After digging around on NASIOC, I found a reputable source for the version 8 motor I’ll be using for my swap, JDM Racing Motors. They were great throughout the entire process – providing me with pictures, compression results, or anything else I requested so I could be certain the motor was in a condition I would be satisfied with. After a couple weeks of discussion, I finally splurged, and the motor arrived only 4 days later.
For anyone considering a JDM Subaru swap, I highly recommend JDM Racing motors (ask for Robert)
If your motor comes directly from Japan it will likely have low mileage; however, because you have it out, it wouldn’t hurt to do some preventative maintenance. I decided to do a few things on mine for peace of mind:
The right plugs to use are NGK 2667 BKR7EIX Iridium, gapped to 0.26″, as recommended by Clark Tuner on NASIOC (very reputable). The cheapest I have seen these are on Amazon… http://www.amazon.com/gp/product/B000GZAUX6
The oxygen sensors that come with your JDM motor may need replacement. Most of them will come with the wires cut, or they will be bent from rough handling during transport. The pre-CAT sensor from the version 8 JDM is located in the downpipe (just after the turbo) instead of the exhaust manifold like USDM cars. It is also impossible to find a JDM part number upstream sensor in the USA. According to Clark Tuner, the standard WRX oxygen sensor will work fine with the JDM ECU. The JDM and USDM post-CAT sensors are the same part number. These can easily be found on Amazon, considerably cheaper than from Subaru…
Timing belt kit
I have had good success with Gates for timing belt kits. They use OEM components for their bearings and tensioners – literally the same bearings you would get from Subaru. I opted for the Racing belt, due to the higher RPM requirements of the JDM motor. The best price I found for this kit was Rock Auto (www.rockauto.com) with a 5% coupon code I found on Google and free shipping.
NOTE: Gates sells a variety of timing belt kits. They all include the superseded bearing part numbers. I think the only difference between the WRX and STi timing belt kits is the water pump size, so the EJ257 kit is the one to go with. If you get a kit without the water pump like I did, be sure to purchase one of those from your Subaru dealer.
The downpipe is one part you can’t overlook in a version 8 swap (version 7 is not a problem). For some reason, Subaru decided to shorten the length of the twin scroll downpipe versus older JDM and all USDM exhausts. This leaves a few options for the swap:
1. Buy a full JDM exhaust
2. Buy a twin scroll flange and get it welded to a USDM downpipe
3. Buy a premade twinscroll downpipe in USDM length (rare)
I opted for option 2 because options 1 and 3 came out to be more expensive. My rolling chassis comes with a Speedtech catback exhaust system. In order to complete the exhaust, I contacted Chad @ Speedtech and he hooked me up with a 200 CEL high-flow cat downpipe with no flange so I wouldn’t have to cut it off before getting the twin scroll one welded on. Chad is a great guy and sounded pretty excited to hear what his system will sound like on a JDM setup. I highly recommended Speedtech for your TBE exhaust needs (www.speedtechexhausts.com).
OEM JDM downpipe compared to Speedtech Exhaust downpipe
Stainless Steel flange from IAPerformance (www.iaperformance.com). This part will be welded on by a fabricator at P&L Motorsports in Chicago.
Here you can see the difference in lengths between the JDM and USDM downpipes
Many enthusiasts know the weakest link in the Subaru oil system is the oil pickup. Killer Bee Motorsports has done quite well with their beefed up oil products, and their oil pickup is a great way to ensure longevity of your motor (http://www.killerbmotorsport.com/index_files/PartsList.htm). I went ahead and got their Windage tray as well for improved oil distribution.
My rolling chassis comes with an ACT full face clutch, so I decided to pair it with an ACT streetlight flywheel. I purchased mine from Import Image Racing (www.importimageracing.com) during their Memorial Day sale.
Rob at JDM Racing Motors also hooked me up with this version 8 gauge cluster so my redline will be correct. It also has a display to show the DCCD state. One thing to keep in mind is the readout will be in KPH instead of MPH. It can be converted by installing a chip to modify the signal to the gauge. I will likely just leave it in KPH and learn how to do math instead. It’s not bad when you think of MPH as base 5 and KPH as base 8. Use 25MPH (40 KPH), 50MPH (80 KPH), and 75MPH (120 KPH) as references and simply add or subtract sets of 8 to calculate the KPH value for a certain speed limit.