If you’re the proud owner of a Harley-Davidson Twin Cam 96, you’re in for a real treat.
The Twin Cam 96 already is a very powerful and reliable engine, but it can easily (and quite inexpensively) be upgraded for even more power.
In this article, we’ll go over some of the best Twin Cam 96 performance upgrades available to take your bike to the next level.
With a little bit of effort, you’ll be cruising down the highway like a true king (or queen) of the road!
Also Read: Twin Cam 88 Cam Chain Tensioner Upgrade Cost
1. Intake & Exhaust
The first place to start when looking for performance upgrades is the intake and exhaust.
After all, airflow is the primary limiting factor when it comes to making power with an internal combustion engine. We can spray as much fuel as we want, but we are always limited to how much air the engine can suck in.
It doesn’t matter whether you have a big bore kit, cams, etc. – they are useless without enough airflow, and that’s what you should focus on first.
The factory air cleaner is pretty restrictive due to noise and emission regulations, so an aftermarket air cleaner is a must. When it comes to air cleaners – the bigger the cleaner element, the better. We want as few restrictions on airflow as possible.
There are many different styles and brands available, so take your time to find one that you like. If you need a recommendation, then you should probably look for Vance & Hines or K&N, as they are very well made and won’t disintegrate after a few months, as most cheap cleaners do.
Once you have a high-flow air cleaner installed, it’s time to help the engine push exhaust gases out quicker – that’s where aftermarket exhaust systems come in. Aftermarket exhaust systems are usually much less restrictive than the stock pipes, which flow quite poorly.
Again, there are many different brands and styles to choose from, but you should look for a full system that’s made by a reputable manufacturer, like Vance & Hines, S&S, or Bassani. Though exhausts seem simple, they are very precisely and carefully designed to have the best exhaust velocity – only a few manufacturers have the resources to perfect that.
Lastly, remember that any potential mods that you will do in the future will depend on your intake and exhaust. An air cleaner or exhaust rated for 100 HP will become a huge bottleneck when you’re ready to make 120+ HP with a big bore kit, high compression pistons, ported head, and aggressive cam. Make sure that you do your research and get the best air cleaner and exhaust system possible.
2. EFI Tuner
If you made any modifications to your Twin Cam 96 (even as little as an aftermarket air cleaner), you will need to tune your engine in order to fully utilize the potential power gains.
Gone are the days of fiddling around with carburetor jets – all you have to do now is connect a tuner, choose a map, and your Twin Cam 96 is now at least 20% more powerful.
A tuner is an essential part of modifying a Twin Cam 96, therefore it’s a good idea to get a good one that has lots of features and controls.
There are many different tuners on the market, but our personal favorites are the Dynojet Power Commander V and ThunderMax. If you go with either one of those, I promise you won’t be disappointed.
3. Performance Cams
Once you’ve made your Twin Cam 96 breathe much better with the performance air cleaner and exhaust combo, the next stage is getting aftermarket performance cams that will utilize the extra airflow.
Cams can make a HUGE difference and they don’t cost all that much, especially bolt-in cams that are compatible with stock valve springs.
Now, understanding and choosing the right cams can be really confusing and difficult, so I would recommend that you seek professional help when making your decision. Most reputable manufacturers, like Comp Camps and S&S, will be more than glad to give you all the advice you need when choosing cams for your riding style and expectations, so make sure you give them a call.
When choosing cams, you will first want to decide whether you want torque or HP, and where in the RPM range do you want it. At low, mid, or high RPMs?
Most riders choose to have peak torque in the mid-to-low RPM range since it’s much more practical to have power readily available without having to downshift, but you can switch it up and move peak HP and torque to the top end. Two of the most popular choices are Woods TW-222 and the SE255.
If you want to learn more about cams, and how they work – check out the excellent Harley Camshaft 101 series by S&S:
Also Read: The Worst Harley Twin Cam Years to Avoid
4. Big Bore Kit & High Compression Pistons
Now we’re starting to get serious.
After you’ve taken care of the airflow, tune, and cams – it’s time to go up in displacement.
You can either go with a 103″ big bore kit, a 107″, or you can go all out and get the 110″. The 110″ is the biggest you can install on stock cases without modification.
This is where your choice of the camshaft can become a bottleneck. A 110″ bore with higher compression pistons will need a cam that is designed to handle the extra compression.
If done properly and tuned afterward, a big bore kit + all the mods above can give your Twin Cam 96 a +40% boost in HP and torque.
5. Ported & Polished Heads
When you’ve got all the mods above (intake and exhaust, aggressive cams, big bore and high-compression pistons), you can move into headwork.
This is where you will make seriously big HP and torque and reach the point where you need a stronger clutch to handle the power. You can expect at least 50% more power at this stage.
By getting ported and polished heads, you will be able to increase the amount of air going into the combustion chamber even further and spray even more fuel.
Headwork needs really aggressive cams, so you might need to upgrade again at this stage. Once again, make sure you consult with a professional when deciding which cams will work best for your application.
6. Larger Throttle Body & Injectors
With the headwork, big bore, pistons, cams, etc. done, the only other limiting factor will be the throttle body and the injectors.
The stock throttle body on a Twin Cam 96 is 46mm, and you can upgrade to a 51mm or even 58mm throttle body. Of course, to supplement the airflow, you need more fuel, and at this point – the stock injectors are maxed out, so you’ll need bigger injectors.
Now, this is where you can make 70-80% more HP, but most riders will not get to this point unless they are building a drag motor.
If you are serious about making as much power as possible, then this is the stage where you will need to get a custom dyno tune to make sure everything is working properly and that your bike is making the most power possible.
Do You Need All These Upgrades?
No, you certainly don’t need all of these upgrades to make more power. In fact, most riders will only do a few of these mods, like a big bore kit, cams, and intake + exhaust.
The beauty of building a Twin Cam 96 is that you can do as little or as much as you want, and you can always add more later. Harley’s are all about customization and you should enjoy the freedom of doing whatever you want with the motorcycle.
Just make sure that you do your research and consult with a professional before making any changes, so that you don’t run into something unexpected later on.
Final Thoughts
If you’re looking to add some more horsepower to your twin cam 96, then these are the best upgrades to consider.
We’ve outlined a few of the most popular and effective mods that you can do, but ultimately it’s up to you to decide what you want to do with your bike and that’s the beauty of it – freedom.
Don’t be afraid to experiment and try different things out until you find the perfect combination that works for you. And as always, make sure you consult with a professional to get the best advice possible for your specific case.
Now get out there and start building your dream Twin Cam 96!
Jake is the site’s primary contributor.
Motorcycles and automotive repair have been a big part of his family for generations, therefore it’s only natural that he decided to become a heavy-duty diesel tech.
Outside of work, you’ll find Jake restoring and riding rare street bikes and ATVs.