Crankcase ventilation. Rather than have vapors from the crankcase go into the atmoshpere they are fed back through the intake system and burned.

I think that one reason hte K&N hoses are smaller than the stock ones is to reduce the amount of flow from the crankcase which increases hte flow through the main tubes.

Hey guys, anyone have any issues with their K & N's? Thinking about putting them on my '11 Z Touring when I get it delivered in April. Everyone keeps suggesting to get the Stillen long tubes but I don't want to hassle with the install. Is everyone happy with the Typhoons so far??

I'm happy with them, no complaints from me!

:iagree:

Good to know. So you guys see a HP increase and a difference in sound as well?

Although I didn't do a dyno, I'll say yes to both.

I didn't notice any significant increase from these intakes and they are pretty noisy. they attract too much attention for me. I just got the hps post maf tubes and switched to stock w/ the hps tubes. to me it sounds and feels better. just gonna go the k&n drop in route with the tubes and be happy. It's also pretty cost effective. the stock intakes are pretty well designed.

I was running the stock intakes with K&N drop ins and the change to the tubes for me showed a change in performance that was dramatic. Noise is not an issue, since I run the Invidia exhaust, and compared to the noise on my BMW K1300S with a Remus pipe, it is no big deal.

After the install, did anyone have any "check engine" lights come on, or is it just a simple "plug and play" with nothing else to do. Is a Dyno necessary? New to all of this...

No check engine light. It is sorta a plug and play. A Dyno is just to see the HP gain it is 100% not needed.

heat soak is also a very big reason I took mine off. if u sit at a light for a few minutes the drop off in performance is very noticeable. I notice it alot less with the stock system with the drop in filters. only intake really worth getting are the stillen g3. proven numbers but expensive.

off topic, but selling my typhoons. any takers?

Never had an issue with heat soak. Especially a noticeable performance difference...

I don't have heat soak issues, then again I live in Seattle. lol

I did a Dyno and got around 6-10 rwhp increase across the board.

Was that with the F.I. exhaust and HFC's already installed before hand? Was that gain with or without a tune?