PORTING

Post by **smorison** » Wed Nov 26, 2003 1:11 pm

the ECU is constantly adjusting the Fuel to air ratio. the even better news is that our injectors even though they are pretty small (166cc) only have a duty cycle of about 50% so you can do substantial changes without having to worry about larger injectors i.e. turbo with small boost / NOS

Blk-Jet · Post by **Blk-Jet** » Wed Nov 26, 2003 10:38 pm

onthe note of turbos,

i have a garett gt2530 waiting around. I'm planning on putting into the car at a later stage. If I only inteand to run a small amount of boost without changing the injectors then how much can i run? 6psi? i'd b happy with that for now.

Can much b done to the intake manifold? I've bored out the throttle body to 63mm and fitted a new brass butterfly to it. Now looking at the intake manifold, i've noticed a bit can b done to clean it up but to port it? How far should I go? I don't have any "ported" gaskets to work from!

Also once this is done i'm moving into the main area, the heads. My plan is to increase each valve size and replace the valves with larger ones etc. Apart form that, i'll honning out the cylinders and shot peening the con-rods. Would it b ok to b thinking about boring the cylinders maybe an extra 500cc each? Tha's with a turbo conversion in mind for later on and of course what parts can you offer me in the way of computers (piggy-backs) cams etc.

Cheers

GPXXX · Post by **GPXXX** » Thu Nov 27, 2003 6:45 am

whoa..!! you want to enlarge 'each' cylinders by 500cc???

i think the stock injectors should be able to cope with fueling needs at 6psi of boost without major dramas, but IMO there is prob no significant advantage to enlarge the valves if you are using stock injectors anyway, because I suspect the design of the head alone gives pretty good airflow to begin with and the amount of fuel that can be injected will largely depend on the injector sizing itself (as well as the ECU that controls the fuel mapping) so even if the valves were enlarged for more air to be sucked into each cylinder, you will still require the right amount of fuel and ignition timing to achieve optimum combustion for the best results...

in a nutshell, i wouldn't enlarge the valves unless i have bigger injectors fitted as well (in conjunction with a bored out cylinder).

ok i'm beginning to sound like i'm just rambling on senseless so I'll just shut up now LOL...

Blk-Jet · Post by **Blk-Jet** » Thu Nov 27, 2003 7:53 am

with larger injectors installed what computer could do the job of re-organising my fuel map? Apexi-afc? or something in that price range?

GPXXX · Post by **GPXXX** » Thu Nov 27, 2003 1:13 pm

not sure about the new-breed of AFCs, but when you turbo a MIVEC, one would usually opt for a new engine management system (although in Scracy's case, it is chock-full of piggyback units).