We used a Sawz-All to hack off the offending tranny mounting hole.
Engine installation
There are no special instructions for removal of the stock B3 engine. Yank that sucker out of there and spend the hour it takes to thoroughly clean the engine compartment. You want to install the B6T engine harness while the bay is empty. You're best off replicating as closely as possible the exact location of the harness, connectors and connected items in the donor engine compartment. If that isn't possible, copy ours. After cleaning and, most likely, some quality time with a spray can, you'll have to find a place to pass the Mazda wiring harness through the firewall.
The B6T installs quite easily-we needed only to trim the passenger-side transmission mount, flip it and install a flat engine mount adaptor plate from CWS Tuning. Well-illustrated instructions for trimming and installation are found in the "Festiva B6T" portion of its Website, www.cwstuning.com. Otherwise, all stock engine and transmission attachment points are used.
Now is the perfect time to upgrade to more capable engine mounts, like those sold by Festiva Motorsport. The rubber seems to be of a harder durometer, and there's a good bit more of it, meaning engine movement will be better controlled.
The CWS motor mount adaptor bracket requires that you flip the stock B6T mount upside down
Exhaust
You can reuse the stock downpipe if your B6T came so equipped, and make a custom exhaust from there. Hotshot Performance is using our car to fabricate a larger diameter downpipe and mandrel-bent exhaust system speicifcally for B6T-powered Festivas, which will be addressed in a future installment of Project Festiva.
Intercooler
The stock B6T intercooler, which mounts in front of the turbo, can be used if you trim the hood reinforcements and shorten the attached rubber hoses. Another popular choice is the intercooler from the '88-'92 Probe GT and Mazda MX-6, as they're fairly efficient and readily available from junkyards. Hotshot Performance is prototyping a front-mount intercooler kit with piping on our car.
Wiring
As the art of the Fastiva is fairly new, a number of wiring schemes have been employed to make the swap work. What we did is very simple and we know it to work well. Procure a service manual, multi-meter and requisite wire working tools and you will be fine. You will use both the stock Festiva harness and the B6T engine harness in parallel. The Festiva engine portion of the harness (the Festiva harness is all one piece) will continue to be used to handle functions like alternator, temperature gauge, oil pressure light, reverse lights, electric fan control and starter wiring.
The B6T is happy dropping in from the top, and having an extra person to tilt the engine f
The rest of the plugs, like airflow meter, ECU temperature plug, idle air valve and injector harness, you simply don't use. You can bundle it and leave it in the engine compartment, which we did, or snip it and insulate the amputated branches of the harness. The B6T engine harness runs everything else engine related. The Festiva ECU, mounted behind the speedo cluster, is difficult to get to. We just unplugged ours and left it in place.
There are minor differences between JDM, Capri, 323 GT and 323 GTX harnesses, but no one has laid them all out side-by-side, so we don't know exactly what all the differences are. You may have to do some junkyarding for connectors like we did. You should check that the constant, starter and ignition wires are correct with a test light at the column of your Festiva to make sure everything is kosher, as the wiring colors changed from year to year. The colors we list, however, should be representative of the majority of cars produced.
If you're nabbing the engine and wiring from a junkyard, remember to grab everything attached to the harness. You'll need the B6T knock box, ECU, airflow meter, ignition coil, MAP sensor, altitude sensor, main relay and the circuit opening relay. Either the Festiva or B6T alternator will work, although the B6T unit provides 10 more amps and is the obvious choice.
Remember the Festiva has an optional tach, so you may have to wire in an aftermarket unit.
The following is a simplified list of the electrical connections that need to be made:
* The ignition power, starter power and constant power wires cut from the same dash terminus plug on the B6T harness need to be run to the ignition power, starter power and constant power wires on the Festiva column.
* The fuel pump wires cut from the B6T dash plug are joined and run to the Festiva fuel pump relay wire.
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This is the B6T dash harness plug, which is the only interface between the Festiva and B6T
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You must take power from the Festiva ignition switch to power the B6T harness. The black/y
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If you use a Capri harness, then ignition power, constant power and tach signal will be in
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That green/yellow Festiva fuel pump relay wire can be found here, under the driver's side
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The two fuel pump wires from the B6T dash harness, both colored green/red, splice to the g
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The black/white and blue/red ignition power wires cut from the B6T dash harness are splice
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A black/red wire is cut out of the B6T dash harness and run to the Festiva column, where y
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You need to use the B6T fuel pump relay, which plugs into the B6T harness. Tuck it somepla
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The Capri XR-2 distributor six-pin plug and the 323 GT harness six-pin plug do not like ea