Hey Guys.

My Crawford Hi-flow cats (magna flow) have cracked near the weld that attaches to the OEM brace. The fracture is hair line and next to but not extending to the weld. Both are cracked in the same place. Anyone else with this problem?

The R bracket also broke where it attaches to the stock brace making the rattle I heard when starting the car.

The cost of repairs (welding, etc.) would be about the price of new test pipes. There is not too much in the forum on test pipes and an NA car. Any suggestions on how my set up will sound with the APS test pipes. My bet is it'll be too loud without a turbo especially at highway speeds.

 

have you contacted Crawford? He might be able to help you out

 

Any problem with a Crawford product - Call Doug at Crawford. Surprised you didn't call them first. No, I have never heard of this problem before.

Lou

 

Same happened to my cats.... 3 times already..... I would have called Doug if I was in the States.... it is way too far for me to reach him from australia...

cheers,

richie

 

mmm.. that brace is supposed to prevent the cats from cracking at the flange.

Is the brace attached to the heat shield or the pipes?

 

the brackets are attacted to the lower half of the cat itself, not the pipes... and the heat shield is located at the upper half of the cat.. not too sure if there is a heat shield at the lower half though... where I got the leak from (right at the joint of the brace and the cat)...

cheers,

richie

 

This is a common problem with test pipes/HF cats that have a brace on them to attach to the stock location when paired with aftermarket headers or exhausts. A lot of stress gets placed on those braces if there is not enough flex in the rest of the exhaust. I simply leave the brace off the car and have had zero problems. My Crawford HF cats don't even have the braces on them. Also, if your muffler shop is charging that much for a weld repair you need to shop around as I was charged $7 to fix a set of test pipes that I bought from someone on this site you neglected to tell me that the pipes I was purchasing had the same problem you are stating.

 

zzzya:

But if you take off the supports from those cats, wouldn't your headers actully stress from all the weight of the Y pipe + 2 heavy cats? If you have an after market headers (SS material), I guess those headers will get cracked easily though...

cheers,

richie

 

Thanks,

I'll call Doug but he can't help me much from Tennessee. Problem with the Z exhaust is that it basically hangs free supported mostly by the headers themselves.

I aggree that the fractures are due to heat stress/expansion in the different materials on the headers and cats. The joints needs more expansion. ? use a different gasket to allow for more expansion?

BTW - there are no heat shields involved. Also I aggree that removing the braces all together is a potential solution. Besides now I'm driving around with out support from the braces.

I'll shop arround for a better welding price. Maybe I can get away with not removing the cats and doing the welding from underneath the car. That way I save an hour of labor time needed to remove/replace the cats.

Any thoughts on APS test pipes and nismo exhaust.

 

Called Doug and he will send me a set of new reinforced cats. Apparently this problem is specific to some Z's with the Nismo exhaust. His solution is to add additional bracing. I'll let you guys know if it works.

Call or email Doug even if you live down under he is certainly a class act!

 

Now that is first class service!

 

Yeah he is not too fond of the Nismo exhaust But I can tell you that I have been running my car for nearly 2 years without that brace and have had zero problems.

 

space_audio:

Good to hear that mate.... I will give him an e-mail and see how it goes!

cheers,

richie

 

Update:

E-mailed Doug and he recognised this problem with nismo exhaust.... and guess what?! he is going to send another set down for me free of charge...... this is a serious first class service..... Thumbs up for Crawford, they do look after their customers no matter where you are!!!!

cheers,

richie

 

Has Doug stated what exhaust he recommends to go with the cats and headers?

 

no... he didn't do that... but he told me that he has already re-enforced the braces on all the new cats... and it will be good for those who are using nismo exhausts...

cheers,

richie

 

Doug runs a Borla on his "Baby II". I, on the other hand run an Invidia G200.

Lou

 

I installed the new cats last night.... got a large rattle noise.... and it happens to be the rattle from the cross member and the nismo mid pipe... (didn't that that before with the previous crawford cats though).. so I added a few washers in and it kinda solved that problem... but right now.. I am getting this kinda of rattling noise from the cat area (even at idle, and can hear more when I accelerate)... any idea???

cheers,

richie

 

Update again:

Rattle problem fixed... due to the heat shield... It goes very nicely now... Thanks Crawford!!!!

cheers,

richie

 

Thanks for the update! I currently have craford cats/borla and am getting the Nismo soon. Nice to know that Doug is so helpful and aware of the situation.