Stillen HFC vs. BERK HFC
 

We've seen plenty of people using the BERK HFC's with great results, but now that Stillen has there's out, which to buy?

BERK HFC:

http://www.thezstore.com/store/graph...arge155813.jpg

Stillen HFC:

http://www.stillen.com/product_images/503436.jpg

hmm there is going to be some slight competition now..

I would love to see some dyno/video/sound comparison with these products. Which ever gets to me I will more and likely purchase.

REVIEW TIME GO GO GO GO :tup:

In for the answer!

I held off on buying the Berks for a reason :)

Stillen's on the way to my house ! :)

In for results.

you a$$ hehe, Between you, semtex and wstar...you guys are steep competition for mods :) I guess this is great because at least for me, its going to push me to get better stuff quicker ;)

If the Stillen had been available when I started, I probably would've bought it just because every other major mod on my car is Stillen, and it's nice to be all one manufacturer. That said, I suspect the real-world difference between the two to be minimal.

I can't believe these parts are so expensive! lol.

We are going to run out of bolt ons soon :(

I think they are expensive because the car is brand new one they the car has been around a while part prices should go down..

i was going to do the same but i had a great price on berks im waiting for it to arrive
im guessing the same on hp output as well

i highly doubt there will be a difference in the two. either way, this is a great mod with excellent gains. i guess its also cool to say u have a full Stillen bolt on tho. I mean, u guys were on point with this car. everybodys buying ur stuff!!

:tup: well, I sort of hit a wall... but looking forward to getting back in the race! :)

The parts need to come down in price, I agree... but coming out of Porsche-land, these prices suit me just fine ! If you haven't already, ask for best price off-line / PM, and I'm sure you'll see some improvement over list

... so we drive! maybe also focus on regional events once we start building critical mass of 370s !

Re Stillen vs Berk, IMO not expecting differences in sound or performance- same core... not even worth testing for difference in my view... differences boil down to having same brand, knowing it will fit, price and support

Yeah, I would love to see dyno results on a 370z, there website is claiming 9hp gain, but is that for the 350z??

Others on here have been getting "almost" double with the Berks :ugh2:

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.

solismo...my CEL went off within 2 days of driving with my berk test pipes. tell me ur secret!! i hate staring at that light

It wouldnt be fair for to say yes or no bc I dont know. Do a search under my name and you can have an idea of what my exhaust sounds like with the vid

Well, I'll share my own past experience and allow you all to draw your own conclusions. On my 350, I ran a set of Kinetix resonated test pipes. They did not have the extended O2 port, and they'd throw CELs every 200 miles or so. The remedy was what's known as the 'non-fouler' or 'anti-fouler' method, where you take two anti-foulers and drill one out so that the other one fits into it. What you do is screw one end into the O2 sensor port, and then screw the O2 sensor into the other anti-fouler. Now, the anti-fouler you're screwing the O2 sensor is not the one directly connected the port. You're screwing the O2 sensor into an anti-fouler that is screwed into another anti-fouler, which is screwed into the port. The anti-fouler that you're connecting into, then, is 'nested' into the other anti-fouler, so it's protected from the actual exhaust gasses. Net result -- no more CELs. By welding an extended O2 sensor port right onto the HFCs, Berk is trying to make our lives easier by replicating this anti-fouler method without us having to manually go buy the anti-foulers, drill one out, etc. Now, I'm not 100% sure on this, but I think they may be missing the 'nesting' part of it. In other words, the O2 sensors are being situated back away from the direct line of exhaust gas, but I can't remember if the end of that extended port is actually blocked off or not. If it isn't, then gasses aren't actually being completely blocked off from the O2 sensors. So that would explain why some people are still seeing CELs. If it is blocked off, then it's properly replicating the non-fouler method.

Here's a DIY link to the non-fouler method:

Stop CEL With Test Pipes - Nissan 350Z & 370Z Wiki

I did the same with my 350z when I added a set of Fast Intentions testpipes. It worked just fine. It was a cheap and easy fix.

But for some reason when we installed a set of Helix v2 testpipes on my friend's 350z it didn't seem to work that well. The helix testpipes he had came with the built-in extensions for the o2 sensors, they kept throwing a code for some reason.

I never did like those kind of test pipes, I prefer the ones without the o2 sensor extensions.

On these Helix test pipes, do you by chance remember whether or not the extensions were closed off at the end where they connected into the test pipes? I think that might be the key.

I know exactly what you're talking about with the 'nested' anti-foulers.

The helix ones weren't closed at all, it's just an extension with threads. I wanted to try adding the non-drilled anti-fouler onto the extensions but the o2 sensor wouldn't fit on. For sh*ts & giggles we tried the drilled out o2 anti-fouler, but that did nothing. One other thing I didn't like about the helix v2's is that the o2 sensor extensions are angled down slightly, maybe 5 to 10 degrees from what I remember.

I just read on another thread that BERK is about to design their own cat-back exhaust. I guess I'll be waiting just a bit longer to see how that comes out. If it fairs nearly as well as the Stillen exhaust, I may be going the BERK route for exhaust (I don't plan on doing headers in either case).

Guys, make note the Stillen ones do NOT have Non-foulers and the HR requires them. You will have to get non-foulers added to them to prevent the engine light from coming on due to PO420 AND PO430 codes. If those don't help which sometimes happens, you can get some SS wool and stick it in the non-foulers to help. Berk took this into their design when they developed theirs. Plus they also have the extra bungs for meters if you wish to add one later.

Just to mention here that I have had my experience with Stillen products in the past and have bought stuff from them since 1995. On the other hand I have recently went with Berk on my HFCs because they have a good history of great customer service! And I have to agree here their customer service is great! Stillen though if you have warranty issues, they try to blame it on other things like your car, and will try to find a way to not warranty the product.

That is all I will say. You guys make the decision.

Put SS Wool in the non-fouler holes and then put your O2s back in and this will resolve the issue. Brilo will also work.

Berk will send it for free if you call them. (Great customer service!)

This will happen with all HFCs as the O2s on the HR motors are more sensitive. Depends on the engine and time as mine didn't do it for 3000 miles and it popped on one day and kept coming on till I had to put the SS Wool in.