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N62 Z3 Part 21: Paint & Reassembly

And finally... the first coat of 2K epoxy primer. I did a light dusting for the first few coats

I was pretty happy with how the seams came out

And another coat

It's nice to see everything in one color now

Then a slighter thicker coat was applied

Then it was all scuffed up a bit to make for a smooth surface and check for any imperfections

If I was building a show car, there were a few more spots I could have touched up, but I plan on driving the car and the things it needed were very minor, so with that in mind I decided to move forward from here

After a final layer of primer was applied. It will cure overnight and be painted the following morning. The final result after the final primer layer looks pretty nice, especially the areas I focused the most on which is that seam from the fender panel to the shock tower

The next morning it looked like this and I scuffed it again and started painting

After the first two coats of paint - I took the pictures while the paint was wet so it looks a little splotchy

I was originally planning on painting an original radiator core support (so that if I wanted to ditch the dual intake someday it was already color matched) but I didn't have enough paint to paint two so I just did this one. There are certainly some areas on this panel that could have used more work but those will be covered when installed anyways

After the final coat

The following day I started re-assembly and finished attaching the brake lines. I still have to bend the ones between master cylinder and the ABS unit

Some more photos from the following day after the touchup areas had dried. We did have a dust storm the night before these photos were taken (or at least it got really windy, my cars were filthy) so there are specks of dust here and there but gives a better idea of the overall look

Then I added some clips for the brake lines to hold them in place, I rivnutted through one side of them to keep them secure and allow the lines to be removable without the clip flopping around

There is a multi-line holder here under the steering shaft - it holds in the two lines that go to the rear

Next I cleaned up some of the wiring around this area, it's starting to come together, everything in this area is just about done except the lines from master to ABS

Some DEI "reflect-a-cool" heat rejecting wrap in the transmission tunnel

Then started to tidy up the electronics area a little bit

Starting to come together

I think this came out pretty well although if the green had a little more contrast against the black I think it would look even nicer

Next was to work on something I had been avoiding for a little while if I am being honest and that is to finish the last little bits of wiring. When I got it running there were a few jumper cables here and there sort of making everything work and my goal was to integrate all of that and also now that the pedal wires were routed through the firewall and it was painted, it was time to install the pedal harness too

Not a lot to show picture wise but there is a little visual evidence of the work... the coolant temperature sensor harness is all wired in and the PWM fan wires are all installed although I don't have a harness on those yet though because I haven't decided what fan to run and different fans have different harnesses. These wires are a couple gauges thicker than stock wiring for this application, just in case that fan is running heavy duty to keep things cool I don't want to worry about the wires melting or anything

I actually went back to the shop one late night because I got so excited about this idea I had and by the time I got there I had worked out an even better version of the idea. The problem I was facing was that I wanted to install the stock electronic pedal that the M54/S54 Z3's got. However, to be perfectly honest, the later assemblies are a more reliable system overall and I didn't want to work myself into a corner where I wasn't able to swap to the newer style pedal if I wanted to. So my initial idea was to pigtail two harnesses off the wires, so that they would effectively "both" be installed but only one would be plugged in at any given time

Then I just thought, well, why don't I just use an extra connector to make an adapter... and because the one side was cut so long I just crimped the pins onto the ends so there aren't any splices in the middle - just nice crimps like factory

I'm probably way more excited about this than I should be but I thought it was pretty clever. It allows me to plug the newer style pedal into the older style connector

After the PWM fan harness is on, I believe I only have one more wire to run, which is the main positive to supply the fuse box. I also was not able to finish wiring the Z3 pedal stuff because I was out of male pins... once those arrive I will finish that and reinstall the pedal box

Then I decided to install the suspension, the first step was pressing out the old bushings and pressing new ones into the "lollipops"

Then installed and the control arms were "complete" - I was given this suspension kit for free and I've always been curious about the quality of Uro suspension parts since some of their parts are actually quite good. I utilized many of their parts for my engine build and those parts seemed well engineered so I will install the kit and give it an honest review once running

This was the steering rack I decided I will be running so I swapped on the new tie rod ends, being very careful to match the lengths as close as possible (although once I hooked up the steering linkage, it felt a little weirder than the old one, so I miiight be looking for another rack some point)

And the suspension all installed! Next is to find or buy some good 3.0 brake rotors and calipers/pads

Installed the PWM harness after deciding what fan I was going to run

Installed the stock Z3 power steering line from the rack to the cooler and the only line I will need to worry about as far as getting that system to work will be the high pressure line from the rack to the pump

Then my male pins arrived so I could finish the pedal wiring

All installed!

And then I installed the rest of the pedals! It is so nice to finally have it starting to look a bit more like a complete car... I also plugged in the EWS and the gauge cluster as well as a few other random modules which were unplugged while I was welding. Everything is done with the pedals except the supply line from the brake reservoir to the master cylinder which is super simple to do

Next focus was the fuel line, I was not able to ascertain whether or not the fuel hardlines come pre-bent. My main holdup with doing it the way I am doing it now was that I wanted to maintain the quick-connect nipple on the fuel line. I did realize though that the quick connect nipple was broken on the fuel rail I have installed currently... I could install a different fuel rail but doing it this method let me kill two birds with one stone because I didn't have to worry about the quick connect anymore; I just cut the nipple off on the engine so it's a rubber softline and flared both ends of the fuel line with a standard brakeline flare. The fuel filter side is already installed and once the engine is installed the rubber softline will just use a normal hoseclamp to install in place. Not ideal but it will definitely work.

I also used my previous pictures to deduce where to route the line... I know I am in the right ballpark but can tweak it a bit if needed

Attached below is picture illustrating which is the supply line, this needs to mate to that hardline I just made. I think it's in the right spot

You can see it peeking up near the brake booster, most of it is covered in the heat protecting sheath though

Detail of how the lines fit into the chassis "pocket" I made earlier. The engine is very close right here, so if it ever hits the framerail now it won't contact any of the lines

Then I went ahead and worked on finishing up the brake lines from the master to the ABS unit and snugged everything down

I like the look, I will see if I can move the electrical wires out of the way a little bit next time I am at the shop

Really feels like it is coming together at this point

Then I added some struts and brakes. I went with stock struts and springs from an E36 M3 as a temporary measure, the stock struts that I removed from this car were pretty gross and those springs are meant to support the lighter aluminum I6 engine, whereas the M3 had an iron block engine (same as the Z3M). Down the road I plan to upgrade the suspension with some other parts I already have on hand but I want to wait until it's running before I throw those parts at it. Struts are very easy to swap out later

Brakes I went with stock E46 330i front brakes and stock rears. The stock brake rotor width was 286x22 and the Z3M including S54 are 315x28. The E46 330i front brake rotor is 325x25 so has 10mm increased diameter over the Z3M but compromises a little thickness, which seems fine to me. It seems like M models usually have thicker rotors as the larger thermal mass helps with heat dissipation, which is mostly a consideration on the track. I am not building this car with the intention of it being a track car so I think this setup fits the theme of the build

Next I finished the fuel pressure reference line, which means the fuel system is totally done as far as what I need to do before installing the engine. The fuel pump is inside the car so I can upgrade that down the road without much hassle

I am almost ready to bleed except I don't like how those E46 lines are sitting... I have some Z3 stainless steel lines on the way

Some minor work next, I got some hardware for the brake line clips to hold them down for good and sorted out the brake booster vacuum line

The final length will be set once the engine is in place but it's in the right position now

Next after the stainless steel lines were installed I was able to finally bleed the brakes

I also wasn't digging the gold tape wrapped DME partition so I decided to swap out a stock black one I had on hand. I'll use the gold one in some other future build but I decided to tone it back on the visible gold and keep the theme black and silver

When I swapped the steering rack the new one felt really weird so the next task was to figure out why, since previously it had felt really good. After more inspection it ended up being the U-joint, I recall when I was installing it onto the rack I hit it a couple times with the hammer to get it all the way down and it must have deformed part of the joint bearing or something. It felt weird when wobbled in one direction Before I even knew what was wrong I had another U-joint purchased and on hand "just in case" and I ended up installing it. A $130 mistake but, I was very careful reinstalling the joint onto the splines to not deform it and am very glad the steering no longer has that binding feel

I also tried to demonstrate how "tight" the steering is, I am hoping this will translate into good steering feel when on the road like the Z3/E36 is known for

I then focused on finishing the engine which first meant welding the V-bands onto the headers

I wanted the flange to sit just between the transmission and oil pan - the OE catalytic converter sits right in that spot so there is room there for exhaust and I had noted previously that there was space there. So I found some exhaust pipe I had laying around that was the right diameter with the correct bend I needed then trimmed it to shape