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Exhuaust Manifold replacement

x2. im looking to run one of those and they have pretty good reviews. while youre in there, make sure your motor mounts are good. i cracked my stainless header in three spots because of crappy mounts.
 
The APN is a great manifold, plus they have some really good customer service and a lifetime warranty, unless things have changed. I've had to swap mine out once, and they were a breeze to deal with.
 
One recommendation is when you get the new manifold put on take it to a muffler shop and have them put in a flex piece in front of the cat to cut back on future problems.
 
dave92cherokee said:
One recommendation is when you get the new manifold put on take it to a muffler shop and have them put in a flex piece in front of the cat to cut back on future problems.
Click to expand...

x2, add the flex piece.
 
Which is the better options, apn header with added flex piece in front of the cat. Or, an oem mopar manifold with the 2 funky flex pieces already on it?
 
iwannadie said:
Which is the better options, apn header with added flex piece in front of the cat. Or, an oem mopar manifold with the 2 funky flex pieces already on it?
Click to expand...

Adding the flex piece applies to ALL headers, it relieves stress on the new header.

Buy what you will, but be sure and add the flex.
 
joe_peters said:
Adding the flex piece applies to ALL headers, it relieves stress on the new header.

Buy what you will, but be sure and add the flex.
Click to expand...

So even with the mopar replacement which has two small flex section you still are saying add another flex in front of the cat? I was just thinking of going with the mopar header to avoid having to have the flex piece welded in place.
 
The 2 flex pieces on the header are to prevent cracks caused by different heating/cooling of the inner and outer pipes. I think the middle of the engine block tends to get hotter.

A flex section below the header protects it from shocks when you drag the tailpipe on a rock etc. It also helps with vibration. Normall the engine vibration makes the whole exhaust pipe vibrates, and that energy has to go through the header. With the flex, only the portion of piping up to the flex section gets vibrated.
 
winkosmosis said:
The 2 flex pieces on the header are to prevent cracks caused by different heating/cooling of the inner and outer pipes. I think the middle of the engine block tends to get hotter.

A flex section below the header protects it from shocks when you drag the tailpipe on a rock etc. It also helps with vibration. Normall the engine vibration makes the whole exhaust pipe vibrates, and that energy has to go through the header. With the flex, only the portion of piping up to the flex section gets vibrated.
Click to expand...

I guess that makes more sense, I was wondering how 2 flex pieces in those positions were supposed to help. I thought most cracking came from the motor flexing and the exhaust being stable. Those flex pieces wouldn't do much as the other pipes are ridged.
 
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