skyl1ne6mt

Several months ago I replaced one of the crawford cats (the right side) on my coupe. It cracked. Fortunately, Doug was willing to send me a new cat for free (best customer service ever). Recently, I just notice that now the cat on the left side got a crack too, to make things worst, the right side that just got replaced several months ago got a small crack again.
The local muffler shop weld both cats today. However, the guy told me that it might crack again due to the design of the system and the bracket.
The cracks on the cats are always at the same spot, which is near the bracket.
Does this ever happen to anyone? at first I thought it was normal to have a crack at the first time, but since this already happened twice in a short time period, it made me worried.
The only exhaust mods i have is crawford cats, Gruppe-s Y-pipe and Fujitsubo exhaust. Is it possible that crawford cats are not compatible with the Gruppe-s Y-pipe and Fuji exhaust?
Someone please help me, why do my cats cracked twice in a very short time period?

Nano

iTrader: (1)

I don't understand what is this obsession with the OEM brackets.

Get freaking rid of the cat brackets! they are useless, it's perfectly fine without them! the exhaust has plenty of support and a good flex-pipe will does a great job at absorbing shocks... bracket evidently doesn't allow flex pipe to do it's job.

I got HF cats(kinetix) for more than 6 months without any brackets and any issues. I even have 7 track days on the car!

Keep the brackets and they will keep cracking

my 2 cents

skyl1ne6mt

so you are suggesting me to just remove the brackets?

is it this bracket that you are talking about?

Beeker

iTrader: (5)

I am still using stock cats but I believe Nano is talking about the bracket that the bracket on the cat bolts up to. Some people seem to think you absolutely need to use it and others believe you don't. I have read many posts saying "my test pipes/cats cracked". Most people say if that happens you should buy test pipes/cats that bolt up to the stock bracket. Most test pipes/cats don't utilize the bracket. They just, more or less, hang and are supported by the headers and y pipe. This is the first post I've come across where using the stock bracket has caused them to crack.

skyl1ne6mt

I have removed the brackets. However, I do notice more vibrations from under the car. Is this normal?

Z350Lover

iTrader: (2)

I had cracked cats before.... but Doug sent me a new pair specially designed for Nismo exhaust (yes, down to Melbourne, Australia)... no problem ever since then!

I think it should be fine to remove those brackets, but you shouldn't get more vibration though unless your cats are touching the heat shields?!

cheers,

richie

mchapman

iTrader: (1)

That was good of him.

TiPIACE

what are the odds Doug will make me some custom cats for the Fuji

002-M-P

iTrader: (12)

If I remember correctly, the Nismo and Fujitsubo are essential the same exhaust with different names on them...kinda like RSR, Invidia N1, and Topspeed Pro-1

350Z_LMS

I have just received my crawford cats and nismo exhaust; currently sitting at home waiting to be fitted. Can someone describe the problem and how it has, in some cases, been dealt with? I have read that crawford have actually supplied new cats to those that have experienced problems: that's great news, but I would rather sort things out BEFORE I go ahead fitting everything than complain afterwards. Please help. Thanks in advance. M

froggy

iTrader: (1)

Same problem here (with Megan y-pipe+Invidia N1) after a "little" scrape under my car, both brackets are cracked, I bought my Crawford cats from Perfnissan, should I contact Crawford directly? I have to put the stock cats on again because it's leaking like crazy and it's getting worse mile by mile.

Rickdogg

iTrader: (234)

One of my test pipes cracked at the track wince I was utilizing the stock cat bracket location. I have since cut off the bracket area and let them hang free and have no problems

skyl1ne6mt

yup... it seems that taking of the brackets sloved the problem. I dont hear the old rattling sound anymore too... Doug also told me that it will do just fine without the brackets. His car doesn't have brackets for a very long time and it's OK.

Z1 Performance

iTrader: (564)

now just hope you don't develop cracks at the flanges...this is what the brackets prevent

zzzya

iTrader: (2)

I took the stock bracket off a couple years ago and no problems. I hope people realize this particular cracking has happened to numerous different brands of TPs and HF Cats that have a bracket mount. Most have to take them in to get them welded.

skyl1ne6mt

Z1 performance, which flanges are u talking about?

Nano

iTrader: (1)

I think he's talking about the flanges at each extremity of the TP/HFC (or whatever exhaust component)

without the bracket the TP/HFC will have more room to flex around... usually the flanges are the weakest part of the TP and it happens that they crack... it depends on a) quality of exhaust/tp/hfc/headers design b)the quality of the exhaust construction and welds c) quality of the install.... if everything is good, it should NEVER crack at the flange.

Note that a minimum of flex of exhaust components is good

John

iTrader: (17)

I have over two years and probably 50-60 track days (4500-5000 miles) on my test pipes, and no problems with my flanges. And if you knew how much I flog the car, you'd understand the significance of that statement...

skyl1ne6mt

I thought that because of the brackets that restricted the HFC to move around cause the crack. Now, without the brackets, the HFC is more flexible to move around and therefore less restriction to make it crack.