Retrospective ceramic coating experiences ?

[DanEC]

I have to admit to some skepticism also. My headers, primary pipes and mufflers on my under car system are all ceramic coated in black inside and out. My mufflers are Spinteck baffled mufflers (no packing). Now how effective they can actually coat the inside of pipes and mufflers I don't know - maybe not too well.

I think part of the problem may be the use of IR guns to shoot surface temps on the headers & pipes. I read a paper once that IR guns are mostly calibrated to a flat black surface and shiny or silver color can introduce error into their readings. Since most people use a silver, somewhat shiny coating - well relying on temperature reading on them can be a problem. My mufflers are under the seat area and I've shot temps on them of around 550 degrees - not excessively hot for exhaust gases but certainly not as low as I would expect from all the claims for outside heat refraction on outside/inside coated mufflers. Since they are flat black I tend to think theses readings might be more accurate than if I had a silver coating. Pretty much same at the headers although I don't recall specific readings.

So, I'm not saying BS on the claims. But I am a little suspicious of their validity.

[AC Ventura]

Originally Posted by DanEC

I have to admit to some skepticism also. My headers, primary pipes and mufflers on my under car system are all ceramic coated in black inside and out. My mufflers are Spinteck baffled mufflers (no packing). Now how effective they can actually coat the inside of pipes and mufflers I don't know - maybe not too well.

I think part of the problem may be the use of IR guns to shoot surface temps on the headers & pipes. I read a paper once that IR guns are mostly calibrated to a flat black surface and shiny or silver color can introduce error into their readings. Since most people use a silver, somewhat shiny coating - well relying on temperature reading on them can be a problem. My mufflers are under the seat area and I've shot temps on them of around 550 degrees - not excessively hot for exhaust gases but certainly not as low as I would expect from all the claims for outside heat refraction on outside/inside coated mufflers. Since they are flat black I tend to think theses readings might be more accurate than if I had a silver coating. Pretty much same at the headers although I don't recall specific readings.

So, I'm not saying BS on the claims. But I am a little suspicious of their validity.

Dan, just watched your links and car looks and sounds gorgeous. The street spec is very similar to my Mk IV
. I'm also running under floor, but am running the downpipes in front of the footboxes (like a sidepipe car) in the hope of unblocking the air out path. I'm constructing this part now, hence worry about the heat issue. What size primary/exhaust and what SpinTech model did you use? Would you recommend?

[DanEC]

Originally Posted by AC Ventura

Dan, just watched your links and car looks and sounds gorgeous. The street spec is very similar to my Mk IV
. I'm also running under floor, but am running the downpipes in front of the footboxes (like a sidepipe car) in the hope of unblocking the air out path. I'm constructing this part now, hence worry about the heat issue. What size primary/exhaust and what SpinTech model did you use? Would you recommend?

Thank you,

I'm running the ERA headers and downpipes. The header pipes are probably the same as for their side exhaust and the collector and downpipe is different and crosses the end of the foot box and turns back about 1 or 2 inches from the edge of the rocker panels. That's in contrast to the original street cars where the downpipes seem to run further inside close to the chassis rails.

The down pipes from the shorty collector are 2-1/2 inch and I ran 2-1/2 inch all the way out of the back. The SpinTech mufflers are 2-1/2 in and out. The are the low profile mufflers (3 inches thick) and they can be purchased in different outside and center inlet and outlet configurations and thickness.

https://spintechmufflers.com/low-profile-mufflers/

If I were doing it all over again I think I might use a 2-1/4 inch outlet model and run 2-1/4 inch pipes out the rear. By the time exhaust gets through the muffler it should be cooling and condensing enough that a 2-1/4" tail pipe should still pass plenty for 450 to 500 HP I think.







By the way, if you're car isn't street able to take it to a muffler shop, I found 2" PVC pipe and 90/45 degree fittings worked well for mocking up a tailpipe to take to a muffler shop for them to bend or weld up the pipes from. I was fortunate on the ERA that the tailpipe routing only requires a 2-D layout to get through the wheel wells and out the back. The tailpipes came out inside from where they do on the originals but the ERA rollunder behind the tires is deeper than on originals and would have to be trimmed or the tailpipes dropped down lower behind the tire to route further to the outside and clear.

Also still a fan of ceramic coating - for durability if nothing else. That VHT paint just doesn't seem to last very long for the most part.

[AC Ventura]

Originally Posted by DanEC

Thank you,

I'm running the ERA headers and downpipes. The header pipes are probably the same as for their side exhaust and the collector and downpipe is different and crosses the end of the foot box and turns back about 1 or 2 inches from the edge of the rocker panels. That's in contrast to the original street cars where the downpipes seem to run further inside close to the chassis rails.

The down pipes from the shorty collector are 2-1/2 inch and I ran 2-1/2 inch all the way out of the back. The SpinTech mufflers are 2-1/2 in and out. The are the low profile mufflers (3 inches thick) and they can be purchased in different outside and center inlet and outlet configurations and thickness.

https://spintechmufflers.com/low-profile-mufflers/

If I were doing it all over again I think I might use a 2-1/4 inch outlet model and run 2-1/4 inch pipes out the rear. By the time exhaust gets through the muffler it should be cooling and condensing enough that a 2-1/4" tail pipe should still pass plenty for 450 to 500 HP I think.







By the way, if you're car isn't street able to take it to a muffler shop, I found 2" PVC pipe and 90/45 degree fittings worked well for mocking up a tailpipe to take to a muffler shop for them to bend or weld up the pipes from. I was fortunate on the ERA that the tailpipe routing only requires a 2-D layout to get through the wheel wells and out the back. The tailpipes came out inside from where they do on the originals but the ERA rollunder behind the tires is deeper than on originals and would have to be trimmed or the tailpipes dropped down lower behind the tire to route further to the outside and clear.

Also still a fan of ceramic coating - for durability if nothing else. That VHT paint just doesn't seem to last very long for the most part.

That’s exactly what I’m doing Dan! And perfect answers. Thanks for all the info. I’m guessing your primaries are 1 3/4”. My existing Mk IV oe system is 2 1/4.....but motor supposedly 530hp. Borderline I think. 2 1/2 must be right and I think too small doesn’t help heat build up issues.