"Velocity stack" question

[DayzBro511]

Hey I have a Baja warrior minibike and I was wondering I'd I took off the performance air filter and just left the adapter on would it increase power and could I damage my engine? I've seen something like this be done to drag minibikes on YouTube.

 

[Cbreiter]

It may increase the power, but the air filter is there to keep contaminants out of the carb and cylinder. In the case of drag mini bikes and things like that, you have to realize that many will replace or rebuild their engine quite frequently. Most average users of the Baja Warriors will never replace the engine unless there is a major problem with it. In my opinion probably one of the biggest upgrades you can do on one of these bikes is to put a torque converter set up on it. There are lots of other little tweaks too, but that is the biggest improvement while not having to modify much else, and still having a very reliable setup.

 

[massacre]

I used to run no filter on my drag bike, my engine builder was like "boy, that's dumb" lol.
All it takes is a little rock from the tire or even from someone else's tire in the pits and that's a quick $500.
I don't see how rebuilding the engine more often would make someone want to spend $500 quicker than usual, but OK.

To clarify, you should be able to run the velocity stack under the filter, so you will still reap the benefits of the velocity stack and still retain the filter to keep out contaminants. At least that is how it is on my bike YMMV
The air filter is most likely not a restriction to airflow, unless it's really dirty or blocked. Just in my experience. Cam/valves/stroke/bore will get you more power, air filters not so much.

 

[DayzBro511]

I would do the internal upgrades but I have no internal engine experience and I know someone who could do those but it would probably be too much work and risk prolems with the engine

 

[DayzBro511]

I would do that but I like top speed as I enjoy driving on roads and rarely go offroad.

 

[massacre]

Making your engine breathe dirtier air can't be good, long term. If you get a decent filter it should not be a restriction.

 

[Twid]

No filter on a motor is like running in a smoked fill room you could do it but not for long.

 

[Bumblebee2]

The issue with a velocity stack is that you loose your air cleaner, as pointed out previously. There are some that have a small flat foam filter over the end, but I would wonder if it would have enough capacity for a days fun. Minibikes are run (or can be) in very dusty environments.

There are some really cool things you can do with velocity stacks, go ahead and mount it, but install a large K&N (or K&N style) air filter over it. I have had good luck with this approach on my flat tracker motorcycle. On that engine (Yamaha XT-600) I installed a setup like this, I got a small performance bump while guarding my engine from the dust and dirt you would find at an oval track.

Now doing this will require some gen-u-wine bodging, you'll need to take that K&N apart to complete the install, then reassemble it substantially to keep it from leaking. You can also do it with a large Uni-Filter much more easily too.

- Bee

 

[massacre]

go ahead and mount it, but install a large K&N (or K&N style) air filter over it.

This is what I was trying to say.
Are we not talking about the same thing? Velocity stack? A filter clamps right over mine.

 

[Bumblebee2]

This is what I was trying to say.
Are we not talking about the same thing? Velocity stack? A filter clamps right over mine.

That would be an easy one. Larger ones don't really fit through the K&N opening. But, I am thinking motorcycle, not minibike.

 

[massacre]

That fits a 33mm Mikuni carb. Not sure how much bigger you were thinking but they do make them from 26mm and possibly smaller all the way up to the 42mm and 45mm Mikuni carbs as well. Those velocity stacks do flow really well and you can run a filter over them which is a win-win in my book.

This is all jr dragster stuff, it's all been done before. viperizer racing should have the velocity stacks and filters if you were curious:

Air Filters

I know choo choo makes some smaller ones as well.