ZX50 2006 SPORT AIR FILTER

[Loroso86]

Hi, i have a zx50 2006 and i plan to fit a sport exhaust. My question is that do i need to fit a sport air filer or the sport exhaust will run well with the factory air filter?

[Stig / Major Tom]

Welcome Loroso!
If you would, please add your location (country would work)
Stig

[TBR125]

You do not have to change the air filter. If you add an exhaust that allows for more flow, then the air-filter will be the limiting factor.

[Loroso86]

How do i know if it allows more air flow? Im planning to fit a giannelli rekord exhaust. Can you tell my if it allows more air flow and do i need to change the air filter if i fit it

[TBR125]

The concrete max flow for a pipe is the output diameter, is it larger than the original. The practical resistance however is the sound muffling system. As it is a "sport exhaust" I believe the muffling will be slightly less than a stock. Also, the stock muffler typically is not restrictive to the point of lowering engine power output. Generally freeing the air flow will increase overall flow even with the stock exhaust.

Short version of the ramble: The stock or new exhaust is capable of conveying more gasses than the stock air filter allows. Installing a filter with more flow will create minimally more power, but the fuel must be increased to keep the stoichiometric fuel air ratio of approximately 14.7:1.

If you only install the exhaust it may make a power difference if properly tuned for your engine.
If you add a hi flo air filter, fuel has to be increased and you become very knowledgeable of carb internals.

Hope some of that helps.

[Loroso86]

What's output diameter? Is it the size of the tip of the exhaust where air goes out?

[TBR125]

Yes. I am sure that the rekord exhaust has less resistance even if the out put is the same size.

[Loroso86]

I think that the diameter on the gianelli rekord is maybe around 0.3 cm bigger. Do i need to change the air filter for that little of a difference in size? And what do you mean by resistance what kind of resistance? What do you suggest i do?

[TBR125]

I would just change the exhaust if you have it and see if you like the result. Changing several things at once can be a tuning nightmare.

[Loroso86]

My goal is to get faster acceleration and higher top speed the top speed now is around 45 mph and i plan to fit a rekord exhaust fit 5 gram rollers instead of 8.5(standard) and to fit stiffer clutch springs. What do you think my top speed will be after these modifications?

[TBR125]

There is no way to know. Increasing power will help both acceleration and top speed. Have you de restricted the drive boss and CDI (if your bike has those restrictions)?

[Loroso86]

I think that the cdi restriction is removed because with it the scooter cant go past 30mph and for the drive boss i dont know i think its removed too but im not sure. I also wanted to ask will i gain power by cleaning the air filter because i think mine hasnt been cleaned for a year or more?

[TBR125]

Depending how dirty the filter is it may or may not change much but the filter should be cleaned anyway. Even with more power your top speed may not increase much if at any if the drive boss is restricted. With a drive boss restriction the variator gearing is limited and the only way to go faster is to spin the engine faster which is hard on the engine burns a lot more fuel and usually has less than max engine power.