I have a 90 RS 305 with full emission equip. The car has to get smog tested where I live so the stock manifolds are a must.

I've noticed that they are kind of brown looking and they may be the originals from the car. I just had it in an exhaust shop and the old mechanic said they look fine.

I had some new Dorman manifolds coming in the mail, but the mechanic said that they are usually cheaper and crack when u put them on. He said that mine will last longer than the ones they make now.

Any truth to this??
I'm tryin to keep this car running smooth as possible with the best upgrades I can give it!

My question is, CAN I wrap the exhaust manifolds while they are on the car??
Would wrapping it be a good improvement??
THE CAR IS A DAILY DRIVER
I've also heard that rust occurs? But I live west USA so we don't see a lot of rust.
From the manifold to the cat, is original piping. Should I wrap that too??

Even if the gain is minimal, Ill take all the small gains that I can get.

 

Leave it alone. The tree you're barking up, is the wrong one.

 

Indeed, rust occurs.

As you may have noticed, your 30-yr-old manifolds are hanging in there, doing their job, in spite of it. In fact if you didn't open the hood and look at them you'd never even know it was there. In terms of function it is TOTALLY irrelevant.

If it REALLY REALLY bothers you though, you could send your new ones - or for that matter, your old ones - to the ceramic coating place and have that done to them. It's THE ONLY thing that has a prayer of surviving more than a few hours of running. They might even have a "rust" color available, so that it wouldn't look so instantly immediately automatically SO BAD the moment the first rust spot pops back through, as it inevitably will.

I don't know that what they make today is any "worse" than it was back then. Who knows. Keep your old ones squirrelled away somewhere just in case.

 

I took my stock manifolds, blasted them, did the prep as instructed by Cerakote and painted them with that. They look as good as the day I installed them.

 

Blast them, and coat them with POR-15 cast iron gray exhaust manifold coating. That stuff lasts for years...

 

There's nothing to be gained by wrapping stock exhaust manifolds; being that they're made of cast iron, they retain heat very well all by themselves.

As far as Dorman stuff goes, your mechanic told you right. IMO, their stuff is junk, and to be avoided.

 

Thank you! Your comment wins! It gave me a great option. Yeah I may take them in and get them coated.

Hmmm.

Thanks everybody!

 

The only reason to have them coated is appearance. It will not make them last longer, work better, make more power...