LT1 32 lb/hr Upgrade Injectors
04-19-2005, 03:38 AM
#62
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Re: LT1 32 lb/hr Upgrade Injectors
Originally Posted by BigJustinZ28
would these help my setup ??? are my stockers insufficient ??? car is in sig
The only way to tell is with a scan tool, fuel pressure gauge and an A/F meter.
04-19-2005, 03:54 AM
#63
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Posts: 151
Re: LT1 32 lb/hr Upgrade Injectors
30# injectors is fine for 450FWHP, and up to 535hp(MorePerformances 396LT1 with Cranes version of the 847 cam used 30#'s). I am using 30#'s on my 396LT1 and they were running just fine with Hot Cam, putting around 400rwhp. And thats with leaning the fuel pressure down.
And now with my XE 230/236 cam, they ar just fine.
Just my 2 cents worth.
And now with my XE 230/236 cam, they ar just fine.
Just my 2 cents worth.
04-19-2005, 03:56 AM
#64
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Re: LT1 32 lb/hr Upgrade Injectors
Originally Posted by vette40th
30# injectors is fine for 450FWHP, and up to 535hp(MorePerformances 396LT1 with Cranes version of the 847 cam used 30#'s). I am using 30#'s on my 396LT1 and they were running just fine with Hot Cam, putting around 400rwhp. And thats with leaning the fuel pressure down.
And now with my XE 230/236 cam, they ar just fine.
Just my 2 cents worth.
And now with my XE 230/236 cam, they ar just fine.
Just my 2 cents worth.
04-19-2005, 04:35 AM
#67
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Re: LT1 32 lb/hr Upgrade Injectors
Originally Posted by vette40th
I run 42#'s of pressure with vacuum disconnected. The duty cycle hovers around 85%
Fuel injector requirements = [Peak HP x BSFC / Duty Cycle / # of Injectors]
If you got 520hp at flywheel;
520 x 0.5 / DC / 8 = 30# injectors (if your fuel pressure is stock pressure 43.5psi)
260/240= 1.083!!!! Your duty cycle is over %100 if you are using 30lb injectors with 43.5lb fuel pressure at 520hp flywheel..!
You definitely should use 37lb injectors..!
If you put 37lb into the formula you will see your duty cycle will be arond %86-87 ,and its good..
Last edited by JustNO; 04-19-2005 at 04:37 AM.
04-19-2005, 11:09 AM
#69
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Posts: 151
Re: LT1 32 lb/hr Upgrade Injectors
Well, its all in the tune guys, cause my TTS Datamaster shows it hangs around 85%. Sorry, but the computer tells me that. I have 30# SVO injectors( arent SVO injectors rated at different PSI), run a GNX fuel pump, and have 11.1.to 1 comp, 396, XE 230/236 cam.
Believe what you want, and I will stick to what works in my car.
Maybe the formula is wrong. Let me go research this "formula"
Believe what you want, and I will stick to what works in my car.
Maybe the formula is wrong. Let me go research this "formula"
Originally Posted by JustNO
its impossible with 42 psi pressure.. I write the formula:
Fuel injector requirements = [Peak HP x BSFC / Duty Cycle / # of Injectors]
If you got 520hp at flywheel;
520 x 0.5 / DC / 8 = 30# injectors (if your fuel pressure is stock pressure 43.5psi)
260/240= 1.083!!!! Your duty cycle is over %100 if you are using 30lb injectors with 43.5lb fuel pressure at 520hp flywheel..!
You definitely should use 37lb injectors..!
If you put 37lb into the formula you will see your duty cycle will be arond %86-87 ,and its good..
Fuel injector requirements = [Peak HP x BSFC / Duty Cycle / # of Injectors]
If you got 520hp at flywheel;
520 x 0.5 / DC / 8 = 30# injectors (if your fuel pressure is stock pressure 43.5psi)
260/240= 1.083!!!! Your duty cycle is over %100 if you are using 30lb injectors with 43.5lb fuel pressure at 520hp flywheel..!
You definitely should use 37lb injectors..!
If you put 37lb into the formula you will see your duty cycle will be arond %86-87 ,and its good..
Last edited by vette40th; 04-19-2005 at 11:17 AM.
04-19-2005, 06:05 PM
#70
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Re: LT1 32 lb/hr Upgrade Injectors
Originally Posted by vette40th
Well, its all in the tune guys, cause my TTS Datamaster shows it hangs around 85%. Sorry, but the computer tells me that. I have 30# SVO injectors( arent SVO injectors rated at different PSI), run a GNX fuel pump, and have 11.1.to 1 comp, 396, XE 230/236 cam.
Believe what you want, and I will stick to what works in my car.
Maybe the formula is wrong. Let me go research this "formula"
Believe what you want, and I will stick to what works in my car.
Maybe the formula is wrong. Let me go research this "formula"
04-19-2005, 06:35 PM
#71
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Join Date: Jul 2001
Posts: 151
Re: LT1 32 lb/hr Upgrade Injectors
Tried to help me? My injectors work just fine, , If it aint broke, dont fix it. and allot of people run 30#'s.
I think the big variable is BSFC, Some cars are more efficient than others. Look at ignitons, compression, manifold design headers. They all make the BSFC change , VE efficiency is important too.
Call LPE, MTI MorePerformance, etc to see what they recommend for a 500 hp, flywheel, engine
I think the big variable is BSFC, Some cars are more efficient than others. Look at ignitons, compression, manifold design headers. They all make the BSFC change , VE efficiency is important too.
Call LPE, MTI MorePerformance, etc to see what they recommend for a 500 hp, flywheel, engine
04-19-2005, 07:04 PM
#72
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Re: LT1 32 lb/hr Upgrade Injectors
Originally Posted by vette40th
Tried to help me? My injectors work just fine, , If it aint broke, dont fix it. and allot of people run 30#'s.
I think the big variable is BSFC, Some cars are more efficient than others. Look at ignitons, compression, manifold design headers. They all make the BSFC change , VE efficiency is important too.
Call LPE, MTI MorePerformance, etc to see what they recommend for a 500 hp, flywheel, engine
I think the big variable is BSFC, Some cars are more efficient than others. Look at ignitons, compression, manifold design headers. They all make the BSFC change , VE efficiency is important too.
Call LPE, MTI MorePerformance, etc to see what they recommend for a 500 hp, flywheel, engine
04-19-2005, 07:10 PM
#73
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Re: LT1 32 lb/hr Upgrade Injectors
You can easily see that 1-2 days before I was thinking same as you.
Originally Posted by JustNO
Hi Racetronix I got an important question for you;
I built a 383ci LT4 with 210cc AFR Competition Heads.. I use your complete fuel system.. I want to ask you about injectors. People said to me that I should use 30lb injectors. But now I read this thread ,and I'm totally #### ! because I have 550hp at flywheel,so is it not enough "lb" for injectors??? Its a daily car,not a race car,nor a drag car..
I built a 383ci LT4 with 210cc AFR Competition Heads.. I use your complete fuel system.. I want to ask you about injectors. People said to me that I should use 30lb injectors. But now I read this thread ,and I'm totally #### ! because I have 550hp at flywheel,so is it not enough "lb" for injectors??? Its a daily car,not a race car,nor a drag car..
Originally Posted by Racetronix
You will need 42# minimum to maintain 80% injector DC on a N/A 550FWHP motor.
Originally Posted by JustNO
Minimum 42#??????? What are you talking about? There are a big size difference between 30# and 42# !! I repeat, this is a highly modified street car,not a race car. Do you approve your reply? Beacuse if you do I will change that..
thanks
thanks
Originally Posted by Racetronix
The application is irrelevant (street /track). The FWHP is!.
To make 550 N/A @ 80% DC @ 43.5PSI that is what you will require.
Do the math!
The other question is what is the problem with 42's. Heck that is a small injector. TR's and imports run 60's with factory type mileage and drivability. Its all in the tune! Why do so many V8 owners subscribe to the just enough or not enough theory. This is not like picking a carb jet.
You can use this vendor's page if you wish: http://www.rceng.com/technical.htm
To make 550 N/A @ 80% DC @ 43.5PSI that is what you will require.
Do the math!
The other question is what is the problem with 42's. Heck that is a small injector. TR's and imports run 60's with factory type mileage and drivability. Its all in the tune! Why do so many V8 owners subscribe to the just enough or not enough theory. This is not like picking a carb jet.
You can use this vendor's page if you wish: http://www.rceng.com/technical.htm
04-19-2005, 07:10 PM
#74
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Posts: 151
Re: LT1 32 lb/hr Upgrade Injectors
JustNo, what pressure are you going to run? LT1's run around 42-43?+-. 58psi is way out of range, granted you can run it, but why? I think staying within the range of the injectors intended rateing is where we should stay.
04-19-2005, 07:22 PM
#75
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Re: LT1 32 lb/hr Upgrade Injectors
"According to formula";
If I go with 42lb injectors (which is too high for me) I should go with 43.5psi fuel pressure..
If I go with 37lb injectors (that will be my choice) I will go with 58 psi fuel pressure to keep duty cycle at around %80-85.
Also I talked with racetronix ,and they told me their disc injectors can handle max 80psi.. So 58 psi is normal pressure. (not hurt the injectors)
BTW: I learned all of things yesterday,and I'm totally confused ,but racetronix have a major experince and knowledge about this off course,so I will go according to formula.
If I go with 42lb injectors (which is too high for me) I should go with 43.5psi fuel pressure..
If I go with 37lb injectors (that will be my choice) I will go with 58 psi fuel pressure to keep duty cycle at around %80-85.
Also I talked with racetronix ,and they told me their disc injectors can handle max 80psi.. So 58 psi is normal pressure. (not hurt the injectors)
BTW: I learned all of things yesterday,and I'm totally confused ,but racetronix have a major experince and knowledge about this off course,so I will go according to formula.