i recently bought a K&NIntake kit for my GMC Sierra....it claimed 20horsepowerand many other good things, but i havent noticed any of them.......obviously some of you haveactually experienced some of these benefits or there wouldnt be forums on them and they wouldnt sell.........has anybody else experienced these problems........or does anybody know any tricks tofeel the difference, or any reasons why i wouldnt be feeling the difference.. please let me know.

 

The only difference you'll notice is at wide-open throttle.
At lighter throttle,the butterfly restricts how much air comes in,no matter what flow filter is there

 

And i have seen a little help in gas mileage.

 

Another thing is too, I am assuming you have a 6.0 L gas engine and not the duramax. At any rate there is an old saying what goes in must come out. Now I am assuming your exhaust is stock and by adding a filter kit you are allowing more air in to the engine. That being said if you have a factory exhaust and on a Chevy especially you will notice the what I like to call (the water heater under the bed) aka the muffler which not only adds weight to the truck but also is very un-efficent. The only way you are going to notice the filter at this point is if you are at full throttle like Argonsaid. So my suggestion even if could only afford a muffler swap its worth switching to a high flow muffler you will notice even more difference. If you have already changed the exhaust you should be feeling a little more difference than you are. My buddy has a Silverado with a 5.3 327 that has split 2.5" duals and a volant kit which is similar in comparison to power gains of what your K&N should provide you. He also installed aTB spacer.His truck had a definate difference in the power. From 2,500 all the way to the shift it felt stronger. Although it wasn't what mostpeople wouldreally notice. The truck picked up about 2.5-3 mpg better average. When you really notice it is when you are towing or you stick some foot in it. We just did a hypertech program (which is not required to do this sort of setup but he had the extra money and decided to do it). I am not sure of the exact hp gain as I don'tremember off of the top of my headbut it was enough to notice a big seat of the pants difference.I believe his truck factory rating was 295 but again I amnot totally sure, it made like roughly 230 hp at the wheels given the standard 20% drivetrain loss factor for an automaticvehicle (and thats no matter what the trans is unless its been modified). Like I said you would notice it just adding the exhaust and programer.

The K&N kit according to the website says 20.34 HP @ 4,894. So realisticly you would feel anything noticeable till damn near when your truck is at full throttle. Now for exhaust I am not in anyway promotingFlowmaster, I am just usingthem as an example. I can't find the dyno sheets but I could be a litte of but I think that they say there is a 16-18 hp increase with a split dual setup could be more though.To be honest in a heavy truck your not gonna really feel 20 increase, now if you hit 40-50 hp increases like an exhaust and intake system you would feel it. Like I mentioned earlier I am not sure what his truck put out after the mods.I will call him later and find out. I see no reason that doing this you couldn't potentially see 285 hp plus rwhp which is damn near what the engine is rated from the factory. Thats 50 more and you could end up with a good tuner who could turn out 60 moretaking you to295 and its just a few more mods awaywhich will help in the hp and gas mileage department. I assume also that since you have a 2500 that you tow. It would be a big help with the tow mileage to.I hope this help give you a better idea.

 

This isn't a Chevy app. but the physics should still apply. I put an AirRaid CAI on my 2K Durango R/T 5.9. Saw a 2 mpg increase and increased throttle response. Yes, only a given amount of air can come in at lower throttles but IMHO if it doesn't have to suck as hard to get that air in it's got to help. For the exhaust, I didn't do anything to the R/T but on my '98 Ram I put a 3" cat back pipe and a SpinTech muffler. They are high flow but not as loud as the Flowmasters. Here is a link to another forum where I detailed the CAI. I think removing the flap in front so the air had a straight shot at the filter made a huge difference. That might not make sense here but if you follow the thread it will.

http://www.4x4dodge.us/forum/viewtop...sc&start=0