C2 Madman

I have a stock 3.6 which I want to allow to breathe a little easier. Putting Fabspeed headers/muffler and looking into cold air intakes but the only one I find is using the existing airbox and square filter, and putting a Cup open housing eliminating current housing (or cutting existing housing to allow free flow of air). Has anyone had experience with sticking with the square filter versus customizing to accept a K&N cone type cold air intake? Can this be done? Any issues I should be aware of? Is there a any/big difference in HP between these?

Thanks in advance for any help.

Indycam

https://rennlist.com/forums/964-foru...ck-airbox.html
https://rennlist.com/forums/964-foru...yet-again.html
https://rennlist.com/forums/964-foru...ed-airbox.html
https://rennlist.com/forums/964-foru...-drilling.html
https://rennlist.com/forums/964-foru...ng-to-cut.html
https://rennlist.com/forums/964-foru...le-or-not.html
https://rennlist.com/forums/964-foru...fications.html

https://rennlist.com/forums/964-foru...-cleaning.html
I am not a fan of K&N airfilters for the street .

meek

May be worth doing a search on this as it has been discussed many times before. IIRC the end result is that a custom filter/drilled airbox add nothing except some fun induction noise at WOT. I picked up a spare airbox cover and drilled it to get the new sounds; worthwhile fun addition for me.

EDIT: beaten to the punch; too slow typing!

springer3

The stock system flows plenty of air. The paper filter costs you about 2 HP. Going to an oiled-cloth filter will get you half of that back, but at the expense of getting grit into the engine. See the threads on MAF and chip upgrades for details.

At your stage (near stock) there is more low-hanging fruit in the area of weight reduction. At stock weight, each 14 lb (6 kg) eliminated is equivalent of adding 1 HP at the wheels (more than that at the crank). Weight reduction also helps with braking and cornering, and does not accelerate engine wear.

Indycam

Kevin Cameron from a while back on airboxes
http://www.snowtechmagazine.com/arti...p/pipetemp.php
"The airbox used to be just an intake silencer and a place to put the air filter. Now it's much more than that, so read on before you gut or toss your box. Just as is being done on new cars and motorcycles, snowmobile airboxes and their intakes are being built as resonant systems. When the airbox is resonating strongly, driven by the engine's suction pulses, its rapid internal pressure fluctuation covers a range of plus and minus 10-15%. This is just like the resonance of a bottle when you hum into it. If your engine's intake events run in step with the positive side of this resonance, it's just like getting a 10-15% supercharge boost for free. That's worth having. And what if you modify your engine, raising its peak-power rpm beyond the range of the airbox resonant frequency? There is a simple relationship you can use to alter airbox frequency by changing the length and/or diameter of the airbox intake pipe(s). That's worth having."

http://books.google.com/books?id=dfV...age&q=&f=false

http://www.amazon.com/Top-Dead-Cente.../dp/0760327270

http://www.amazon.com/gp/product/076...BZS5C6256M2M25

race911

And no comments so far about this "wisdom"?

Indycam

What are your thoughts on that header / muffler set up ?
Whats the latest on the track day at L.S. ?

race911

I'll reserve my thoughts about what's really gained with bolting on this and that to these engines.

As far as Laguna, yellow car's in the trailer here at home and a friend is picking up the RSA to drive it down. So come on down! Bring a helmet if you've got one.

Indycam

Silence speaks volumes ?

springer3

I'll bite:

Two problems with aftermarket exhausts: prone to crack, and prone to flat spots in the engine response. We hope and trust the Fabspeed units are free of both problems. As I recall, Fabspeed sold some kits in a group buy, and then dynoed a customer car to prove it worked. They sold them without first testing. I wonder what would happen if they found flat spots or other problems after selling whatever number went into the group buy.

I am tempted by the significant weight reduction, but for a street car, aftermarket exhausts are too expensive unless the stock system needs replacement.

The buyers are happy, and that is what counts.

C2 Madman

Thanks for the threads Indycam and Meek. Should've searched before posting. Joined rennlist today and the wealth of help and info is pretty amazing; well worth the membership. Not interested in more noise, and hp gain appears negligible at best, so not changing or drilling airbox. Will report back on Fabspeed once I've had a chance to roadtest it in the next couple of weeks. Keeping everything I take off in case I need it.