Ok so, I've got a 2003 Honda Civic si ep3 with the 9.8:1 k20a3 roughly 160hp. I was thinking of rebuilding the bottom end. 11.5:1 compression Pistons and new rods. On top of this I was going to get the k20a2 head. My question is, if I change the compression ratio do I need a new ecu that is preprogrammed with that high compression tune? Could I use an oem one from a k20a2? I'm not looking to go crazy with price and performance parts but the 200hp of the k20a2 is a little more of what I'm looking for.

 

If you use a stock K20A2 complete cylinder head, and you increase the compression by changing the pistons to one that makes the same compression as a A2 engine has, and use an A2 intake manifold... yes, a stock PRB ECU should work reasonably well.

 

Sell your motor, buy an A2.

It will cost you MUCH less in the long run. And less to worry about and go wrong.

 

Well I can't sell a motor with a bent valve an have enough to buy an a2. Plus I don't have time to try to sell the motor. What I'm asking for is information not an opinion. Thanks though