I just finished with the install of a K&N 77 Series High-Flow Performance Kit on my X. The differences are like night and day! The engine now breaths so much more efficiently, and it produces quite the attractive breath when you punch it. If you thought the engine was loud when accelearating before, install one of these and it's like Nascar. I would highly recommend this aftermarket upgrade, one of only a few to boast the already powerful engine. I purchased mine from eBay fo $240.

OK..so it makes your engine loud. I tolerate noise if the resulting hp gain is significant... I'm not sure you noticed or cared?

is it qwik?

--Well, I've got the K&N filter, but just the airbox addition and the cleaning/oiling kit- I figure the Cone airflow additions are most efficient above 5000rpm and I'm too old to try and realize that!! --JIMBO

I just installed the KN 77 myself and it truly and noticibly increased response, acceleration and it is truly a cool sound... two days later I installed the Gibson side swept cat back exhaust (did both myself and I'm no mechanic) and let me just say... WOW... I went to a local gear head shop here for kicks and giggles and had them do a diagnostic on the performance of the engine... hold on to your seats.... documented 292 hp at 5200 rpm!!! wooo hooo... keep in mind mine is a 6speed... don't know if that makes a difference... oh... by the way... I've also noticed an improvement in the gas mileage... the combined sound of the gibson exhaust and the high flow air intake.... truly awesome

Where did you get the Gibson, and for how much?
A Gibson exhaust is the next upgrade for my X, which I'll be doing this summer.

Wow...are those numbers off a dynomometer so we're talking Rear-Wheel HP?

Damn, wanted that Gibson bad. When they were asking for 2005 Xterras several months ago for testing and fabricating, I put my name and got a call since i'm so close to Corona, CA. Long story short, they had moved on from 2005 and now working on 2006 so I didn't get in. Bummer! Free exhaust and I know it would have been a nice little noise and power boost.

B.

Maybe crank HP. Definetly not wheel, but I am gonna say that there dyno wasnt calibrated right.

As I said... I'm no expert... the proof is in the pudding... I notice a real difference... when I hit about 3500 or 4000rpm I can hear a big tone change at the filter and a kick in the pants on the road... don't know what a dyno is vs. at the wheels... they hooked up some gizmo to the engine not the wheels... as for where to buy I got my exhaust at lil devil motor sports online... I got the all stainless steel which was more expensive
http://www.lildevilmotorsports.com/advan...48&inc_subcat=1

$489 bucks

What you notice is the variable valve timing (CVTCS)kick in and the variable intake system. My X does the same thing around 3000RPM because of the CVTCS and the tone change you mention at the filter is the variable intake sytem, basically different length intake runners and one is closed up to a certain RPM and it opens up when you hit the higher RPM. It allows the engine to have torque at the lower RPM without running out of breath at the higher RPM.

Your 292HP is crank HP not wheel so that gives you more or less 233HP at the wheel. Just curious as to why your peak HP went down the RPM range though since stock peaks at 5600RPM.

Pics? I'd like to see some of the intake and exhaust and how they look. Thanks!

Always wondered why my intake starts sounding like ass around 3k rpm.

K&N has a dyno chart that shows around 230hp at the wheels on a VQ40 frontier with the FIPK. Stock was 215hp, so a 15hp gain (at around 5000 rpm) is claimed with the FIPK

Which means I was off by 3hp in my previous post in the Performance 06 topic.

I don't think you can get 62hp from the Gibson so the 292hp claim can't be from the wheel.