My 1990 300zx Twin Turbo build by megaDan

11 minute(s) of a 414 minute read

It took exactly 6 hours to button everything back up. Surprises were minimal (steering column to turbine housing clearance) and mistakes were none (I forgot to tighten lower engine mount bolts prior to test fire; but I remembered before it came off the lift so...). It started up on the first try late Friday night; but the weather was supposed to be garbage all weekend so I didn't rush to get it prepped for a Saturday road trip.

I got a quick wash and test drive in yesterday while the kid napped and encountered no issues. I brought it in to work today to continue slowly stretching its legs before I start to have fun with it. I've hit about 7psi so far. Each time I disassemble the intercooler piping it usually involves one or two adjustments before it can handle 24psi without drama. I'm extra cautious now because of the fact that I've got new turbos, new wastegate preload, older fuel, and the ever-lingering fear that I've missed something.

My optimism IS growing. The past two years or so I've been getting increasing amounts of smoke during in-gear deceleration. An annoyance at first to embarrassing at the tail end of last summer. I haven't even seen a puff yet, during my 30 minutes of seat time....🤞

5-27-2022

It's not too bad when a) appropriate measures have been taken to make all these activities easier b) I have a quickjack and a clear workspace and organized tools c) I've done this a bunch of times before

Even with all these precautions I generally underestimate timing by 1/3; so I was shocked when everything went exactly as planned.

I got a longer drive in this week, roughly 35 minutes each way, highway/city combined; and everything was spectacular. It felt so good to be back in the drivers seat and confident in the car again. I left the boost controller on the low setting (~17psi) and had some fun. I stomped on it nearly every opportunity and encountered no hiccups, aside from discovering I need to modify some of the settings on the Greddy unit with the new turbos, as I kept hitting whatever my limit warning was set to. Yehaw!

Upon parking the car and doing a post drive-checkup I noticed something had splattered and left dropplets on the AC belt...which is interesting because the Z has 3 belts and only the AC belt exhibited this. I also heard one drop sizzle on something hot, and found a few drops of coolant in an area where there are no coolant lines. Something to monitor but not freak out about yet. I found a few hose clamps that were only medium tight....maybe those were contributing factors.

It's Friday and rain is threatening; but our family has had a hell of a week so the Z is in the parking lot at work now. I couldn't resist another chance to drive. I was also shocked at E85 prices. It used to be ~50% the cost of 93oct; now its 80%. Yowza.

I'll have some more fun on the way home and monitor the coolant situation. Despite that I'm on cloud nine with the Z and ecstatic that things are going as well as they are following two weeks of intense focus on getting this done before summer.

A 60cm bike fits pretty nicely in the hatch, even with the woofer. I could probably get a duffel bag back there if I needed to.

Took the Z out to Madison today for 60 miles of highway driving each way. The plan was to meet up with a friend after our ultimate team practice for a bike ride. Following a clean bill of health after a post drive inspection yesterday (apparently medium-tight isn't enough for some hose clamps), I elected to play around with a little more boost and dialed the boost controller up to 20. 17 was 'sporty' and feels like a freight train in 3rd. 20 feels like being strapped to a rocket and causes uncontrollable giggling. 20 with the GT2554R's feels like 23 did with the slightly smaller Sport 500s. I'm excited and scared to dial it up more.

Unfortunately the weather didn't cooperate and we were met with rain as soon as practice ended. No bike ride, just lunch at a tasty Peruvian place. It was much warmer on the way home, so I gave the AC a try and was met with instantly cold air. I guess my AC fix last summer was successful too. Halfway home I hopped off the freeway hoping to find some more enjoyable roads at a more palatable 55mph. I got a few open stretches but mostly dealt with holiday weekend traffic. Oh well. Coolant stayed in the radiator, temperature stayed in the normal range, and everything felt good. Everything's coming up Milhouse!

6-7-2022

Got all ready for the first potential C&C of the season and...wasn't able to attend. Oh well.

Used the kiddo's nap time on Sunday to do work that was neither beneficial to the family nor the household: construct my prototype ethanol content gage! Good news: Version 1 works 'flawlessly'. Live ethanol content is great, and the accelerometer is also functioning as built....but not as intended.

Solid copper wire not ideal. What a mess! OD of the printed housing is standard 52mm.

Installed and functional! Not pretty, but neat nonetheless.

Warning: Stream of consciousness.....
Really happy with how this turned out for a first attempt. Ethanol content works great. Accelerometer not so much. I attempted to compensate for the orientation of the dash in how the accelerometer was mounted in my 3d printed housing. No luck. What I should have done was tell the accelerometer to zero/set level every time it is stationary for X number of seconds. Also I thought I had a data smoothing function built in, but I don't so that is needed also. Lastly there is no peak hold; so my nonexistent passenger is the only one who would be able to see the data. Ideal state would be to draw a 1.5g circle and have dot trace that clears itself every 20 seconds or so. I used solid copper wire which is NOT great and will likely fail at some point. I found some 30 gage hookup wire that is very small and very flexible that I'll replace this setup with whenever I get around to reprogramming the board.

So ~3 years ago I ripped most of the dash and center console apart to greatly improve my wiring setup. It was a nasty bees nest of wires supporting my triple gage pods, my boost controller, aftermarket headunit, amp, woofer, digital > analog converter and associated inputs, and....I think that's it. I made common power/ground bus bars which really improved things. But it's still not where I want it. I need to find a common power/ground solution that I can mount to the center bezel itself; so I don't have 8 separate connections I need to add/remove each time I want to remove the gage pod/boost controller. Anyone have a good solution for low voltage modular connectors? To amazon I go.

I plan on building a 2nd custom gage as soon as I come up with a solution for measuring coolant temp. Then I'll run all my other sensors that are currently going to my DAC to a 2nd arduino and use it to display a selectable scrolling line graph of whichever input I chose to monitor. If I get real fancy, I can simulate a touchscreen by monitoring the accelerometer for a 'tap' and use that as input to change displays. The challenge will be looking for a tap while ignoring road vibrations.

Last bit of good news; I'm inching closer back to my max previous max boost setting. I hit 21 psi on the way to work today....still no drama. 🐌🐌 Now that I think about it, I should do a log on the way home to find out how much injector ceiling I have left. I don't recall how close I came with my old turbos, and these are fractionally larger. Safety first!

8-15-2022

It's been another whirlwind of a summer. Went to Ireland for Ultimate Masters World Championships. Took 8th. Had an amazing time and was so incredibly thrilled to finally realize my potential and truly play at the top level (for my age group at least). Drove a Renault Clio Saloon. Was afraid of the challenge of driving on the wrong side of the road on little sleep. After 2 hours or so of practice it became second nature and we had a great time exploring during our 10 day stay.

Ireland is beautiful and definitely worth a visit; but as a foodie I was very disappointed. Nothing but burgers, curry, and fish and chips regardless of the venue. We got to see the Cliffs of Moher, a few incredible castles, and tons of beautiful scenery. Our kid had a great time but sadly she'll never remember it.

Finally got covid on the trip back. The Dublin airport was a zoo and there was plenty of it going around during our visit. Thankfully we both had mild cases and it made adjusting upon our arrival a bit easier thanks to working from home for a week.

The first day I was cleared from quarantine was also the Elkhart Lake Councours D'elegance. I've always wanted to hit up one of the vintage weekends and never had the chance or made the time. I took a trip up with some friends and we had an awesome time. It was a zoo, but the drive up and back down was beautiful and the turnout was unbelievable. The only pic I took was of an Alfa GTV6 and a Ferrari 250 GTO (replica?) with 'NRVOUS' plates. Sorry for the disappointment. I'm hoping to make the same trip next year with the same guys, but make a whole day of it. We had no idea it was such a big deal. People were pregaming, tailgating, etc. We definitely did it wrong driving up 30 minutes before.

On more Z related news, I gave the Z a fresh coat of wax inside and out during my quarantine. And got no pictures. I got REAL bored while nursing both Covid and a sprained ankle. On the few occasions I've had it out, it's still running flawlessly. Oh yeah I also made an employment change. Went out to celebrate at Central Waters with the wife and it was the first time she had been in it since our daughter was born. Wow. AC was great, but I plan on adding some ceramic tint this fall. The AC blows cold(is), but it can't keep up when the sun is torching everything inside.

No big plans for the fall. I plan on taking the JCW down to NC again over Thanksgiving. But the wife doesn't want to fly with the kid so we'll be taking two vehicles on a 1600 mile (round trip) road trip. It seems sort of crazy; but with 3 people, 2 dogs, and 9 days worth of stuff its not bad. And it's still cheaper to take the mini down there than a track day up here. And more fun.