need perfomance advice

Discussion in 'GM Powertrain' started by towens, Jan 21, 2009.

  1. towens

    towens New Member

    hello all. im new here and i have 97 chevt suburban 4x4 , just had my motor replaced 5.7

    its now bored 30 over, 1.6 rocker, mild cam, and a few minor things done just dont remember
    but it seems i havent gained any more power than what i did when stock. all is NEW from the
    injectors to the oil pan, 100% new... was told maybe a power programmer or a new computer
    will let the motor release its potental. machine shop says that build should produce close to 350+ hp
    any suggestions...

    thanks in advance.
  2. tlperry68

    tlperry68 Epic Member 5+ Years 1000 Posts

    You should be pushing about 350hp or so. You might want to change the rear end to a lower gear ratio so you can feel the quick throttle response.
    Sure any programmer will help. Good luck.
  3. 04sierracrewcab

    04sierracrewcab Epic Member 5+ Years 1000 Posts

    welcome to the site!!:glasses:
  4. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    New motor but hows the transmission?
    Even without a power programmer you should feel some improvement with that build.
  5. black jack

    black jack Rockstar 100 Posts

    id suggest getting it tuned. sounds like you have the stock settings and by getting it tuned to all the mods you did it will liven up you truck. also do you have headers and good exhaust. if not id go lt headers.also like has been said a lower rear will help too.
  6. towens

    towens New Member

    the machine shop said it should be 350+ ... the exhaust is new from manifolds to the rear, high flow dual in / dual out cat and straight to the back. as for the rear end its still stock. transmission will be rebuilt this spring with torque converter from a zr1 93 vette, shift kit, clutchs, bands, etc. any suggestions on a good programmer or should i have a professional shop do tthis..

    thanks again. tim
  7. towens

    towens New Member

    any advice on a programmer? or should i have this done professionaly
  8. phoebeisis

    phoebeisis Epic Member 5+ Years 1000 Posts

    The extra power will only be at higher RPMs, so you really shouldn't notice it much around town where you rarely go over maybe 2700 rpms.
    Is the compression still stock-9.4 or so?

    Your mods are mainly higher RPM mods. The slight increase in displacement can slightly increase torque and HP at all RPMs, but it is just about 2% bigger-6 cubic inches-so it isn't much.
    The cam, 1.6 rocker arms, intake and exhaust mods are all things that increase higher RPM power. You probably don't make any more power at 3500 RPMs or so, and hotter cams usually give something up at lower RPMs.

    A change in gearing might be what you need-along with some computer type tuning.

    The stock motor is rated 250 hp,I think. 350 HP with just a cam (rockers are just "cam" also) intake and exhaust seems a little optimistic.

    GM claims 340 hp with their 383E stroker motor which has the increased displacement and a cam and slightly less than stock compression. The 340 hp are with stock intake and exhaust I assume.

    Run the RPMS up from 4500 to 5500-that is where you should feel your increased power. The computer/chip tuning should help-maybe a lot.

    You rarely get a free lunch-you should lose a bit at lower RPMs, but should gain at higher RPMS with your set up . If you get higher compression you can get the low RPM power back and maybe still run on 87 octane.

    Last edited: Jan 26, 2009
  9. 95CTburb19

    95CTburb19 Epic Member 5+ Years 1000 Posts

    If you have the cash I would get a custom tune. People seem to get more bang for their buck that way.
  10. vncj96

    vncj96 Epic Member 5+ Years 1000 Posts

    I would contact or give them all the specs and they can send you a new ecu that is updated and when you eventually get some other mods they can reprogram again for free or very small fee

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