Tuesday, November 3, 2009

Raceland header wrap & install

Updates at bottom.
This weekend, I installed a new header in my Miata. I bought one of the very inexpensive ones you can find on eBay, though I went through their Web site. (I also bought a windblocker; details on that later.)
For the incredibly low price of $80, I felt like the Raceland unit (part number RO-HMX5NA-1.6) was worth the gamble. I also bought some generic header wrap on eBay for $25, and a new oxygen sensor on RockAuto.com to accompany this project. This modification is legal in the SCCA's autocross STS class, which means I have nothing to lose.

The installation, unlike nearly every other major project I've taken on, went without a hitch. I had no major difficulties, outside of one bolt I had to snap off. Nothing was too difficult to get at, or too hard to remove. I didn't even have to run back out to the store. It was surprisingly painless. I've heard that the 1.8 liter models have more fitment issues, but everything was fine on my 1.6L engine.

Click the photo above to go directly to my Web photo album. There are some close-up pictures of the header, details and tips for the installation process, and a surprise crack I found in my original header.

It's quieter at cruise than my OEM header (probably thanks to that crack), though it sounds racier at WOT and at higher revs. It's also smoother and stronger in the middle and top end. I won't attribute all of this to the header alone; the new O2 sensor and the wrap probably helped a lot too. All in all, I'm very satisfied. If I had spent $450 on the Racing Beat or Jackson Racing headers, I don't think I would've been as happy. This is a significant improvement for a little price. Kudos, Raceland.

Update: The header wrap didn't seem to like snow very much. http://sentimentalmechanic.blogspot.com/2010/06/this-is-what-happens-larry.html

Update 2: After little more than a year, the thing has rusted -- yes, rusted! -- badly enough to break apart.

Update 3: Raceland honored their 2-year warranty and sent me a new one.


  1. Good job! Looks clean!

    The 4-2-1 collector also sends torque and HP to the bottom end, exactly how you wanted it.

  2. Good job on the install. I'm about to do the same on my 2000 1.8l. Any advice you could give me, I've done a lot, but never header or exhaust work.

  3. 2 things to consider on your NB Miata:

    I've heard that the 1.8L engines sometimes have fitment issues with cheap headers (i.e. OBX or other eBay specials). By that I mean they'll fit, but will hit against the transmission bell housing. I've not heard this with Raceland specifically, but that probably makes a lot of noise if it does happen. Make sure you remove the center bracket that supports the OEM header at the bell housing. If you look at this photo, you'll see the piece that grabs onto the header, and the bracket it bolts to:

    Shouldn't be a problem with name brands (Racing Beat, Jackson Racing), but you'll pay quite a lot more for it.

    You'll also have the EGR tube to deal with. I've heard you have to manhandle it into place, but shouldn't be super difficult. And make sure you shoot some PB Blaster or other penetrating lubricant on all the bolts involved a day before you start, to make things easy to remove.

    Search around ClubRoadster.net or Miata.net for more information. ClubRoadster is probably more helpful.

  4. I have the Raceland header on my '91 GRB coupled with Raceland Coilovers. My car is now a go-cart on steroids. Love the Raceland products, I don't know how they can sell a quality product so cheap.

    But to be fair, I have never raced my car.

  5. How has the header wrap held up? Were engine bay temperatures reduced over the stock set up?

  6. The header wrap came loose on the bottom half; I wrapped it all the way to the cat, and the snow did a number on it. My Miata is my year-round daily driver. Here's the update:

    I can't speak to underhood temperatures with any accuracy, since I never measured it nor did I have issues with overheating. The ghetto heat shield between the intake and exhaust though does make a big difference.


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