Today the 911 left the house on its next steps to become a finished car for Fred. Before leaving there were a few last minute checks and adjustments from the test drive to Martinez.

Checked all the rear suspension and bolts for anything that could cause the odd clunk/grind. I found a few slightly loose, nothing about to fall off, but another reason why we always must torque and check everything. Just to be double sure I also checked fluid levels in the transmission, full and smells normal. Hoping those few loose nuts solve our issue.

Next up was to get the front turn and marker lights working via proper connections and labels. Most of my headache for this effort was just finding the plugs and I couldn’t find both. I’ll keep my eyes out, but for now I just labeled the wires via heat shrink and marked the terminals to make it easy for the next person. For anyone in need of them, the plug for a 993 front marker light (not the fog light):

Extended and Terminated

Heat Shrink with that?

I also spend a bit of time trying to sort out the boost control issue, the ECU seems to not have control of boost via the 3-port controller. Currently I’m running without it and just relying on wastegate spring pressure (~12 lbs). First step was to test and check the solenoid is getting proper signals.

Breaking out the oscilloscope and my rusty electrical engineering skills.

25% Duty Cycle

Monitoring controlled side of boost solenoid, when pulled to 0V it is ‘active’. 75% DC at 12V means ‘inactive’ 75% of time.

75% Duty Cycle

Similar to 25%, the plot appears inverted because of pin I am monitoring. Other pin is constant 12 V.

After simulating WG duty cycle outputs from ProEFI I was able to at least confirm it is commanding the same value as the controller is getting so wiring seems correct. Leaving only boost sense lines or ECU settings to question. After spending about an hour reading and tracing vacuum lines it would appear things are correct physically. Everything is connected as such:

MAC port 1 - open
MAC port 2 - connected via tee to the port of each internal wastegate
MAC port 3 - connected via tee to intake manifold
Port on Turbos - connected via tee to another port on intake (very close to spot for MAC port 3)

Following my understanding:

A - MAC inactive i.e. 0% (same for not connected)

Port 2 & 3 connected...Internal WG port connected to intake connected to turbo port. Thus it sees all the boost and spring controls things. I think...

B - MAC active i.e. 100%

Port 1 & 2 connected...WG port sees atmosphere

I could be wrong as I am still learning. Hence documenting the setup for future reference.

Sources of ‘knowledge’:

Cruising along 580.

Overall a great ride out to Ripon, CA. No major concerns or issues, mostly just tuning bugs.

The Good:

No more grinding or rattles from the rear, whatever I tightened fixed it.
Throttle response is better, more drivable
- I re-adjusted the pedal to throttle blades mapping. Originally it had a large jump up at low pedal %’s
Power on highway rolls in smoothly
Engine coolant temps are solid and cool
Great oil pressure (~4.0 bar)
No leaks

Less Than Ideal:

Tune needs work for cruising or continuous part throttle. Can pulsate a bit during constant RPM.
Still dies when returning to idle once warm
- I didn’t change anything and expected this to still occur
Drivers door still has locking issues, need a locksmith to look at tumbler
Radiator fans are always on. Unclear why. (Settings appear okay when checked on way home)