Downpipe Hard Lagging, Soft Lagging, and Coating Discussion

[blueroadster]

@blueroadster

Choose a good downpipe to begin with, and you won't have warranty issues to be concerned about. Something with a cast turbo flange is in my opinion a must for serious circuit work. Catalyst quality being the second most important aspect. Catless takes away the risk/concern with the catalyst breaking down since it's not there.. but this choice depends on your application.

Thanks...I have this SBX downpipe that I intend to hard lag. It checks the boxes that you mentioned. Car is a daily so I need to run a cat for emissions purposes. Down the road and if things change to make it a dedicated track car, the internals of the cat can always be punched out.

Galvanic corrosion between inconcel and stainless is low risk. The metals are similar in potential difference. Again, I've had no issues. If there were, after several years of service, you rip the hard lagging shell off, and redo the job. Nothing in life lasts forever, and you got your money's worth.

Great point.

You raise a good point in regards to heat and exhaust flow. I think the hard lagged dp and fp would mean the heat and thus the internal pressure of exhaust gases in the piping will go up. So it stands to reason that a pipe ID that wasn't restrictive without the hard lagging may become so after hard lagging. Obviously it does depend on pipe design, elbow angles, and power output of your current set up. It is likely a non-issue under 500hp. Above that you probably would start to run systems above 3" ID anyway.

Good to know that my thoughts were not way out in left field.

Something I forgot to mention with hard lagging, is that it will add another ~10mm to the OD of the pipe. So tight areas such as the front pipe elbow (depending on the particular front pipe) need to be modified to clear the sump. So you are best to install the system, check where it is tight, and make necessary modifications to ensure sufficient clearance before having it hard lagged.

Currently, I have the TSP downpipe mated to a Fujitsubo SS front pipe and Fujitsubo A-RM+C Titanium exhaust. When installing the Fujitsubo SS front pipe, I remember the tight areas that you mentioned and will double check clearance measurements. For hard lagging, I am leaning more towards ZircoFlex SHIELD. Zircotec seems to be the industry leader in hard lagging. My plan is to use a hard lagged SBX downpipe and hard lagged front pipe (hopefully being able to reuse my existing Fujitsubo one) mated to my existing Fujitsubo exhaust.

As for ceramic coatings, I have never seen these coating systems last, and do anything meaningful other than look good for the first few months, and then crack, peel, and fail.

IMHO, agreed with the exception Jet-Hot, Swaintech, and Zircotec. Those coatings seem to bond better to the base metal providing corrosion protection.

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