FC ABS not connected yet, but it should be no problem.
There are more challenges to be done yet, one of them being converting FD3S PS pump to run with FC S4 speed sensing (3 hole) PS rack and FC PS computer....
And as well stock FC cruise control.

 

Today i made steel spacers (55mm height) for rx8 swaybar mounting, clearance to rim at full lock is tight, but its there.
Of course spacers could use some cosmetic adjustments, but for function, they are there
Then i started measuring/preparing airbox connections to twins, will get it done tomorrow or day after.

 

FC airbox modification in progress

 

Some recent progress

- wired in airpump (using FC A/C relay for that)
- swapped relay in fuel resistor/relay box (needs to be NO, compared to NC which is originally in S4)
- pulled replacement dash from storage and cleaned it up a bit
- pulled old dash from car
- installed headlights, headlight motors, FTPs, turn signals, fixed some wires
- wired RPM signal to dash and Defi box
- wired speed signal from PS computer to ECU and Defi box
- replaced seals under brake master reservoir
- installed windshield trim (except the top one)
- installed wiper washer tank, brake ducts, wheel well liners and inner tow hooks
- airbox still under works

 

I like it! It's a cool kind of retro!

 

this great info and pics, thank you!

 

Recently been working on other stuff and cars, but here is some update :

Heater fan had faulty resistor, replaced.

US S4 dashboard wiring using different connector than EU dashboard wirign, had to make jumper

started on FC PS bracket modification to fit onto REW block (oem FC PS pulley setup, oem FC hoses to rack, just modification to FC bracket and installing front FC PS pulley on engine instead of original multirib)

 

All your mods typically have good rationale and I'm sure these are no different, but a couple choices appear odd.
Dash: Why not just pull connector pins and reinstall into USDM connector? (or vice versa) Are the pins incompatible with the connector shell?
PS: Very understandable that you'd go this route and retrofit FC PS pump onto REW block, but you're losing a great benefit of the FD - the serpentine belt system. Has anyone ever figured out how to adapt the FD PS pump to the FC computer ? I've never seen it done before.
And you better paint that PS pulley before it rusts.
You're almost there.

 

Yes, pins are incompatible and i made jumper harness for simple reason. To keep both harnesses stock, so anyone else than me can refer it to factory manuals if ever needed.
I have never had issues with vbelt on PS pump, even when competitive drifting FC for some years, not worried about it in street car. Serpentine belt setup is of course retained for water pump and alternator, that stays FD. Pretty much like 20B setup.
To keep serpentine and OEM FD pump, you would need to do lot more modifications which i was planning before, but this was much easier.
Another easy route is custom making serpentine belt pulley for FC PS pump, which i might eventually do later on.
PS pulley wont rust, its been sandblasted and silver zinc coated.

Today i mounted it on car, filled up and tested. All good
Actually mounted on airbox and took it for short test drive

 

Incredible - looks like the FC/D is ready to roll. What ECU & boost control system are you using?
I now see many steel underhood brackets have been zinc plated as well.

 

So far i am on stock FD ECU on stock FD engine harness, including stock boost solenoids.....

 

Little updates, rewired fuel pump resistor/relay, but right now i have FD ecu error code 51, fuel pump relay.
With PowerFC car runs in boost, in stock ECU it goes into limp mode. Need to troubleshoot that fuel pump relay, maybe FD ecu is not liking FC relay/resistor

 

Another little updates today.
Fixed wiring to fuel pump relay/resistor, stock ECU now does click relay prior start and no more error codes / limp mode.
Tested idiot lights, all good.
ABS works.
Plugged in PowerFC for swich/sensor check, modified FC clutch switch to revert its operation.
Next to do :
Unplug diode between clutch and stop switch. Check if brake booster leak is not just the oring between booster and MC and dress up interior

 

Got a datalogit? Can you post a log with sensors/switches enabled in monitor window?

 

Sure, will do

 

Interior work today, rear hatch, rear bins dress up.
Then i made cruise control cable and shortened throttle cable.
Have not been driving it to test it, will see if cruise works tomorrow once i finish up some interior bits.

 

Cruise control works.
Had to put in back stock clutch switch and do change in wiring - FC ecu is grounding clutch switch, FD ecu is providing power to clutch switch.
And diode between clutch switch and stop light switch needs to be removed.
That very likely means kicking clutch will not turn cruise off, but i always use brake to turn cruise off and that works.

 

Last few days progress :

Front licence plate bracket
Custom undertray bumper to radiator
Oem oilpan undertray with very litte modifications fitted.
Interior all dressed up

For now, stock ECU for break-in, then it will get PowerFC

Still need to do some small stuff, but its driveable as it is now, just need licence plates

 

First 200km trip today, on JDM ECU
(EUDM was acting up, maybe its faulty, some cold solder?, no issues with JDM today)
Few small issues (passenger window switch, something rattling in drivers doors with window down) and annoying issue of 3rd gear grind.
Other than that, no problems and car feels good. Still breaking in, but twins are really hard to keep from spooling

Will switch to PowerFC soon and start logging.

 

Finally got licence plates, still tweaking small bits.
After first 450km testdrive on hot day, i knew i will have to install second oil cooler. Prior installation, my oil temps went over 110C.
All that still during break-in period.
Couple days ago i installed it and yesterday took it to local meet, oil temps perfect.
Coolant temps going to 100C, which i dont like, still need to work on that. Better ducting, low temp thermostat maybe will help....
Still on JDM tuned ECU, have not plugged in PowerFC yet.
Tires on s5 FC wheels were rotted, installed some other wheels with better tires
Next is transmission/diff swap.

 

I like the simplicity of your car, FC + REW = FUN^2. It also looks spectacularly clean! Also, in a sea of S5s and S5 retrofits, a clean S4 is quite refreshing. I made a decision a while back not to do any S5 updates to the body of my '87 and your car makes me think I made the right decision.

87 psi after two coolers? I'm very impressed and now I have solid frame of reference for doing the same thing. Great stuff.

 

 

progress slowed up, working on FD which i just brought back from painter and is priority, but there is more planned or in progress for this FC

 

modified RX8 5speed trans installed
6 puck sprung disc
new front diff seal

new problem with oil pressure (wont go over 4 bar once temp will reach 60 c and thermostats in oil coolers will open)