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Vortec TBI stock tune ?

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Old Aug 30, 2009 | 03:21 PM
  #1  
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Vortec TBI stock tune ?

I have a 1996 vortec 305 engine and heads and i want to put a TBI intake on it , Will my 305 Vortec run with the PCM 16197427 with stock 305 prom chip and 305 TBI injectors and the TBI fuel pump 10 psi



Last edited by webcat; Aug 31, 2009 at 06:22 AM.
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Old Aug 30, 2009 | 06:45 PM
  #2  
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Re: Vortec TBI stock tune ?

u are gonna need the vortec intake. it should run, but not perfect.
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Old Aug 31, 2009 | 06:17 AM
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Re: Vortec TBI stock tune ?

I'm trying to put TBI intake on
here's what i got
stock Vortec 305
stock Vortec 305 heads
stock vortec cam
carb intake
adapter to mount my TBI
PCM 16197427--------------------------------for 1995 TBI 4l60e
stock 305 prom------------------------------for 1995 TBI
40 LB 305 injectors-------------------------for 1995 TBI
Stock TBI fuel pump 10psi-------------------from 1988 TBI

Do you think it would run with the stock prom chip ? What should i expect ?
I was thinking of getting a mail order chip , it may not work perfect but it probally would work better then the stock chip
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Old Sep 3, 2009 | 04:42 PM
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From: West-Central
Car: 91 Trans am
Engine: built 360 TBI
Transmission: built 700r4
Axle/Gears: 10bolt/3.23
Re: Vortec TBI stock tune ?

WOT you will probably be out of fuel by 2000rpm using 40lbs injectors with only 10psi FP.
A stock TPI fuel pump will allow you to bump the FP up to support way more hp, dataloging and tuning will be a must.
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Old Sep 3, 2009 | 05:30 PM
  #5  
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Re: Vortec TBI stock tune ?

Yea your right , i've been researching and it seems i need 65 lb cop car injectors with stock fuel psi or 55 lb injectors with 18 psi of fuel psi
Big problem is the tune , since i dont know how to burn chips i'll have to forget about this idea!

Last edited by webcat; Sep 3, 2009 at 05:33 PM.
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Old Sep 3, 2009 | 08:29 PM
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From: Hurst, Texas
Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: Vortec TBI stock tune ?

Originally Posted by thomas1976
WOT you will probably be out of fuel by 2000rpm using 40lbs injectors with only 10psi FP.
A stock TPI fuel pump will allow you to bump the FP up to support way more hp, dataloging and tuning will be a must.
The only thing is he has 55# injectors currently in the stock 305 as thats what ALL 305s had.
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Old Sep 3, 2009 | 08:41 PM
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Re: Vortec TBI stock tune ?

Hey 355 , check out my van
http://www.fullsizechevy.com/forums/...ortec-tbi.html
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Old Sep 4, 2009 | 04:22 AM
  #8  
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From: West-Central
Car: 91 Trans am
Engine: built 360 TBI
Transmission: built 700r4
Axle/Gears: 10bolt/3.23
Re: Vortec TBI stock tune ?

Originally Posted by Fast355
The only thing is he has 55# injectors currently in the stock 305 as thats what ALL 305s had.
I dident even know they still used tbi in '95, leave alone injector size.


Originally Posted by webcat
Big problem is the tune , since i dont know how to burn chips i'll have to forget about this idea!
You can find great support to dial in your set up here on tgo.

Last edited by thomas1976; Sep 4, 2009 at 04:26 AM.
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Old Sep 4, 2009 | 10:17 AM
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Re: Vortec TBI stock tune ?

So is this chart incorrect ? this is where i got the idea that 305 injectors are 40lb and 350 injectors are 55lb
so are 305 injectors 55lb and 350 injectors 61lb ?



Last edited by webcat; Sep 4, 2009 at 10:28 AM.
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Old Sep 4, 2009 | 12:13 PM
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From: Chasing Electrons
Car: check
Engine: check
Transmission: check
Re: Vortec TBI stock tune ?

The chart is wrong. Early 5.7l injectors are 61#/hr and the 5.0l injectors are 55#/hr. This is at 13 psi of fuel pressure.

Later 5.7l injectors are 65#/hr and 68#/hr.

RBob.
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Old Sep 4, 2009 | 12:16 PM
  #11  
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Re: Vortec TBI stock tune ?

Originally Posted by RBob
The chart is wrong.
RBob.
Ok , i wonder where this chart came from originally ?
Thanks for the clarification!
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Old Sep 4, 2009 | 04:25 PM
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From: Chasing Electrons
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Transmission: check
Re: Vortec TBI stock tune ?

Originally Posted by webcat
Ok , i wonder where this chart came from originally ?
Thanks for the clarification!
The chart originated on the diy-efi.org email list some years ago. Maybe back in '95 or '96? At that time the list server was supported by Ohio State. Lots of good info made the rounds to the DIY EFI folks with that list. We didn't always get it right, but we did get a lot of it right.

My biggest issue with that chart (and other early information) is how it ends up on so many other sites and they treat it as gospel.

RBob.
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Old Sep 4, 2009 | 05:25 PM
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Re: Vortec TBI stock tune ?

yea, it can really screw you up !
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