Toyota MR2 Message Board - View Single Post - 4A-GE MK1 Engine Ceramic Coating a new Exhaust Manifold?

q-authority · 09-01-2009, 07:53 PM

I wouldn't pay too much attention to those claiming the oem exhaust manifold is no good, or that significant gains can be made from TRD or other after market manifolds. If you go back and search through this or other forums regarding this issue, you will find that no one has ever published data to support those types of claims. All of the old timers acknowledged that the TRD headers look great, and can save you some weight, but you will be lucky to get more than 1 or 2 hp gain out of it unless you do massive internal modifications, and even then you're maybe only looking at a couple more. I had one on my original '85, and it did absolutely nothing except melt the fiberglass firewall material, and save me a few pounds in the rear. I then put heat wrap on it, and it collapsed in about another 6 months due to the trapped heat, since they were only made out of mild steel.

Ceramic coating a new oem exhaust manifold could have the following advantages:
a) prevents manifold from rusting, and will look like new for a very long time;
b) will keep the manifold cooler and will likely prevent it from cracking on the #4 runner;
c) will supposedly improve exhaust flow due to keeping the exhaust temp up (I don't know the math on this one, and I doubt it really does much, but it is claimed on all ceramic coating sites); &
d) the smoother interior finish will also likely minimize carbon build-up, and therefore help provide a slightly smoother/more free exhaust flow over time;

I coated a new SC oem manifold and collector pipe a year ago and they still look like brand new. They also both run significantly cooler (exterior wise that is) than without the coating. I also had them coat the outside of the original catalytic converter, which looked like it had been left on the bottom of the ocean for decades, and afterwards it came out looking brand new. It should also keep the cat inside temps up and provide for a cleaner exhaust come smog time. I used a Titanium (very dark grey) coating which I am very happy with.

But if you really want a nifty looking set of headers check out the following link. They make TRD knock-off headers, but with better steel, and they will make them in SS if you want. And hey, they are just south of Seattle.

Headers for Toyota, Suzuki, Honda, VW, exhaust parts for home built do it yourself automotive, marine headers.

09-01-2009, 07:53 PM	#10 (permalink)
q-authority Professional Multislacker Join Date: Feb 2008 Posts: 506 Thanks: 0 Thanked 17 Times in 17 Posts My Google Map iTrader Rating: (4/100% )	I wouldn't pay too much attention to those claiming the oem exhaust manifold is no good, or that significant gains can be made from TRD or other after market manifolds. If you go back and search through this or other forums regarding this issue, you will find that no one has ever published data to support those types of claims. All of the old timers acknowledged that the TRD headers look great, and can save you some weight, but you will be lucky to get more than 1 or 2 hp gain out of it unless you do massive internal modifications, and even then you're maybe only looking at a couple more. I had one on my original '85, and it did absolutely nothing except melt the fiberglass firewall material, and save me a few pounds in the rear. I then put heat wrap on it, and it collapsed in about another 6 months due to the trapped heat, since they were only made out of mild steel. Ceramic coating a new oem exhaust manifold could have the following advantages: a) prevents manifold from rusting, and will look like new for a very long time; b) will keep the manifold cooler and will likely prevent it from cracking on the #4 runner; c) will supposedly improve exhaust flow due to keeping the exhaust temp up (I don't know the math on this one, and I doubt it really does much, but it is claimed on all ceramic coating sites); & d) the smoother interior finish will also likely minimize carbon build-up, and therefore help provide a slightly smoother/more free exhaust flow over time; I coated a new SC oem manifold and collector pipe a year ago and they still look like brand new. They also both run significantly cooler (exterior wise that is) than without the coating. I also had them coat the outside of the original catalytic converter, which looked like it had been left on the bottom of the ocean for decades, and afterwards it came out looking brand new. It should also keep the cat inside temps up and provide for a cleaner exhaust come smog time. I used a Titanium (very dark grey) coating which I am very happy with. But if you really want a nifty looking set of headers check out the following link. They make TRD knock-off headers, but with better steel, and they will make them in SS if you want. And hey, they are just south of Seattle. Headers for Toyota, Suzuki, Honda, VW, exhaust parts for home built do it yourself automotive, marine headers.