I was looking at a 2005 Civic Si the other day w/ my father and he seemed to like it. I like it (would prefer an RSX but whatever) but i was wondering if the K20A3 in the Si can easily be tuned up to the 220hp that the RSX has. IDK what type of K20 the RSX has, but is there a diff intake/exhaust mani, ECU, or is it a different VTEC cam??

My question is what makes the RSX have 220hp and the Si have 160hp if they are the same engine?

The new rsx has 210 but its close enough to 220. The block is basically the same except the a3 has a little weaker internals and doesnt have oil squirters. The heads are pretty much completely different. The rsx-s has actual real vtec while the si only has vtec on the intake side which kicks in at about 2200rpms. You could swap out the rsx-s head and ecu on to the si's block and have about the same hp but the si's block due to it not having oil squiters and the weaker internals it isnt safe to rev it over 8k.
If you want more power out of the si then I say get an older si (02 or 03) and drop a k20a2 in it with the rsx-s 6 speed tranny, its a simple swap because most all of the k-series engines/trannys are swapable with no modifications.

So simply put they are not the same engine
si = k20a3 - 160hp
rsx-s (new model) k20z1 -210hp
(previous) k20a2 -200hp

The K-series in the Civic is a SOHC, and the more powerful RSX K-series is a DOHC (though the lower models of the RSX has the same engine as the Civic).

The K-series in the Civic is a SOHC, and the more powerful RSX K-series is a DOHC (though the lower models of the RSX has the same engine as the Civic).

The civic has DOHC

Hmmm... I really thought they had SOHCs in there, I'll have to check out the car of a few guys I know who have them,

I can see mine when I look out of my window, its DOHC.

LOL, yeah you're right. It was dark when I looked at the engine bay, but I should have known better before I responded with my ignorance :D. I don't know why I thought it was sohc.

LOL, yeah you're right. It was dark when I looked at the engine bay, but I should have known better before I responded with my ignorance :D. I don't know why I thought it was sohc.

Probably from its crappy stock power output and its fake vtec....but the motor is just soo darn cute!

their crankshafts are also made differently

Basically they are way different tho and the Civic engine sucks comparitively right??

Think of it as the b-series vtecs. They're not completely different but they do have their differences with internals (higher compression, wilder cams, etc). Even the hp ratings are similar to the B's; the Civic motor has 160hp (like the b16a), Type S has 210hp (like the ITR).

sorry about using this thread as an oportunity to drop my question, but I want to know something.
If I dont want power streering and air conditioner, can I just take those two pulleys out? would this affect my peformance? or I have to leave then hanging on the engine?

sorry about using this thread as an oportunity to drop my question, but I want to know something.
If I dont want power streering and air conditioner, can I just take those two pulleys out? would this affect my peformance? or I have to leave then hanging on the engine?
:wtf: Dude, this has nothing to do with the K-series motor. This isn't the first (or even 10th) time you've jacked a thread with something different from the actual topic of the thread. If you have a question then search, if you don't find an answer then start your own thread. :slap:

Relax men, is only a question. You could either ignore me or just delete my replay, but dont come wiht "Start your own trhead" shi*. And for your information, everytime I JACK a trhead like you said is actually something related to it. This is the first time I come wiht something like this (not related to the thread). Try to be more polite because you wouldnt like it if somebody try to make you look stupid. I dont think you should come up to me like "dude, what the F***?". After all, we all need help wiht something, and I even said "Sorry about using this thread" It means I have some more morals than you do.
Anyways you did not answer my question. And dont think that you are smarter than everybody around here, you've done some ignorant mistakes and nobody said anything.

First off, when I make a mistake I have the ballz to admit it. Of course I make mistakes, I'm not going to be stupid and deny that. And I don't think I'm smarter than anyone here, I do however clearly have more common sense than some. If you'd like me to waste my time and show you the threads where you've done this before, I will. Morals? I'm not going to comment further about that because this is the internet, and you don't know sh*t about me or anyone else on here. If you want to discuss this further I suggest you PM me instead of us taking over this thread any more.