Going to dyno in a few weeks,what psi did the stock injector max out?

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Sep 7, 2005 | 02:19 AM
  #1  
I'm prolly going to dyno tune the car in a few weeks,the car's a 95 5sp,with walbro 255,stock injector,A32 maf(I got the Z32 maf also),fmu,fpr at 44psi,1 step colder plug and emanage(got injector and ignition hardness also),and full 3" exhauste.At what PSI do you guy think the stock injector and maf will be max out?I'm seeing .42 bar(6.3psi) on my Blitz DC II Turbo Timer with Boost Gauge right now.I got the Greddy type S boost controller.I was hoping for 9psi,yes or no?
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Sep 7, 2005 | 08:04 AM
  #2  
The injectors are maxed out right now I bet. You got plenty of head room on the MAF
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Sep 7, 2005 | 08:42 AM
  #3  
I'd agree. I run 6 psi Supercharged and see 90% duty cycle, flow depends too on what disk/pressure you're running the FMU at. If you want to run 9psi, I'd upgrade injectors.
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Sep 7, 2005 | 09:19 AM
  #4  
I'm runnning a 12:1 disk now.
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Sep 7, 2005 | 12:35 PM
  #5  
Quote: I'm runnning a 12:1 disk now.

Yeah, with a 12:1 disc, you're running pig rich right now if you're only hitting 6.x psi. For 6 psi... I'd probably get a 6:1 disc.










Or just turn the boost up
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Sep 7, 2005 | 11:26 PM
  #6  
Well,so how do one datalog with Emanage?I got the AEM Uego WB,so I can't use it with the Emange correct?

I'll UP the boost Joffe,but I'm taking it UP slowly,LOL!
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Sep 8, 2005 | 07:21 AM
  #7  
Do you have a fuel pressure gauge.

At 6psi with a 10:1 disk I was rich and leaned it out with an SAFC. I was also at 90psi of fuel pressure as well, which is not a good thing. You got to be at 100psi or more with a 12:1 disk....not good to run that high of fuel pressure.

I would suggest getting larger injectors before you try and go beyond 6psi.
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Sep 8, 2005 | 09:40 AM
  #8  
My friend has a 4th gen and he runs 9psi with just a 255 fuel pump, and a super afc. He blew his motor once when his boost spiked up to 12psi( he didn't know he was running lean because he doesn't have a wideband, and he still doesnt) He has been running this past year on 9psi without any problems, Im not getting any injectors right away either. I think I should be able to run 5-7psi with stock injectors, with a fuel pump and a super afc, as long as im tuned right. What do you guys think?
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Sep 8, 2005 | 09:53 AM
  #9  
Quote: My friend has a 4th gen and he runs 9psi with just a 255 fuel pump, and a super afc. He blew his motor once when his boost spiked up to 12psi( he didn't know he was running lean because he doesn't have a wideband, and he still doesnt) He has been running this past year on 9psi without any problems, Im not getting any injectors right away either. I think I should be able to run 5-7psi with stock injectors, with a fuel pump and a super afc, as long as im tuned right. What do you guys think?
I think that you can get a car to run and boost with limited fuel management... but it may be far from a good or safe tune. To run 9psi on stock injectors and just an SAFC is kinda crazy...the adjustments needed via the SAFC would be very very high. Has this guy ever seen his AFR's with this set up? How did he make his SAFC corrections...was he just guessing? Actually, the power one would normally make at 9spi is way outside the stock injectors capabilities. If he does not have the ability to increase fuel pressure with an FMU then his stock injectors are maxed out at about 250-260 whp. I my injectors were maxed out at 260whp and trying to add fuel with an SAFC at that point is unless because it can't be done. With a decent set up and everything working properly, 9spi should be 300-320 whp...way outside what stock injectors and an SAFC can handle.

You are gonna need to add an FMU and a fuel pressue gauge to your set up. You could add the FMU and even forget about the SAFC actually. Use the FMU to bring the AFR's down to a resonable point and use the SAFC to fine tune the AFR's.
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Sep 8, 2005 | 11:53 AM
  #10  
Quote: I think that you can get a car to run and boost with limited fuel management... but it may be far from a good or safe tune. To run 9psi on stock injectors and just an SAFC is kinda crazy...the adjustments needed via the SAFC would be very very high. Has this guy ever seen his AFR's with this set up? How did he make his SAFC corrections...was he just guessing? Actually, the power one would normally make at 9spi is way outside the stock injectors capabilities. If he does not have the ability to increase fuel pressure with an FMU then his stock injectors are maxed out at about 250-260 whp. I my injectors were maxed out at 260whp and trying to add fuel with an SAFC at that point is unless because it can't be done. With a decent set up and everything working properly, 9spi should be 300-320 whp...way outside what stock injectors and an SAFC can handle.

You are gonna need to add an FMU and a fuel pressue gauge to your set up. You could add the FMU and even forget about the SAFC actually. Use the FMU to bring the AFR's down to a resonable point and use the SAFC to fine tune the AFR's.
He has no air/fuel gauge so he has no idea what his ratio is.

I can't use a regular fmu remember, my vq35 is fuel returnless, I will need an electric fmu.
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Sep 8, 2005 | 10:20 PM
  #11  
Quote: He has no air/fuel gauge so he has no idea what his ratio is.

I can't use a regular fmu remember, my vq35 is fuel returnless, I will need an electric fmu.
That is the most retarded thing I have read on here. 9psi with just an SAFC and has no idea what his AF ratio is....
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Sep 9, 2005 | 06:57 AM
  #12  
Quote: That is the most retarded thing I have read on here. 9psi with just an SAFC and has no idea what his AF ratio is....
I tell him to buy a wideband, he doesn't want to spend the bucks. My other friend has a turbo altima, and he uses a super afc on 12psi. I dunno, I don't want to blow up so im going to make sure I can monitor whats going on with my motor, instead of running lean and not knowing it, and the next thing you know.....BOOM!
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Sep 9, 2005 | 07:13 AM
  #13  
Quote: I tell him to buy a wideband, he doesn't want to spend the bucks. My other friend has a turbo altima, and he uses a super afc on 12psi. I dunno, I don't want to blow up so im going to make sure I can monitor whats going on with my motor, instead of running lean and not knowing it, and the next thing you know.....BOOM!
I don't see how people do it, you have got to know what you are running so you don't go too lean, what's more a wideband or a new motor+downtime and labor to swap?
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Sep 9, 2005 | 09:43 AM
  #14  
Quote: I don't see how people do it, you have got to know what you are running so you don't go too lean, what's more a wideband or a new motor+downtime and labor to swap?
I try to explain that to them, but they don't listen. When my car runs better than their's I guess they will know why, Tuning.........
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Sep 9, 2005 | 11:31 AM
  #15  
Quote: I try to explain that to them, but they don't listen. When my car runs better than their's I guess they will know why, Tuning.........

Got any pics of these turbo 4th gens?
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Sep 9, 2005 | 03:04 PM
  #16  
The guy wants to spend the bucks on turboing his car, swapping new motors in every year because he blows them, etc but doesn't wanna spend $300 on a simple wideband? Sounds like he's a smart guy...

I wanna know what the hell he's even bothering with the SAFC for though. What is he doing just putting in random numbers? Hmmm 33% here, 12% here, 49% here, 2% here?
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Sep 10, 2005 | 02:58 AM
  #17  
Quote: The guy wants to spend the bucks on turboing his car, swapping new motors in every year because he blows them, etc but doesn't wanna spend $300 on a simple wideband? Sounds like he's a smart guy...

I wanna know what the hell he's even bothering with the SAFC for though. What is he doing just putting in random numbers? Hmmm 33% here, 12% here, 49% here, 2% here?
LOL,yeah maybe guessing huh,NOTHING to monitor(WB or EGT),
Well,I know I'm pretty much close to max out the stock injector right now,but I want to run the stock injector for a little while and getting use to,that's why I ask did anyone know at what psi the stock injector max out.So when I'm ready to get bigger injector(maybe 555),Z 32 maf,I'm going to swap out the MEVI from the wife 96 at the same time,400-450 whp is my goal.
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Sep 10, 2005 | 04:01 AM
  #18  
Quote: LOL,yeah maybe guessing huh,NOTHING to monitor(WB or EGT),
Well,I know I'm pretty much close to max out the stock injector right now,but I want to run the stock injector for a little while and getting use to,that's why I ask did anyone know at what psi the stock injector max out.So when I'm ready to get bigger injector(maybe 555),Z 32 maf,I'm going to swap out the MEVI from the wife 96 at the same time,400-450 whp is my goal.
It is not a "psi" that they max out, it is a power level that they max out at, and that is dependant on what fuel pressure your running. I had them maxed out at 260 whp (5.5psi) and my fuel pressure was in the high 70's. But I still needed more fuel because I was a little lean. So I had fuel pressure bumped up to almost 90psi. So I was running 100% duty cycle at 90psi on the stock injectors at 5.5psi and making 260 whp.
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