What are the Pro and con for changing my air filter from factory to say a forced air or simular filter? Does this effect warrenty ?

 

You can't really expect much - a peformance air filter is one tiny part of a much larger system. On its own, it won't do much, but a bunch of little add-ons like this will improve the overall performance.

Shortly after I bought my Expy, I got a K&N FIPK (the intake with the K&N conical filter). After an oil analysis showed elevated levels of silicon in my oil (silicon = dirt creeping past filter), I decided to ditch the K&N. I really haven't noticed any difference -my gas mileage, performance, etc. is all the same.

My new setup is a hybrid system using the K&N intake (more airflow) with the stock air-filter box (better filtration). I also took off the small pipe that connects the airbox to the firewall and replaced it with a 3" rubber hose. I'm very pleased with the setup.

Before I ditched the K&N, I researched their effectiveness in order to make sure I was doing the right thing. I found dyno printouts that actually showed losses throughout the powerband with a K&N, with a few boosts here and there. Also, if you look at the chart on the back of the K&N box (and on the website), you'll see that the massive power gains they promise only occur at 4000+ RPMS - our trucks usually shift around 3500, so we're not getting these massive 3 HP gains all the time. Also notice that the fine print states that the truck was in 2nd gear. If the best performance boost you can get with a K&N is a couple of HP in 2nd gear, then it's sure as heck not worth cost, hassle, and elevated engine wear from lousy filtration.

That said, your best option IMO is the WMS Velocity Tube. It's an intake that uses your existing airbox + filter, like my K&N setup, but cheaper and not ghetto-rigged. You can order them from WMS' site for about $115 or so (compared to +/- $250 for the K&N FIPK)

An air filter won't affect your warranty, BTW.

XXL

 

I have been looking for an Intake but heard the same stuff about the K&N FIPK as BigMatt has suggested, I looked into the WMS Velocity intakes, anyone have any experience with them? Any other suggestions?

 

I think 1999XLT has the Velocity Tube; he likes it. I'm sure he'll pop in any minute now.

XXL

 

my belief is this.

If you are looking to add to the performance levels of your truck, and intend to do other things such as exhaust, throttle body work etc, then it is worth the $ and you will see a significant performance gain by all of the additions combined.

If you intend to do only the filter change, and expect any kind of gain, you will be dissappointed with the results.

phil