doctorg37xs

No, actually the welds look great. I bought them used from a member on this forum and they performed well (i.e. rattle-free) for almost 2 years then suddenly I started hearing a rattle. I thought it was a heat shield or my brakes or something but after exhausting all possibilities we narrowed it down to the cats. I was only able to confirm when I removed them to put on the Z1 high flow cats.

The catalyst material dislodged in both and was the culprit of the rattles. You can shake my FI RHFC around and reproduce the rattle. Otherwise, the cats were completely intact. No crumbling of the cat material, no cracking at the welds, no damage to the resonated portion. Very weird.

I should add, though, that they did continue to work as catalytic converters. I didn't have any smells, and I passed inspection just fine. I'm trying to sell them now as resonated test pipes haha.

I'm really not sure what caused the above to happen, but after reading your post a while back I suspect this might have had something to do with it. Maybe too much transferred vibration from the engine onto the cats in the setting of high temperatures causing the catalytic material to come loose? I mean, there's an OEM bracket for a reason, right? Anyway, I feel much more confident with the Z1 HFCs having brackets to attach to the chassis like OEM cats do.

I'm no engineer, but I do think it is a design flaw on Fast Intentions' part although when I called them they (and everything I've read) would suggest that it's not a design flaw at all. Who knows.

If you're planning on getting any HFC that doesn't have brackets then I'd do what Rochester did to keep consistent with the OEM setup.

Rochester

iTrader: (9)

Based on nothing else except my own car and watching comments here on the forum for the last decade, I think FI has earned a reputation for making high quality, well-designed exhaust components. So when they say their cats and test-pipes don't need to be integrated with the OEM bracket design (even when every other manufacturer does), and when they say their cat backs don't need any flex section (even when every other manufacturer does), the not-an-engineer side of me steps backs and says "Um, OK..."



Then goes ahead anyway, and does the thing that gives me peace of mind.

obsidiansamurai

From personal experience, I wouldn't touch the things without a bracket. I was told by FI not to post anything about my experience, which already doesn't sit right for someone who's naturally defiant. That being said, I still didn't say anything and scrubbed my social media posts about it.

Recently, though, I've been seeing more and more people complain about the RHFC's quality. I also wonder how many of us are out there, keeping quiet at the request of FI. I realize I'm not supposed to say anything about my experience, especially on myg37, but I don't think I'll ever go with a FI product again. It's a shame, because I had a lot of hopes and lost 500 bucks of labor in the process (install and removal).

BULL

Almost everyone with non gasket related exhaust leaks don't use this bracket. A lot of us that have previous experience will take this out because...... F that bracket. only to find out cracks later on.

With the bracket the only flex point is the flex pipes, without the bracket, the cats/manifold take this vibration.

KImChee

iTrader: (1)

Thanks for posting this. I have been looking at the FI RHFC for a while, but read about people having cracks and talking about the bracket, so I went with the Berks, but still wish I had the FI. Now I think I made the right decision.

2010sedanS

To make a long story short, the chrome trunk trim decided to take a crap and I figured it would be a perfect opportunity to upgrade to the spoiler. After four cancelled orders for new oem spoilers from different infiniti dealers I ended up purchasing the stillen spoiler which fits right over the chrome finisher with just 3m tape. Wasn’t too impressed with stillen quality and after a few weeks the center of the spoiler started lifting. I was finally able to source an oem spoiler from a junk yard. I searched for the install templates but couldn’t find anything. My plan was just to drill out the one hole next to the camera and use the two bolts with the 3m double sided tape. During the install a light bulb pops up, what if the old guts from the chrome finisher fit on the spoiler. I lined it up and it sure did fit and was able to install without Drilling one hole. The only caveat is that my trunk button is recessed a lil bit. All in all very happy with how it came out. Spoiler will eventually get wrapped or painted as I mod on a budget.

Lynn49

Unfortunately I had to get new wheels after wrecking the front left, fortunately these look pretty good.

doctorg37xs

Very interesting! Thank you for sharing that. I'm sure it'll be helpful info in the future for anyone looking into exhaust setups for this car.

Joyryde

iTrader: (1)

I opened my driver’s side door, sat in, buckled up and turned the car over and let it idle for a minute. Then, I drove off to my local grocery store. Upon arrival, I shut off the car, un-buckled, opened my door, and stepped out. I then locked my doors. Made my way to the store and bought some products. Came back, unlocked the car, put my groceries on the passenger side floor, and sat inside. I turned the car over and put on my seatbelt. Drove back home, shut off the car, unbuckled my seat belts, and then proceeded to step out with my groceries. I drove my G37 sedan today.

Rochester

iTrader: (9)

LOL

Reading this, and having some sense of your history here, the thing that surprised me is that you wear your seatbelt.

FrogmanKouki

Didn't happen today but about a month ago, got my wheels back from powder coat, they are coated in Prismatic Speedway Grey PMB-4911. The last picture really shows how this powder coat looks in the sun. All four wheels are forged G35 Rays rears at 19x8.5 with 255/40 tires, I did this so I could rotate tires to my heart's content and also not upset the differentials. Also I've been waiting on Swift springs for nearly 3 months about as long as I've owned the car lol, it really needs a drop. In that time I've also done a full Diode Dynamics update inside and out as well as black out the widow trim and partial debadge of the trunk.

doctorg37xs

As an update, I had everything installed and the sound is ALMOST perfect for me.

Here are some important details I noticed:

1. The cold start up is loud but quiets down within seconds
2. There is an unbearable (for me) drone between 1500-3000K RPMs, which I read/knew could be a possibility with increasing the mid-pipe diameter to 2.75" with Tanabe in addition to their less-than-stellar resonators
3. The rasp on acceleration created by the Z1 HFC is made more apparent with the Motordyne XYZ pipe, which I also read can be a thing.
4. Beyond those drone-y RPMs, which is where I kind of live at on a day-to-day cruising basis, and the increased rasp on acceleration, the VQ note is really incredible.

Anyway, I kind of expected to have to do some more adjustments before things would sound ideal. I have already picked up two Vibrant 1143 Ultra Quiet Resonators (2.75 inches) to add the Tanabe mid-pipe, which from my understanding will tone down the drone and rasp.

I keep going back and forth, however, between replacing the existing resonators on the Tanabe mid-pipe versus adding the Vibrant 1143's after the existing resonators (they are 14 inches in length, and I think there's room). See pictures below:

RMB5190

iTrader: (2)

I have those exact same resonators on my set-up. I have circuit werks testpipes, eBay Y pipe, to a topspeed Y- back. I welded the resonators on the two legs of the Y pipe right before the test pipes and it gave me the exact sound I was looking for but that location doesn't leave a lot of clearance. The 1143 are a lot bigger than I thought and I'll rub every once in awhile if I don't take certain slopes right or go over a speed bump too quickly. I saw you were looking at swifts and you may want to consider coilovers to max out the height; as I'm not sure if the swifts will leave you too low.

doctorg37xs

Thanks for the insight! I'm hesitant to cut into the Motordyne XYZ pipe as it's a pretty difficult piece to find especially for the AWD. The Tanabe mid-pipe can be found relatively easy, however, so I don't care as much about cutting into it.

Good to hear, though, that adding in two of the Vibrant 1143 resonators--as I was thinking of doing--gave you the sound you were looking for. Do you think you actually needed two of them? Is the car "too quiet" at all?

So, it sounds like you added the Vibrants before and in-addition-to the resonators that came on the Top Speed mid-pipe?

I wonder if I'll still get good results with placing the Vibrant resonators more downstream, i.e. after the Tanabe mid-pipe resonators but before the Tanabe mufflers? Do resonators work better on rasp/drone the closer they are to the catalytic converters? I've read that they work better for rasp the closer they are to the converters and that the placement for fixing drone would depend on what RPM range your experiencing the drone in.

Also, I'm actually lowered on IMPUL springs, which are even more mild of a drop than Swifts. What are you lowered on?

EDIT: I think I answered my own question. After reading this thread: LINK TO THREAD

hexotic

Love reading FI issues after I just ordered a set... Lol.
Anyways, I finished building the rain guard for the Z1 intake filters. Made from 1/4" lexan.