430 - secondary cat to exhaust inlet loose

Clean the pipe ends up and use fireclay, then clamp it up and start engine to cure the fireclay

 

Did you use a new clamp? Those clamps are designed to be used only once, so when you loosen it you need to replace it with a new one (yes, there are ways to reuse one but they're not all that expensive). The pipe OD is 63mm which is just under 2.5", however in my experience a 2.5" clamp will not work. Get the 63mm clamp and it works fine.

 

The center piece between the two clamp ends is a tight press fit onto the bolt shank. When you tighten it for the first time that piece gets moved into position. But if you loosen the bolt, you normally can't get the piece back up into its original position and it doesn't tighten again as effectively. The WSM states you must use a new clamp if you loosen it.

I've tried a 2.5" clamp on my 430. It almost worked but not quite. I could have made it work by adding a piece of .010" shim stock, but I opted to get the OEM clamp. It's not ten times as expensive as a non-Ferrari labeled part, only twice as much

One other thing: These clamps should hang off the end of the pipe about 1/8". The original Ferrari clamp has a small weld to hold it in the correct position. Make sure you put the new one in the same place.

 

Any type of exhaust pipe paste, comes in a similar cartridge style as silicon or you canget a smaller one like a toothpaste tube. It goes on like tooth paste to give a gas tight seal- once you have the clamp tight it should squeeze out between the 2 pipes, starting the engine and letting it tick over will harden the paste and thats your gas seal. Plumbers use similar to seal the exhaust gas on your gas or oil boiler flu pipe

 

You would never get a seal on the pipes just clamping it up dry, they put this stuff on new exhausts.
What do they call this stuff in your area ?

 

Ironically I’m now dealing with the same issue. I’d like to buy new clamps but I heard that they may be tack welded to the cat. If that’s the case how do you get the old ones off? just b be bang it off with a hammer LOL? And then I guess just clamp the new one without the tack weld?

 

They are not tack welded, you need to pull the pipes apart and clean up the inner and outer with a rotary wire brush, then spread exhaust paste on them and assemble- when you tighten them up the paste should squeeze out. Run engine on tickover to harden

 

will give that a shot. Tried some corner auto parts store paste but I don’t think it was rated for a high enough temp. Also, I didn't clean up the pipes as you recommended. Probably should not have skipped that step!

 

Local plumbing store, used on heating boiler exhaust pipes. Needs to be toothpaste type consistency

 

Thanks man. Just ordered. My issue is baffling. I fit the agency power titanium x-pipe. Its so light I didn't even mount it to the gear box with the supplied bracket since that bracket has zero give and is rigid, and I want it to be able to "float" and move with the cats/headers (since my firm belief is that you get cracking/issues if the whole system is too constrained and can't move/expand with the heat cycles (scud has nothing "hanging" to the sides like the f430's). I've put about 300 miles on it hasn't moved a millimeter up/down, but the cat connection pipes keep sliding "out" towards the back end of the car. I can't perceive any leaks at all even when I put my hand down there, but sure as s---- those pipes slowly "creep" forward, even with paste. Will try these and update!

 

If this pipe is titanium , what do the makers say about clamping it. Will it compress given how strong that stuff is said to be. Never worked with it in pipe form

 

I bought it second hand, so I don't know. But I do know it is designed to attach using the oem clamps, so I can't imagine oem style clamp force (espcieally with a clamp that spreads the load a little better with more surface area than the skinny oem clamp) is going to be a problem. Moreover, the titanium tubing slips inside the cat tubing, so its the oem steel that is going to "compress," onto the titanium pipe, so I don't think I need to worry much about the titanium.

 

More paste then

 

The OEM clamps are tack welded to the tailpipe (the end of the cat goes into the pipe). Ferrari did that just to hold them in position before they were tightened. If you totally unscrew the clamp, you can just bend it back and forth a few times and the weld will break. It will leave a small bump of remnant weld on the pipe. You can use that to position the new clamp.

 

Just to add a bit more data. I tried two types of "paste" and nothing kept my exhaust pipes from slowly slipping out of the cat outlet pipe. Seems the clamps had just lost their strength or had been stretched to the point where they no longer exerted the required pressure to keep things tight. And to confirm, mine were indeed tack-welded as strongx indicated above. I took his advice and removed the bolt, opened the clamp up and gently moved it back and forth until the clamp broke free. Because I'm OCD I used my dremel to remove the tack weld remnants on the cat pipe.

I bought two 2.5" clamps on ebay as pictured (15 bucks). They look rather "agricultural" but after 50 miles no slipping. I like this clamp design because not only does it employ two bolts, but the clamp is long and "stepped" so that the part that clamps over the outer diameter of the cat pipe is just a bit larger than the part that clamps over the muffler piping that slips into the cat pipe. In other words, you can get them nice and tight on both ends and there is pressure on both the cat pipe and the muffler pipe to keep things in position and "tied together." I'm happy.
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Mine has marks where is slides back and forth from expansion