How to Make your Honda Grom Faster with TST Industries

One of the biggest complaints we hear about the Honda Grom is that it needs to go just a little bit faster, and we sort of agree. On one hand, the Honda Grom is what it is, which is a low-powered and cost-efficient mini bike meant to deliver cheap thrills. That ambiguous description can lead riders to customize their Grom to fit almost any riding style, whether it be off-road, track, or daily commuting. The one thing that the Grom is not though is a face-melting speed machine, but it also doesn’t pretend to be. It’s upfront about its 125cc power plant and mini-performance. I mean, just look at the 12″ tires, those don’t scream “I can hit 120mph in 2nd gear” the way a CBR1000RR-R does. With that said, we do understand the want for just a little bit of extra oomph when twisting your Grom’s throttle, because who doesn’t like a little more power?

So if you’re on the quest to add more power to your Honda Grom, there are a lot of paths that quest can take you. One of those paths is you can ditch the Grom’s 125cc motor entirely and throw in a Ducati motor like one lunatic did a few years ago, and then pray that the torque doesn’t rip the swingarm off the frame (spoiler alert – it would). Or, you can go with something a bit more common and swap in the Honda CBR300R engine with the help of a donor bike. That path is still expensive and requires a lot of mechanical skill and labor. Or, you could modify the stock engine with a big bore kit and hope there aren’t any reliability pit-falls. Those all require a good bit of knowledge, mechanical skill, and a fat wallet. For this deep dive though, let’s stick with the path that keeps the engine stock, meaning we aren’t going to dig into the engine components at all. We’re just going to look at other changes you can make to your Grom without breaking the engine apart but still result in a power boost and a wider grin every time you crack the throttle.

The first thing you want to do is enable your engine to breathe a little better, so we’ll start with the exhaust.
Swapping the stock exhaust for a full system aftermarket exhaust will not only increase engine performance, but it’ll drop a good bit of weight from your Grom as well (more on weight reduction in a minute). Both the increased airflow and decrease in weight help your Grom accelerate, brake, and handle better. Our friends over at Yoshimura produce a killer exhaust for the 2022+ Honda Grom that claims a 13.9% increase to peak horsepower and 14.3% increase to peak torque when compared to stock. Those are significant increases in performance for one fairly simple installation! We can’t ignore the fact that the exhaust looks amazing, too…but let’s focus on performance.

So you installed a Yoshimura exhaust and have increased airflow going out of your Grom…now what? Well, let’s increase the airflow going in the engine, and this time, it’s an even easier installation. Our TST WORX Airbox Cover is specially shaped to do just that, plus it works with the stock fairing mounts and stock air filter. The texture-matched ABS plastic cover features a unique design that is proven to optimize airflow, resulting in an unmistakable roaring intake sound that we absolutely love. During our extensive R&D testing, we found that this cover provides up to 9% power increases at certain RPMs compared to the stock airbox cover.

Now we are really cooking with some solid bolt-on parts, but how do we optimize the new parts for our Grom and ensure we are getting the absolute most out of the increased airflow parameters? That, my dear reader, is going to require a tune. One option you can go with is the ARacer RC MiniX ECU, which features adjustable parameters so that you can dial in your air / fuel ratio just right. ARacer has become the go-to standalone ECU for the Grom crowd, and in doing so, has developed a solid reputation and online community that can help you dial in your Grom if you’re new to messing with ECU parameters. Another option is to take your Grom to a reputable tuner and have it professionally tuned on a dyno. No matter how you go about it, a proper tune is going to be the icing on your performance cake that really ties all of the components together and ensures you’re getting the most out of your bolt-on components while keeping your engine running safely and reliably.

Okay, so after a tune, you have the engine optimized for your exhaust and modified intake….now what? Well, depending on where you want to add speed, you can adjust your gearing with a new sprocket. Our WORX engineers have developed a rear sprocket for the Honda Grom that’s available in multiple tooth counts, enabling you to go up or down to your desired number and either increase your low-end or top-end speed, depending on what you choose. You can increase low-end torque with a larger rear sprocket, or increase top-end speed with a smaller rear sprocket. Just remember that you’re not “adding” speed to your Grom, you’re simply rearranging where the speed is applied. Each benefit will come at a cost from the other end of the spectrum. For instance, if you install a larger rear sprocket for increased low-end torque, you will sacrifice top-end speed, and vice versa.

Our advanced engineering and manufacturing techniques combined with our specialized hard-anodizing methods enable us to create a lightweight aluminum rear sprocket that not only looks awesome, but helps your Grom transfer more power to the rear wheel by decreasing parasitic powertrain loss. That’s achieved by decreasing the component weight by roughly 65% and using our proprietary ultra-smooth tooth profile.

Speaking of decreasing component weight, another important factor to gaining some extra performance out of your Grom is to decrease the amount of work it has to do. By that I mean you should decrease the amount of weight the engine is having to work to move the entire assembly. This means ditching any unnecessary weight like empty cargo bags, your girlfriend sitting behind you, or that heavy fender hanging off the back. You’d be surprised at how heavy the stock fender is, coming in at whopping 3.35 lbs. With its steel tube construction, it’s essentially a bulky boat anchor hanging off the tail of your Grom. We offer a sleek Elite-1 Fender Eliminator solution that performs the same function but with a tiny fraction of the weight. You may think that looking at a fender eliminator as a weight loss / performance solution is dumb, but when the fender weighs 1.48% of the total bike weight, it’s not an insane stance to take. There are race teams out that would kill for a 1.48% decrease in weight.

If you keep in mind that the Grom is never going to be a face-melting superbike, I think you’ll be surprised at what kind of difference the methods mentioned above can make. You can tailor your Grom’s power output to match your riding goals, all without having to break into the engine or the bank vault, and that’s what makes the Honda Grom so great!

Have more tips on improving power or have a question about any of the methods mentioned above? Leave us a comment below!

About Robert Callahan

I ride a 2013 Honda CBR600RR and 2022 Honda Grom...oh and I do some marketing stuff, too.