An ill-advised 300ZX build

This one goes back a bit. 

In June of 2005, I was driving down the road after pouring another $1200 down the air conditioner of my single-slammer (KA24E) 1989 240SX.  It chose exactly the wrong moment to blow the high pressure line off.  I was exactly across the road from a lemon lot next to the fairgrounds.

Then I saw it: a 1992 300ZX twin turbo, with glorious BBS RS wheels. 

It came with a tiny bit of provenance, in that its previous owner was a fairly well known guy who owned a Ford Lincoln Mercury dealership in town.  He'd kept it at his South Padre Island house.  He was enamored with the Stillen SR-71, which was a package sold by Stillen for a very few Z32s in the early '90s (HKS turbos, 17" BBS wheels, and the bulk of Stillen's parts).  By the time he'd read about it, they were no longer doing it, so he bought the wheels, some 13" Brembo brakes, a JWT tune, a JWT intake, a JWT exhaust, some Eibach springs, and a Stillen short shifter kit.

In my first week owning it, I blew up the clutch (broke a spring retainer in the hub and jammed the spring).

So I did my first clutch job, and then put it on the dyno, for some baseline readings.

I was happy to just thrash it as is, except that in 2007, the driver-side turbo called it a day and sent its bearing down into the oil pan, then started machining the compressor housing, the turbine housing, and both wheels into hot sparkly garbage.

I did a compression test, without any great hope, and found out that my lack of hope was justified: 1, 170PSI, 2, 175 PSI, 3, 170 PSI, 4, 170 PSI, 5, 175 PSI, 6, 70 PSI.

Also, the inside of the plenum was covered in oil that looked like it had spent the night at the strip club, as it was just chock full of glitter.

So, in my 26 year-old wisdom, I decided it was time to rebuild the VG30DETT, but with bigger turbos and bigger injectors and bigger intercoolers and forged pistons and rods.

I used a local machine shop to do the work of: balancing the rotating assembly with the new pistons and rods, boring the cylinders .020" over, align honing the mains for ARP hardware, replacing the bearings, replacing the valve springs and valves, and grinding the valve seats (and lapping the new valves in), and assembling the short block.  I also had the bearings and pistons coated (a thernal crown coating for the piston tops, a dry film lube coating for the bearings and piston skirts).

I got busy doing my first engine pull.

I stripped it and delivered it to the machine shop, then they got to work:

And I got to work buying pieces.

(the spindle pins are for my 240Z, ignore them)

These are GT2560R turbos, a fairly substantial upgrade over the little T22s that came stock, but they spool in a remarkably similar way.  Combined with (then) some 740cc/min injectors, you could say things were looking up.

So, I packed all that stuff up in the back of my 240Z and took it down to the friend's garage I was fadoodling in.

New injectors

Got to cut some strength off of the motor mount so that the turbos would fit.  That was about the time I knew things were going to get spicy.

Then I just went ahead and put everything on.

Supervisor periodically stopped in.  He was about 3 or 4 at the time.

Hung it, put the second new clutch on (this one was a heavy duty unit):

And finally sent it home:

Moar!!!!!

Very nice.

Subscribed.

Love it. The Z32 is by far my favorite of the 90s Japanese performance cars. Though I hear I might change my tune if I ever had to work on one.

So, with all that new stuff under its belt, I got a "chip tune" done by a local guy.  His name's Eric Dotson, and he's had his hands all up in the guts of all my fuel injected cars (though not the Datsun, since it's still carbureted).  He set up his Moates emulator and used a couple long-past-their-prime tools that edit fuel and timing maps, and we came up with this (at 15PSI of boost) and then flashed it to a 27c256 chip:

Which, at the time, was badass.

I elected to take things further and clean up the awful wiring harness to fix and eliminate what I could (like the coil drivers being located on the timing cover, having the wrong fuel injector connectors for my injectors, removing the aux air input valve plugs entirely).

Ready for install:

The igniter was moved into the footwell with the ECU:

Then I came across an HKS EVC 5 boost controller, and I committed the sin of butchering my clock to put it in:

I don't have the dyno run saved for whatever reason, but it was somewhere near 400HP at 17PSI instead of 15, which was about all I was comfortable running with the knock sensor and the boost control being done separately.

Will said:

Love it. The Z32 is by far my favorite of the 90s Japanese performance cars. Though I hear I might change my tune if I ever had to work on one.

The Stockholm syndrome in me says "yeah, it's great, it never hurts me!"

My wallet says "my anus is bleeding."

So then I tried to drive the car in the Great Winter Storm of 2008™, which didn't go my way, and I ended up in the neighbor's Yucca.

I parleyed that into an opportunity to put the '98 J-spec front end on it (along with all the accompanying bits that I broke, which included the AC lines, the fog lamp, several intercooler joints, the undertray, and the fender liners:

I also found the time to nearly ruin an ECU at a bikini car wash.  It turns out, you shouldn't spray down the stupidly complicated engine with old connectors and iffy cavity seals.  It kept blowing the "Eng Cont" 10A fuse, which controls the idle air motor, the EGR solenoid, and the safety boost solenoids.  I went to buy a new ECU from a local yard, asking only for an 8-bit, federal, manual, twin turbo models, which he reassured me was what he had.  It wasn't.  It was, in fact, a 16-bit, California, automatic, NA model ECU.  The only thing that could have been more wrong is if he'd had an OBD-II '96 ECU.

So I opened up my old box, and found the issue: a PWM driver had been crispified:

Fortunately, the new ECU had several identical ICs on board, so I desoldered one and put it in the old ECU, and got it back to fighting shape again.

I'm in for more.

Flash forward 4 years to 2012, and my friend convinced me that we should paint the car, because the clear coat had failed in places, and the red on the bumper wasn't really the same as the red on the doors, and the spoiler was suffering the rot that all the '90-'92 spoilers eventually get.  I also wanted to get rid of the rear wiper and orange peel texture on the rockers.

So I got started.

I eventually adjourned to another friend's spot who owned/operated a body shop and wrecking yard.  I used methylene chloride to strip most of it to bare metal, and then zinc chromate primer, followed by high build buff, then the usual guide coat, sand, fill, guide coat, sand, fill, prime, topcoat.  I used Martin Senour products, because Bill worked with Napa's paint and body supplies, and it was easier to pay him to get things dropped off than it was for me to go stand in lines and invariably forget one thing or another.

But a guy eventually did get his poop in a group.  It took me a while, and between the start and finish of this one, I finished my master's degree (computer science) and was diagnosed and treated for metastatic testicular cancer, moved jobs three times, and pulled up stakes and moved houses (same city) once.

I also trawled the hybridz website and managed to snag the last new old stock OEM '90-'92 spoiler from a guy who'd bought it thinking it was an actual aero device he could put on his NA Z for autocross purposes.  He'd left it on the shelf for 20 years, and I scooped it up for $100 plus shipping.  I feel like an actual criminal typing that.

It was a long time, and I'm sure the only reason why Bill let me keep coming around on weekends was because he enjoyed laughing at all the mistakes I made doing the job.  Sure, he eventually set me straight, but he watched me pursue blind alleys for a long time before he'd step in.

The finished product:

And after all that sanding and polishing, you can really see the dead bug in the light fixture in the garage:

Oh and at some point during that paint job, I got rid of HICAS.  There's a local track to me (now called "Suika Circuit") where there's an off-camber transition to a back straight that was always right on the transition between in- and out-of-phase rear wheel steer.  So I grabbed an NA Z32 power steering pump, reservoir, and mount and got rid of about 30 feet of leaky hydraulics, and added this fancy billet aluminum piece that the vendor forgot the helicoil for on the driver's side.

But hey, now I don't end up spinning into the weeds if I'm going too slow around that corner anymore!

By chance, I was invited to the Japanese Nostalgic Car's Touge 80s (as the Z32's first year was '89, my '92 was eligible as a "continuation" year).  So, the same guy who convinced me to repaint it and I drove the car out to Los Angeles.  To get ready, I embarked on my first powdercoating project, my BBS wheels.

I started by picking up a gallon each of xylene, alcohol, MEK (substitute), mineral spirits, and methylene chloride.  The cashier at the home depot looked at me weird, so I held eye contact for about 5 seconds too long before saying, "I know how to party".

After a lot of finger-mangling, I ended up with clean center stars, stripped lips, and new hardware.

Then I knocked together a fabulous "spray booth" out of a wardrobe box, a box fan, and the cheapest air filter I could find, I started powdercoating the centers Spanish Gold (with a clear) and the lips just clear.

Then I shod them in brand new Nitto 555 G2s and went to California.

Running down I-40 through Arizona, we noticed that the car would buck and lean out whenever we came out from behind a semi.  I had a hypothesis about this, that the air was buffetting the MAF, as the MAF is up under the nose panel and no longer had the splashguard (since I ripped it off on the yucca), so we stopped in Kingman, and bought a 50¢ plastic flower pot, then cut half of it off.

This worked perfectly, no more bucking, no more lean spot when heading into the airstream.

On the touge, we drove some California roads North of and then down into Los Angeles.

My partner in crime (in the Bret Michaels wig here) drove the car back through Reno to visit his family, and I flew back from LAX.

Watching with keen interest!

Following along.  I have an irrational love of these cars.  Some days I wish I had never sold mine.

Can't wait to hear about the yellow car too!

A couple years down the road, my tuner called me and said, "a dude with a Z32 dropped a valve on the dyno, and he wants to sell it all off to get a 2JZ, you want to buy an AEM series 2 plug-n-play for cheap?"

And I was all, "hell yeah bröthør!"

So I went and picked it up, AEM's 7 bar map sensor, some GM IAT, an AEM-swapped crank angle sensor (different chopper wheel), and all the fun a growing boy needs.

First, TIG'd the IAT into the passenger side intake pipe, just forward of the throttlebody.

Then built a sub-harness for the dual widebands, the IAT, the MAP, and the flex fuel sensor.

Then moved the fuel filter out of the engine bay, back underneath the car where the fuel lines come out of the tank, and stuck the flex fuel sensor down there with it.

I also got rid of Nissan's stupid 3-valve monty for the idle air control, and just put a Ford valve with a Supra check valve onto a -10AN nipple on the back of the balance tube.  The prior setup was a warm-up air valve (thermostatic), a fast idle control solenoid (for AC and full-lock steering), and an IACV (for most other situations).

Initial install:

Tucked away where it belongs (driver side fenderwell, behind a splash shield):

I also got a new EFI harness from Wiring Specialties, which meant I had to take out the lower plenum (which is home to a timing belt idler) to get to the harness that the knock sensor lives on, so I broke out the paint stirrers and vise grips:

That led to mounting a catch can to those -6AN nipples on the valve covers, and a whole new set of fuel rails and injectors (still side feed, but pintle-less and ball-in-socket nozzles instead of drilled plates, and 1100cc/min).

Post-makeover engine bay (also featuring VAG coils, because I didn't need that stupid igniter anymore with an aftermarket ECU):

The ECU fit basically where the original did:

However, now that I had some badass mac valves controlling the boost via the ECU with safety features like knock retard and boost cut, I could get rid of the old HKS EVC, which left a hole in the console.  However, at this point, I had a friend with a 3D printer, so he knocked this out for me:

I haven't put any of the silly stereo stuff up that I did to it, but let's face it: I'm a child of the early 1990s, so a guy's got a system in there (some old school Alpine amps, some Infinity speakers, and a nice Boston Acoustics sub in a custom fit enclosure, on a pretty nice Alpine HU):

But, now Harry Podder had a spot in the dash, and it's almost like I don't need the clock there.

At any rate, it was once more time to get the thing tuned.  Red was pump, blue was e85.

I hadn't yet put higher pressure than stock (8 PSI) wastegates, so I pretty much top out at 17 PSI of boost.  Still, 20HP extra feels pretty good.

This was when my tuner had settled in at a local shop (NM Imports), which has their own dyno, so from there on out, I have a baseline and a history with a machine, and that doesn't feel so bad.

Oh, and I ditched the stock fuel pump too.  Nissan ran a controller that put 6, 9, or 12V to the pump depending on the demand of the engine, and used an FPR and a damper (which is just another FPR, but on the inlet side of the fuel rail).  The stock pump will move a lot of fuel at 12V, but it also won't run at 12V for very long, and it will eventually just burn out.

So I got rid of all that nonsense, and put a Walbro 485 into the tank:

A Tomei Type L (for large diaphragm) FPR in the bay, and bypassed the pump controller to use a relay from the 2 gauge I have back there feeding my stereo, and a Radium bulkhead connector:

Then I 3D printed a new cover that would fit over the bulkhead, and still let me run the O-ring to keep the cabin less stanky.

I keep reading this thread waiting for ill-advised behavior to surface, and it hasn't yet! I recognized the name Eric Dotson too.

MadScientistMatt said:

I keep reading this thread waiting for ill-advised behavior to surface, and it hasn't yet! I recognized the name Eric Dotson too.

I did buy a Duralast water pump, which cost me a water pump, a radiator, a hood, a clutch fan, a timing belt, and a fan shroud, so I got that goin' for me.

I was at wide open throttle when the water pump casting cracked, allowed the clutch fan to helicopter up into the radiator, and then explode.

Usually, I only buy OE stuff for things that go near the timing belt, but for some reason I ended up with a duralast water pump and I don't rightly remember why.

If you look, you can see the issue reflected in the hood:

So I got to pay the stupid tax on that one, and ended up sourcing a new (used) hood and painting that in my garage.

Then, I took the car to Radwood SoCal 2019, which was a ton of fun.

I met a man there with a tattoo of a 1st gen Previa, and took a photo of him in front of a Previa that wasn't his.

But on the way out, the clutch broke.  Again.

I limped it most of the way through California (we were in Tustin), all the way through Arizona, and halfway through New Mexico.

When I got it home, I found this:

The spring retainer had failed.

So this time I decided to go extra heavy duty, and got the sprung hub Southbend clutch, a Fidanza flywheel, an NA clutch pedal and overcenter spring (because the clutch vacuum booster, yes, you read that right, was leaking), and also a single-piece aluminum driveshaft (because the carrier bearing on the 2 piece was toast).

Naturally, the clutch pedal was worn out.

So I used the welder and fixed that.

Then I sized it up for a bush:

To my surprise, the Southbend feels very nice, even lighter than the Z1 heavy duty clutch, but it's rated to take almost double the torque.

In for more

AngryCorvair (Forum Supporter) said:

In for more

Sames. 

This car has also been to a couple national Z conventions (though never in the judged car show, I learned my lesson about that when I entered my 240Z in the "daily driver 240Z" category in 2012 and won by default with less than half the available points adjudged to my car).

In 2017, it was in Austin, and both the Zs got driven in anger on COTA.  My wife took the Z32, I took the 240Z.  I learned that I can hold my own in the corners, but it'll blow me out on the straights.

It was 113°F(reedumb) in the shade there though.  oof.

After the HPDE, we got a group photo on T16.

We also drove it (and the 240Z) out to Zcon 2021.  It was hosted in Colorado Springs, and between the proximity and the opportunity to stick my booger hooks all up in what was (at the time) the "Proto Z", I couldn't turn it down.

The guy with the 240Z in frame there with the parachute has a monstrous 2JZ installed, and entered himself in the autocross as well.  Its first feature was a left hand sweeper that he consistently started with a 2-step and then dumped it into a monstrous smokey drift.  I was faster than he was in terms of times, but I think he enjoyed himself more.

I also drove up Pike's Peak in the 240Z, which was entertaining, even though it started with 150HP and ended with about 30HP.

There was an autocross which I neglected to take pictures of, but did take a few videos.  I drove the 240Z again, and my wife drove the 300ZX.

Man,

I am LOVING this history thread...

My son and I have a 300zx TT thread going on here:

https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/a-build-thread-in-search-of-a-project-car-jacks-first-daily/273141/page7/#post3975660

I mention our thread because we are looking at buying an OBD tool for the data stream and other Consult functions.

We have a Wolf modified ECU and a spare we assume is OEM. We don't really need to tune at this point,  but having that option (additional hardware likely needed) as a part of the future expansion of the system would be cool.

Right now we are looking at drive-ability and maintenance stuff... lots of parameter plotting etc..

I've seem a few and have an idea or two... but I'm guessing these are roads you have been down.

I like my advice backed with expereince. :)