deviant1

iTrader: (2)

With the weather warming up around here, I finally had a chance to get under my car and figure out where my exhaust was leaking. I was really hoping it was just a loose bolt or flange connection, but sure enough, my passenger side Helix Cat was cracked all along the lower side of the weld. The only exhaust mod I have are these cats, the headers and catback are all stock

I'm very pissed off about this, and I hope Gruppe-S will help me out with this. I think I'm done with exhaust mods on this car (cracked Y-pipe, now cracked cats )

99atlantic

iTrader: (1)

you're going to be screwed; they havn't made ANY helix cats since like feb. 2005, so nobody has any they can offer as a replacement, heh

deviant1

iTrader: (2)

Thats just wonderful </sarcasm> At this point, I don't want replacements, I want my money back or some form of compensation. After my Gruppe-S y-pipe cracked in a similar fashion, I have serious doubts about putting any exhaust parts on this car.

99atlantic

iTrader: (1)

grupee-S = ****

have a muffler shop re-weld and solidify the break?

edit: btw, something of interest that i've observed, it seems that almost everybody who had stock y-pipe exhaust, high flow cats, and aftermarket y-pipe had their cats cracked after a while.....so it may not be the cats fault themselves, but rather the y-pipes.

diwun67

iTrader: (13)

That's what I would do.....can't be more than $60

ZinMiami

iTrader: (2)

I don't think anyone in the aftermarket has designed properly for the long haul. That is my opinion after what I have been through.

I have had cracked mid-pipe welds, cracked Helix cats similar to what Deviant is having, and cracked welds at different flanges. I think that until someone designs a set of cats that can correctly utilize the factory cat brace and where all components line up properly to each other at the flanges, undo stress will be put on the exhaust components and issues like the ones that are starting to pop up on this board will continue and escalate.

I had to trash a Fuji exhaust due to various cracks and ensuing leaks. I now have a Borla TD. I am also in the process of looking at cat alternatives as I have had the Helix cats worked on 3 times now. I am hoping that I can find a cat that will utilize the OEM cat brace or at least that can be adapted properly to use it. Tried to adapt something to the helix cats and all that happened was that the canister gave way at the welds. They appear to be pretty thin.

plumpzz

iTrader: (10)

No offense, but if u ever get a chance to look at the inside of the helix cats, they have pretty bad welds. The weld doesn't even go to the other side (only welded on the outside).. I had megans w/ similar welds.. I sold them for reasons other than the weld and i got expensiver stuff, hoping it would have better welds, and it defnatlye did. i'm not trying to sell u something, but APS has a really good weld on the test pipe, its thick and on both sides of the flange. Just get ur self a better set of test pipes. the APS test pipes also have a bracket to attach to the body

barthelb

I've had my Helix Test Pipes and they are fine, 15mo 25k miles. But i have an after market Y pipe and nismo exhaust, maybe the stock exhaust isn't flowing efficient enough that doesn't allow for the heat to disipate quickly.

99atlantic

iTrader: (1)

I've read in the past that te reason Kinetix and Crawford stopped producing cats that using the OEM cat brace was because it was causing MORE stress on them causin them to crack more freuqnelty.......

ZinMiami

iTrader: (2)

I don't doubt that is the reason. Unfortunately it may save the cats but I beleive it puts more stress on the entire exhaust system. It would be great if someone just came up with a proper design that can properly support the use of the brace.

Many say it is not needed due to aftermarket cats beign so much lighter. I don't think the brace is only for the support of the weight. I think it must be limiting the stress that the engine twisting is putting on the entire exhaust down the line.

My modded Helix cats that utilized the brace helped with exhaust rattle and just felt more solid. Unfortunately they only lasted 3 months before they cracked at the welds where the mounting tabs were placed.

Zquicksilver

iTrader: (5)

All IMHO...

The reason the kintex and crawford cats ripped/cracked at their brackets was because they were not properly engineered to handle the stress implemented by the U-brace. Do you see anyone having problems with the stock cats?

I knew this was going to be a problem ahead of time with my HELIX HFCs, so I came up with a means to support my exhaust system at mid point. I drew this up because someone was asking about brackets and braces a while ago.
I feel the U-bolt around the HFC allows for a bit of play but keeps the overall system in check.



I'll be re-checking my setup this spring when I install my Nismo exhaust. At that point I'm going to remove the flexible part of my bracket and replace it with a more rigid bar. After looking at it a few times and pulling on it, I feel the U-brace allows for enough flex as is...

Ever wonder what your suspended exhuast system does at high speeds when bouncing up and down. IMO (a theory), the system flexes up+down fatiguing from the header flanges to the B-pipe hanger. A lot of parts (welds, flanges, bolts) undergoing unecessary stress do to the lack of a mid support (the OEM brace). Could this be the problem compounded with bad manufacturing and improper fitment, most likely.

All in all I think it sucks


Zquicksilver

BlueBlur

I did have a problem with the stock cat ripping & it completely broke off around the weld at the "U Bracket" creating a hole the size of a quarter

That is why I got the Crawfords & now the Carwfords have done the same thing on the drivers side...

Yes, I believe that it is poor engineering & that there should be 1 more hanger under the body.

ZinMiami

iTrader: (2)

Blue,

I am looking into your observation of one more hanger under the body. I am deciding where to have an additional hanger or hangers installed to hold the exhaust up just beyond the cats. I don't want to try hooking up the cats again and cause more cracks.

BlueBlur

Actually I think it should go where the Y-pipe comes back together that seems to be where the most stress is...

The crack is about 6 inches in the cat & I can't see it being that bad but I guess the crack ran.

ZinMiami

iTrader: (2)

In my case I now have a Borla TD so my choice for support placement is different from the conventional Z type exhaust.

BlueBlur

ahhhhh.....ok well I hope you can work something out to relieve the stress because it does need it....I wonder if they rushed this design a little through enineering?

Good Luck & I hope it works out!!

King Tut

iTrader: (1)

I just removed my Helix cats and they looked just like the day I put them on. I think the cracking issue is definitely caused by poorly designed exhausts/Y-pipes. Most vehicles have a flex type setup integrated into the header/cat connection or it is on the cat. For some reason Nissan decided to put no flex until after the cat in the Y-pipe. Now obviously some Y-pipes and exhausts have not been designed to flex well enough to not crack some of the aftermarket parts. If you are worried I would recommend welding in another flex pipe in the cats. There is plenty of room on the Helix.

deviant1

iTrader: (2)

Just a lil update: Gruppe-S replied to my first email quickly and offered to weld them back together, or give me some store credit. I told them I'd take the store credit, and they haven't replied to that or any of my follow up emails either Guess I'll have to call them to get soem answers.

When I first installed the Helix Cats, I had a Gruppe-S y-pipe on teh car already. Within 2 weeks, the weld at the y-pipe's collector was split about 3/4 of the way around the pipe. There have been many other cases of Gruppe-S y-pipes cracking just like this.

I just think the exhaust for these cars is poorly designed. I've read many cases of many different brands of exhausts parts cracking and braking I give up on this stuff, I'll stick with the stock setup.

ZinMiami

iTrader: (2)

It's not a design issue on the OEM stuff, it's the aftermarket stuff. different components don't always line up to each other and the fact that the OEM brace for the cats is not used also puts too much stress on the rest of the exhaust.

Just look at it. The nearest hanger aft of the cat brace is pretty far down the line. There is no support for at least 1/2 of the total exhaust length without the cat brace. Unfortunately no one has figured out how to use the brace properly. Crawford and Kinetix did away with the bracket on their products due to cracking.

Until a set of components come out that address proper support of the forward exhaust components and the parts like y-pipes, mid-pipes, etc are built to better tolerance levels so that they align better at each joint, cracking and related issues will continue.

deviant1

iTrader: (2)

I agree, and I think one reason why most companies have scrapped the bracket is because their design was too rigid. The bracket was attached to a solid piece that had no give, so all that force from the motor twisting was being felt right where the adapter was welded to the pipe/cat. While reinstalling the stock cats, I noticed that they have room for some movement at the mounting point, and this seems to help avoid focusing all that stress on the welds, which will eventually break due to the constant stress.

Who knows, maybe an additional flex pipe on the cats, or an additional hanger or 2 for the y-pipe area would help solve all these problems.