worf928

I installed one SLC x-pipe with the too-big cats circa 2008-ish and discontinued the practise after getting nowhere with SLC. In the meantime I've had to deal with the aftermath of several 'prior' installs.

If the shipped cats became, at some point, actually installable, it sure wasn't broadcast.

You must live on a different planet? Yeah, Texas I know. Lived there for 18 years. I guess after-market cats are the only thing that's smaller in Texas.

This is the latest example, removed a couple of weeks ago. Perfectly good set of GT resonators ruined.

hacker-pschorr

I'm as confused as Sean. I've installed 3-4 and don't recall having any issues or having to cut up the stock exhaust.

I do plan to modify mine but that's so the CATS & test pies are connected with V-band clamps for easy swapping.

worf928

Every SLC x-pipe with cats I have seen (half-a-dozen or so) looks more or less like the one above: too-big cats smooshed together and splayed-out so that the mid-pipes will not fit and seal without a very serious hassle.

Maybe every one I've seen was cobbled together before these mythical small diameter cats materialized.

Anybody that wants the POS pictured above can have it for free - if you come and get it. And bring your own Sawsall.

SeanR

I live on a planet where i wouldn't install a fvcked up looking pipe like that on a car. I'm seeing there might be a common problem there. Find a new fabricator if that's what he's churning out.

Been using the clamps with no issues except a tightening down the road or welded, and none come out looking like that jigsaw puzzle you've got there. Am going to save that picture as a demonstration for what not to do. Thanks for the amusement.

worf928

Mrmerlin

Thats some funky routing for sure. Based on the picture , you have an early stainless X pipe,

without knowing the depth that the cats are on the X pipe they could have been routed straighter IE moved more to the rear of the car.
That said the original pipes that were cut off the X pipe have been welded onto the rear of the cats.


The normal cutoff point of the X when cats are fitted is back further, this lets the cats fit properly side by side with no issues and thus properly connecting to the resonators with the supplied clamps.

maybe someone cut the pipes off too close to the X and thus the cats have to be moved up to cover the pipe this results that the cats are bumping and then makes the exit of the cats not be inline with the resonators.
Its also curious why the aft ends of the stainless X pipe have been welded onto the rears of the cats. As these cut off parts are not used when cats are fitted.

From the pictures provided someone didnt fully understand the installation instructions before they started cutting the X pipe, once they made the cut wrong, the welder came into play to rescue the screwup

That said when fitting cats its advisable to test fit the X pipe then fit the cats to the pipe and resonators along the out side of these pipes, then mark the X pipe prior to cutting

Ketchmi

Stan nailed that one on the head, somebody "reworked" that crossover after cutting it too close to the "x". I am sure it did work to some degree but I would never put that on a customer's car in this lifetime or even the next one.

As far as Worf tossing them away, lets form a line for his toss off's. Granted, this one needs tossed but I could bring it back from the dead if necessary. I have almost 1,000 crossovers out there and you are the first I have encountered that could not make them work even if it required some additional help from myself or one of my resellers. That's one tenth of a percent for a hand built item but yet you have "tossed" how many yourself? Many hundreds worked just fine with the early cats and sealing system. We have now found better clamps which makes the whole installation much easier. We have had to change cat designers a few times as they change their designs as often as a back street hooker's panties. Sometimes it's for the better, sometimes it's for the worse but they all end up functional with a little extra effort.

I am currently making a custom pair of clamps for one of our customers to get him by until we find a way to make the new cats easily bolt on. They will be shipped out today as I was off the past two days with physical problems.

Ketchmi

BTW, I have seen one worse and the customer was still happy with it. He figured that if the crossover gave you 25 hp and the "Y" gave you 20 hp that the pair should give you 45 hp! Yes, an "X" inline with a "Y" and a single 3" exhaust from there. He's still a good customer and I still give him a really bad time every chance I get.

ROG100

Definitely f***ked up by a PO or his welder. Some people should not be allowed to own a 928 or work on one.
I will repeat - all the X pipes I have fitted and or supplied - with cats - fit nicely together in the correct position under the car so I do no know who you are getting your X pipes from Worf.
As for throwing them away that is just stupidity. Send them to me as I have a backlog of X pipe orders to fill 8>)

ROG100

I do not think I ever supplied you with an X pipe Dave. Maybe you bought then from you know who and might want to ask him why he did not fix the problem for you. I do not want to get banned so can't mention THE name 8>)

ROG100

Here is a picture of an early cat X pipe when the cats were large with edges. Plenty of room. Once the new cats were available it was easy peasy to fit them.

polecat702

I have the SLC X-pipe, no cats with the RMB. Everything fit perfectly. My car is loud, but I just remove my hearing aids, and it sounds sweet to me.

worf928

I admit to hyperbole in my original post. I apologize for using the phrase "unless you destroy the rest of the stock exhaust." It isn't necessary to do so. I have been able to make the SLC pipe with cats work.

This was an uncalled-for slur on Dave Lomas' work for which I, again, apologize.

I should have written that in my experience the SLC X-pipes have not, historically, worked well with the supplied cats and require extra effort (as compared to the OE exhaust and to a no-longer-available alternative) to install and also require extra effort each time the exhaust is touched.

The exhaust I pictured above (and one other) was destroyed by someone (who was not me) attempting to make it work.

The stock exhaust is ~98mm pipe-center to pipe-center. The cats on the abortion pictured above are ~108mm wide. So, when pushed together such that they touch they have a center-to-center spacing of ~108mm. Which - let's do the math - is 10mm wider.

The x-pipe downstream pipes have the same ~98mm center-to-center spacing? Yes? No? I recall that they do, because SLC X-pipes without cats are a direct fit and work just fine.

So, regardless of where the pipes are cut on the X-Pipe the cats will not, ever, slip over the x-pipe without the ends of the cats splaying-out to more than 108mm. Since they are splayed-out, mid-pipes will not align.

Thank you for posting a picture. It shows clearly and precisely what I describe: the cats are touching and the downstream ends are splayed-out, because the cats are too big around. The passenger-side mid-pipe enters the cat at an angle. The cats slip over the X-pipe at a slight angle because they want to slip over a set of pipes that's ~10mm closer together than the cats can tolerate unless they are 'angled-in'.

Whoever did the install you picture did exactly what I have done to get SLC-with-cats pipes sealed: They bought four preformed band clamps and tightened the crap out of them to attempt seal the gaps created by the too-big cats not aligning with the x-pipe and mid-exhaust.

Furthermore the mid-pipes are now under a 'spring load.' If you disconnect the muffler/RMB the mid-pipes splay-out even further which means that the muffler/RMB doesn't go back on and seal without the mid-pipes being 'man-handled' back into place. (I futz with a ratchet strap to bring mid-pipes into alignment.)

You have not, as far as I know. You may have shipped one that was installed by someone else that eventually found its way to me.

At the time I was being asked to install X-pipes with cats, (as opposed to now where I'm being asked to remove them) there was an alternative that did not require any futzing-with whatsoever. The pipe, clamps, and cats fit together as easily as the stock exhaust. No funny angles. No man-handling. So, after my first experience with SLC-with-cats, where someone else had installed the system and could not get it to seal with the supplied components, and I was able to seal it with the same method (plus ratchet strap) you picture, I began using the alternative. For a subsequent SLC install that I did, I sourced different cats that were eccentric and thus aligned perfectly with the stock ~98mm spacing. All SLC-with-cat experience after that was either identical to the first or was an abortion like the latest.

Assuming we are talking about the same Supplier Who Cannot Be Named, I did not. I have had enough experience with 'VoldaParts' offerings that I will not install them.

As for having a stack of x-pipes, their owners drove away with them in the hatch (double-bagged.) I may have one in my 'forgotten parts' shed which is covered in a mound of snow and inaccessible until Spring. The first abortion was cut into pieces. The second is available for local pickup.

I suspect that the feedback you have gotten isn't completely representative of your client base. Once again: I have yet to see one of your pipes installed with cats where all components lined-up without non-trivial issues. The two weld-together abortions I have removed from 928s further suggest that some 'installers' (using the term very loosely) have 'resorted to violence' to make them work. I will not apologize for using the phrase "resorted to violence." Cutting up a perfectly good stock 928 exhaust to make an after-market part work is an act of violence.

I do not write that cases where everything lines up do not exist. However, Roger's picture above is not such a case.

I do not maintain that you are still, now, shipping too-big-to-fit cats. Though you did at one point. It may also be that one or more of the installs I have seen were done with cats you did not supply. But, at least two of the installs I've either sealed (as above) or removed did come with cats you supplied.

Last, I think it very likely that I have a different definition of "non-trivial issue" than do most.

I have removed about half-a-dozen (with-cats) at the request of the client. In all of those cases the x-pipes featured these too-big-around cats. In one previous case - in addition to the above case - it was welded into another abortion that had lots of problems even though it was sealed.

I am glad that you are continuing to improve your product offering. I really would like to be able to recommend to my clients an X-Pipe Solution that they can run with cats where everything lines up nicely and seals well with the components you supply without resorting to 'man-handling' at the time of installation and for any subsequent service that requires disassembly of one or more of the exhaust components. Perhaps you have already done this and someone can post a picture. If not, I look forward to what you can develop.

ROG100

Worf - very very professional response.

The picture I posted was the early "larger" cats with the lip. I agree not a perfect installation but it worked. That was years ago and then the bullet shaped cats were added to the kit giving a much better none interference fit.

While not perfect the large two diameter joggled clamps work pretty well at sealing the joint. They are specifically made to deform to take up the small imperfections and you can torque the **** out of them and they do not break. Pretty straight forward for the home DIY car guy.

It would be better to have V flanges and clamps but that adds costs most are not prepared to pay. Welding is another option - you pays your money you takes/makes your choice.

worf928

I would like to see a picture of these? Anyone? Better yet, a largest-diameter measurement. Not that I think they don't exist, but that I'd like to know that if I tell a client they will work with no muss or fuss that they will.

Assuming we're talking about the same type of clamp (called 'preformed exhaust band clamps' when I buy them) then yes you can torque the redacted out of them. I went through a lot of variations on the first 're-seal' job. If you tighten the clamps last, the angles of the various pipes are such that no amount of torquing the clamps will seal all the gaps. If however, you leave the muffler/RMB un-attached and allow the mid-pipes to 'spread-out' then you can seal the cats. But, of course, then you need to 'man-handle' the pipes together to fasten the muffler.

I would think that exhaust clamps should be just as fool-proof for someone charging for the work as for someone labeled 'home DIY car guy.' We're not putting rockets together in a clean room.

This is a non-option in my book on the same list as cutting a hole in the chassis to get to the clutch master cylinder.