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Thread: Vortec Head swap on my '92 TBI 350. Tuning questions.

  1. #31
    Fuel Injected! woody80z28's Avatar
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    I put a heavier spring in the stock regulator and made it adjustable. There's a how-to around somewhere...I think it was third-gen.org. I also went at the housing with a grinder so I can adjust the PSI without tearing it all apart. Here are a couple pics.



    80 Camaro Z28 - 550hp AFR 383 / T56 6spd (Holley HP EFI)
    91 Beretta "SS" - 260hp 3400 MPFI / HM282 5spd (7730/$A1) sold! for crazy money...but I miss it
    94 Silverado Z71 - 300hp Vortec 357 TBI / NV4500 5spd (7427/$0D) gone but not forgotten
    96 Beretta "T56" - 4.8 LS RWD swap / 6spd (0411/2156)
    01 Silverado 2500HD - stock Vortec 8.1 / ZF6 6spd (0411/8322)
    https://www.youtube.com/c/GEARHEADdezign

  2. #32
    Fuel Injected! devind's Avatar
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    What vacuum port are you using for the MAP?




    Disregard I got this post mixed up with another thread where the guy was having a flooding issue.
    Last edited by devind; 07-03-2013 at 05:38 PM.

  3. #33
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    Quote Originally Posted by woody80z28 View Post
    I put a heavier spring in the stock regulator and made it adjustable. There's a how-to around somewhere...I think it was third-gen.org. I also went at the housing with a grinder so I can adjust the PSI without tearing it all apart. Here are a couple pics.



    Mine is essentially adjustable as well, but the spring that came with the kit when i rebuilt my TB last year seemed shorter but stiffer. I have absolutely no clue what PSI the injectors are running at. I've had it hooked to a scanner and it kinda bounces between lean and rich at idle, so at least it's not only running lean.

    Does it matter what fuel pump I drop in it, as long as I have the stock FPR (with pressure raised up a bit)? What should I be looking to run as far as fuel pressure into the injectors, and how would I go about measuring it?

  4. #34
    Fuel Injected! woody80z28's Avatar
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    Quote Originally Posted by jdyates View Post
    Mine is essentially adjustable as well, but the spring that came with the kit when i rebuilt my TB last year seemed shorter but stiffer. I have absolutely no clue what PSI the injectors are running at. I've had it hooked to a scanner and it kinda bounces between lean and rich at idle, so at least it's not only running lean.

    Does it matter what fuel pump I drop in it, as long as I have the stock FPR (with pressure raised up a bit)? What should I be looking to run as far as fuel pressure into the injectors, and how would I go about measuring it?
    It doesn't matter as long as there is enough flow at the higher pressure and it's not so crazy that it overflows the stock return. I just know that the TPI pump works well and it's cheap. I plugged some specs in to a calculator online and came up with 20psi to support 300hp at 80%DC. I would think 18-20 would be the range you're looking for. I got an adapter from cfmtech for the fuel inlet fitting for a cheap gauge from Summit as you can see in the pic.
    80 Camaro Z28 - 550hp AFR 383 / T56 6spd (Holley HP EFI)
    91 Beretta "SS" - 260hp 3400 MPFI / HM282 5spd (7730/$A1) sold! for crazy money...but I miss it
    94 Silverado Z71 - 300hp Vortec 357 TBI / NV4500 5spd (7427/$0D) gone but not forgotten
    96 Beretta "T56" - 4.8 LS RWD swap / 6spd (0411/2156)
    01 Silverado 2500HD - stock Vortec 8.1 / ZF6 6spd (0411/8322)
    https://www.youtube.com/c/GEARHEADdezign

  5. #35
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    Quote Originally Posted by woody80z28 View Post
    It doesn't matter as long as there is enough flow at the higher pressure and it's not so crazy that it overflows the stock return. I just know that the TPI pump works well and it's cheap. I plugged some specs in to a calculator online and came up with 20psi to support 300hp at 80%DC. I would think 18-20 would be the range you're looking for. I got an adapter from cfmtech for the fuel inlet fitting for a cheap gauge from Summit as you can see in the pic.
    Does that adapter measure what is going to the injectors, or just what the fuel pump is putting out? And which TPI pump should I use? I was looking on Summit and there was one for about $50 stock replacement for a IROC.

  6. #36
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    Got some assembly done today. Got some brass barb fittings for the heater core hose and brake booster line, sealed everything up, and took the TBI and CTS off the old intake to put on the new one. The 1-1/2" carburetor studs I got to mount the TBI were too short, so I'm gonna pick up some 2" studs tomorrow, as well as a new thermostat and housing, and another set of head bolts. Next week on payday I'm gonna order the TPI pump like you guys are recommending, then hopefully she'll be on the road and kickin' hard! Assembly pics below.

    Old and new, WOW!


    New intake assembled:


    Comparing clearances, shouldn't have a problem with the stock hood :D


    All done, save for the new thermostat and housing:


    And pics of the old stuff, nasty! And no wonder why I was having EGR problems!



  7. #37
    Super Moderator dave w's Avatar
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    I'm wondering if there are any clearance problems with the 350 TBI throttle blades being able to open all with way with the adapter plate you are using?

    dave w

  8. #38
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    Quote Originally Posted by dave w View Post
    I'm wondering if there are any clearance problems with the 350 TBI throttle blades being able to open all with way with the adapter plate you are using?

    dave w
    Not at all. I imagine I would if it were a 454 TB with bigger bores, but so far they work great.

    EDIT: Without the adapter plate they would not clear, but it spaces the TB perfectly that they have just enough clearance to open fully.
    Last edited by jdyates; 07-06-2013 at 10:18 AM.

  9. #39
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    Alrighty guys, the 062 heads are on, and intake assembled and ready to be bolted on. Just need a new thermostat and housing, and a few hoses and clamps and i should be good to drive, while i get the Camaro fuel pump shipped to me.

    Two questions,
    1. Will the Camaro pump bolt right in in the stock one's place? No modifications?
    2. When buying it, which pump should I use? Off a '90 IROC 5.7?


    Also, who thinks they can whip me up a tune? Need EGR deleted and whatever else done to get her running tip top :)

  10. #40
    Fuel Injected! woody80z28's Avatar
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    Yes it will bolt right in and I think the 305/350 pump is the same but I ordered for a 350. And the PSI gauge shows what the injectors are seeing, and therefore their new lb/hr so you can set the spec in the tune.
    80 Camaro Z28 - 550hp AFR 383 / T56 6spd (Holley HP EFI)
    91 Beretta "SS" - 260hp 3400 MPFI / HM282 5spd (7730/$A1) sold! for crazy money...but I miss it
    94 Silverado Z71 - 300hp Vortec 357 TBI / NV4500 5spd (7427/$0D) gone but not forgotten
    96 Beretta "T56" - 4.8 LS RWD swap / 6spd (0411/2156)
    01 Silverado 2500HD - stock Vortec 8.1 / ZF6 6spd (0411/8322)
    https://www.youtube.com/c/GEARHEADdezign

  11. #41
    RIP EagleMark's Avatar
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    Quote Originally Posted by jdyates View Post
    Also, who thinks they can whip me up a tune? Need EGR deleted and whatever else done to get her running tip top :)
    This guy may be able to help...

    http://www.gearhead-efi.com/Fuel-Inj...1776-TBI-Chips

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  12. #42
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    Got the new pump and last few parts today! Went with a '90 IROC 5.7 pump. Gonna finish up assembly tomorrow afternoon and hopefully have the pump in by Friday afternoon. Thanks for all the recommendations and help guys, will post updated pics when I get to a computer!

  13. #43
    Super Moderator dave w's Avatar
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    Quote Originally Posted by jdyates View Post
    Also, who thinks they can whip me up a tune? Need EGR deleted and whatever else done to get her running tip top :)
    Remote tuning usually requires the vehicle owner to do data logging. How are you setup to do data logging? There are some AWESOME .adx files available here: http://www.gearhead-efi.com/Fuel-Inj...Information-42 (that are free)

    Remote tuning can be done in real time with "net meeting" software that will allow the remote tuner to have control of the vehicle owner's laptop using WiFi connection to the internet and an emulator.

    dave w

  14. #44
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    Quote Originally Posted by dave w View Post
    Remote tuning usually requires the vehicle owner to do data logging. How are you setup to do data logging? There are some AWESOME .adx files available here: http://www.gearhead-efi.com/Fuel-Inj...Information-42 (that are free)

    Remote tuning can be done in real time with "net meeting" software that will allow the remote tuner to have control of the vehicle owner's laptop using WiFi connection to the internet and an emulator.

    dave w
    Unfortunately, i dont even have an aldl cable. And my home internet is via satellite, pretty mich doesn't allow anything close to "live" to happen. Too slow. I wouldnt mind getting a cable, but i did a quick search once and only found one, like $80.

  15. #45
    Super Moderator dave w's Avatar
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    Quote Originally Posted by jdyates View Post
    Unfortunately, i dont even have an aldl cable. And my home internet is via satellite, pretty mich doesn't allow anything close to "live" to happen. Too slow. I wouldnt mind getting a cable, but i did a quick search once and only found one, like $80.
    On the topic of tuning a performance TBI engine, a few things pop up in my mind:
    Tuning is not low cost. - Increase the budget?
    Tuning is not easy. - The more you know about TBI will make tuning easier. More homework?
    Tuning is not quick. - It can take several maybe even dozens of data logs to get a good tune. My tool of choice is Microsoft Excel to do data analysis with.

    dave w

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