Naturally aspirated RX-7 FC. Frame-off restoration after been hit by a SUV. Converting to ITB intake system with Haltech standalone engine management system. Quest to ultimate NA power. (Profile pic by De Sousa S Photography)
Model code FC
Purchase date June 2010
Doors 2 Doors
Body type Coupe
Fuel type Petrol
Aspiration N/A (Normally Aspirated)
Engine size 1.3 Litres
Engine position Front Engined
Driven wheels Rear Wheel Drive (RWD)
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Engine & Transmission
- ---------- ENGINE ----------
- Full Function Engineering trigger kit with hall IC for 13B / Haltech compatible
- 98 Octane only
- 13B 6-port NA 1.3 liter rotary block
- High comp. 9,7:1 induction hardened rotors
- Lapped 6 port NA irons
- FD rotor housings
- Raceport (largest streetport)
- RX8 eccentric shaft & stationary gears (modified)
- Fully lightened / balanced / clearanced rotating assembly
- Ianetti 2 pc 2 mm ceramic Apex-seals
- FD oil pressure regulator (+- 100 PSI)
- Turbo 2 high flow oil pump
- Oil gallery modifications
- Large thrust washer assembly
- Painted engine (Gold / Cast iron)
- To come: Defined Autoworks tuned length header for the 6 Port 13B
- ---------- INTAKE ----------
- To come: EFI Hardware ITB velocity stacks
- To come: 6 port webber manifold (machined and extended to 50 mm ID)
- To come: K&N hotrod air filter assembly
- ---------- ECU ----------
- Haltech PS1000 Standalone ECU with wiring
- 2 x Injector Dynamics ID850 cc/min fuel injectors
- 4 x AEM IGBT coils setup for direct fire
- 8,5 mm MSD plug wires
- NGK NTK wideband sensor & AFX controller
- ---------- TRANSMISSION ----------
- Stock transmission and internals
- Mazdaspeed transmission mounts
- ---------- OTHERS ----------
- Zircotec heat insulation on div. parts
- Gilmer drive belt kit
- 5W30 probably Motul
- NO AC and PS (Manual rack conv.)
- RA 2 stroke OMP adapter & tank
- To come: Probably K&W custom made coilovers
- To come: Complete PU bushing set
- None -> racing interior
- Ronin Speedworks Widebody
- Ronin Speedworks GT wing
- Paint: Titanium grey 25G (Same as the Spirit R Mazda RX7 FD Spec A)
- In progress: Custom aero undertray
Stats & Figures
- Targeted "Power to weight ratio": 3,85 Kg/HP
Wheels & Brakes
- Vented & slotted Stoptech discs front & rear
- To come: VOLK TE37 bronze 18" 10,5" +15
Extras & factory options
- Factory Aero package
Planned future mods
- Thanks for not asking me when I'm done ...
- Newest first
- Oldest first
59 updates 19 followers 48 mods2013-09-28 14:38:56Removing some of the interior, AC blower and heater core are now gone. Steering column disconnected and front subframe ready for dropping :) I did all of that last week and the subframe bolts were pretty tough, I soaked them in wd40 but I doubt that will help. We will see
59 updates 19 followers 48 mods2013-09-02 00:26:46Now to the business end of the whole thing: V-mount radiator setup :) Ideal for high speed circuit driving with turbocharged cars, it will provide massive amounts of airflow to the engine radiator to cool any amound of heat this normally aspirated rotary engine can throw at it. With some luck I can even fit an oil cooler somewhere in front of the radiator, avoiding the dual side mounted oil cooler, reduced plumbing and less prone to leakage.
I like this radiator position. It will be fine tuned as soon as I get my hands on a welding machine and I can make some mounting tabs. There are still some rust spots and old sheet metal that needs to be taken care of before I can weld anything.
I layed out a provisonal v-mount opening on the stock aluminium hood. Its just a sketch to check how it would match with the overall design and widebody.
59 updates 19 followers 48 mods2013-09-02 00:13:17Looks much better now, even with the stock under tray installed and pressed firmly upwards, the radiator fits great.
59 updates 19 followers 48 mods2013-09-02 00:05:41To reach my goal I had to remove some of the front crossmember stuff, most of this stuff serves no higher purpose and can actually be removed.
There were a few crossmembers installed:
Front crash zone, connecting both frame rails together. (This one stays obviously) This one goes wide into the front bumper, it does not disturb airflow at all.
Lower bar, holding the oil cooler in place. This bar has already been removed, it was not structural since it was only held with 4 tack welds on each side. I will replace it with something better.
Middle crossmember holding various relays and wires in place. Provides the lower hood release mount. Has been removed.
Front crossmember, providing the upper mounting point for the front bumper. This one has been removed but will later be reattached with different air ducting.
Upper crossmember, providing the upper mounting point for the hood release. Removed.
Looks pretty mean without any crossmembers up front. You can see straight through the tunnel from front to the back.
59 updates 19 followers 48 mods2013-09-01 23:50:22Cooling version 3.0.
Yes I know, another change :) I was poking around under the hood to find the best radiator setup and experimented with various positions. In the end neither made me happy. They were either too low and therefore to close to the ground (imagine debris hitting the radiator) which is something I want to avoid.
From all, this is the position I liked the most, well it was not perfect but I was getting closer.
59 updates 19 followers 48 mods2013-07-04 20:59:05My race engine will now be installed into my 1987 FC (http://thrll.com/car/1987-mazda-rx7-12670) as this one needs a new engine right now. I thought it would be a great oportunity to install the race motor into a road legal car to get familar with it and give it a good break in period.
This might sound weird, but I will run it with the stock intake manifold (6 port) and exhaust system. Even the fuel injection will remain stock. I am not seeking to make any big numbers here, I just need an engine right now to get that car moving. The engine is drop in, as its practially the same block as the old one. So I can use the stock ECU and dizzy cap to run it. It won't make any more power than stock. (Which is not the goal)
The next step after break in and extensive test period will be to hook the haltech up to the motor and remove the stock ECU and dizzy. This allows me to start tuning the motor on a stock setup without risk. If this works out then I can test it with a true ITB velocity stack and maybe a completely new exhaus system to get up to power and unleash the full potential of the motor, making it ready to swap back into the white FC - ready to run. In the end it doesnt matter how the Haltech gets tuned to do its job.
59 updates 19 followers 48 mods2013-05-11 01:19:59Worked a bit on the engine, removed all the accessories and turned it over to get a new oilpan installed. I will order a pineapple racing oilpan pretty soon. 1 quarter more oil, baffled & finned sump and deairing plate is well worth the expense. Plus this pan doesn't use gaskets, its sealed, period. The motor actually looks pretty stupid with the stock pan ^^ If I put another engine side by side for comparison you wouldn't think that one is 10 times as expensive as the other by looking at it. It just looks plain stock now.
Plus I got some other parts delivered, RX8 plugs, clutch master/slave cylinders RacingBeat sandwich adapter for the oilfilter (not sure if I am gonne use it, if I can put my sensor somewhere else), mazdaspeed engine mounts and some minor stuff like freeze plugs for the rotor housings (mind you I got FD housings which have open external coolant passages, they will be shut close as there is no intake that makes use of it) Might be good time to order my flywheel and clutch assembly :)
59 updates 19 followers 48 mods2013-05-11 01:16:12
59 updates 19 followers 48 mods2013-05-06 19:59:38Cutting out the front oil cooler bar (8 spot welds to drill out). And then some of the side plates that hold the radiator in place.
59 updates 19 followers 48 mods2013-05-05 22:15:54A short drawing of the new radiator mounting. There will be some cutting and welding involved. A new undertray will be designed at the same time. unfortunately I cannot keep the plastic (stock) one as its to small, this would greatly limit the size of the radiator.
If everything goes as planned the new radiator will hold around 3,5 gallons of coolant (13,5 liters) ! Thats around the same volume a stock RX7 has in the entire system. Now, talk about cooling ! ;)
Engine & Transmission98 Octane onlyExteriorRonin Speedworks GT wing
59 updates 19 followers 48 mods2013-04-20 17:42:11The new radiator layout has been determined, 90 de standing radiator bolted to a solid frame. The frame requires custom working and cutting some of the sheet metal in front to make a 90 deg mounting possible. The bar underneath will be removed and replaced with the frame. it should be solid enough. New ducting will be done too. The main opening on the bumper is exclusively dedicated to feed the engine radiator with incomming air. The oil cooler will be split into 2 huge units mounted behind every brake vent opening.
59 updates 19 followers 48 mods2013-04-20 15:13:15
59 updates 19 followers 48 mods2013-04-14 23:13:29Going to switch over to an electric waterpump system instead of a belt driven engine mounted unit. Poorly engineered and fabricated OEM pumps is not the quality standart I am looking for. The remanufactured pumps aren't better. If you're lucky you might even get a working one ;) If you know me, then you know that I like to get things perfect, or near as perfect as reasonable possible.
Looking at the previously posted pictures I realized that I made a mistake when I initially planned my cooling system. I had various ideas and designs to improve the cooling system as the stock one is barely acceptable for a stock motor, but a no go if you are running a modified motor, let alone a racemotor ... Some of these ideas are actually pretty neat, but they were totally overkill for a naturally aspirated 13B. I still think they are worth a try if you seriously need cooling capacity. Finally I decided on a more classical method, much like the stock one but with some tweaks here and there and of course better hardware. Fuzzing all over radiator placement, sizeing and venting I did not realize the flow importance. The pump might be fitted with an underdrive kit to prevent cavitation at high rpms, but that is not going to solve the initial problem, that these pumps are old and not good designed. So now I am going over my coolant system again, and shortly I will present version 2.0 of it ;)
Besides having better flow characteristics (Actually an EWP operates with its maximum flowrate all the time, engine in idle or full load) they also allow for cooling down the car after a stop, which is pretty nice on a rotary. Just leave the pump and fan running a few minutes after engine shutdown ;) After looking at the pro/cons of each design, I choose the electrical water pump design (EWP).
Switching to EWP requires some changes to my initial plan, the custom made aluminium crossflow radiator will be ditched. I need to cnc machine an adaptor that fits on the engine block for the feed/return line. I already have a brand that looks promising in terms of reliability and performance. I will update as soon as there are news.
59 updates 19 followers 48 mods2013-04-14 22:36:33That 100 $ pump is remanufactured, and it has a badly cracked impeller and a mildly cracked housing. That thing simply isn't going to make it on my race motor ! Thats a fucking joke (sorry), what kind of retarded mechanic does refurb a cracked housing thats clearly visible and presses on a cracked impeller ? And to top it off, the gasket supplied doesn't fit, its from another model. Do you see that thing spinning on a 12k rpm motor ? I don't ! Its trash, and thats where its going now. Never buying from that dealer again.
Bye bye ~