Exhaust Coatings
- Thread starter Wildman
- Start date
OP
I went over and picked up my exhaust from Performance Coatings and snapped some pictures of the different colors they offered.
@cpwolf Here is their chrome they do. These are the headers for a BBC drag car
And then here are the mufflers.
And a close up of the headers.
This is an older set of headers where they had rusted before.
You can see the intake manifold on the floor too. I found out I could have had my gears coated too to help reduce the heat.
@cpwolf Here is their chrome they do. These are the headers for a BBC drag car
And then here are the mufflers.
And a close up of the headers.
This is an older set of headers where they had rusted before.
You can see the intake manifold on the floor too. I found out I could have had my gears coated too to help reduce the heat.
OP
Here is a good read for Techline coatings.
I use many of their products when building engines, if good enough for NASCAR why not use for my engines.
https://techlinecoatings.com/wp-content/uploads/TLC-Catalog-Web.pdf
I use many of their products when building engines, if good enough for NASCAR why not use for my engines.
https://techlinecoatings.com/wp-content/uploads/TLC-Catalog-Web.pdf
I wonder in tech line coating would hold up to cam break in temps. Would a 4.6 strocker header would exceed 2000 deg
If you are Cerakoting exhaust for heat reasons, specifically ask for "Piston Coat". It's the same as regular cerakote but with lower emissivity, meaning it has maximum heat retention capability, and will provide the best thermal barrier.
I had a local shop do an exhaust header inside and out, as well as the intake header and catalytic converters on the outside only. Haven't road tested it yet, but so far I've seen a massive reduction in heat at idle.
My infrared thermometer seems to significantly underestimate the surface temperature, so it must actually have lower emissivity than the default setting of the thermometer.
Lower emissivity also means lower absorptivity in the same infrared frequencies, so coating the intake header should also have some effect on intake air temperature.
I had a local shop do an exhaust header inside and out, as well as the intake header and catalytic converters on the outside only. Haven't road tested it yet, but so far I've seen a massive reduction in heat at idle.
My infrared thermometer seems to significantly underestimate the surface temperature, so it must actually have lower emissivity than the default setting of the thermometer.
Lower emissivity also means lower absorptivity in the same infrared frequencies, so coating the intake header should also have some effect on intake air temperature.
Local place called Duck N Cover coating. He mainly does firearms, but will also do automotive parts
https://www.dnccoating.com/welcome-to-duck-n-cover-the-blog
Prices were quite reasonable too
https://www.dnccoating.com/welcome-to-duck-n-cover-the-blog
Prices were quite reasonable too
Curious if you felt any difference in power with the intake, exhaust being coated, and the insulation on the intake tube? I feel like the answer is a hard maybe, when in hot hot summer temps lol.
So far, seems to have been a modest improvement. The Windstar intake made a huge difference, far more than I expected. I've made a number of changes beyond just the ones here and the Windstar intake, but I've managed to boost fuel economy from around 12 MPG to 15-16 MPG (6-speed Rubicon on 35x12.5 and heavy everything) altogether even before these items. I don't have good data for after the coated headers were installed yet.
The big issue the TJs have is that higher air intake temperatures lead the computer to pull timing aggressively, meaning less power is made for the same fuel burnt. If you can get the computer to pull timing less, you can get major gains in torque and fuel economy.
That said, you can't just go in with a tuner and tune out the timing modifiers without doing anything else since they actually have a purpose. They are there to prevent preignition and detonation in the cylinder to protect the engine at the price of power and fuel economy.
If you can (1), increase the threshold for preignition and detonation, and (2), convince the computer that preignition or detonation is not a risk, you can get pretty significant gains in torque and fuel economy. By itself, the computer will recognize the colder air coming in the intake, and as a result, pull timing less. But it won't recognize colder manifold air, since the computer estimates manifold air temperature based on IAT, ECT, and a few other factors. However, you can in fact change the tune to account for the lower MAT from coated intake and exhaust manifolds and get extra gains that way without much risk to the engine.
In short, it all has to work together as a system. Simply slapping a header on is going to net you very little. But a properly built intake and exhaust system with an appropriate tune can net you quite a lot.
Colder IATs will also directly increase power to a small degree by providing more dense air to the engine. The engine will provide more fuel to compensate, so you will get a proportional increase in WOT torque, but it also makes the engine less efficient at partial throttle due to pumping losses. In this case, denser air is a net gain if it allows you to hold a lower gear, but is otherwise a net loss at partial throttle. (This is why some highly efficient cars actually have a warm air intake.)
Note that I attribute the vast majority of my gains to getting the engine to pull timing less, not due to the denser air.
Well fucking said. So few people actually bother to learn how and why this works in general or with our PCMs specifically.
I hear you, I’m fully aware that tuning is a part of the trifecta if you will… I do aftermarket tuning on the side myself. I was curious if without a tune it seemed peppier, but sure as heck knew with a proper tune it would… even completely stock.
I need to upgrade my tuner device before I can tune the jeep lol… thats why.
Exactly. Very well explained, Steel.
Personal experience. When I built the Hemi, I needed a custom tune before starting it for the first time. So at first I slapped an air filter directly on the intake assembly to get it running for a chassis dyno tune. The big Hemi makes a crazy amount of heat, the IAT’s were well into the 200’s, and the ECU was pulling lots of timing to compensate.
Knowing it was a problem, I built and installed a cowl intake, getting the IAT’s very close to ambient. I then had it dyno tuned again. The difference was huge - 50 ponies at the wheels.
I also run ceramic coated (inside and out) headers to help with the under hood temps.