock header pipe...

The full systems give you more top end, but leaving the stock header pipe gives a nice low end increase..... The guys in the woods felt that the full system was not giving them as much low end as the stop header with the slip on pipe. And since in the woods you are rarely riding in the top end of the power band, it seems most people are happy with just the slip on and a jetting change.

As far as the power-now product, some people prefer it over re-jetting, some don't..... Dirt Wheels did one on their latest project z400 and they seemed satisfied with the results..... they also left on the stock air box lid..........

I think no matter what you do it will be good........

But wait until you break it in and get the heavy break in oil out... you will notice a decent power increase right there....

 

This is what I would do:
-yoshimura exhaust, i would recommend the entire system. I modified a z250 spark arrester to fit in my yoshi and it quiets it alot, sounds good and will still outrun a 450r with it in.
-remove air lid and put an outer wears on the box. leave the stock filter, an aftermarket will give you no gain.
-13 tooth front sprocket, makes it easier to ride slow, and picks up the bottom end a good bit.
-jet kit
-parking brake block off, it will lower drag on your rear brakes, you can just put it gear to park it anyway.
-power now valve
-1000rpm rev box, with these mods you will be on the stock rev limiter alot.
hope this helps....then when your ready for that dude to really scream, you can put web cams, port the head, and change the base gasket on the cylinder to raise the compression and a lightweight flywheel.

 

If you are trail riding, you need a lid of some sort. The easiest(and fastest) way to trash your motor is to let it suck in dirt/mud/water. If you want a bit more airflow, buy one of the aftermarket lids or install airbox vents. Stay away from K&N if you can, I prefer foam for a filter where you are going to be riding in muddy conditions. Uni and Twin Air are both good choices here, and the filters themselves are cheaper. Buy 2 and you can keep a spare clean and oiled in a plastic baggy. While a full exhaust will get you another hp or 2, you would be fine with a slip on. Here it is really all in how much $$ you want to spend. The main restriction is really at the can, the header is a more subtle gain. As for Power Now stuff, I just stay away. When this stuff first came out for cars it was pushed as raising HP AND gas mileage. This has been pretty widely debunked. Still, the bike and quad mags have all seemed to like them, it is your money. Finally, replacing the stock skid is the first thing I do. To much $$ and inconvenience to replace sprockets and rotors if you hit a rock or log wrong. I don't know about the product you mentioned, haven't seen it myself. I do know pretty much any .190+ aluminum skid will work great for years. Personally I am running AC skids, but would probably use Pro Armor if I ever have to replace the current one.

 

1)if you read what I said a the beginning, you will see I mentioned using a pre filter on the box.
2) the power now valve works nothing like the car product you are talking about. If you do not know, do not give your opinion. I have one on my bike and it does make a difference. thanks.

 

Agreed, LTZGUY. The Power Now is not like the "tornado" for car intakes. The Power Now staightens out the air charge, that's why it works & add throttle response and H.P.

There is a product for 4 barrel carbureted car/truck engines that does the same thing as the Power Now valve does, it's straightens & smoothes out the airflow, and it too works. The "tornado" thing is crap. The smoother, straighter, & faster air can get into an engine, the more power that engine will make. You don't want the air tumbling or spinning.

 

EXACTLY.

 

Thanks a million guys. This was exactly the type of responses I was looking for. I am going to pipe it, power now, after market airbox lid, jet kit, nerf bars, skid plates, remove park brake, new rev box, and install a smaller front sproket. I can't wait to see and feel the results. Thanks again for the input.