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The 5 Best Twin Cam 88 Performance Upgrades To Wake Up Your Harley Davidson

If you own a Twin Cam 88, then you’re in luck. Those engines respond extremely well to mods and there are plenty of aftermarket parts available to turn your Harley Davidson into a rocket.

From exhaust systems to big bore kits – we’re going to take a look at some of the best Twin Cam 88 performance upgrades that will completely transform your motorcycle.


The 5 Best Twin Cam 88 Performance Upgrades


1. Big Bore Kit

twin cam 88 with a big bore kit

The Twin Cam 88 is a great engine, but as far as Twin Cam engines go, the 88 is relatively small in comparison. Because of that, the best and the most cost-effective performance mod you can do to a Twin Cam 88 is to increase the displacement.

That’s right, a big bore kit is by far the best way to get more power out of your Twin Cam 88. There’s no replacement for displacement.

Now, there are a lot of options to choose from, but the most popular bore sizes are 95, 98, and 100 ci.

The 95 is the perfect choice for riders who want to wake up a tired Twin Cam 88 without having to purchase new cams.

On the other hand, some riders want the biggest displacement possible and go with the 100 ci big bore kit. The 100 ci big bore kit is only available from S&S Cycle and it’s the largest displacement big bore kit for the Twin Cam 88 without the need to machine the stock crankcase.

The 98 big bore kit strikes the perfect balance between power and cost, and it’s the most popular choice for many Twin Cam 88 owners. If you go even further and combine the 98 big bore kit with Wood TW6-6R cams, you’ll join the 100 HP club.

Our recommendations: S&S Cycle 910-0481, FuelMoto FM98-0611.

For more recommendations, check out our review of the best big bore kits for Twin cam 88.

2. Bolt-in Cams

harley davidson aftermarket cams

The second best performance upgrade for the Twin Cam 88 is high-performance bolt-in camshafts.

Sure, the big bore kit alone will give your Twin Cam 88 a huge power boost, but adding cams will take it to the next level.

We highly recommend going with aftermarket cams and big bore kits. The Screamin’ Eagle kits are good, but they’re expensive, and you can get better performance for less money with aftermarket parts.

Now, understanding camshafts is quite a difficult task, especially for those who are new to the world of performance upgrades, but you can narrow down your search by considering our recommendations below. These cams are really popular and we used them before, so we can vouch for their quality.

Our recommendations: Wood TW6-6R, S&S 509G, Andrews TW21.

Related: Average Harley Stage 2 Upgrade Cost

3. Performance Intake & Exhaust

twin cam 88 performance exhaust

A performance air cleaner and exhaust are the most important yet cheapest performance upgrades you can do to your Twin Cam 88.

We can always spray as much fuel as we want into the combustion chamber, but we are always limited by the amount of airflow entering the engine, thus it is crucial to first upgrade the intake and exhaust system.

If you haven’t replaced the stock air cleaner and exhaust on your Twin Cam 88, then you’re seriously restricting the engine’s potential. We do not recommend buying other performance mods unless you’ve already upgraded the stock air cleaner and exhaust.

Now, the OEM air cleaner is pretty restrictive due to emission and noise regulations. Same story with the OEM exhaust.

By getting rid of them and replacing them with a high-flow performance intake and exhaust combo, we let the Twin Cam 88 breathe better and evacuate exhaust gases quicker. This means we can get the maximum amount of airflow into the engine, which in turn lets us inject more fuel for more power.

Our recommendations: ‎K&N HD-0800, Vance & Hines VAH-17221.

4. Carb or EFI Tune

dyno jet tuner

A lot of riders forget about it, but you can get a noticeable increase in power by getting your Twin Cam 88 tuned.

Getting your Twin Cam 88 tuned is a must after you upgrade the cams, increase the displacement, increase compression, port heads, etc. You can get away without having to tune your Twin Cam 88 if you’ve only upgraded the intake and exhaust, though you would still get a nice power increase regardless.

You can get your Twin Cam 88 dyno tuned, but you can also buy an off-the-shelf EFI tuner and tune the EFI with a single click in your garage. With that said, a dyno tune by a professional will always beat off-the-shelf tuners as far as performance goes.

Our recommendations: Dyno Jet Power Vision J1850, Vance & Hines Fuelpak. 

5. Headwork

twin cam 88 head porting

Last but not least, we have headwork. Headwork is an umbrella term for porting and milling heads, and it can seriously transform your Twin Cam 88.

Interestingly, the Twin Cam 88 has a pretty low compression ratio, and by bumping the compression ratio to 10.5:1, you’ll squeeze out around 15% more power. Combine that with ported heads and you’ll be looking at 20% to 25% more power.

Now, there are a few ways to increase the compression ratio on the Twin Cam 88, but the best and most popular way is by milling the heads. You can also get high-compression pistons, though we recommend to stick with milling.

But if you’re really short on cash, you can slightly increase the compression ratio by replacing the stock head gasket with a slightly thinner one. This can be done at home if you’re a decent mechanic, but if not, then you’re better off just milling the heads. You’ll have to take them off anyway, so you might as well do the job properly and be done with it.

Also Read: Harley Breather Bypass – Everything You Need To Know

Final Thoughts

There you have it, the best Twin Cam 88 performance upgrades that will give you the biggest bang for your buck.

Harley Davidson motorcycles are all about customization, and the Twin Cam 88 is no different. With a few simple modifications, you can turn your ordinary Twin Cam 88 into a 103 smashing machine.

We hope this article has been helpful, and if you have any questions, please feel free to leave a comment below.

Ride safe!

1 thought on “The 5 Best Twin Cam 88 Performance Upgrades To Wake Up Your Harley Davidson”

  1. My 88 started top end tapping and my thoughts were it’s got to be torn down and why not eliminate the hole problem. You article was more than helpful. I’m somewhat lost . Been riding knuckleheads and shovels. Thank you

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