Stillen Headers + Berk HFCs self-install report

LiquidZ

Just some pointers if BERK is looking to make a catback for these cars:

1. Please make it all T-304 SS
2. X-pipe
3. No single muffler designs. Something similar to the Stillen and GTM units.

BerkTech

1. Of course!

2. Debatable. We will build & prototype no less than 3 different configurations (true dual, X pipe, conventional Y-pipe). One of them will have the best overall characteristics of sound and where you are trying to improve that power curve (mid range or top end). The perfect exhaust is one that would vary in length and size dynamically with engine speed & load, but that doesn't exist yet. Maybe in 20 years......

3. Yes, I agree with you here. Single muffler systems tend to act like a giant baffled muffler which hurt performance. If designed properly we will be able to use dual mufflers while still maintaining good exhaust tone.

And sorry about the thread hi-jack! We'll start another one later for the soon to come BERK 370Z exhaust.

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wstar

No worries, this thread has outlived its purpose anyways

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wstar

The delivery guy just showed up with my Cat-back and intakes . The cat-back is definitely going on ASAP, maybe tonight after I get done working. The intakes maybe this weekend (I may delay on the intake though, there's some other things I might want to do at the same time while all of the intake is out and the bumper is off). New video with a full exhaust setup (from engine block to rear bumper) should be up in a new thread by tomorrow.

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LiquidZ

Definitely keep us posted.

As for point 2... I said that because I'm not a fan of Y-pipes. I am assuming they tend to be the worst in terms of performance.

wstar

Ok I'm re-hijacking my thread back for a bit.

Just got the Stillen cat-back installed. I raised the "center" section at the spot indicated in the instructions with a floor jack to try to get the system clear of the chassis crossmember, but in the end after I torqued everything down, it still dropped in a bit and came to rest on that crossmember. So clearly, I'll have to go back and loosen all the bolts and tweak this some more to get it to sit right.

However, I went ahead and fired it up for a short test drive. Words cannot describe how awesome the full exhaust setup sounds, and when I make an audio recording later, I'm sure it won't do justice to the live thing. Whoever was worried about the headers making it too high-pitched, I don't think you have anything to worry about. It's a really nice low growl (at low rpms), and changes predictably with load and rpms.

All that said, on the test drive I still had an odd rasp/buzz/whatever sound at certain RPMs under acceleration load on the road. Although the sound characteristics of the exhaust have completely changed, I recognize this as a sound that was bothering me before, ever since the cats/headers went in. I'm starting to think I must have a leak issue somewhere up in the area of the cats/headers still, which I'll also have to sort out. I may just run down to an exhaust shop sometime tomorrow and have someone who looks at this stuff every day listen around under the car and try to find it.

Anyways, minor install issues that are undoubtedly my fault aside, it's awesome. I think the catback really let loose a lot of pent-up gains from the headers and cats, I could definitely feel a real difference on the road. And the sound is amazing, although it borders on the territory of too loud, in a "My neighbors are all going to hate me now" sort of way. Not loud like a fart can on a civic, loud like standing in the pits at a NASCAR event.

Audio soon...

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