Fueling & Injection Fuel Pumps | Injectors | Rails | Regulators | Tanks

injector size question

Old Jul 11, 2007 | 04:16 PM
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Default injector size question

my car made right at 400rwhp and i am being told that i need to upgrade my injectors if i am planning on sprayin the car so i am buying a walbro255 pump but have no idea what size injectors to be looking to buy... any suggestions??

thanks
daniel
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Old Jul 11, 2007 | 05:41 PM
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anyone???
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Old Jul 11, 2007 | 06:37 PM
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I make 397 and am running SVO 30's. You could run 36's so you wouldn't have to worry about a high duty cycle while spraying and be fine.
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Old Jul 12, 2007 | 02:47 PM
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Just get the SVO 42's.

The 36's would probably work but the 42's will give some room to grow with your N2O shot.
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Old Jul 12, 2007 | 05:40 PM
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42#ers huh..... sounds ok to me i guess... fuel injection is way over my head anyway! i just dont wanna buy some and then later down the road when when i plan to up my shot or possible a cam/head swap have to change em again
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Old Jul 13, 2007 | 12:37 PM
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My stock injectors were fine up to 450whp. It depends if you plan on getting a wet N20 kit or a dry kit. The dry kit will require more injector. In this case the 42lb. injectors would work well. It cant hurt to upgrade them anyway but you will have to get a new tune for the car to run properly.
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Old Jul 13, 2007 | 06:35 PM
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yea....im goin dry cause i like to be sneaky!!

and i am gonna get a retune anyway cause im gonna have to have my timing dropped a little for the n2o hit
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Old Jul 13, 2007 | 10:14 PM
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I'd go with the 42s also. I ran them on my old head/cam setup. Great idle, easy to tune, room to grow....
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Old Jul 19, 2007 | 08:03 PM
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mine is 38# from speedinc work verey well .and i have 150 dry shot
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Old Jul 21, 2007 | 07:11 PM
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I run 36's with heads/cam and a dry 100 shot, on the stock fuel pump. It stays dead nuts on 12.5 air/fuel and the injectors run about 80% duty cycle.
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Old Jul 21, 2007 | 11:00 PM
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i'm running #30's in my car and im running 446hp/410tq
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Old Jul 29, 2007 | 12:29 AM
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i was running my stock injectors at a 230% duty cycle. they seemed to work fine. afr was good, i upgraded to 42's but i still see a duty cycle of 120%
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Old Jul 29, 2007 | 02:01 AM
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Go with 60s from the get go. The 60s are easy to tune and will give you plenty of injector for the future. Trust me. I had to upgrade from 42s to 60s. When I just could have went straight to 60s. These injectors are easy to tune. Bob at EPP can get you 60's at a great price.
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