Progress report, since there is real progress and a milestone achieved, it's time for an update. [Insert essay of excuses why this is taking sooo long].
I do want to point out Driver's education in the Cruze and ATS:
6 autocross events
1 track spring Waterford Hills road course
1 track day Mid-Ohio road course
Otherwise, please find out why by what happened over the past 6 months with this side project Solstice twincharger build below:
Overall when I'm wrenching on the car, I'm going back through what I've done years ago and cleaning it up, and then labeling everything more or again with proper nylon cloth label tape out of a Brady M210 which is a great label maker, because it uses that nylon cloth tape (haha) which is made for wiring. From as thin as a hair to as big as you want, the genuine tape is worth it. My prototype wiring is, what it is, spaghetti, that can make things less efficient and daunting as you will find out how much custom electronics is going on.
Tuning: made major progress on tuning cold start and idle, return to idle which I was struggling with last year. Then working on transitioning the bypass valve has also seen success in boost control. With my system there are 2 boost controllers, wastegate (via gofastbits) + bypass (emu black ecu), right now they're are playing nice with each other.
Turbo: I have been battling a leak around the center section of the AGP 5757 turbo. Tech led me to install a oil pressure regulator on the feed line from here
https://turbosmart.com/products/opr-turbo-oil-pressure-regulator and in addition I also added an electric air injection pump to use as a vacuum pump. If the pump isn't on, the turbo starts smoking even at idle with 15-20 psi feeding the turbo. I installed a cheap $50 air injection pump here:
https://www.amazon.com/dp/B07SBTDS38 and will be getting a GM ac delco unit as the cheap one is failing. When it works, it works well, it will suck the oil cap back on at idle.
However, fed up with the leak and complications of the vacuum pump (what happens if I lose it), I purchased a 0.82 A/R v-band turbine for the original Precision 5558 that made the 444 whp, which was rebuilt by Precision shortly before getting the AGP. I never had these leaking problems with that turbo, with a bigger A/R it will work and probably what I should have done in the first place.
Alternator: had stopped charging. An inherent challenge is controlling the alternator output with the factory ecu disabled. It wants to see a 5V 128 hz pwm signal. In addition, there is quite a bit of electrical load on the alternator. Engine fan, heat exchanger fan, vacuum pump, second fuel pump all adds up. I looked into the high output alternators, they are quite expensive however $400-600. It may need a cooling duct for air flow since it's tucked in there, however other plans may solve the front space constraints in the form of a rear mounted radiator.
Starter: finally died, it was talking to me prior to this with clicks and slow cranking. Installed a new ac delco 3371026 starter. Much improvement there. I did some voltage drop testing on rear mount battery connections and did see improvement after cleaning up connections and also added another ground to the engine for good measure, that's now 3 engine grounds (factory cable + steel braid + custom 4 ga cable).
In addition, the 14 month old car battery died, this time instead of replacing it with the absolute cheapest one I can find (I have issues, yes), I got an optima for it and am impressed by it's performance and ability to hold a charge compared to the junk I've been running in it all this time.
Analog signals-to-CAN bus output module: fried the onboard 5V regulator so was sending through a higher voltage to the microcontroller. That is my rookie mistake not feeding it 5V directly (I was feeding VIN regulated 10V). That may have fried something in the bypass throttle h-bridge controller because that stopped working after working around the blown CAN bus output module, that I can power it through USB for now.
Bypass throttle controller: the h-bridge blew, found that out after a deep diagnosis. These electrical faults with the custom hardware is tedious and time consuming. I replaced the h-bridge (why I got the 2 pack, yowser!) and got it working again.
Head gasket: I've been seeping a small amount of coolant somewhere unseen via coolant level creep, and oil seeping around the head and putting it off for the time since I'm running a coolant pressure transducer and don't see a head gasket leak in that data. I've reused the SCE copper head gasket 2-3 more times than recommended. After a wonderful day tuning, I bore scoped the cylinders and saw a coolant drip in one of the them (my camera can sweep around and look up at the valves. Picked up a new SCE copper months ago, and what I got was not for a stock ecotec, looks like it was cut for an upgraded block with 2mm larger hardware. The original gasket is a line on line fit. Under a time crunch to make it to the Woodward Dream Cruise, I went with a felpro MLS locally sourced. I'll be returning the SCE copper. After buttoning up the head gasket and burping this baby, I lost alternator control, it was not charging sitting at 11.8V.
Alternator control module: This is another custom microcontroller module to output a 128 Hz PWM signal, the forth arduino microcontroller on this car. That died, the cpu gets hot and it doesn't communicate. Swapped that out since I have a bunch of nanos in stock and added protection between the alternator PWM input and the microcontroller (in-line 220 ohm, 10k pull down, 5.1V zener).
CAN bus input module: this reads a stream from the ECU, throttle position, map, rpm, and also outputs the bypass throttle position to the other CAN bus output module so I can log it. This also lost it's onboard 5V regulator. I then retrofitted the bypass controller, alternator controller, and can bus input module to run off direct 5V power which solved this challenge.
Milestone reached: Yesterday, while road tuning the car and WOT, I hit 93% duty cycle with my injectors at 6900 rpm (current redline 6950). After a 1-2 gear pull, I said in my brain as it presses against the back headrest, "she's back". Maxing out my injectors with the proper AFR means the car is putting out the power like the good ol' days on the top end. It was too late last night to make out to Woodward this year, and it's rainy today. I still got it done enough I think.
Moving forward...
Autocross: yes.
Big wang: got an alert from Wing-Logic.com several months ago that their stuff is back in stock so I immediately got a WingLogic 74" MSHD Racing Wing Kit Rear Car Spoiler
https://wing-logic.com/product/winglogic-74-mshd-racing-wing-kit-rear-spoiler/ The smashed rear fascia will need to come off anyway, will be looking at 3D scanning it and designing a bumper mounted swan neck (I'll custom design it, then send cut send it), that will also allow the trunk to open as normal, so thinking there needs to be a way for it to tilt back.
Injectors: it's time for the ID1050 injector upgrade like I said before if I max out the injectors again I'll get them. I would like to try and run something like E50 because it's harder and more expensive for me to acquire 260 GT 100 octane unleaded, however am running it to dial in the tune before playing with the flex fueling.
2nd ECU to replace the 4 arduino microcontrollers: after much research I landed on a rufis uaEFI, a less expensive engine controller that can run custom code that should be able to control the bypass throttle, CAN bus I/O, analog inputs, control the alternator, and more if I need it. Being an ECU for engines, it is better suited to handle the electrical environment than a $3.50 arduino nano. The microcontrollers proved the concept out, helped me see what I needed, so now I can move towards optimizing it.
Rear mount radiator: it's going to happen, I just don't know when because....
Roll cage: I'd like to acquire a proper bender, practice with it and prove I can do it; then build a proper custom cage for this kappa. Like time attack / hill climb qualified, and for safety over all things.
This is where I can look at the rear radiator mod and go back to an air-to-air intercooler for the turbo. This car is front heavy already with the turbo and supercharger up there. And rear aero needs to be considered, how do I get enough airflow to the rad without interfering with under car aero like a rear diffuser that you don't want to make inefficient with ducting or heat exchangers. The one airflow simulation of the Solstice shows that big vortex coming off the rear sides of the car, maybe that's a good spot for some scoops.
