PERFORMANCE
BOLT-ON'S?
I've done a number of bolt-on upgrades for other cars; but the Datsun is a little different. I don't want to go and stick a bunch of random stuff on this thing, at least not yet. Right now, it has its original straight-6 engine. It's pure and it's beautiful. Is it fast? Far from it... but it's still fun to drive because it's old and it's quirky. The transmission has a heartwarming clunk every time I shift gears. It has the 5-speed transmission from the '79 ZX so I get that extra gear and am able to keep my RPM's just a little lower, but performance wise, it's nothing special. That said - I've only just moved into the engine section so who knows what I'll end up doing.
VALVE LASHING
Ok now I'm in the guts of the engine. Removing the parts and pieces to get to the valves wasn't hard at all. Pulling a few rust-free bolts, and there I was, staring at my camshaft and valve springs. The reason I decided to take on this endeavor was because I had a light tick when the car was idling, and I wanted to see if a) I could fix it, and b) I could figure out how to do it. Again, I found a video on YouTube of a guy doing exactly what I was after - and by the way, this guy's video was awesome. Not only did it show me what I needed to do, he explained very simply why I needed to do it. I went and picked up the necessary tools and went at it. The tools in this case were a feeler gauge, and a pair of wrenches (14mm and 17mm). I did exactly what he did - cardboard and all - and did my adjustments. To my surprise, they were already really close to where they needed to be. I probably didn't have to adjust anything, but I wanted to feel like I accomplished something so I made a few adjustments. It was an easy process, and in the midst of it I replaced the gasket as well.
EXHAUST
I'm not sure exactly what the previous owner had on this car - all I knew was that because of how low it sat, it was pretty badly dinged up. I wanted to replace it, and while I was at it, I wanted to try and get that rumbly muscle-car sound out of it, so I opted to do headers as well. I bought ceramic coated 6-1 headers from Motorsport Auto, and from the same place, the header-back exaust system.
The headers were by far the more challenging of the two to install. Not because they didn't fit or I had to modify anything, but because it's just hard to get to all the bolts to mount them to the engine. The nuts are in just the weirdest place and are tough to get to. I had to twist my arm in all sorts of uncomfortable positions just to get the nuts loose.
Before that though you have to remove the intake manifold because it's gigantic and in the way. You have to remove the throttle assembly and a handful of hoses to get it off. That part wasn't so difficult, just make sure when you do it you put all the parts and pieces in a bag and label them, and set them aside and in-order so you know where to put everything when you re-assemble.
When you finally get to the stock headers, beware that getting to those nuts is hard. The top ones are a piece of cake and will come right off. It's the weird hidden ones underneath that present the real challenge; plus the clearance between the sides of the nuts and the header assembly is very small, so if you're trying to do it with thick-wall sockets, it's not gonna happen.
Once you get that off, you'll find that most of the nuts come off clean, while others will take the studs with them. No matter - the kit from Motorsport includes new studs. Once you get the header off, you'll be happy to realize just how heavy it is, and that the new header kit is way lighter weight. Use a vice grips or channel locks to reef on the remaining studs to remove them from the engine. You'll get a real workout doing this part. While I was there, I took a few photos of the insides of the intake manifold, looking for carbon buildup, oil leaks, whatever. I was thrilled when I saw just how clean it was in there - this thing has a rock solid heart.
When I was done, I installed the new studs. I made sure to use threadlock on these because several forums said that they'll loosen over time if you don't. Is that true? No idea, but probably. Checking them around 500 miles later, all was in order. Slip the headers over the studs, fasten the down and reassemble the rest.
I was super happy with not only the way this looked, but how it sounded too. It has this tinny sound - I know that sounds like a bad thing, but I don't know how else to describe it, especially on a cold start. Once it warms up, it rumbles like a monster. I am super happy with the sound and feel I got after putting on these headers.
EXHAUST
I don't know exactly how many exhaust options are out there for the Z cars, but I think the answer is 'a lot.' To be safe, I went with the Performance Exhaust from Motorsport Auto, since I went with their 6-1 header system. This system is pretty straight-forward. It bolts right up to the headers, all the way to the back of the car, and includes every piece of hardware required. That's a pretty common theme for Motorsport - they're great about making sure you have everything you need. Before installing the exhaust system, I chose to cover it in heat wrap in the interest of keeping heatsoak from getting in the cabin, as well as insulating the sound a little bit. The exhaust system does not include a resonator, so in my head, this would help prevent some of the inevitable drone I'd get otherwise. It might help a little, but can still sometimes be droney at just the right (or wrong) RPM. That's my only complaint.
This was pretty simple - line up the pipes, bolt the rotary-shaped (god I love Mazda too) flanges together, until it's installed. The only 2 things I came across that were difficult here was the clearance I had to work with when bolting the pieces together, and fidgeting with the muffler to get it at just the right angle to fit up under the bumper cover without it being super visible, and also keeping it from touching the fuel tank. A little patience and I was on my way.
THE REST
That's about it so far for performance. As I said, I'm just getting into the engine bay and I'm sure several upgrades are on the way. The only other things I did was install a pair of Cusco strut-tower braces and an inline fuel pressure gauge. The car starts and runs well, but turns over way more than I'd like it to. My first inkling was fuel pressure, and I think I'm on to something. It builds up the right amount of pressure and runs just fine, even under acceleration - but overnight, the fuel pressure gauge drops to 0. Somewhere, I must have a leak but haven't found it yet.
The strut tower braces made a huge impact from a structural standpoint. Any time I'd jack the car up it'd creak and moan in pain. I hated that sound. It made me nervous every single time, so I bought the strut tower braces and installed them. One thing to be aware of though, which I learned the hard way - the kit I bought was for the 240Z, not the 280Z. Because of this, I had to make some slight modifications to the mounting brackets with a Dremel to make the mount points larger on the rear tower brace. The front fit like a gem, but the rear was a challenge. Totally my fault - I didn't even see they specified 240Z... whoops.
