An Unexpected RX-7 Sleeper

We do not feature cars on our blog often, but when we come across something unique, we find it hard to resist. The car featured is owned by a long time friend of ours and has been a project in the works for a few years. It was put together slowly, with care, and everything was done "the hard way" in an effort to make it the very best that it can be. Assembly, fabrication, wiring, etc. was done in a cramped garage in Portland, Oregon. No high dollar tools or 2 post lifts were used. We are talking jack stands with poor lighting.  All custom parts were hand formed using small tools and whatever Harbor Freight had that could do the job. It is amazing that something so clean, unique, dialed, and fun could emerge from that garage.

The car is a 1985 Mazda RX-7. A very clean example that was bought locally and used as the host for a wild engine transplant. It sits on Enkei Bortex F17x7/R17x8 wheels with Toyo Proxes 4 tires.

The exterior is dent free and all the plastic trim is in perfect condition. Notice the custom decal that was made...

The front and rear brakes are directly off a Mistubish Evo 8. Not just the calipers, the complete brake system including the vacuum booster, brake master cylinder, and rotors. The calipers attach using custom fabricated brackets.  Each Brembo caliper was completely disassmbled, sand blasted, then powder coated silver and rebuilt by the owner. All new stainless steel hard lines were bent up by hand.

The super clean interior of the car keeps the totally 80's RX-7 vibe. Much effort went into making sure all factory gauges worked correctly with the new engine and stand-alone EMS. More on that part later. The seats are from a Lotus Elise and are mounted on custom fabricated brackets.

The driver's door panel features a unique touch. The owner hand stitched a new panel and while he was at it, he inset an aluminum "Franken Speed" plaque to play on the Frankenstein engine swap idea.

The underside is just as spotless and just as sorted as everything else. Poly bushings, aftermarket swaybars, Koni shocks, Ground Control coilovers, etc are all put to use keeping the chassis in check. All components were cleaned, powder coated and reassembled with fresh nuts and bolts. The rear differential is a limited slip unit from a GSL-SE, rebuilt by the owner. The 3" stainless steel mandrel bent exhaust was hand fabricated by the owner and exits through a discrete black Vibrant muffler.

A Nissan 240sx rack and pinion with power steering was retrofitted into the front of the car and is fully functional.

Now for the really fun part. When the forward hinged hood is openend, there is something that catches everyone off guard.  What is it?  Is that a....Nissan engine....? Why yes it is. A fully built turbocharged Nissan KA24DE. The short block was machined .040" over and put together using Wiseco pistons and Eagle rods and ARP fasteners. The head underwent hours and hours of hand porting (by the owner in his cramped garage) and received Brian Crower valve springs and oversized valves. The cams and titanium retainers are also from BC. The head was put back on to the block using large 11mm ARP studs.

Supplying boost is a Garrett GTX3071R turbocharger that sits on a custom fabricated stainless steel Schedule 40 tubular manifold (made by the owner) and uses a water cooled Tial 44mm external wastegate fully plumbed into the cooling system using stainless steel hard lines.

The owner sanded down the TWIN CAM 16 VALVE  lettering on the stock valve cover then welded on a laser cut plaque and sanded that smooth. The valve cover was then airbrushed and clear coated. Custom hand-bent stainless steel fuel lines feed the modified AEM fuel rail and ID 1000 injectors. Notice the hand made gussets on the intake runners, those aren't stock.

The aluminum intercooler piping was also all hand fabricated and feeds the Xcessive Manufacturing intake manifold and Nissan/Infiniti Q45 throttle body. Maybe this is a good time to mention the car has working cruise control. The intercooler is a modified unit from a Evo 8 and sits stealthly behind the bumper and under the car. The engine also features an Xcessive Manufacturing cast aluminum large sump oil pan, which incorporates their windage tray and crank scraper.

The owner hand-made the strut tower brace from scratch as well. Under the engine is a matching chassis brace.

Built into the strut brace is a a hydraulic engine torque damper, you would not even see it if you weren't looking. The car uses an OEM RX-7 radiator and an electric fan. The car was converted from distributor ignition to individual coils using GM LS2 coils, mounted out of site in the cowl by the windscreen wiper linkage.

A set of Radium Engineering oil catch cans were used to tackle the blow by gasses present in any turbo engine.

A Radium fuel surge tank and first generation fuel pressure regulator were also used. Notice the custom hand bent stainless steel hard line feeding the engine bay mounted surge tank. Those stainless hardlines run the length of the car.

The Infiniti Q45 remote-mount throttle body cable pulley system was adapted and incorporates electronic cruise control.

The engine is controlled with an AEM Series 2 EMS, tuned by John Reed Racing. The car makes 400whp at 16psi of boost on pump gas (92 octane). The plan is to eventually run race gas in an attempt to hit the 500whp mark.

The owner has driven the car to Southern California and back and drives locally on a regular basis. The brakes work very well and are quiet and smooth with a firm pedal. Power comes on smoothly and linear all the way to redline. It idles perfect, starts up instantly, and overall is a pleasure to drive on the street. Doing everything the hard way seems to have paid off on this build.

See more pictures at our Flickr Gallery HERE.

New Product Release: FST-R....Two parts in one!

Radium is proud to release the first ever fuel pressure regulated surge tank. The innovative FST-R (Fuel Surge Tank - Regulated) is a fuel surge tank that houses a single internal fuel pump and has a fuel pressure regulator integrated in the top cap. This revolutionary idea eliminates the need for an external regulator along with the extra hoses and fittings associated with it.

This setup offers multiple benefits:
1. Reduced overall system cost
2. Reduced fittings resulting in less potential leak/failure points
3. Reduced hoses resulting in a lighter FST system
4. Reduced fuel temperature from the elimination of fuel returning from the engine bay
4. Quicker, easier, and cleaner installation

The FST-R is machined from 6061 Aluminum and like all Radium Engineering products, it is fully anodized and compatible with all fuel types.

The integrated fuel pressure regulator has all the features of a market-leading regulator. The output pressure is adjustable using the screw on the top cap. It is also capable of 1:1 vacuum reference by securing a vacuum hose to the nipple on the top.

The clean and compact package does not add significant size to the Radium fuel surge tank. The regulated output port is located on the side of the cap.

Shown above with an AEM 50-1200 E85 compatible fuel pump.

Inside the surge tank, many of the popular fuel pumps we currently supply can be used including: AEM, Walbro, Deatschwerks, and Aeromotive. At this time, the FST-R can only hold a single fuel pump. If a dual pump surge tank is needed, please see our other surge tank offerings:

The regulator features interchangeable orifice sizes to match the output of different pumps.

When purchased with a pump, the FST-R will come fully assembled and pressure tested. Radium assembles the FST-R with the properly sized orifice for the pump. Two extra orifices are provided should the user ever decide to change pump.

A fuel pressure gauge/sensor should be installed on the high pressure output line (or fuel rail) to adjust the regulator. The Radium Fuel Pressure Gauge is perfect for this duty.

This FST-R works by converting to a returnless dead-end system. Unlike a "returning" fuel system, fuel sent to the fuel rail(s) is not returned back to the fuel tank. See the diagram below which shows the difference between a returning and a dead-end system.

One of the benefits of a dead-end system is that fuel heated by the engine is not circulated back to the surge tank or main fuel tank. This keeps heat out of the fuel system. Most modern vehciles use a dead-end fuel system for this reason and for improved EVAP emissions.

Is fuel flow restricted or fuel delivery "uneven" in a dead-end system? See the picture below of Dean Kearney's Formula Drift Viper which utilizes a dead-end system. Notice the FPR mounted in the image. This car runs a single -8AN hose up to feed the 1,000+Hp engine.

Radium also has extensive experience with E46 BMW fuel systems for S54 (inline-6) engines making over 1,000whp. BMW is one of many manufacturers that use dead-end fuel systems.  Radium also successfully runs a dead-end system on their turbocharged Lotus Elise. 

Radium's Lotus Elise running a prototype FST-R and dead-end fuel system. The OEM Lotus (and Toyota) fuel system is returnless as well.

Please feel free to contact Radium Engineering with any questions about your fuel system needs:

The RADIUM FST-R is in stock and ready to ship, see details here:

VIDEO: JTP Drifting the Radium Turbo Elise

Here is a test and tune session with Portland Speed Industries at an abandonded lumber mill in Packwood, Washington. Our long-time friend, Pro Drifter Justin Pawlak (JTP) was on hand to give our car a good work out. He did very well putting on a show despite several characteristics that make the Elise a less than ideal drift car.

More information on this event can be found here.

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