Lighter = Faster (N/A build thread #2)

[speedjunkie]

Damn, looks good man!

[dakar318]

Apparently i have missed this build thread for the past couple of years.

Great work, I hope it makes over 230 with it being a big 4 port. SCCA Eprod motors make ~230hp with a 6port street port and a Webber IDA with 42mm chokes.

[infernosg]

Originally Posted by dakar318

Apparently i have missed this build thread for the past couple of years.

Great work, I hope it makes over 230 with it being a big 4 port. SCCA Eprod motors make ~230hp with a 6port street port and a Webber IDA with 42mm chokes.

Is that to the wheels? If so, that's reassuring since I'm effectively running a 55 mm IDA setup.

There's really not much left to do. I need to mount the radiator shroud and fan, wire in the reverse lights and oxygen sensors, and get some spark plug wires. After that it's a matter of setting up the ECU and display and getting a baseline tune. I've been poking around Haltech ECU Manager and RacePak DataLink programs and I think I understand the setup process. It's setting up an initial tune that has me stuck. If anyone is in, or knows someone in the Richmond, VA area familiar with tuning rotaries let me know!

[project86]

what door panels are those?

[infernosg]

Originally Posted by project86

what door panels are those?

I made them myself out of the original vinyl top halves and ABS plastic. Since the car is a base model it was easy to separate the halves of the door panels. I used the original cardboard bottom pieces as templates for the ABS plastic. I painted the vinyl black and covered the ABS in knock-off Recaro fabric from eBay. The door pulls are just red nylon straps secured using two of the holes for the original handle.

[infernosg]

I think I've often complained how much I didn't like my original ignition coil mounting location (behind the driver's headlight). I'd been toying with the idea of moving the coils to the top of the engine, and even went as far as making a temporary mount out of ABS to see if it would work. I finally decided to transfer the concept over to .060" aluminum:





My intake really has made life difficult. If it weren't for this thing I'd still have a top-mounted alternator and I've have more room for the coils. They're about 1/8" from the bottom of the filters.



Add some custom Magnecor wires and that's all:



I'm nearly done with the sub-harness for the reverse lights and oxygen sensors. After that I'll mount the radiator shroud and fan. Then, it's done, I guess. My engine harness isn't ideal, but that's getting resolved later in the Summer. But really, the only thing preventing me from getting it started is my lack of knowledge/confidence to set up a base tune.

[Pete_89T2]

I have the same set of coils on my FC. I managed to mount all 4 of them in the space vacated by the stock trailing coils, and even repurposed the lower stock coil mounting bracket & upper stud mount in my design. I'll post up pictures later (don't have them on my work computer).

Anyway, I fabricated up some simple AL brackets, and using a combo of long bolts, AL spacers and strategic stacking of the coils in a 2X2 configuration, and a bend on the top bracket (to line up with the top stud), it all in fits neatly there.

[infernosg]

It's been a while since I've updated this. I had to pull the engine a couple weeks ago because it started leaking coolant when tried to fill it up. Apparently I forgot to add sealant around the threads of the engine studs, which isn't required if using tension bolts. I got that sorted out and put the engine back in last weekend.

I'm now getting very close to firing this thing up. The engine is back in the car and it's holding oil and coolant. I powered up the ECU and display and everything works. I calibrated everything except the fuel level input. I attempted to synchronize the engine and ECU but by then I think I drained the battery too much and wasn't getting any spark. I got one or two flashes from the timing light and then nothing. The steady-state battery voltage was 12.0-12.2V but I failed to note what it was while cranking. The cranking amperage must have been low because my display was resetting every time I hit the starter. I'm getting a good, steady engine speed signal so I don't think it's a trigger problem. I checked the IGN fuse and it was intact as well. I suppose I could have fried the relay but I put the battery back on a trickle charger and I'll try again tonight. If it turns out to be a battery issue I'll pull the larger battery out of the yellow RX-7 and try that next.

[infernosg]

Not sure if this is going to work but here's a picture of the completed engine bay:

[project86]

geez dude.... can you come help me with mine.... I want mine to look like that haha

[infernosg]

I got the engine and ECU synchronized and calibrated the fuel level sensor on Saturday. Sunday morning I primed the fuel pump for the first time to make sure there weren't any leaks. Fortunately there were none so everything was looking good for a Sunday afternoon start up. I pushed the car out of the garage, enabled the injectors, primed the fuel pump, hit the starter, and... nothing. Maybe one or two little bumps of ignition but no start.

Time to pull the plugs to look for signs of fuel. I pull the L1 plug and it's bone-dry; not a whiff of gasoline. I pull the L2 plug and immediately there's a strong fuel odor, so the front rotor isn't getting any fuel but the rear is. I've already verified the injectors are good by hooking them up to a 12V power source so I broke out the multimeter and started testing for continuity:

Injector to sub-harness break-out connector: "Beep"
Injector to engine-side bulkhead connector: "Beep"
Injector to ECU: "Silence"

It turns out 3/4 wires in the sub-harness connector were wired incorrectly. After de-pinning and correctly re-pinning that connector there's continuity from the ECU to the injector. Just to be sure I also went back and checked the ignition wires. Fortunately those are all good.

[FC Zach]

Originally Posted by infernosg

It turns out 3/4 wires in the sub-harness connector were wired incorrectly. After de-pinning and correctly re-pinning that connector there's continuity from the ECU to the injector. Just to be sure I also went back and checked the ignition wires. Fortunately those are all good.

Hmmm. . Mine was that exact same way!

[infernosg]

Originally Posted by FC Zach

Hmmm. . Mine was that exact same way!

I assume yours wouldn't start either? I figured it might at least start on one rotor.

Last night I tried to better set the base fuel pressure without the engine running. The Aeromotive FPR doesn't hold pressure long after the pump is turned off so I had my wife watch the gauge and note the peak pressure during priming. It was ~60 psi at first time around so that might explain the excess fuel. I got it to ~45 psi and called it good enough.

I'm certain I flooded the rear rotor. I squirted a 1/4 teaspoon of 2 stroke engine oil into the both rotors and cycled the starter until I just about drained the battery. My intake and garage still reek of fuel though so I don't know how much good that did. Tonight I may put the spark plugs back in, keep the injectors and fuel pump disabled, crank the engine, and see what happens.

At least I got the display set up. I won't know if the speed or odometer works until the car is moving but everything else appears to be functioning properly. The only issue is I can only display fuel level in liters.

[FC Zach]

Mine wouldn't start because of a number of factors, not just from the injector wiring. But yeah, I would think it would fire on one rotor.

[infernosg]

Well, I got it started. I think it was a combination of too much fuel and the throttle being too open. I backed off the throttle stop to around 3% (was 5%) and immediately the engine started to catch more and more with each start attempt. When it finally caught it idled around 700 RPM and was running super rich (<11:1). After adjusting the throttle stop and the fuel settings I got it to idle fairly consistently around 1000 RPM. I played with it for over an hour, varying engine speed from <1000 RPM to just over 3000 RPM. I ultimately stalled the engine with what I think was a lean condition. I tried to restart it but after two failed attempts (too lean again?) I had drained the battery. I'll try again tomorrow but I'm thinking I may have to set up some kind of post start enrichment strategy.