YIKES!

Thanks for bringing VeeTec's comments to my attention, Victim64. I missed them in this thread, but I read what he had to say in the thread Eric posted.

Quick question for you VeeTec. Do you think your driving habits had anything to do with why your flex section failed so quickly? In other words, did you race your Maxima or drive it very aggressively after you installed the Y-pipe?

 

Has Brian addressed this at all?

I have no idea what this problem is ... can someone post a pic of what I should be looking at and for? Or at lease a schematic or conceptually explain it in words?

Tkx!

 

He had it at the track shortly there after, so I would say yes. But isn't the Y-pipe a performance mod, so aren't most people that get them going to see how well it performs?? lol

I am getting one soon, but leaning heavily toward WSP.

 

Absolutely. At this point, I'm just trying to figure out if there's a relationship between the flex section failing and the vehicle being driven hard. So far, that appears to be the case.

 

Even if driving habits DO have an effect on the flex....it's irrelevant....aftermarket y-pipes are RACING exhaust pieces...which means they should stand up to the kind of abuse that racing and agressive driving doles out.

Think about it this way...if you are going to spend money to get more hp out of your car...are you going to drive it like an old lady all the time in fear of breaking the part that gave you the more power that you now cannot use?

I personally drive agressively and race my car...and I've had THREE...yes THREE cattman flexs go bad on me...the latest one only took 2 weeks!!!!!!!

 

Yes I raced my car, but I didn't buy my Y-Pipe for looks.

I didn't abuse it with excessive wheel hop and my motor mounts are all fine.

I personally think its the flex pipe design. The stock Y-Pipe allows for more give and I have yet to hear of one failing, not to say that it couldn't happen, but my stock flex pipe saw a LOT more racing than the Cattman. Then there was the initial fitment issue with my Y-Pipe. That disturbed me a bit too.

The Cattman appears to have the best design for flow and power, but the flex pipe is obviously not up to the standards of the Y-Pipe itself.

I hope the problem is resolved soon.

 

Well, I drive my Maxima to the ground. However, I don't drag race, I road race. Don't know if it makes any difference. I've had the Cattman Y for a little over a year now and I average about 1-2 road race events per month with a couple SCCA events thrown in every now and then. Aside from the official events, I'm very hard on my car on the streets also. But as far as I know, the Y is still in perfect working order, however, I'm going to check it later today since this post will be in the back of my head all day long, I'll post back if I find any problems (or not find any problems).

Now, if I could only get my wheel bearings to stop going out...

 

Thanks MaxedBandit, VeeTec and BriGuyMax. I'm glad you guys decided to post your comments.

BriGuyMax, once again I'm not arguing your point. I agree that an aftermarket Y-pipe is designed for racing and should be able to withstand the kinds of stress racing imposes. But that doesn't answer my question. All I'm trying to determine at this point is whether stress is a factor in Cattman Y-pipe flex section failures.

VeeTec, obviously there's something wrong with the flex section. But it may have NOTHING to do with its design. Perhaps it's a flaw in the materials used in the liner or the construction of the liner itself. Frankly, I hope that turns out to be the case. I suspect it would be easier to correct a defect in materials and workmanship than a flaw in the design.

MaxedBandit, I'm very interested in hearing the results of your inspection. It sounds like you put a lot of stress on your Y-pipe. If your flex section shows no signs of detioration, then Brian may be correct and the failures may be random as he suggests. Please keep us posted.

Now here's an idea nobody seems to have thought of. I notice that the Cefiro Y-pipe referred to in another thread has two flex sections. I wonder what would happen if you cut the Cattman Y-pipe and added an additional flex section to it. Would it eliminate the problem? And how much noise would the additional flex section generate?

 

I was told by a muffler/exhaust shop that wheel hop and bad motor mounts can break a flex section in a ypipe.

 

That wouldn't surprise me at all, skeelo34.

 

I am all for supporting Cattman, but for now I am going with a WSP Y-pipe. It gives the same amount of performance increase, but I haven't heard of near as many problems with it? Good Luck to everyone and I hope this issue is resolved.

 

guys .. help me out ... what's the flex section n e ways?

 

Under the circumstances, I can't say as I blame you. I just hate to see Brian take a hit when he's willing to step up to the plate and fix the problem to the best of his ability. And there's no guarantee that you won't run into a flex section problem with a WSP Y-pipe. Time will tell, of course . . .

 

Perhaps this will help:

http://www.stevetek.com/R-DIY_Exhaust.html

Read the section under "Procedure".

 

I wouldn't quibble about it being a month or two out of warranty, we'll fix your pipe.

An order of great new lined flexes are on the way and should be here on or about the 26th. We can start installing them immediately.

No reason not to send it in, and I an very confident about the durability of the new flexes.

Brian C. Catts
Cattman Performance

 

I've been too busy to follow this of late, but let me make some things clear.

The problem is entirely the result of a particular flex section design because a different type used in some pipes does not have any failure pattern.

Two basic types have been used in Cattman pipes (I find out now, though they were from the same supplier, same part number so we can't know the proportions of each). In one type, the braided liner is held in place just inside either end with a metal ring/band that is spot welded to the materials underneath. Looking in the end you can see the edge of the braid under the metal ring. In some pipes, the spot welds holding the ring in place have broken and the liner has come loose on the inlet end and gotten bunched up like a sock as its driven inwards by the exhaust. Simple as that, its a defective design.

Obviously with a weak design, the failure rate will be higher/quicker the 1) the harder the car is driven and 2) the worse the condition of the motor mounts. I'll make it absolutely clear, that the flex should not fail simply because the car is driven hard, but if the mounts are really shot, that is asking too much of any flex over long periods of time.

Ask any Nissan-specific master mechanic, the Maxima mounts are relatively weak, and will fail anywhere between 30k and 100k, depending entirely on how the car is driven. A car like mine, a 97 5-speed, with 70k+ miles, driven "robustly" throughout its life, will certainly have shot original motor mounts, its a fact of life. And, they're shot long before you can see they're shot, there's not visual evidence unless they're so bad that they've torn or the fluid is leaking out of the liquid-filled versions.

I'm not making excuses for my flexes failing -- once again, its the result of a crappy design -- but you cannot overlook the extreme stress put on any flex section by shot motor mounts on a transverse-mounted engine and, if driven hard with those, the resultant extreme wheelhop is absolutely deadly to flexes.

Back to the second "correct" flex design. Now we see that some of the Cattman pipes have been made with the proper flex design, where the flex lining is tucked under a double-walled endcap and welded into place. The edges of the braided lining are not visible at all. There is no funky ring to come loose. There has been no indication that any of these have failed.

What we're doing about it... We'll begin fixing pipes as soon as the new flexes come in, due on about the 26th. We've ordered longer 8" flexes (includes an inch-long cap at each end) made in the US by a real solid company with an excellent reputation. Even though this firm sells a braided-lining flex that would work well, we're upgrading to a spiral stainless steel interlock lining that's like the flexible metal casing that protects the handset cord on a payphone.

Its pretty basic -- the new flex, whether installed in new pipes or used to replace a defective flex, is of superior quality and will not suffer the pattern of problems that the flexes that have the bad design.


For those wondering what I'm doing about fixing the bad flexes, there is a semi-permanent post on this forum that explains the return policy. We'll first fix the pipes still under 1-year warranty (with a little flexibility on the warranty term). Then we'll deal with any older ones that have flex issues, though there will have to be some modest cost recovery on those.

A couple of people have written to say they cannot return the pipe for whatever reason and asked me to send them a loose flex for local installation. I don't really advocate this approach but if the owner wants to assume responsibility for the local work (please insist on TIG welding), I'll send the flex and $20 to cover or help with labor (that's what I pay to fix each one here). When someone wants a flex to be sent without returning the old pipe I require a photo depicting the interior of the failed flex, with something identifying the owner visible in the picture like a business card.

ASo far I've heard from perhaps 12-15 people. Combined with the ones fixed previously, I'd say about 20 flexes have failed and notified me. Based on the customer base out there, that represents between 2 and 3 percent. More than I'd like, but not an epidemic.

We are also in the process of changing to a new fabricator of y-pipes, a great ISO9000-certified machine shop here in Tucson that does a lot of aerospace and medical device work and will raise Y-pipe fabrication to a new standard. They're making up a very sophisticated fabrication fixture that will turn out a more consistant product than has ever been accomplished before.

Obviously we'll be using the new flexes. All tubing steel will remain T-304 stainless with over-thick fully CNC machined mild steel flanges. The tubing is from the Rath Mill and mandrel bending will be done by Burns Stainless; I understand this is meaningless to most, but to those who know, Rath makes the best s/s tubing and Burns is legendary in racing exhausts -- design, fabrication and materials.

Oh yes, the new ones will not only be better, they'll be available at a new, lower retail price!

Really long, but this has turned into a complex subject, fraught with conjecture. I hope that this information is useful and puts some rumors and misimpressions to rest.

We've obviously taken a hit with this flex issue, but you learn from your mistakes and as far as I'm concerned the future is bright with our new y-pipe fabrication and improved subcomponents.

Brian C. Catts
Cattman Performance

 

Is it possible that fitment issues also added stress on the flex pipe?

I am glad to hear the new flex pipes will be there soon, and look forward to getting my Y-Pipe back.

 

Brian,
Thanks for addressing the issue. I paid 400 bucks for the AGX's when I bought them from you, and I did so because I believed in your name/reputation. I have your y-pipe installed on my 99 Max and I am not experiencing any problems so far (KOW). My receipt from you is dated 6-22-01. Please keep us updated on your 4th gen catback. Thank you for your continued support.

 

Roger that! You can purchase a cheaper product than Brian's, but you can't purchase a better-made product. And ANY PRODUCT can have a design defect. It isn't whether a defect occurs, it's what the manufacturer does about it when it happens.

As far as I'm concerned, Cattman continues to earn my confidence.

PS: Brian, I'd recommend that you take your last post in this thread and add it to the sticky thread so that everyone knows what you discovered and how you're addressing it.

 

OK, sorry for the long delay, but I wasn't able to get inside to look at the pipe until late last night. Anyhow, the flex section is perfectly fine besides being murderously dirty. And since I checked it after reading the post from Cattman about the motor mounts, I had those checked too and it seems that they are just about to go...joyous. I must give respect to Cattman for making a high quality part...thanks!

 

chalk one up on the ok for now side. See photo at link:
Cattman flex - 8K - 2k maxima