c8 corvette header installation

New headers for the C8 Corvette? It’s an easier upgrade than you think

It’s been out for a while but many of us have yet to see the eighth generation of the Chevrolet Corvette in person. It is known as the mid-engine Corvette, as the engine was moved from the middle, where it was in the seventh generation Corvette, to the middle, where it is in the eighth generation Corvette. Yes, you read the right, fight me.

That shift of the engine from the middle-front to the middle-rear has a lot of people concerned about the ease of working on it. The great news is that there should be no concern. Read on and look at my mediocre quality phone pictures to understand.

My 4Runner needed an oil change and rear brakes. As always, I went to my friend’s shop, Ace Performance. Because I am a nosy SOB, I just walked around the shop the whole time they worked on my car. You can do that when a good friend owns the place. Front and center was a brand new Corvette convertible. I think it was the loaded model, a 2LT or 3LT as it had cameras all over the place.

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It was in the shop to get a set of headers and high-flow cats installed. The cat-back part of the exhaust system was on backorder and not available at this time. But that didn’t stop the owner of the Vette to have the shop install what was available.

As seen in the lede image, once the engine cover is removed the LT2 looks… pretty ugly. In intake manifold or a cover thereof, inside the vee, looks like a back of a television. There are random lines and hoses, and the rest is covered with a large number of heat shields. Ferrari would never allow for this but Ferrari doesn’t cost eighty grand, either.

Step one is to remove the engine cover. Since this is a cabrio, it was a bit different and more challenging than a hardtop. It was held to the operating mechanisms by three bolts on each side. It’s power-operated as it opens when the top is being lowered. The roof gets sandwiched between it and the engine cover.

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If you hate skid plates on 4x4s because they get in the way of servicing, you’ll just love this. The whole bottom of the Vette is almost flat, as it should be. It basically looks like panels of sheet metal bolted to various strong points. And that’s exactly what they are.

The good news is that they all unbolt fairly quickly, at least on this brand new vehicle. I wonder if the tops of some of the bolts will shear off during years of driving.

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The super good news is the oil filter is nicely accessible. Note that rear lower wishbone suspension.

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This is what the driver’s side manifold looks like with the heat shields removed.

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Replacement headers. Between them, the high-flow cats, and the cat-back, a ten horsepower gain is expected. But that gain from the exhaust is likely to go up once more if being pushed out from the engine, if you know what I mean and I think you do.

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This is how the exhaust manifold connects to the stock catalytic converter.  The cats are hidden between the engine and the trunk wall. I’m guessing the trunk gets pretty toasty, so don’t put ice cream there.

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This is the view from the top with the driver’s side manifold removed. The manifold is held to the block with just five bolts. It lifts out with a surprising amount of ease. What cannot be seen in this picture is the vast amount of room to the left side of the engine block, under the frame rail. It’s as if the extra space there was purposely left there for some reason. Hmm. [thinking emoji here]

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Stock manifold and heat shields out. It looks like a pretty efficient design

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Aftermarket header versus factory manifold. I wish I had the technical know-how to explain how the design differences impact the overall airflow. Air volume and velocity are the keys. These are American Racing headers, by the way.

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The passenger side manifold did not want to play nice. There were fuel (?) lines in the way and an oil filler/breather is there, too. Its removal had to be very careful.

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The silver thing mounted to the firewall in front of the engine is the oil tank. The Corvette uses a dry-sump oiling system. It allows the engine to be placed lower and provides better lubrication under high gravitational loads.

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The driver’s side engine block, looking from the top. Spark plugs and coil packs become visible once the manifold is off. Some other LS engines have the coil packs mounted on valve covers but in this case, they’re handing off the side of the engine. Don’t mistake your Vette for an off-roader and drive it through water.

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These are the new high-flow catalytic converters. Unfortunately, I was not able to stick around long enough to see them get installed. I didn’t even get to see the factory ones being removed.

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Removal of the cats required the opening of the trunk lid. That required the closure of the engine cover, which in turn required the installation of the engine cover. Unfortunately at this time, my 4Runner was ready to go, so I have to end this here. As Haynes manuals famously state, reassembly is the reverse of disassembly.

The important takeaway here is that in the end, all cars are just machines. Machines that are assembled from various parts into one. They are all rather similar to one another, too. If you can spin wrenches you can take them apart and hopefully put back together. Don’t be intimidated. It nice to know that the new rear-mid-engine Corvette is not hard to work on, perhaps even easier than the front-mid-engine Corvette of the past.

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19 responses to “New headers for the C8 Corvette? It’s an easier upgrade than you think”

  1. Victor Avatar

    10 horsepower ? seems wretched excess to me .

    1. Lokki Avatar
      Lokki

      That was exactly my thought –

      …Replacement headers. Between them, the high-flow cats, and the cat-back, a ten horsepower gain is expected.”

      I’m speculating you’re very conservatively looking at probably $1,000 -$1,500 in parts and (again guessing but noting that Kamil couldn’t stick around for the CAT install) three or four hours of labor. So, roughly a couple of grand for what’s going to be an invisible (see: engine cover) and since Chevy says that the base engine puts out 495 HP, two percent horsepower increase.

      But hey, why not? If you got the money, go ahead.

      1. Victor Avatar

        Must be new money looking for some noise to attract attention LOOK what I got.
        Looks like at least a 40 hour job, @ $ 70.00 ( local rate ) that was an expensive upgrade.

      2. 0A5599 Avatar
        0A5599

        Two percent horsepower increase, but it’s going into a “loaded model, a 2LT or 3LT” convertible. So only a 2% horsepower gain, but the cost is about 2% of the MSRP of the car.

    2. mdharrell Avatar

      I’m planning to do an entire engine swap in my HMV Freeway just to gain four horsepower, even though this requires removing the body from the frame for access. This means I can, um, totally relate to this. Yes.

      1. Zentropy Avatar
        Zentropy

        Yeah, but isn’t that like a 33% power increase in your case?? Much better investment, IMO.

        1. mdharrell Avatar

          I’m happy to subscribe to any line of reasoning that suggests my Freeway is a better investment than some other thing.

          1. Victor Avatar

            I put a mast and rudder on a pontoon boat and sailed away.

  2. neight428 Avatar
    neight428

    I can sympathize with whoever wants to upgrade something like this for minimal benefit. Sounds like something I would do given enough money. Try putting headers on this:

    https://i.ytimg.com/vi/x8cXhNWI97I/hqdefault.jpg

    1. Zentropy Avatar
      Zentropy

      I have my eyes on a bigger upgrade for much bigger benefit. When the 3.3 gives it up in the Kia Sedona, I’m thinking LS3-RWD conversion. Inspiration video below.

      https://www.youtube.com/watch?v=-j0H5sP-prk&feature=emb_logo

      1. neight428 Avatar
        neight428

        Respect.

        If left to my own devices, I’d already have one of these…

        1. Zentropy Avatar
          Zentropy

          Oh yeah, the Dajibans are very cool, and the whole V8+RWD conversion isn’t necessary. Such an odd thing to develop in Japanese car culture, though.

          I grew up around Ford vans (my dad was a carpenter)– wonder what “Econoline” is in Japanese?

    2. 0A5599 Avatar
      0A5599

      Be sure to change the #8 spark plug while you have access.

      1. Kamil K Avatar

        I think those could have been easily accessible from the bottom.

        1. neight428 Avatar
          neight428

          With stock manifolds, it was a challenge. With headers, you needed a shortened and partially hollowed out socket that would slide over the plug. You could turn it with a stubby enough wrench going completely by feel. It was an unsatisfying process to say the least, though not as bad as swapping out rocker arms and valve springs; that was an especially poor use of time and money.

        2. outback_ute Avatar
          outback_ute

          The shop that specializes in hot Fords here, Herrods, quickly moved to dropping the front crossmember complete with suspension uprights to do header installs, using a lift.

          Not so much dropping the k-member as lifting the rest of the car.

          1. neight428 Avatar
            neight428

            With the right shop and a couple of extra pairs of hands, I could see it being a rewarding experience. Done alone, on a Harbor Freight budget, when you need the thing running to get to work on Monday, I do not recommend.

          2. outback_ute Avatar
            outback_ute

            Not even extra hands: upper balljoints, brake calipers, a dozen or two bolts for the crossmembers, wiring connections, tailshaft and fuel line and that’s about it to lift up the body, leaving the guts on a stand with very easy access.

            The 5.4 quad cam engine is so tight in the engine bay it would be very hard to do in situ.

  3. neight428 Avatar
    neight428

    Also, does anyone else ever crawl under your car and get that oddly satisfying feeling of (at least semi-) understood mechanical complexity?

    You would necessarily need the lift to do so with a Corvette, but what a bummer that its all covered up. The mid-engine probably takes the fun out of it anyway.