2003 Honda Accord modifications

I have a 2003 Accord with a K24A4 engine, and I’m looking for some mods to give it more power. I’d like to know where to start and what I could do later on.

And just to clarify, I know my car isn’t anything special, but it’s my first car, and I want to see how much I can improve it. My friends are doing the same with their first cars, so getting a new car isn’t an option. Thanks!

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The only ways to get more power from your engine are to use forced induction or increase the compression ratio.

Adding bolt-on mods won’t make much difference because the ECU is set to run in a specific way. If you change the temperature or amount of air or fuel going into the engine, the ECU will try to adjust, but it can only do so much. If it can’t adjust correctly, you’ll likely see a check engine light, and the ECU might run the engine with too much fuel to avoid damage.

You’ll get more value from handling mods. I suggest adding a thicker rear sway bar and lowering the car.

Get some good tires instead. Save your money and the trouble of adding serious power for a car that’s really worth it. Your Accord is a great daily driver, not the kind of car that needs a manual swap or a turbo.

You’re in luck because the K series is great for mods! Are you using a manual or automatic? That will really affect how much power you can add. Here’s my list of things you can do, roughly in order:

  1. Cold air intake
  2. Aftermarket Tri-Y header
  3. Full exhaust system
  4. Manual swap (if you have an automatic)
  5. Lightweight flywheel and good clutch
  6. KTuned or Hybrid Racing shifter
  7. ECU and tune
  8. Bigger injectors
  9. Aftermarket intake manifold (like Skunk2)

After these, you’ll need to decide if you want to add a turbo or stay all motor.

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Right now, it’s automatic, but I plan to swap it for a manual this summer. This info is really helpful! I have a quick question about the ECU. I’ve heard that the 2005-2007 ECU can be reprogrammed with Ktuner. Should I go for one of those years, or is there a standalone ECU you would recommend?

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I had a 2004 i4 manual and drove it hard. I bought it when it had 140,000 km and sold it at 340,000 km. Just make sure to keep up with oil changes, and keep track of how much oil you’re burning because you will burn some. I recommend either rebuilding the engine at some point or doing a JDM motor swap.

You could add adjustable coilovers, 2008 Acura TL Type S anti-sway bars and end links, stiffer engine mounts, and 6-cylinder strut brackets. If you’re up for it, you can swap the whole front knuckles from the TL to get bigger brakes (I think they’re called Advics, which are basically Acura’s version of Brembos).

The only way to really get more power is with a turbo kit, but that involves a lot of tuning and work. However, when you can take corners without slowing down and floor it in second gear on on-ramps, driving a slow car fast can be just as fun as driving a fast car since you don’t have to worry about going overboard.

There are a few forums for the Accord that cover all of this and provide great how-tos for important maintenance.

People are right that it’s cheaper to buy a better car, but my 2004 was my first car. I spent a lot of money on the mods above and had a great time learning about cars over the 8.5 years I owned it. Just be ready for maintenance if you push it hard!

I’ve seen great things done with a KTuner, especially at it’s price point. Personally, I’m a Hondata guy, been working great for me for years. Or, if you really plan to make the thing nuts one day, go for a FuelTech