i have read a few things on the differences between the a3, a2, and a motors, but i was wondering if i would be able to put the dc5 R pistons from the k20a motor into my a3 block. just want a little extra hp until i'm ready for the swap.
and also just to double check, a header for a k20a will fit on the a3 correct, it's just the intake manifold side that doesnt work? please help me out, and i'm sorry if this has already been covered, i searched and couldnt find what i was looking for.

 

well first off, the bolt patterns for the exhaust and intake manifolds are the same for the A2/A3 and ITR A heads...its just the itr and type-s rsx downpipe angles are different than that of the si.....

yes you could put in the pistons...but our EP3/base rsx ecu's are not tuned for 12-1 compression! you would have to do the headswap with the rsx type-s ecu in place of the EP3/base rsx ecu....vtec in the base K20A3 is WAY different than in the original style K20A2/A

yes you could, but it wouldnt work that well due to the Air fuel ratio....and the high compression pistons wouldnt even reach their peak power potential due to our low redline and a/f mixture yada yada....do you get me?

 

thank you for your reply. so basically, if i get the pistons, header, exhaust, etc. i will just have to run a different ecu. i dont want to swap the head out on this motor seeing as how i will be getting a k20a eventually. i just wanted to get a little bump in hp besides that which will come from the header/exhaust.
thanks again.

 

i dont think the a3 head will work for 12.0 comp. compared to the stock 9.8 your would need more then the ecu if you did run it i think there will be some vavle train problems

 

yeah that makes sense too. damn this stupid a3 head, why did honda even bother with this thing. oh well, looks like i'll just save for the k20a instead.
thanks again.