legacycentral bbs

I installed my hybrid build this saturday, and when it came time to plug it all in I realized the 20g manifold doesn't match my car. The car (93ss) has 3 plugs by the battery. 2 are square and one is round. Then it has a few connectors on top of the transmission (knock, cam, crank sensors?) The 20g manifold has the 2 squares by the battery that plug in, but no round, and it has one square connector by the transmission. also, the manifold uses the cam/crank/knock sensors that plug in to the harness, not the ones with their own wires like the 93 had.

the harness on the manifold may have been merged with a 1996 OBS, but I am not sure.

what's my best plan of action to get this thing running?

thanks!

I'd recommend using the harness that matches the chassis or merge the two harnesses together. There's not a simple solution, but maybe someone else has some suggestions.

The simplest way to get it working is to use your 93 ss intake manifold harness. That's what most of us with the dohc build did.

You can use the 93ss cam and crank sensors on the hybrid build too.

I used the newer style crank sensor on mine and made my own harness out of a broken crank sensor w/ wire attached and a fuel injector plug. Worked just fine. I would assume the same can be done for the crank sensor.

So to use the 93ss harness you bought the ignition converter from
robtune? I was attempting to use the COP ignition.

Either way you need the harness that fits the car. Along with adding in any wires you need and or lengthening/shortening wires. For cop you need some wrx coil on plugs (20g cop require a seperate ignitor and they're old and crack) and you need to run 4 signal wires off the ecu and source power from your ignitor harness and groud them to the bolts that bolt the cops to the heads.

I didn't run the robtune ecu. I just used the factory ecu with twin turbo heads and intake manifold.

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The manifold has already been fitted and wired with the WRX coils. The problem is that I believe the PO of the intake modified it's harness to run in a 1996 Impreza along with the 20g ECU.

How did you control bigger injectors without the Robtune ECU?


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Its the common swap that was always done. The turbo ecu runs the jdm 440s just fine. The car runs rich with this setup. I had a vf39 and set at 18lbs for a couple years until my fuel cut defender crapped out on me. Then the turbo took a dump and i downgraded to a td04.

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Oh good to know. I'm running a td05h-16g. So I can just swap over the harness/coil pack from the 22t manifold on to the 20g manifold?


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Yes

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cj91legss wrote:The turbo ecu runs the jdm 440s just fine.

The engine may "run" with the 440's, but it's certainly not optimal, and I wouldn't recommend it as something to use long term.

I don't recall the knock sensor cam and crank sensor wires being attached to the manifold at all on my Touring Wagon or the 20G swap. Im pretty sure they came off the firewall/bulkhead harness and just ran around/under the manifold. The only change on the manifold was swapping the 20G harness for my 22T one, then replacing the wires that didn't reach with the longer ones from the 20G harness. Kimo covered he other changes I made to run the GD WRX coils. However, if you're using the 22T ECU I'm not really sure how you'd wire it in to run wasted spark off the 2CH system (maybe just tie together the signal wires for the front and rear pairs of coils?)

Legacy777 wrote:

cj91legss wrote:The turbo ecu runs the jdm 440s just fine.

The engine may "run" with the 440's, but it's certainly not optimal, and I wouldn't recommend it as something to use long term.

Had mine for almost 4 years. The car just ran a little rich all the time. However gas mileage was crap, 18mpg.

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cj91legss wrote:Had mine for almost 4 years. The car just ran a little rich all the time. However gas mileage was crap, 18mpg.

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How did it run in comparison to one that had the proper ECU?

James614 wrote:I don't recall the knock sensor cam and crank sensor wires being attached to the manifold at all on my Touring Wagon or the 20G swap. Im pretty sure they came off the firewall/bulkhead harness and just ran around/under the manifold. The only change on the manifold was swapping the 20G harness for my 22T one, then replacing the wires that didn't reach with the longer ones from the 20G harness. Kimo covered he other changes I made to run the GD WRX coils. However, if you're using the 22T ECU I'm not really sure how you'd wire it in to run wasted spark off the 2CH system (maybe just tie together the signal wires for the front and rear pairs of coils?)

The manifold I have already had the wiring on it swapped to plug in to a 1996 OBS but running the COP and 20g ECM.

I am in the process of swapping over my 22t wiring to the 20g manifold, except for the ignition coil, and then I'm going to wire in the COP To run with the 20g ECM.


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Josh, i only used the turbo legacy ecu. Never got around to using any of the 20g ecus.

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Legacy777 wrote:

cj91legss wrote:The turbo ecu runs the jdm 440s just fine.

The engine may "run" with the 440's, but it's certainly not optimal, and I wouldn't recommend it as something to use long term.

I can attest to using jdm 440s i have a wide band aswell they had been on my car for a while now before i got it yeah they dont run optimally and are definatley on the rich side i got about 14 mpg best with those injectors but i was running 12 psi on a td04 and it ran great under boost

I got 17 on stock ecu with 440s, vf39.

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