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Old 04-24-2006, 09:28 PM   #1
WRXDrUnKiE
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Default Bigger Injectors with a stock STi?

I am going to be rebuilding an STi I just bought and I would like to put some forged pistons and helix 860cc injectors. Does anyone know if I can do this and keep it stock without running into any problems. I am upgrading to a gt30R kit later on and dont want to have to replace injectors and pistons then if it will be out of the car now.

-Matt
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Old 04-24-2006, 09:41 PM   #2
STimo
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DO NOT run bigger injectors without engine management, you can ruin your motor.

If you plan on installing forged pistons, i would also look into doing to whole bottom end while you are in there. It costs quite a bit to pull the motor and open it up. My suggestion is while you are in there, you should upgrade everything so you don't have a weak link.
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Old 04-24-2006, 10:06 PM   #3
WRXDrUnKiE
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What weak links other than pistons would I have to worry about? And I couldnt use an SAFC or anything or an AP?
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Old 04-24-2006, 11:16 PM   #4
STI2005PR
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Quote:
Originally Posted by STimo
DO NOT run bigger injectors without engine management, you can ruin your motor.

If you plan on installing forged pistons, i would also look into doing to whole bottom end while you are in there. It costs quite a bit to pull the motor and open it up. My suggestion is while you are in there, you should upgrade everything so you don't have a weak link.
And why will he ruin his motor? He will run very rich and that's about it.
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Old 04-24-2006, 11:25 PM   #5
TypeC
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Quote:
Originally Posted by STI2005PR
And why will he ruin his motor? He will run very rich and that's about it.
For one, the car won't start nor idle with 800cc injectors. Secondly, you'll wash the bores and contaminate the oil with overfueling.

Simple answer, don't do injectors unless you have EM. Used EM is only $500 anyway.
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Old 04-24-2006, 11:29 PM   #6
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if you're gonna spend money to get pistons put in,you might as well do everything at one time to save money.mine is in the process of being rebuilt as we speak.my valves floated so i decided i might as well get it rebuilt since it was gonna cost me a lot to get them fixed.I dropped $8k for the project.Custom forged pistons and rods,rod and main bearings,arp headstuds,darton race sleeves,new gaskets,ferrea valves,retainers,locks,seals.other mods on the car right nowerrin catless race pipes,hks 3inch turboback,perrin 816ccs,perrin fuel rail,walbro fuel pump,utec,fp green,aps dr725,clutchmaster single plate clutch w/flywheel
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Old 04-24-2006, 11:36 PM   #7
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forgot to add that i was upgrading from the green to gt35R.i'm selling my green if ur intersted.1500k miles on it.1250shipped
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Old 04-25-2006, 12:04 AM   #8
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Quote:
Originally Posted by TypeC
For one, the car won't start nor idle with 800cc injectors. Secondly, you'll wash the bores and contaminate the oil with overfueling.

Simple answer, don't do injectors unless you have EM. Used EM is only $500 anyway.
100% correct. Engine Management should be THE FIRST MOD EVERYTHING ELSE DEPENDS ON TUNING WITH IT.

Buy a Walbro pump.

Think about calling a reputable performance shop/vendor and discussing an upgrade path. If you are yanking the motor, there's tons of stuff you can do while it's out. I recommend www.worldoneperformance.com becuase I know all of them well.
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Old 04-25-2006, 09:20 AM   #9
STI2005PR
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Quote:
Originally Posted by TypeC
For one, the car won't start nor idle with 800cc injectors. Secondly, you'll wash the bores and contaminate the oil with overfueling.

Simple answer, don't do injectors unless you have EM. Used EM is only $500 anyway.
Actually your wrong. My car started fine, idle fine and drove fine with 810cc injectors. The problem came when I past 4,000rpms that it would run very rich.
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Old 04-25-2006, 09:36 AM   #10
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Swapping injectors with the motor in the car is really easy.
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Old 04-25-2006, 04:15 PM   #11
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Quote:
Originally Posted by jays05
Swapping injectors with the motor in the car is really easy.
^^^^^^^^
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Old 04-25-2006, 04:18 PM   #12
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Quote:
Originally Posted by Uncle Scotty
^^^^^^^^
it is with the sti (not sure on the newer 06 2.5 wrx's), but 1/10th as hard as the GBOD's and the 2 litre
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Old 04-25-2006, 05:14 PM   #13
WRXDrUnKiE
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Im coming off of an 02 wrx, injectors took a while for us.
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