UPDATE: 1st semester (MAR-JUN) 2015
Hey guys, wassup?
9 months without posting, the car completed its 2nd year in-build march 31st. Many things changed since then and i will update. In fact, i spent December (2014) , January and February (2015) without working in the car. Then in march i started my Masters Degree Course (Material Science and Industrial Processes) wich also took a toll on my time schedule (but allowed me to talk to many engineers and talk with many engineers, teachers and colleagues that sparked many more ideas into my project). Lets review the original goals and what i have at hand so far, shall we?
The Goal (Stabilished in March 2013):
Convert the car to RWD (its an AWD unibody, the JDM version has AWD as option), reach close to 200 horsepower, hoon the streets at night in my local mountain pass and hit trackdays without being a trailer queen. I will be keeping it road legal, so no big power numbers, full interior trim will stay (though i plan to change the seats in the future), air con is staying too, the summer is scorching.
The Plan (As in March 2013):
I managed to get my hands on some parts of the only miata wreck that is known of in Brazil (the little car is being sold in spares FAST because of the its rarity), getting the essential parts of it and i will be fabricating the rest. The BP and FS engine are much alike on transmission fittings, a flange will do the job. So i I will be using a lot of local brands, since importing here costs 80% of the item price PLUS shipping. Thats for taxes.
The Goal (As in July 2015)
RWD was properly achieved and tested (to 6000RPM , i plan to retain the original 7000RPM cut). A failure in the flywheel center bearing made us end the dyno session in 6000rpm , we clocked around 150hp (125hp is the original standard) on 10.4 CR and 87 octane peewater-gasoline. The Fueltech EMS provided great adjustability and capacity to improve the torqueband. We didn't saved any sheets, the car was running a safer-than-safe map, righ and without much timing dialed in. It was just a session t o test the RWD.
The car
has reliable RWD, i swapped the r160 welder for a r180 LSD from a turbo SF5 Forester (street driveability improved a lot, also better axles n such) .
The wilwood brakes were sold. The car is light for its size (1150kg / ~2535lbs) and the balance was too much forward oriented, the front wheels locked easily. Over-engineering at its finest. Cashed in good.
The rear suspension was a big mess. I prototyped over and over and cut and welded the hubs to a point they were a big big mess. I don't see it in a bad way, i think it is part of a process, i never thought i could nail it on the very 1st try (though we nailed pretty much 70% of what we done on 1st tries, working through the measure-twice-cut-once method), because geometry and stuff. I also wasn't liking the way the rear shocks were working, they were banked like 30 degrees or so and the rubber bushings on top were rattling.
This leads to some great news. By the end of 2014 i met a great friend (who was following me both in here and on a brazilian website called Flatout that hosts build threads and such), and he invited me to join INTERSTADUAL a local drift crew of crazy guys running Audi EA827 turbo engines on Chevrolet/Vauxhalls Chevettes (or Opel Kadett C). Check on out those vids.
This is brazilian grassroots drifting scene, the chevette is our cheapass s-chassis/miata/86 equivalent, the EA827 turbo is the "that cheap SR banger". You get the context, these guys keep drifting fun. The guy in the silver Chevette sold me a set of toyota mk2 coilovers he would use in his track car (no, i mean, seriously. Seriously).
Though they had to be massaged to fit the 626, of course.
While the customized coilovers and camber plates were getting ready , i worked with the lathe to build custom rear wheel hubs, so i could use a complete subaru suspension kit, replace the messy rear suspension (i hacked and soldered cast iron way past the point it was still safe or had enough resistance), i could have the adjustability i needed and would be able to retain more components in a more OEM-ish style (also, driftworks doesn't fabricate geomasters front and rear kits for RWD 626s).
Wanna know a funny thing? the JZX is roughly 300kg heavier than the 626, and the cusco coilovers are far stiffer. I have set them 5cm lower than the originals, just to take a pic and...
It seems the springs are a little too stiff (way stiffer than the OEMs), not only it didn`t got any lower, it was in fact a bit HIGHER than the original (the coils were set using a jig , considering the overall height of the original shocks) so off they went for another round of massaging. While at it, i decided to remove the engine and check for the flywheel bearing (that one that failed during the dyno pull) and found something weird. When i was working to put the clutch togheter after replacing it, the whole assembly made an ugly "clunk" sound. Uh-oh, problem. Upon disassembly i was reeeeeally disappointed... somewhere, somehow, someone (some service provider) assembled the crank without the thrust bearing. I was very sad and very disappointed with it. I would had to overhaul the engine because of it.
I was seriously shocked and sad when i found this. No clunking noise when driving, nothing weird... nothing, just that damn thrust clearance all wicked upon disassembly. I've put my nerves togheter and decided though, if i have to rebuild it, i have to do it right, i have to do it better. I`ve sourced the basic parts and contacted two big companies , AFP Racing (
AFP Racing Components) and Susin-Francescutti (
SUSIN FRANCESCUTTI - Virabrequins e Comandos de Válvulas - Susin Francescutti), the 1st one forges custom pistons , the 2nd one, custom con-rods (with matching ARP2000 bolts). A fully forged engine with a turbocharger will (hopefully) be enough to drift properly. Not taking chances this time, i will rebuild the engine myself, in a trustable shop with huge experience on import engines, triple checking all tolerances and specs
So far, this is the status of the project: I am awaiting the pistons to be ready (they`re being manufactured as i post here) , they will be sent to chemical treatments (friction-reduction at the skirts and heat treatments for the top). The CR will be around 11, enough to run proper E100 fuel (we have it 30% cheaper than the peewater 87 octane gasoline) and have decent NA power (i have to recover financially to install the turbo and do all the custom piping needed, so i will run NA until the end of the year, most probably). I just mocked up the turbine inside the engine bay, just to see how it will work in the future.
I am hoping i can have the car ready to visit (not as a competitor, perhaps to run the track on the free time avaliable) a drift event in October 12th.