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View Full Version : JDM Heads,or cmas,and goodies??


shouldaboughtanSTI
03-04-2006, 04:52 AM
I have a version7 shorty..and am trying to work out a solution for the rest..If i buy the jdm heads..Then,thats it..I wont have the money for the wiring,ecu,etc,,So, No AVCS..for awhile..But, if i buy cams,springs,etc to put into my heads..Would that be close to as good as the v7-v8??Or,should i just get the jdm heads,and wait until i can get the rest,or just install them without it??Any help apreciated..Jason..

petawabit
03-04-2006, 05:11 AM
buy my heads :p
I think you should break it down.

US heads:
better valvesprings and retainers
better cams(depending on which ones)
smaller intake and exhaust ports
smaller valves

Labor+cams+valvesprings and such:~1700 or so depending on labor, cams and valvesprings you get

JDM heads:
decent valvesprings and retainers
lesser cams
bigger intake and exhaust ports
bigger valves with the exhausts being lighter and having better heat dissipation(sodium filled)
avcs(which is pretty big)

labor+heads:~1900 or so

Also if you buy the JDM heads, you can sell your wrx heads for 500 or so. Not much value in wrx valvesprings/retainers and cams

PeteDucati
03-04-2006, 01:26 PM
These cars suck. No one really knows if higher flowing heads are necessary with higher lift/more duration cams. You might be pissing into the wind by adding better cams to USDM heads without having them ported.. but I don't think anyone really knows - but everyone has an opinion and theory.

Ported WRX heads with cams+springs+retainers= ~$2500-3000

djviper
03-06-2006, 09:02 AM
id port before changing cams, as the cams will only work as well as the ports. IMO

PeteDucati
03-07-2006, 07:16 AM
id port before changing cams, as the cams will only work as well as the ports. IMO

Where and who has done the proper testing to prove this. Most think the opposite is true.. that the stock cams are so damn mild they're the restriction, not the heads.

djviper
03-07-2006, 08:04 AM
Where and who has done the proper testing to prove this. Most think the opposite is true.. that the stock cams are so damn mild they're the restriction, not the heads.
IMO = IN MY OPIONION

thing is there are that few differences between the two heads youd get a better result for the same money if you worked on the wrx/sti heads, i mean a quick look on uk e bay theres a us sti 8 head an cams for $1700!

ill be honest if it was my car i would port n polish the whole inlect tract and combustion chamber, inlarge the valves on the exhaust side, fit 272 duration cams with titanium springs, retainers, and collets, id install bronze guides and then dial it all in corerectly using the ecu and cam verniers as if youve got the heads off you might as well do the lot! itd probably cost about $3000 if you port your self and youd also be 85% of the way to an 8000 safe redline

like i say though this is my opionion and as we all know there are many theories to "the black art"

PeteDucati
03-09-2006, 02:52 PM
I was hoping you actually had concrete information. I went with CNC'd heads using a v8 STi program for the specs along with Crower Stg. II cams, springs, and Ti retainers.