Yes that's the same spot mine hits at. It won't destroy anything in the short term, you just don't want to hear it rattling. After I failed to get it clear myself, I went to a nearby random exhaust place earlier in the week, and they didn't do much good either.

Then I hit a well-known performance shop around here early this morning, who in turn referred me to a muffler shop down the road where they said the guy was an exhaust genius. Just got back from there. He got me clear of the crossmember and the rear swaybar and those diagonal links, but it took some pretty intense tweaking (he heated up the pipes at a couple of strategic points with a torch and bent them a little).

He also welded up the slip-fit seams for me. I'm definitely not rattling against anything anymore. I'm going to get under it tonight again myself and try to triple-check the bolts on the headers (and everything else) to make sure I'm not leaking (it's hard to tell rasp from leak under load, at least for me). I'm hoping I find a loose bolt or a failed gasket somewhere honestly, because the rasp is kinda intense. Regardless, I think a design with some kind of flex joints up in the Y-pipe section (like the stock ones had) would probably cut some of the rasp though.

I posted this in the other forum, but I'll repeat here.. with hopes this helps others find the right adjustments.

Well I think the raspiness I was worried about is mainly only audible from inside the car. I finally got to hear it from the outside when I got it Dyno'd today, and it sounds great from outside. The place I was planning to go (that had a Dyno Dynamics) had some scheduling issues, but I might go back there Monday. So for now, I went to Carboys here in Houston where they had a DynoJet available. They did 3 runs, they looked pretty consistent. Max HP was 305.3, Max Torque was 241.2. These numbers sound a little low to me for full intake/exhaust compared to what else we've been seeing (given that its a DynoJet), but on the other hand (a) This is a 7AT, the rest have all been 6MT so far, (b) It was extremely humid in Houston today, and (c) Every dyno and every car is different :)

Anyways, I realized after I got home that I've got no way to make the graphs. He gave me the raw DGP file for the runs that has all the data (including A:F ratio), and you're supposed to download some free software from DynoJet to view it and make your custom graphs. However, I'm all Mac here, and their software is Windows-only. Anyone else wanna take my file and make graphs for me? :) Video is uploading to youtube now too, I'll make a separate thread for the vid and the graphs (if someone can make them).

They also gave me a printout of the best run, I guess I could find somewhere to scan that in. The printout has lots of "gaps" in it, I'm not sure if it's just this run or if they're all like that. The tech said it was his sensors or whatever that were at fault for the gaps in the lines. Anyways, for a text analysis of what I can see on that, the torque curve is pretty broad and flat from about 4.5k to 6.5k, the horsepower is basically on a 45 degree slope that hits peak a little under 7k and stays there to where he cut off at (7.5k). Crossover point is about 6.6k.

Edit: bleh that DGP file he gave is like 95 bytes long, clearly I don't have the data, gonna go back by there later and get the real thing.

Thx for the update. I'm glad to hear that the torque curve remains flat! :tup: If you want me to try to generate a graph, PM me. But yeah, 95 bytes sounds suspect. Not sure why he did it this way tho. He could have saved the actual graph as a jpg file. I just bring a jump drive with me and tell them to make a copy to my jump drive.

I did go back and get the correct files right after. There's a zipfile of the full raw data and a link to the dynojet software in the other thread: http://www.the370z.com/intake-exhaus...c-e-dynod.html

Crossover is always at 5252 rpm because HP is calculated from torque according to this formula:
HP = (Torque x RPM) / 5252

You might have different scales for torque and HP which would visually throw that off on the printout.

Heh, good point. Why on earth they put two different scales down the sides of the paper for values that are so close to each other is beyond me :)

Great thread here. Lots of good info. To answer some of your questions, the Berk HFC's locate the flanges & support braces at the same points as the OEM cats. They will fit the same as the OEM cats do.

Every exhaust will take a tiny bit of adjustment in order to line everything up correctly. With slip fits you have even more adjustment available in the alingment of the pipes. On tip that will ease fitment issues is tighten bolts/slip fits from the header towards the exhaust tips. It's easier to straighten things towards the end of the exhaust vs. the middle of the exhaust.

Out of curiosity, do any of you guys with the OEM cats and aftermarket exhausts hit that same part of the car under there?

Cheers guys!

RCZ's exhaust hits the crossmember, and he has the stock cats still.

Yup, mine has stock cats and it was sitting on the cross member. All fixed now.