How to Make 300hp on a 10th Generation Civic L15
So you want the formula on how to make 300+ whp with your L15 powdered Honda CivicX? I’ll let you in on a little secret. It’s actually pretty easy to achieve that power goal and it can be hit with 100% bolt-on parts. No crazy exotic or custom parts required. Plus it’s been shown that with a good tune you can safely hit 300HP on a stock engine. No need for a built motor with upgraded rods and pistons. In this blog, I’ll share with you the parts and resources you will need to join the 300hp club with the 1.5L turbo engine.
Disclaimer: Every dyno reads differently. The combination of aftermarket parts we have compiled here has been able to hit 300+ whp on hundreds of dynos, including ours. Don’t be discouraged if you put all these parts on but don’t see 300hp. Remember, we always focus on the delta or what we have gained over stock.
First, let’s dive into the ingredients and you’ll get the recipe by the time we finish.
Cold Air Intake
The first piece of the puzzle is a cold air intake system (CAI). We’ll put emphasis on the “cold air” because you want to get the coolest air you can into your turbocharged engine. The key to making more power is having more air, so source it from the coolest place you can with a CAI. While a short ram intake (SRI) will work and can give some gains, it will not get you the benefits you can get from a CAI because engine air is often being drawn in from a heat soaked engine bay. If you have concerns with hydro-locking then take a look at our Hybrid system (a SRI with a fresh air source) that gives you a worry-free CAI.
High Performance Downpipe With Front Pipe
The next thing you’ll want to upgrade is your factory downpipe and front pipe to a more free-flowing exhaust system. As we have said before, the engine is nothing but a glorified air-pump. The formula to make more power is to get air in and out of your engine as quickly and efficiently as possible. The OEM downpipe is small and very restrictive. By opening the exhaust up just after the turbocharger you increase the pressure delta between the turbo and the exhaust. The greater the difference, the faster the exhaust gases get out. A downpipe can easily stack on 15+whp and increase spool.
Front Mount Intercooler Kit
Not only do you want to get the air in and out as quickly as possible; we want it nice and cold. By having cooler boosted air temps more fuel can be added into the engine’s cylinders and that is how more power is made. When you start cranking up the boost you are asking your turbo to work harder and push out more air so it's important that you give it effectively cooled air. An FMIC upgrade can easily net over 20+whp.
Drop-in Turbocharger
The key to it all. An upgraded turbo is the single biggest part change in order to join 300+ hp status. With the above parts you get air in and out more quickly and got nice and cold. With this upgrade you get more of it. That is what a turbocharger upgrade is great at doing. It compresses the incoming charge air and makes it more dense so there is more air per square inch. And with more air (you guessed it) comes more fuel therefore more power. A drop-in turbo straps on 40-80 hp when tuned correctly.
Tuning Solution
Wrapping up the power mods is a good tuning solution. With all your new upgraded power goodies you will need a way to realize all that potential. A Hondata or KTuner is the brains to it all. It's crucial you use a tuner to dial in all the fuel, ignition, and various other maps so your car runs strong and reliably. Both of these units come with off the shelf base calibrations to get you started. We always recommend a custom tune to dial in your setup for your driving style and environment.
Clutch Kit
A clutch is on this list not because it adds to your power figures but simply because the OEM unit won’t hold the extra levels of horsepower and torque that your car will now be making. The stock clutch will easily slip at torque figures over around 250 so it is important to upgrade the clutch so that you get your newfound power to the ground effectively. All that extra power does not mean anything if you can’t use it!
The Recipe for 300 HP
Cold air intake system
High-performance downpipe and front pipe
Front mount intercooler kit
Drop-in turbocharger upgrade
Tuning solution like Hondata or KTuner
Clutch kit (for manual transaxles)
Optional (nice to have/might need)
Flex-fuel kit
The above modifications on 91 octane fuel will leave you a bit shy of 300hp. On 91oct fuel most land in the 280-285 range. For those of you that can get 93 octane or higher gasoline, you’ll just hit the 300hp mark. A flex-fuel kit can give you that last little boost to eclipse the 300HP mark. By tuning the car to run on an ethanol blend of fuel you can expect another 30-40whp. These cars love ethanol and it's a great way to add power. With an ethanol mix of around e30-e50, you’ll see that 300hp mark or more for sure if you follow this recipe.
That’s the list. Welcome to the 300hp club!
-Vincent