Air Intake!
 

hi i have a M4 race exhaust and jetting, done on my 2002 sv650 , i heard that cutting a larger whole in the air filter could add some extra horsepower, if anyone has any comments pm me or post, thanks.

Yeah, I heard that, too. There's a website that shows you what to do. But, I guess if you cut right along the seam in the airbos (where the intake goes) it lets mroe air in. There is a catch; if you don't have a full exhaust kit, it lowers power from 5-7,000, and you may also notice a whistling noise.

You'll need to rejet after if you do this as well... Shame if you've already had it done but it should make a big difference.

so once i cut the whole larger i will need to rejet again?

also how much horsepower will this give my bike, can you notice a big difference??? I will still do it whether or not it's a huge diff. because it's a race bike

The guy with the website didn't mention anything about re-jetting, but, I imagine that's just common sense. You have more air, so you need more petrol, otherwise you'll be running lean.

http://www.geocities.com/catpoopman/sv650_snorkel.html

"You will have to rejet the bike and I recommend you only do this if you have already installed a performance exhaust. If your bike is already rejetted you will have to bump up your main by a few sizes up to 152.5 and you may want to consider drilling the Slide Lift Hole.."

I'd say, after all the mucking about I've done iwth my bike, any breathing mod that doesn't require rejetting isn't trying hard enough... You can get away with a little better breathing since the bikes tend to be rich to start with, mind, but nothing that'll give a real kick.

The desnorkel's supposedly up there with the Race RS in the chart of "Standard-type filters that kick ass", and the RS with a race system quite simply will not run without a rejet, it's quite entertaining to try though :) Personally I reckon the RS should be better- it has a wider opening, and is designed that way from the ground up. Plus it cost me money so it'll be pretty hard to convince me I wasted it :)

With a race system, the jet sizes you see vary from 150-165DJs with the desnorkel...

Also you need tank spacers if you change hole size or go RS.

After this you begin thinking why didn't I buy a ******* GSXR!

No you don't. It's just that if you're going to all the effort, you'll want them. You'll also probably want to remoe the undertank foam.

Changing your filter, fitting spacers, removing the foam and rejetting is a little cheaper than a GSXR, in case you find yourself wondering about that again :)

What is the point of the foam? I was wondering if that was a safety issue.