Hello I am new to these forums and have decided to get some questions cleared up. I have a 2004 Honda Civic Si coupe. It's slightly strange, as the VIN is registered as an EX though it is a VTEC SOHC. Anyways, i have got a SRI and Exhaust system installed, and would like to do more for performance and I'm having lots of trouble determining what to do next. I have a decent amount of spending to do so money is not necessarily an issue; I'm not planning on going as far as a turbo. Everyone I have talked to already says I am out of options; I was told that there is nothing i can really do for noticeable gains. I know my ECU options are very limited, and anything else I want to do will be lots out of my pocket. However i really like my car and plan on putting in as long as it puts out. Just looking for any recommendations, it would help me out alot, thanks

 

who ever told you that your car is a Si was wrong a Si has a DOHC VTEC. as far as options what do you want out of your car, handling, 1/4 mile time, or what?

 

Oh, well the car has "Si" on the rear, and it came with an Si manual. What i was told was that in 2004, Canada made a Si coupe with an SOHC, which is kind of confusing and makes it more difficult to find parts for it. In the manual it also has info for what they call "Canadian Si", however i mostly consider it an EX when finding parts so I'll stick with that. I would like to add photos but i do not have access to a camera ATM. Anyways I am mostly looking for more gains in HP and low end torque if possible.. so 1/4 mile time. Which i understand is hard to accomplish with a stock ECU..

Please excuse my lack of some terms, as I am still learning.

 

yes the canadian SI is the american EX the canadian type R is the american SI its slightly confusing. but if your not going with turbo or engine swap then you said it yourself there's really no hp gains to be made.

the only other option not mentioned was to upgrade your camshaft for a crower stage 1 that would gain you around 20hp along with a full header back exhaust your looking at close to 30hp all together not much but its better then nothing Honda Camshaft - Camshafts . is your car manual or automatic ??? if manual then a light next stage clutch and short shift would improve performance.

the the one major thing vastly overlooked is tires they make all the difference in the world as far as handling goes along with some quality coilovers and you can make it ride on rails.

 

Thank you, that information is really helpful, I think I know where to start now. And yes, it is a manual trans. so I will upgrade that along with my camshaft to start.
I have just recently put new tires on my car; treating me well. Would swapping my current ECU with something like Hondata give me more gains after all said and done, or would it not even be necessary (or worth the expense)?

 

You need tuning if you plan on installing a camshaft.

Yes, Canadian SI = USDM EX. Everytime someone comes onto a Honda forum with this type of car, people freak out. lol