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Old 11-30-2006, 03:08 PM   #1
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Default Yet another injector question

Hello. First off i'm sorry to ask a question that has been asked before i'm sure but i'm haveing trouble finding the exact answers. First off, my goal as of now is 9psi maybe a little more later. Right now on my 96 i'm at 7psi with a HP Walbro 255 fuel pump, vortech 12:1 fmu, msd/bipes highbreed starting a 10 degrees retarding to 4. I have a turbonetics evolution wastegate with the 7psi spring in it but i have the 9psi spring as well, so it's painful not using it. Braineack said in another post that 9psi is pushing my stock injectors a little far. So that means bigger injectors. What I guess i'm looking for is a plug and play injector that can handle up to 12psi of boost and maybe be compatible with a emanange down the road. what are my options? What used injectors should i look for (i.e. 96 supra, rx7 ect....)? And when will I start to feel the limitations of the vortech and should move on?

On a side note I would like to thank everyone on here for all the help in making my turbo project happen.
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Old 11-30-2006, 03:21 PM   #2
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9psi on the 1.8s with the correct FP is the most I'd put in them. depends on the setup. But you need a 6:1 or 7:1 disc in the FMU. you're already pushing 135psi, just at the limits of the pump and more than most would typically run.

you should be able to idle 305s without a hitch. only 11% bigger. read the injector section on my FAQ for a large list of PNP injectors.
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Old 11-30-2006, 03:30 PM   #3
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nice avitar braineack
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Old 11-30-2006, 03:31 PM   #4
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I wouldn't go up to 9 psi on those injectors.

Yes, I know I'm at 9psi. But I'm running less displacement, some what better fuel management, and dyno tuned.
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Old 12-01-2006, 03:04 PM   #5
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The supra injectors look like the way to go. Is it safe to buy those used and stick them in the car to see if they work or should you get them cleaned and tested first? Where do you get them cleaned and tested? What disk would be better 7:1, 6:1, 8:1 and where is a good place to buy one?
Thanks
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Old 12-01-2006, 04:38 PM   #6
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that's what i did. but then I seem to have had a failed one. it's worth the $50-60 to have them cleaned. plus you'll see exactly the condition before and after, get all new parts. Brads is seeing 315cc in his.

do the math to reach 100-110psi at full boost, if you need the formula read my FAQ.
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Old 12-03-2006, 02:54 PM   #7
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So I have looked at the formula a few times and can't figure out a couple things. First how did you get that a 12:1 fmu supplies 10 psi per 1 pound boost? Second, is there any way around buying a temp fuel pressure gauge to get idle pressure? Another question, What if down the road I wanted to get stupid and go to 12 psi. What would I need to do? Would the 315 cc injectors work? I really don't think I'll want to go that high but I hate doing things twice or more importantly buying things twice. Thanks.
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Old 12-03-2006, 03:45 PM   #8
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typo.

you can't adjust your idle pressure unless you remove the stock FPR.

im running 12psi on the votech, choose a correct FMU disc and injector that can support the HP.

yes, they are what im using.

that's why some people are turning to engine managment. no need for a bipes, o2 clamp, fuel pump, fmu....that's a good chunk of change. I'm nearing the limits of the stock ecu and I'm by no mean ideal in AFR after 5k.
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Old 12-21-2006, 01:37 AM   #9
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OK. I got some 312cc injectors on the way and I just got my 7:1 disk in the mail. I should be good for 9psi. Right?
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