American Racing Headers Launches CARB-LEGAL C8 Corvette Longtube Headers!

While the E.O. number remains pending, American Racing Headers has earned California Air Resources Board 50-state emissions approval for their C8 Corvette longtube headers!

We live in strange times for auto enthusiasts. Sports cars (and just about everything else) have never been quicker or safer from the factory. And enthusiasts have never had more aftermarket ways to add power and build cars. From tuning and boost to suspension, building or buying an 800 horsepower monster is shockingly common.

But it’s also time of transition.

Global emissions standards are rising dramatically, threatening the future of the internal combustion engine itself. And here in the United States, the Environmental Protection Agency is cracking down on shops and aftermarket manufacturers to prevent the sales of power adders that (they say) add extra pollutants to our air.

It’s in this context that I saw a thread by CorvetteForum vendor, American Racing Headers (ARH) touting CARB-legal (aka 50-state legal) C8 Corvette long tube headers. For those who don’t live in California, long tubes are a YUGE no-no. So of course I had to reach out to ARH to learn more.

I ended up spending an hour talking to ARH’s Nick Filippides about his company, developing C8 Corvette headers, and the product itself. If you’re not familiar with American Racing Headers, they’re a New York speed shop that built itself around the Corvette. C5s at first, before expanding to earlier and later generations as well as LS swaps. They handcraft each of their products — headers, racing systems, catbacks, etc — and make everything right here in the USA.

What follows is a condensed version of my conversation with Nick. But the quick version is this: American Racing Headers earned CARB certification for their new C8 Corvette Headers (click HERE to purchase!), but they’re still awaiting a specific E.O. (Executive Order) number. Because of the headers’ specific length, they’re technically longtubes. But, thanks to the C8 Corvette’s unique engine bay, ARH placed the headers in such a way that the OEM cats remained in their stock position, which is why they pass despite their length.

The Benefit of Headers 

Nick Filippides: Typical gains vary because there are so many different avenues for upgrades. From a guy who just throws a header system to the guys doing heads and cams and all kinds of other upgrades. Take your basic LS engine. They come with cylinder heads, that, 20 years ago, would have been outstanding in a NASCAR race car. And the ability to make power with these engines is incredible. But, of course, they are limitations.

I don’t care what vehicle it is. If you take a Toyota Tundra, headers could give you over 40 extra horsepower because it’s an amazing engine that’s really corked up badly. And it goes for the Hemis, Coyotes, it’s really across the board. There’s a lot of power to be had when you free up these engines [and let them breathe].

NF: We do things in ways that are old-school. Some people use CAD drawings. But it doesn’t work. Not for headers. There’s a human element involved. It’s an art form truly designed to maximize performance when done properly.

Frankly, I was not a happy camper about the C8 going mid-engine because I had no idea what to expect in terms of space. Would we have to drop the engine to replace headers? But the vehicle surprised me in how easy it is to install headers and our C8 Corvette catback system, which requires taking the rear-bumper off. My team does [the catback and headers] in about six hours. Our headers only take three hours and you can leave the bumper on for just-headers.

So we had to bring a [C8 Corvette into our shop]. And the first thing we do is acknowledge, “what did the factory do? Is there room for improvement? And where can those improvements be made?” The C8 was very generous because, although it comes with a tubular style manifold, again, there was plenty of room for improvement.

The first thing we saw was that the tube size had to be larger than factory. So that was a no-brainer. We also knew that we needed to get more length in the primary runners but not get the length to the point where you’re making sacrifices. Typically, you want (the runners) to be around 28 to 30-inch range, but collectors are where the magic happens so we’ll sacrifice length for collector design. The C8 headers are in the 25 to 26-inch range. And we’re very happy about that.

Power Gains

NF: The car we actually did the prototype work on belongs to a gentleman by the name of Jim Duffy, based out of PA. Jim is a hardcore drag racer and he wanted to have the quickest and fastest C8 naturally aspirated with the fewest amount of mods. So we ran his car on the dyno, testing three different runner tube sizes — 1 3/4″, 1 7/8″, and 2″ — back to back to back. The car never came off the dyno.

We didn’t know what to expect. The 1 3/4″ was tested first as a baseline and we gradually went to the bigger sizes. When all was said and done, the 1 7/8″ was far superior, picking up 17 peak HP and 33 lb.-ft. of torque at the rear wheels (and 37 HP and 37 lb.-ft. across the mid-range) with the factory cats and exhaust. The 2″ header ended up losing six horsepower and five ft.-lbs. of torque over the 1 7/8″.

Improved Fuel Economy

NF: Mileage improved on [our header prototype car] significantly. Wow. I put 125 miles on the car prior to giving it back to Jim. (He suggested it.) So I drove out to Eastern long island. Put her at 70 miles an hour in Eco Mode with the cruise control on. And the car was getting 37 miles per gallon on the highway!

This is not uncommon to see improved gas mileage with headers if you can keep your foot out of it.  I just didn’t expect that on the highway doing 70 miles an hour. I don’t know EPA-rated highway mileage is, but 37 sounded like quite a bit. And I saw it with my own eyes.

CARB Legal C8 Corvette Longtube Headers

NF: [A California customer] called to inquire about headers. And we asked him if he’d allow us to use his vehicle [for CARB testing] and he agreed. After a delay related to a stored transmission code, we went to SEMA Garage. They work with companies like ours to get EPA certification for a variety of gadgets and upgrades.

There’s a lot to the testing. I don’t know all the details. But I’m told the test is done three times to confirm that the results are accurate. I had a feeling it was going to pass even in advance based on how we designed the headers. But you just never know.

It’s also important to note that the C8 Corvette is unique in that the catalytic converter location and the overall design of the engine compartment allowed us to build a header where we can get the primary lengths we wanted, where we can design the collector the way we wanted, and still keep the factory catalytic converter [in the stock location].

My main goal with all this and the reason why we’re doing this is that I want the community to be aware there’s a legal option for making more power right now. And that’s a good thing. I want dealerships around the country installing these on their customers’ C8s. And I’m also hoping it also helps build our company’s reputation. It’s awesome. No other way to describe it. Lifetime guarantee. And made in the USA.

American Racing Headers C8 Catback Exhaust

NF: The factory catback is ridiculously heavy. We were able to knock out about 30 pounds, but incorporate an x-pipe. We also bypassed the dual-mode [active valve] exhaust. We’re not fans of dual-mode because there are compromises in sound when you try and make a dual-mode muffler we’ve found. I’d rather build a catback that sounds amazing all the time. Not loud or intrusive cruising around town. No cabin drone. But comes on real strong when you’re rolling through the gears. So it kinda has a natural split personality. And the combination with the headers is just phenomenal.

Photos: American Racing Headers

Corrections: We’ve updated this article with a few factual corrections requested by American Racing Headers.

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