I'm looking to do a few mods on my civic Si 2008. I'm not completely sure on what I'm going to do yet though.
I was thinking about these. But I would like to know about really any mods that aren't super expensive, easy to do, and add some performance, even if it's not a whole lot.
So the ones I was thinking about are:
-Cold air intake
-Catback exhaust.
-New header - Specifically this skunk2 header - https://skunk2.com/exhaust-tuning/he...ha-header.html

Any help would be much appreciated. Thanks!

 

The header will make the most power of the three alone... a quality intake will be the second best choice... and you will gain a couple/three wheel HP with a quality cat-back.

 

header will only make so much until you get 3" exhaust. without 3" exhaust your robbing your motor.

if I was you I wouldn't bother buying anything until you get flashpro. stock everything and flashpro will net more power.
flashpro first.
then exhaust
intake. hybrid racing has a real race proven quality product.

ditch weight. keep things cool. lower the car.
also get the lighter pulleys. makes big difference
consider valve lash, very important and can pick up power if they have never been adjusted.

 

 

I guess I kind of assumed that the OP would buy FlashPro (or at least a license) first, because tuning is absolutely necessary no matter what mods you choose.

Now, when you say FlashPro first and THEN exhaust... are you saying a header and cat-back or are you speaking only of a 3" cat-back ???

The order in which I listed the suggested items is in order of how much power they will make by themselves (independently)... so if you bolted on one at a time, the header and a tune will make the biggest HP improvement. Adding the cat-back to the header will improve the performance even more, but a 3" cat-back by itself makes almost no gains because the cat and downpipe are so restrictive. The intake will pick up a few regardless of the order in which it is installed.

So again to the OP... FlashPro first, then your header, and then you can flip a coin as to which you buy next. A cat-back exhaust will improve performance when installed and tuned after a header (it will do almost nothing but make a ton of noise if you buy it first and bolt it up to a stock cat and downpipe) and a quality intake will gain a few ponies as well.