getting to know my sti
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This is a discussion on getting to know my sti within the New Member Hangout forums, part of the Community - Meet other Enthusiasts category; Heya everyone, I was just wondering if anyone knows the best shift rps to get max performince out of the ...

  1. #1
    Registered User AtomicBanjo's Avatar
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    Red face getting to know my sti

    Heya everyone, I was just wondering if anyone knows the best shift rps to get max performince out of the sti...I have a 04 sti 47000 miles got it 7 months ago, also when i am cruseing around at 60 mph at 4th or 5th gear and i decide to get on it a bit it moves like a turtle (is that boost creap?) i know the car has balls but at higher speeds i would think it could go from 60 to 100 like it goes from 0 to 60 mph is it my car or me lol , thanks for all your help

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    Administrator TheJ's Avatar
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    You have to understand how the whole small turbo engine works. You don't get instant crazy power, at lower rpms and/or high gears (cruising in 5/6th gear). The power builds extremely quick in the STi but if you want tons o' torque at low rpms, the 4 cylinder is usually not the best platform.
    Although you will not have the same power trying to take off from cruising in 5th gear as you would launching in first, it shouldn't really be "dog-slow" either. If you feel like there is a real problem, take it to a shop and ask them to look at it.

    For information on Boost Creep visit this THIS LINK and learn more.
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    Registered User AtomicBanjo's Avatar
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    (YBNormal07- On the stock system, you have backpressure in your exhaust line from the cat, resonator, muffler, and piping sizes. This works to keep the exhaust flow through the turbo to a rate that can be managed in conjunction with the wastegate.

    Once you remove these items and free up exhaust flow (reduce backpressure), your turbo now has more exhaust flowing through it at peak throttle than it did before. The wastegate is sized with the stock backpressure in mind. It now can't flow enough exhaust at peak pressure to slow the turbo down, leading to a slow buildup in peak boost pressure, otherwise known as boost creep. This ultimately leads to an overboost condition, usually exhibited by a CEL and fuel cut (your car suddenly lurches and dies or cuts out and back in at full throttle.....a horrible experience believe me!!!!)

    Oh i see i have a stock system so boost creap is not possable, I dont think there is anything wrong with the sti i just thought it might be faster at higher speeds but it makes sence what TheJ was talking about....((TheJ):You have to understand how the whole small turbo engine works. You don't get instant crazy power, at lower rpms and/or high gears (cruising in 5/6th gear)) I do have one more question about the stock turbo, is it a stage 1 ?? thanks for all your help
    Last edited by AtomicBanjo; 06-03-2007 at 08:24 AM.

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    Registered User abhiwan's Avatar
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    Quote Originally Posted by AtomicBanjo View Post
    I do have one more question about the stock turbo, is it a stage 1 ?? thanks for all your help

    The stages refers to the different levels of engine modifications that are done on the wrx

    Stage 1 commenly refered to just an ECU reflash

    Stage 2 is a downpipe and reflash

    Stage 2.5 is a vf34/vf39 turbo upgrade with supporting mods


    if i understand your question correctly, stage 1 as well as stage 2 are on your stock turbo.
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    Edit:
    Quote Originally Posted by abhiwan View Post
    The stages refer to generally accepted standards of the different levels of engine modifications that are commonly done on the wrx/STi

    Stage 1 commonly just an ECU reflash

    Stage 2 is reflash PLUS down pipe (to eliminate the cat right after the turbo).
    Basically yes.

    Note: The OP has an 04 STi so he wouldn't be upgrade to the vf39 (since it comes stock the 04 STi).
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    Registered User D0WNxSH1FT's Avatar
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    Quote Originally Posted by AtomicBanjo View Post
    when i am cruseing around at 60 mph at 4th or 5th gear and i decide to get on it a bit it moves like a turtle
    Is this your first manual car? You need to downshift. Downshifting will increase your RPMs and thus your torque will increase and the car will accelerate faster. At 60mph you are under 3,000 rpms. The VF39 will require you to press down on the gas pedal and get the rpm's up for the turbo to fully spool. Do you have a boost gauge?

    Quote Originally Posted by abhiwan View Post
    The stages refers to the different levels of engine modifications that are done on the wrx
    Stage 1 commenly refered to just an ECU reflash
    Stage 2 is a downpipe and reflash
    Stage 2.5 is a vf34/vf39 turbo upgrade with supporting mods
    Stage 1 = Reflash
    Stage 2 = Reflash + Downpipe (TBE)
    Stage 3 = Reflash + TBE + Larger Top Mount Intercooler
    Stage 4 = Reflash + TBE + TMIC + Larger Turbo (add fuel pump and injectors as needed)
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    Registered User AtomicBanjo's Avatar
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    Quote Originally Posted by D0WNxSH1FT View Post
    Is this your first manual car? You need to downshift. Downshifting will increase your RPMs and thus your torque will increase and the car will accelerate faster. At 60mph you are under 3,000 rpms. The VF39 will require you to press down on the gas pedal and get the rpm's up for the turbo to fully spool. Do you have a boost gauge?)


    Actually yes it is my first manual car owned but driven manual in the past.. yes a boost gauge came with the sti but i dont really understand it it just moves when i press the gas ... i can tell when i am at low rpms by looking at the boost gauge that the turbo seems to work harder but as far as -.5 -.1 0 .05 ,ect makes no sence to me on the gauge..... i have been looking at car comparison on the stock sti vs whatever and noticed that the sti has a big issue with understeering, is this a easy fix or a money pit? thanks for all your help
    Last edited by AtomicBanjo; 06-03-2007 at 03:20 PM.

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    Administrator TheJ's Avatar
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    Quote Originally Posted by TheJ View Post

    The stock boost gauges, on both my WRX & STi, measure in MPa. "MPa" is Megapascals (The pascal unit is named after Blaise Pascal, the eminent French mathematician, physicist, and philosopher noted for his experiments with a barometer. The name pascal was adopted for the SI unit newton per square metre by the 14th CGPM in 1971.)

    The conversion of Mpa into psi is basically: .10 MPa = 14.5 psi (Actually it's more like 14.503770000000001 psi, but 14.5 is close enough.). Or you could always just go to one of the many conversion calculators on the web like this one.

    As far as what it is going on when the gauge is moving... read here


    Book mark THIS PAGE and start doing a lot of reading from it.
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    Registered User AtomicBanjo's Avatar
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    TheJ you ROCK
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    Administrator TheJ's Avatar
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    Quote Originally Posted by AtomicBanjo View Post
    TheJ you ROCK
    Thanks. You may also want to bookmark THIS PAGE TOO as it is a good one.
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  12. #11
    Registered User D0WNxSH1FT's Avatar
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    Quote Originally Posted by AtomicBanjo View Post
    Actually yes it is my first manual car owned but driven manual in the past.. yes a boost gauge came with the sti but i dont really understand it it just moves when i press the gas ... i can tell when i am at low rpms by looking at the boost gauge that the turbo seems to work harder but as far as -.5 -.1 0 .05 ,ect makes no sence to me on the gauge.....
    Ok, when you are off the gas the boost gauge is negative or in Vaccum. when you press down on the gas pedal the dial moves to 0 and then to positive numbers. Every tick past 0 is building boost pressure. The turbo is spinning and putting more air into the engine. The lower the gear and higher the RPM the faster the turbo will spin and build more boost faster. So if you are in 5th gear and you floor it the car is at a low RPM and so it takes longer to build up boost. If you downshift the RPM's will increase and the turbo will spool faster and the car will go faster.

    You cant just put the pedal down and go, well you can, but it takes longer. In an automatic you put your foot down and after a second or two the car seems to randomly speed up...that is because the car downshifted for you. So now you have to manually do it. Now, I can floor my car in 5th and it builds enough boost and HP/TQ that I can pass people on the highway but if I need to do it very fast I will downshift to 4th or 3rd gear.

    You'll get the hang of it. The Sti is a very powerful car.
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    Administrator TheJ's Avatar
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    ^^Well put.
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