We’ve ridden the Indian Chieftain a few times, and we’ve always been fond of its engine and power delivery. Still, the semi-secret, unofficial MO Motto is “More is more.” So, when the Indian PR folks asked us which model Chieftain Dark Horse we wanted to take home to cuddle up with, a stocker or one that had been blessed with the complete listing from the factory performance catalog, you can probably guess our answer. Then toss in the fact that, with the exception of the model-specific exhaust, all of these modifications could be made to any Thunder Stroke 111 engine, and we saw the opportunity to share our bounty with our readers.

2014 Indian Chieftain Review

2016 Indian Chieftain Dark Horse First Ride Review

Thunder Stroke 111 hop-up

The Goods

Naturally, you’re curious about what the Indian Parts & Accessories department have cooked up. So, without further ado, we’ll move through the engine along the same path as the atmosphere would. The Thunder Stroke High Flow Air Cleaner – Black retails for a surprising $499.99 and allows the beefy V-Twin to breathe deep without endangering small birds or children. The removable filter element can be washed to maintain the engine’s peak performance, and the 1-inch narrower profile gives the rider a little extra room on the left side of the engine. Finally, the blacked out style matches the Dark Horse’s look perfectly. Still, $500 for an air cleaner?

Thunder Stroke 111 hop-up

Aside from the increased breathing capacity, the High Flow Air Cleaner creates some extra room for the rider’s left leg.

To take advantage of the freer-flowing intake, the Indian Motorcycle Stage 2 Performance Cams offer a claimed increase of 13% horsepower and 7% torque all while maintaining 50-state emission-compliance. Throttle response will also be significantly increased. These $499.99 cams can only be bought at an Indian dealer and must be used in conjunction with the aforementioned air cleaner and matching Indian slip-ons. The why of this requirement is that the modifications require the EFI to be recalibrated for emissions compliance. Additionally, having the parts installed and the EFI updated by a dealer maintains the factory powertrain warranty. The loss of warranty is one of the big compromises of going to the aftermarket.

The Stage 2 Performance Cams make it possible for the Thunder Stroke 111 engine to take advantage of the increased flow from the performance intake and exhaust.

The final pieces of the puzzle are the exhaust modifications. All of these parts are available in both chrome and blacked out, so if you want to maintain the chrome exhaust instead of the fully-blacked-out look of our Dark Horse, the cost will be a bit less. The functional components are contained in the $699.99 Touring Thunder Stroke Stage 1 Slip-on Exhaust Kit. These dual mufflers attach to the factory headers (hence the slip-on name) and allow more prodigious exhaust flow. Still, according to Indian, they maintain 50-state compliance – which is quite a feat. If you’re changing the finish of the exhaust, you’ll need to add the $279.99 Exhaust Shields (black, in our case). The slip-ons also require the purchase of exhaust tips, which range from $199.99-$299.99. The Six Shooter Exhaust Tips shown here check in at the top of the scale.

Thunder Stroke 111 hop-up

The Touring Thunder Stroke Stage 1 Slip-on Exhaust Kit with the matching header shields and the Six Shooter tips deepens the Dark Horse’s blacked-out style.

The Results

After even a short ride on the stock Chieftain Dark Horse, stepping onto the hopped-up version is a revelation. The throttle response is quite snappy with the more muscular low-rpm torque apparent from the saddle. And then there’s the exhaust note!

Thunder Stroke 111 hop-up

Out on the road, the modifications combine to make the Thunder Stroke more powerful and responsive across the rpm-range.

Around town, the throaty sound is more than pleasing to the ear – though bordering on a little loud for my delicate sensibilities. I’m particularly cognisant of the sound when entering or leaving my driveway in my very quiet neighborhood early in the morning or late at night. Although the motorsports-crazy grandmother next door did shout to me from her front porch, “What is that new bike you’re testing? I love the sound!” I figure that not all of my neighbors spend their weekends watching two races at once (thanks to PIP). So, I try to keep the revs down on my street. Venturing onto the freeway or out into the countryside highlights the Thunder Stroke’s basso profondo.

Whacking open the throttle in an environment where you can run out the engine reveals power that keeps on building throughout the rev range. My only quibble is that neutral throttle is more difficult to hold at lower rpm – like when poking along in stop-and-go traffic. Since this does not translate over into engine speeds at which riders typically corner, the chassis is never upset, relegating this criticism to the type that motojournalists are paid to complain about.

Thunder Stroke 111 hop-up

The dyno chart illustrates how at every engine speed both the horsepower and torque are greater than that of the stocker. The slight dip in both graphs around 2,000 rpm is unnoticeable from the saddle. While the 18% increase in horsepower exceeds Indian’s claims about the performance gain, we need to stress that the before numbers did not come from the same bike prior to the changes. Rather, they were from our previous test of the Chieftain run on the same dyno. Updates to the stock EFI in the current model year Thunder Stroke 111 or simple variations in manufacturing tolerances could have slightly decreased the stock numbers and inflated the percentage of change. Still, the peak torque of 113.1 lb-ft is a 10% bump. What is most noticeable, however, is how the gap between the stock and modified curves increase throughout the rev-range for both horsepower and torque, showing the engine’s improved breathing ability. The tested 38.0 mpg is pretty respectable for a modified bike, too.

So, if you’re the type of rider for whom the MO More philosophy applies and you’re willing to pony up $2,280 plus labor, you will probably be quite happy with the upgrades. The price may be steep, but it will pay dividends every time you twist the throttle.

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  • DickRuble

    Sounds like it’s time for a head to head with a… Royal Enfield. .Or maybe a Ural.

    • Starmag

      Those both have less than 40HP, what’s your point?

      I used to think I was negative. You win.

      2280 divided by 13HP = $175 per additional HP

      • DickRuble

        On a $/HP basis it’s still a ripoff. Just piles of overpriced scrap metal in all three cases. They also have state of the art engines, for 1939.

        • Donald Silvernail

          Can’t we agree that this is a very fine machine of it’s type? Surely you don’t mean to compare it to a Ducati or Aprilia?

          • DickRuble

            I am willing to say it is even the finest machine of its type.

          • john phyyt

            Or KTM 1290 GT.. Of course not. Very fine; but slow, heavy, old tech, and expensive in comparison.

          • Donald Silvernail

            The price of the KTM and the Indian aren’t very different and you get so much more bike (in pounds per dollar spent) with the Indian! I bet that 1290GT is a real wizz-bang of a bike but will anybody want to pay good money for one 75 years from now?

        • TheMarvelous1310

          It’s definitely a ripoff, but any motorcycle without an electric motor is technically antiquated, and every motorcycle without airbags is overrated, so I don’t see your point.

          • DickRuble

            .. you just said it “it’s definitely a ripoff”.. that’s my point…

          • TheMarvelous1310

            …you can make your point without ragging on the basic motor, though.

        • Starmag

          These folks seem to have had a really great time on RE 350’s. Maybe motorcycling isn’t all about spec racing and horsepower.
          https://www.youtube.com/watch?v=LYRhzYREk90

          • DickRuble

            Do those bikes have the “factory package”?

          • Starmag

            Given their condition I’m sure they have less than the 19 horsepower they left the factory with. Less than 20 Hp yet everyone can’t wipe the smiles off their faces. Riding bikes that are antiquated scrap by your view. As for Harley’s and Indians, at least they sound good (stock pipes) and are comfortable when the road is straight and boring, which is much of the US. FWIW my friends with cruisers who don’t care about HP numbers put far more miles on their bikes than my spec racer friends.

          • DickRuble

            I don’t mind antiquated scrap. Cool by me, I would ride a 25 yo Nighthawk or 40 yo MZ, or Jawa anytime, but not antiquated scrap at $25K. That’s just antiquated CRAP.

  • allworld

    These up grades should be stock on the Thunder Stroke, or at least have them as a factory package at the time of purchase.

    • Auphliam

      They are available as a factory package according to their web site

  • sgray44444

    Still looks undercammed to me. I’d go with something more aggressive from the aftermarket; warranty be damned! Less than 80hp out of a 111″ motor stock? That is laughable.

  • Luigi Stugatz

    Make ’em that need some umph then sell accessories or options to put them where they should have been to begin with, is a marketing ploy that works! HD has been doing it for 75 years.

    • Craig Hoffman

      Indeed, that is precisely their game, and it is a pity. Yes, more money is extracted from the customer, but it also gives the rest of us to continue pointing our fingers, laughing, and riding something else.

  • Uncommon Sense

    These cruisers essentially have a power to weight ratio of a maxi-scoot despite all the thunderous exhaust notes.

  • mikemin07

    I don’t wish to mortgage my house for 10 ppercent more power. However I have changed the paper air filter to a K&N free flow and I will have a power commander ignition control installed then have the engine dynoed for peak power and economy. the generic ECM loads leave a lot to be desired