? concerning bike of the month

[fotoguzzi]

I noticed in the pics of the new bike of the month that he has pod filters directly onto the throttle bodies.. wouldn't you loose considerable torq with out the intake tubes?

[antonio carroccio]

I noticed in the pics of the new bike of the month that he has pod filters directly onto the throttle bodies.. wouldn't you loose considerable torq with out the intake tubes?

Please explane your statement fotoguzzi!!!

[fotoguzzi]

I can't explain it but it was a concern I got from Guzziology or somewhere else when i put a EV1100 motor in my Convert. Somehow I was led to believe I had to keep the 4" long tubes that go to the airbox... so i put my pod filters on them but they are taking up a lot of room i could use for the other EV stuff... right now i have to put the battery under the tranny and sacrifice the crossover, not really a problem w/a Convert since it's not running up and down the rev band.

 

 

[antonio carroccio]

What can I say, with open filter can the motorcycle better breath.

So it suppose to get at the desired torque so fast possible.

Do not know if you get higher torque, but you get it very fast. Full throttle or not the response is immediate.

Better torque or higher torque you can choose for another camshaft. Like Millepercento has.

I will highly recommend you the OSS camshaft.

[belfastguzzi]

There have been discussions about the 'best' or 'required' length of intake tube. I don't know what threads they were in. You might be lucky and find them, if you try a search with some suitable words.

[GuzziMoto]

It is a general rule of thumb that short intakes are better for top end power at the expense of torque, and longer intakes promote torque at the expense of top end power. This is just a general rule of thumb and not an absolute.

There is also another concept that smooth airflow thru the throttle bodies/carbs is important and will improve power at all rpms. I find that on older bikes you lose less by fitting pods like that (you may even gain power), but the newer the bike the more you lose doing that. Airflow in is as important as airflow out.

[Greg Field]

Do you like or despise intake noise? That is the question. I despise it. If you do not, then pods are an OK option. Keep in mind, though, that none of them are as good at filtering dirt out of the air as your airbox nd paper filter are. Will that matter? How long will you be keeping your bike?

[antonio carroccio]

Dunno Greg. I doubt it. I have got 50k miles with the pods of K&N and never have had the idea dirt or whatever gets into the cylinders.

Good maintenance will help.

I have the strong idea to fix this filters in my new 1200sport too.

I am not such brave person

[pasotibbs]

It is a general rule of thumb that short intakes are better for top end power at the expense of torque, and longer intakes promote torque at the expense of top end power. This is just a general rule of thumb and not an absolute.

There is also another concept that smooth airflow thru the throttle bodies/carbs is important and will improve power at all rpms. I find that on older bikes you lose less by fitting pods like that (you may even gain power), but the newer the bike the more you lose doing that. Airflow in is as important as airflow out.

I read somewhere that modern bikes (and cars) have airboxes designed to use the energy of the various pressure waves generated in the inlet tract (I assume that's the induction noise that we hear) to help charge the induction stroke by bouncing them off the rear wall of the airbox (a simple forced induction).

I can't see Guzzi using this though!

[GuzziMoto]

Unfortunately I fear most of Guzzis R&D for the airbox goes into figuring out how to make it fit and not so much how to get max power. But even the tube that connects the throttlebody to the airbox has an effect on power output. Getting rid of that tube should change the power delivery. Will it make a large difference?No, I doubt it.

[richard100t]

The first mod I did to my bike was adding the pod filters. It was purely for cosmetic reasons as I like the look of it. The other benefits are less weight & the bike is easier to clean & work on with out the box in it. Just clean the filters once a year with the k&n filter cleaner & after that keep then oiled.

[John A]

Any filter that you put on, foam or gauze should be at least 2.5 tmes the diameter in length. In other words you dont want the end cap of the filter too close to the opening it atatches to or it interfers with the pulses of air. 2.5 is the theroretical minimum, I have gone less with no noticable effects. Where it really makes a difference is foam caps over velocity stacks. She wont run at wide open throttle that way.

[gstallons]

How'd you know that?

[emry]

Also remember that paper maintence is replace, foam or gauze is clean an re-oil. While paper can filter to a smaller micron level it will quickly clog and then flow substanstially less than a comparable foam or gauze. Foam or gauze will flow a lower volume of air intially but will remain fairly consistant until a saturation point is reached, then it will pass air and dirt. To be honest the filter maintence of most aftermarket foam or gauze filters is very optimstic. Many should be cleaned and re-oil at far greater intervals than is recomended. In reailty is works out though because generally something else wears out or breaks before we suffer a failure due to dirt ingestion, on street motorcycles at least. (Some locales may vary) So run the paper with the box, or run pods with the gauze. Either way if you service them regularly you should be alright.

 

As for the power issue. Tuned length intakes are very well documented here and in other locations and have been in effective use since WWII. Do a little web seaching and figure out what works best for what you like.

[Tom M]

Here's a good explanation of how intake runners are "tuned": http://auto.howstuffworks.com/question517.htm