Its seems that the Berks have a built in CEL fix on their HFCs. Id be curious to see if the stillens throw a CEL......

will have to let stillen speak for themselves, but josh told me the hfcs will not throw a cel

I'd go with the cheaper one. Both are quality parts from good companies, so can't really go wrong.

For no reason really, I'd go with the berks.

Kyle,

so what is the scoop on these, any dyno data with the 370z, CEL issues??
the Berks are showing a lot more then 9hp gains, is the data on your site for the 350z??

Also, what about a group buy? I'm looking to get something this next week, almost ordered the Berks about an hour ago, they are offered at a better price.

Arent all HFC's manufactured in the same factory just stamped differently?

I know magnaflow makes the cores and some shops pick those up and fab up the rest. From there is what each shop does is what makes a difference. It's all about the details.

correct but the core is where the air flows through making them all the same. Small changes here and there might yield +1 or +2 more HP which for the price increase on name brands isnt just worth it, to me atleast;)

Im currently running Ichiba test pipes which I paid $250 for on my G37. I wrapped them in header wrapped which eliminated all the rasp and have no CEL light either and their quality was pretty damn impresive:driving:

If you compare the photos of the two carefully, it appears that the Berks have two things that the Stillens don't. First, the port for the O2 sensors on the Berks are extended out to make them more resistant to throwing CELs. Secondly, notice that the Berks have a second set of O2 sensor ports built in for hooking up wide-band O2 sensors on a dyno, whereas the Stillens do not. Just making a couple of observations.

Edit: They also appear to yield less gain and are significantly more expensive than Berk. (Sorry Stillen/Josh/Kyle -- you know I love you guys but I have to call it the way I see it.)

On my G37 forums Berks HFC's are infamous for throwing codes almost all of them. The popular brand that they seem to be going with are Fast Intentions

My HFCs have yet to throw a single code on me. Of course, that's not to say it won't happen in the future (knock on wood). In any case, if the Berks throw codes even when they went to the trouble of extending the port out to give the O2 sensors some protection, what does that say about a design that doesn't do that at all?

I aggree, Im not picking sides just giving the information to help you guys that I have recieved and seen. Like I said my Ichibas have the extended port and havnt had a light in over 1k miles:driving:

Yes, I noticed the ports for the O2 sensors too, does that make a huge difference in throwing a CEL??

I have test pipes with that desing and havnt thrown a code:ughdance:

Do the Berks have any rasp too them?? if so, will wrapping them help as well?

Yes, that's correct but what I meant was the quality of the part and not the power output. I've seen some crappy parts, I've seen some nice stuff too.