Wednesday, November 11, 2020

Widebody Bugeye Race Car Build - Part 1 - JDM EJ207

So, we’re like you.  We like cars.  We like project cars.  We also happen to like Subarus.  So, when we happened upon the opportunity to buy an ex-road-race Subaru race car project, we couldn’t resist.  Fully gutted and caged, lexan windows, wide-body – oh yeah.  We had to have it.  

That’s not to say it didn’t need….a little bit of work though...

So the story goes this car was built many years ago by a well known Subaru shop.  They built up this bugeye with some serious go fast parts, they gutted it, they caged it, and they made it real pretty-like.  They…may have raced it?  Not sure on that one. Then it got parted out and sold.  From there it basically languished in “project car hell” for many years.  Then it popped up for sale, kind of running, kind of not.  It needed a lot of love.  So we jumped at the opportunity to save this race car and bring it back to it’s former glory.  

How it showed up to us - barely running, lots of stock mis-matched parts, wiring nightmare...but with potential!

We got it with a bizarre combo of running gear and parts, and it was…not running well. It had stock parts from a number of different year cars, the wiring was a nightmare, and it wasn't tuned.  So we basically took the car all the way down to the bare chassis and started over. The valuable bits were the intact widebody, cage, and straight chassis with zero rust - everything else had to go. We were on a budget, so this wasn’t going to be an all out wild “money is no object” big-peen shop build.  We all know that a small budget project car turns into a big budget one…and starting as a big budget car would mean, financial ruin (cue tiger king meme).  We wanted to be practical about our approach and keep things fun but do-able.  

We also wanted our clients to see what is possible with a decent budget and a solid plan – and to showcase real-world recommended parts from our partners that we work with on a daily basis – Not one-off fancy billet pieces that nobody can afford. We recommend it, we use, and you can see the results. A track car that anyone could build on a reasonable budget.

Boom, let’s do this.

Old engine and trans out, cleaned up engine bay, new 6 speed in!

We will post a full mod list below, but the basics are as following:

-2005 STI running gear (transmission, rear diff, hubs, axles, Brembo brakes, suspension)

-JDM Version 8 EJ207 – Completely rebuilt with fresh King bearings, OEM piston rings, and refreshed heads

-Forced Performance Blue XR turbo

-HKS Equal length header and up-pipe, downpipe, and Hi-power exhaust

-Advanced Clutch Twin Disc clutch

-CSF Radiators Racing radiator and oil cooler

-ETS FMIC core and custom piping

The STI running gear will give us a proven 6 speed transmission and active center differential.  We will be running the DCCD controller to take advantage of the active center diff and the improved handling it provides.  The STi rear diff is not only strong, but also comes with a limited slip, and STi axles all around give us peace of mind.  The bigger 5x114.3 hubs can take more punishment than the stock 5x100 WRX hubs, and the Brembos are normally up to the task for stopping on most tracks (although they can overheat on big-boy tracks without proper ducting).  Coupling this all together will be a brand new ACT twin disc clutch.  Until now ACT has not offered a twin disc for Subarus, but that has changed!  We’ll be testing out this clutch on our Race Car as it is rated to hold over 1000hp and can take the punishment a track car will be dishing out.

The heart of the car is a JDM Version 8 EJ207 – Completely torn down and rebuilt with fresh King rod and main bearings, honed stock-sized cylinder bores with OEM pistons and new OEM rings. JDM stock pistons are more stout than their 257 brethren - the top ring land is much thicker and can handle more abuse. The heads were machined, performance valve job, all new seals, etc. The heads get clamped down onto RCM head gaskets with ARP studs to hold it all together. We'll be running more boost than a stock engine normally sees and the upgraded gaskets and studs will help to keep all that boost from sending the heads into space.

Performance oil pump via Roger Clark Motorsports - pressure relief has been shimmed and internal passages and gerotors de-burred and smoothed for the best possible flow.

So, Why not go with a "built" engine?  Well…that budget thing comes back to mind…But we also really wanted to see what sort of punishment a “stock” JDM V8 engine could take.  These 207s are stout, but a lot of times the imported engines are in questionable condition with unknown miles, and that can lead to problems.  Our rebuilt engine is basically factory new, so it will be a great test-bed in this car. We advocate the 207 engines as good swaps for single AVCS cars that need an engine as they generally do really well in racing/track applications due to the thicker cylinder walls, better rod ratio, and better oiling when compared to the USDM EJ257 engine.  Yes, we’ll be running AVCS to take advantage of it’s benefits through a stock JDM ECU.

Finishing it all out is all new OEM timing parts, with an HKS Fine Tune belt, an RCM upgraded oil pump, and Tomei adjustable lower cam gears.  
Why Tomei gears? 
Well the stock lower gears are plastic, and we have seen them crack and fail with age, so the all metal Tomei gears are beefy insurance against failure, plus they’re red and pretty so they got voted in.  We buttoned it up with a Fluidampr crank pulley, which should absorb any harsh harmonics and vibrations in the rotating assembly of the engine and help it to live a longer happier life. A Killer Bee cast aluminum oil pan, and upgraded oil pickup and baffle get bolted to the bottom of the engine – This will give us extra oil capacity and hopefully provide better oil pickup in track conditions.  We’ll be adding an oil cooler to add even more capacity and improved oil cooling as well (more on that later).

Moving outwards we bolted up an HKS equal length header and up-pipe, which we heat wrapped with DEI titanium wrap.  The equal length header is more efficient than the standard un-equal arrangement. It also sounds cool, kind of like one of those fancy rally cars you see Subaru so famous for.  The heat wrap will help to keep the rest of the engine bay from becoming a furnace AND it helps to keep the exhaust gasses moving quickly – which is what we want to spool up our brand new Forced Performance Blue XR turbo.  This turbo features the Xona Rotor ball-bearing billet housing and billet impeller wheel.  The FP Blue is well known for spooling fast and making power, exactly what we wanted with our 2.0 track car build.  The goal is about 400whp, on race gas – we want to limit power as it’s a stock engine after all and we want it to live!

The car will breathe through a Cobb Intake, and then through an ETS 3.5” FMIC core, with the charge pipe wrapped in gold foil heat-reflective tape.  The FMIC will keep the intake charger cooler and more consistent out on track.  To keep the engine cool we will be running a CSF racing all aluminum radiator – their patented “B-Tube technology” allows for more heat transfer over a similar surface area as compared to a traditional tube-and-fin radiator design – which is good – because that’s means more cooling in the similar sized package.  The name of the game with keeping a track car happy is keeping it cool -  engine coolant, oil, intake charge, brakes etc. – the cooler the car runs the better it will perform (within the optimal temp range of course).  Which is why we will also be running a CSF “Boss” bar-and plate oil cooler – the design is compact but engineered for maximum cooling and durability.  It features a dual-pass design and inlet/outlets on the same side, which is great for packaging and routing the lines to the sandwich plate we’ll use to install it.

Other details include:

-Hawk DTC70 aggressive track pads with slotted and drilled rotors

-Kartboy TiC Tallboy shift lever and Cobb knob

-Small diameter suede steering wheel

-Sparco Swift racing buckets with Racequip 5 point harnesses

-AEM gauges in center stack pod

-Enkei 17x10 wheels wrapped in Bridgestone RE-71 tires

-Vented hood

Completed car at Road Atlanta for testing.

Overall we are pretty excited for this build.  We have long wanted to put together a solid GD chassis track car with a JDM 207.  After some shakedown track events we may even look at doing some Time Trial events to see how it stacks up against some of the other sweet Subaru builds out there.

We’ll dive more into some of the above modifications, their uses, and how the car tunes and feels on track in our next installment – Plus Dyno results and our first track event, so stay tuned!

Mod List Continued:

  • V8 JDM EJ207 w/ AVCS and trans all OEM
  • Injector Dynamics 1050x's
  • Radium Engineering fuel rail and filter
  • TI Automotive 450 lph fuel pump
  • Forced Performance Turbochargers FP Blue turbo and turbo inlet
  • COBB Tuning SF intake and 3 port electronic boost control solenoid
  • Extreme Turbo Systems front mount intercooler core w/custom piping
  • Turboback exhaust w/ equal length header
  • AEM Performance Electronics 3.5 bar MAP sensor
  • iWire Wiring Services speed density harness w/ GM IAT sensor
  • CSF Radiators monster radiator 
  • Advanced Clutch Technology twin disc clutch
  • Sunoco Race 260GT 100 octane fuel
  • Tuned through opensource on the V8 JDM ECU with the Carberry ROM on full time speed density.
  • Tuned by Stew at  Rogue Art Tuning

Circuit Motorsports is a performance auto shop located in Orlando, Florida.  We specialize in performance upgrades, ECU tuning, engine builds, and fabrication.  If you are interested in performance upgrades or a full build consultation contact us today!

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