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Swapping from an 87 3sge to an 89 3sge, what needs to change?

Discussion in '3sge' started by smoothinto2nd, Mar 22, 2014.

  1. smoothinto2nd

    smoothinto2nd Well-Known Member

    Hey guys,

    Pretty much as the title says.

    My 87GT-S's 3sge just started billowing smoke and the transmission has bad 5th gear pop out. I found a supposedly rebuilt 89GT-S's 3sge with a good transmission. I now am realizing that there are a few things that were revised like egr operation, and exhaust header. What else was changed, or more specifically, what will I need to change to get the 89 3sge in my 87 GT-S?

    Reading the thread just below this one and a few others I'm thinking I might need a different ECU too? Does that mean changing some wiring too?

    I'm planning on just capping the egr as the car is smog exempt now, so I'm not to worried about that.

    Any help would be awesome!
    Last edited: Mar 22, 2014
  2. smoothinto2nd

    smoothinto2nd Well-Known Member

    I was thinking. Can I just swap the delivery pipe and injectors to solve the possible ecu issues?

    Other than the EGR setup was anything different as far as ports and bolts go?

    So I guess the main difference ECU wise is the injectors, maybe the o2 sensor, and a egr temp sensor or something?

    I think I'd like to move my throttle body from my old engine to the "new" one as the "new" one is all gummed up.
  3. Stig

    Stig ST162 Guru Donated!

    1)What ECU issues? Swap the motor and it will work fine
    2)Bolts are the same, different heads have small differences in the inlet ports.
    3)No, different ECU's are programmed differently

    There are 3 types of head - early has no markings, GE has 1111-3360 on the exhaust ports, GTE has 1111-3380 on the exhaust ports.
    Best is the GTE head with GE cams fitted (better torque), for both n/a and turbo apps.
    You can use any of the above heads on any "S" type block

    Ditch the EGR if you can, clean or replace the TB.

    Not all AFM's are equal, try a few and you'll see what I mean. They can be adjusted but best performed by your tuner.

    EGR injectors (295cc) are bigger than non-EGR (246cc) - using the bigger injectors shouldn't make much difference - I use 315cc on my modded motor.

    The biggest difference is in the ECU - JDM (non-EGR) ECU makes 10-15 more HP stock. They are now hard to find.

    Use a gen2 GE exhaust header and 2.5in free flow - it's a huge improvement all through the range.

    There are no internal differences between 87-88 engines, only the few very early 86 motors (rare) show any differences.

    Be aware there is also a GT version - only difference was the pistons which are identical to Gen2 pistons. I believe these also came standard with GTE heads but hard to prove as many heads were swapped around over the years. Skimming your head/block and reboring will give more compression than these pistons, so be carefull or like me you will be stuck using 98+ RON fuel

    Check my car thread for more info & pics
    Last edited: Apr 25, 2014

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