no worries jarrydsNIZ12!

Yeah thats right superbin, i wouldn't go anything over 10psi on stock internals on an A-12. 8PSI is a good starting point.

I had a little 1.5 honda civic that I ran on 10psi with all standard internals on with 9.2 comp ratio it had a t 2.8 off a saab and made 141kw on the fly and 272 nm so I think keeping the suck trough setup in mind 8 to 8.5 should be fine at about 7 psi just always! Make sure you have enough fuel to your motor or you will! Melt pistons. Good luck its gona be fun!

very helpful thanks mate

There are a few ways to lower the compression ratio, you can use a shim(spacer) plate that goes in together with the head gasket. i have also heard of people using 2 head gasket to gether to do the same job. If you're planning to built a reaonably low boost set-up this method is fine as long as you don't go overboard.


Or you can have the pistons and/or head machined to reduce the compression ratio,i.e dishing the pistons etc, i would recommend this method for higher boost applications.

If your doing any sort of engine work i would recommend a suitable turbo cam, i'm pretty sure you can get on from a decent cam place, crane or crow would be a good start. I would recommend a full rebuild if you're going that far.

Yeah I think its something like 7.5:1 that ya want, but arent 100% sure need to make up a spacer, or I think some hav got away with an a14 low comp head and maybe an extra gasket. can allso do stuf like resces valves and open(grind out) chambers to some degree

i have an a12
yeah t25 sounds like fun

not sure yet itd be a good idea what should i get done? i thought your meant to have low compression?

Are you using ?A12-A14 or A15?

Not that it matters much, perfect size turbo is a T2 off a ET, EXA pulsar (E15T) but it runs out of puff late in the rev range? Personally i use a T25 off a CA18DET, its a little laggy but its not the noticable. You can drive around normally in traffic without hitting boost but soon as you wat a bit of gusto the turbo winds up and it boosts like a freaking hurricane!!!

Are you going spend some money on the engine internals? and head work?

my mistake
the turbo is after the carby so it doesnt need any piping off the carby just air filter??
ill have to get a custom made manifold but wont i to fit the turbo from the carby to the headers?
also what turbo do u recommend?

Quote:

huh? there is no piping that goes to the top( air fiter side) of the carby in a draw through set up, only on blow through.

ah yeah cuz id have to get piping to go to the top of the down draft?
where as if its a side draft itd be easier yeh?