There are benefits (other than appearance) to ceramic coating on SS headers...

From Jet Hott:

Heat: The coating promotes denser, more potent fuel/air charges by insulating the engine bay from exhaust heat.

Also, it accelerates the pulsed-vacuum effect on “tuned” headers, resulting in more effective scavenging of cylinders. The increased velocity of exhaust gases produced by higher exit inertia not only clears each cylinder more quickly; it also draws in the next fuel/air charge more efficiently.

IMO most people just don't want to spend the money to coat their headers for what they perceive as a negligible benefit. I wanted my LG Pro long tubes coated....I like them that way.

 

The problem is you have to trust what Jet Hot is telling everyone. They have a good product, but believe me, they are also doing a marketing job. You need the coating for carbon steel, it keeps the carbon steel from rusting AND it helps insulate a material that transfers heat very well.

On the other hand, 300 series stainless steel already does NOT transfer heat very well. It has one third the thermal conductivity of carbon steel. Yes, Jet Hot will help the stainless a little bit (10% better), but not much. The ability of a material to transfer heat is the conductivity of the material divided by the thickness. So a low conductivity steel that is the full wall thickness of the tubing is a lot better than a coating that is only a few thousandths thick.

Remember, the only reason Jet Hot is advertising hp increases is due to velocity increases from keeping the exhaust gas hot. Stainless already does this, adding coating helps just a bit more. The other reason I'm leery is that I've asked Jet Hot for the conductivity and thickness of their coatings. They will not give these out, so I assumed some numbers (and my numbers are probably better than what Jet Hot gets, I used .006" thick with the same thermal conductivity as aluminum oxide) and by my calculations Jet Hot only decreased the heat transfer by 10% for a stainless header (that uses .065" wall tubing) and by 25% for a carbon steel header. But, remember, since stainless is so good, even without a coating, the stainless transfers under half the heat than a Jet Hot coated carbon steel header.

You guys that have the coating, go ahead and believe that you are getting more from it than you really are. At least they are really pretty. I'd really like to see someone do some dyno pulls before and after Jet Hot coating on Stainless headers. You will not see it on the dyno. Jet Hot makes a GREAT coating. I had the coating on my 94 Z28 when I had cheap carbon steel headers. I'm just not going to waste the money for coating a stainless header, it's past the point of diminishing returns.

 

I recently bought a set of headers directly from one of the top vette header manufacturers. I asked about coatings and was told he would sell them to me either way but coatings were a waste of money on Stainless headers. I took his advice.

 

I have been told my several tuners that since coated headers hold the heat inside the pipes, the heat ends up inside the motor and heads, presenting a greater challenge to tune the car, and it is also said that the engine will be more prone to pinging, therefore the tune needs to be more conservative.

I have coated headers on my 07, and will most likely not coat the ones for my 08. The quality of my JET-HOT coating was horrible, and their customer service is even worst. Their Arizona plant is a disaster.

 

You would have to launch the space shuttle in there to flake it off.

 

Lots of great info here!

Thanks!

 

IMO, less costly steel headers will last just as long as their ss brothers if coated. I would prefer to see manufacturers offer a steel, coated header. Bet they'd cost half of the ss costs.

 

I had uncoated Dynatech headers on my C5, and yes, it got very warm in the cabin on long drives. I have coated Dynatech headers on my C6 and I don't notice any extra cabin heat. For me, I don't care about the looks one way or the other. I think the performance difference is negligable either way. It will cut down on cabin heat though.

 

Another possible negative. From previous posts over the last few years; The coatings cause problems if you need to dis-assemble the exhaust after a few heat cycles.

 

I had my Kooks headers, cats & X pipe all coated by Swaintech in SW NY state. Their coating is (I believe) even better than Jet Hot for reducing heat transfer, in fact you can actually touch my headers (albeit briefly) when the car is running!

 

This makes no sense. Keeping heat from transfering to the atmosphere is doing nothing but containing wasted energy. All it would do is increase the velocity of the exhaust flow, further aiding in overall flow and REMOVING the heat from the engine more quickly. I don't see how this could even remotely effect cylinder combustion considering the fact that the cylinder is sealed off from the header by the exhaust valve and then separated from it by the exhaust port. Are they claiming that coated headers heat the head up?? Thats a load of garbage. Coated headers on SS are doing a marginal percent better job of removing heat anyways, so even if there were an issue with tuning, it certainly isn't going to be the coated headers fault. That same "knocky" engine characteristic would be there with plain jain SS headers as well. With the latest offers coming from forum vendors, there is no reason NOT to coat your header. They are offering free coatings with the only downside being you have to wait longer for them to arrive. If you are not on a time crunch, get them coated. EVERY little bit adds up and I see no negatives in coating your header with a quality coat.

 

I posted this on another forum-

Saying you don't need to coat headers because they are stainless is a massive load of junk. Most of the people who say that do so because they want to sell you a header, and get you out their face. There is no money in coating, and it is a hassle shipping things around, so most companies don't want to be bothered. Even in my own business, it is a PITA for me to manage because of all the headers going to different plants, and the time it adds to orders. Now I have to worry about two tracking numbers for each header, and making sure the coater does not loose the hardware or whatever. That being said, I push the product because I believe in it, and feel that it makes my customers happier with their product.

[B][COLOR="Red"]Here is what I tell all my customers-

Cast iron is a great insulator. Your stock manifolds do a pretty decent job of keeping exhaust heat inside and not letting it in the engine bay. Stainless steel on the other hand is much thinner and simply leaches heat in the engine bay. The analogy I use is that an uncoated header is like a garden hose with a million tiny holes in it. Because the hose dissipates water through all the tiny holes, the end result is that water comes out the end of the hose slower. An uncoated header is is the same way. Heat leaches out the entire length of the primary, and the end result is that exhaust is less pressurized, and velocity to the collector is slower. This is a bad thing because you want heat, and exhaust to leave the engine as fast as possible. Also, the quicker exhaust gas leaves the cylinder head, the quicker new air can replace it. If you coat a header, it seals all the "holes"/pores that exhaust gas "leaks" out (going back to the hose analogy). With no where to go, the hot exhaust gasses become highly pressurized and leaves the engine much faster. As it leaves, it creates a vacum effect that pulls the next pulse of air into the cylinder header, which will actually makes your engine breath much easier.

Now you understand why I chuckle when someone says there is no need to coat a stainless header because it will not rust. Coating has performance gains that IMO take precedence over any corrosion/looks advantage. I am personally a firm believer in coating, and run it on every car with headers we have owned.

Take that with a grain of salt. A manufactuer wants to sell you a header and be done with it. Not send a header out for coating...which add three weeks to how long it takes to close an order.


I would laugh at a tuner if they told me that. By holding the heat inside the pipes, it pressurizes it, which makes it leave FASTER.

We use Jet Hot 1700 now on all of our headers, which looks nicer and lasts longer. Also, all of our headers go through the PA plant, which does a better job because it is near the home office.

Never had an issue taking apart coated headers?

 

Looks great, how much and what was the proceedure? Did you have to ship them to get them done from you or get them shipped to them when you order?

Thanks!

Also isnt coating them better for the cats to work better since all the heat is kept in and goes to the cat?

 

Branden is totally right on this, I opted for the free jet hot coating, which he handled on his end. If I were to do it on my end, it would have been very costly due to shipping. MarylandSpeed took care of all that for me and I got a set of very purdy headers. My friend has uncoated LGs and they are discolored from the heat.

Here is a picture of my Kooks Jet Hot Coated headers installed.

 

I have used Swain Tech coating on more than a few of my cars through the years. They don't look the best . But they work the best reducing heat transfer and last a very LONG time.

 

More good stuff! Maryland Speed thanks for all the info.

What city are you in?

 

I also was told by a top vendor NOT to coat stainless headers. That it would raise the temp in the heads and cause problems

 

I'm in the market for LG Headers and I like the look of the coated headers, but I am hesitant due to my past experience with coated LT's.....I had SLP LT's on my LS1 Trans Am, and they started to flake and rust in less than a year. I believe they were Jet Hot Coated....SLP sells them that way. I don't know If i want to drop coin on that option again, eventhough this car is garaged and not a daily driver.

 

Were the SLP's stainless?

 

Well there are 2 top vendors pushing them, so who is correct? I don't see how anyone can say a coated header keeps the heat in the heads once they look at the physics. Not to mention, it not like a coated header is 50% more efficient than an uncoated one(at containing energy).