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More goodies are arriving. This magnaflow 4" round muffler just appeared on my doorstep (thank you amazon prime) and supposedly a new Vibrant Ultra Quiet resonator shouldn't be far behind (damn you amazon prime). Last time I had a round muffler like this paired with a motorsport 6-1 header, it was loud enough to wake the dead. Neighbors used to say it sounded like a Cessna coming in for a landing when I'd come home from work. With that in mind, I opted for the Ultra Quiet resonator, after some deliberation around the SIZE of the silly thing. 4" tall by 6" wide oval body. I took some measurements, and I think it should fit snugly in the tunnel and only hang out 1/2 inch approx. 



Once the system is all welded up, I intend to powdercoat it, from end to end. I've been trying to decide on a color that is timeless, semi-low key, and a good match for the orange paint. It's really hard to make a decision about metallic finishes by looking at images on your computer screen, so I paid a visit to some of the local powdercoating outfits to see high temp coating finishes in-person. The "Titanium" high temp coating from Amerikote (2nd from the right in the above photo) is my #1 choice right now. It dips more into the gold/brown hues than the titanium offered elsewhere, and the guys there tell me that it has the 2nd most desirable heat transfer properties of all their high temp coatings. Seems like a nice balance of form and function. I used to have their super shiny coating on my last set of headers, and it eventually got a little thin around the high-heat bends in the primaries. These guys are telling me that the Titanium finish does not do this, so i'm excited to try this out! I'm also looking forward to seeing the magnaflow with a nice even color on it. It arrived with the makings of a good patina starting around the welds, but that's totally not the look i'm going for. 

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So this is interesting. I was re-installing the intake manifold and headers last night, and I thought to myself, "dang, looks like i'm going to have to modify some washers again, because the mounting surfaces of the intake manifold and header are different thicknesses."  Then I took a look at the washers that came with the car, and they had already been modified. 


Leon, if you're reading this, I'd love to hear your thoughts on this. Did you modify these washers yourself? Is this only a problem with the Cannon manifolds because it's the same manifold and the same issue I had last time. Is this SUPER common? How do other people deal with this issue? Does anyone sell "pre-clearanced" washers? Do people just modify their manifolds with a die grinder? Do other brands like TWM fit any better, right out of the box? 



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Ahhh yes. Got the car back from the exhaust shop and the guys did a nice job mounting the muffler at the exact position and angle i was hoping for, and also managed to shoehorn that Ultra Quiet resonator in there, with surprisingly good ground clearance. 



You can see in this pic, that center section of pipe bends up a bit to get that resonator as tucked as possible. I can also swap that section out for the straight 2.5" pipe that came with the MSA exhaust kit. So if I ever want to open her up, the setup is kind of modular =)



And in the rear, a nice subtle angle. Nothing too crazy. Just enough to compliment the contour of the body.




Also, I decided to make a before/after video of the exhaust sound, because I wasn't able to find any examples of this particular combo when i was exploring options. Hopefully this will help the next guy make a decision. All in all, I'm pretty darn pleased with the outcome. The resonator reduced a ton of drone in the cabin... to the point that it sounds quieter than the previous exhaust, at idle. But when you floor it, all hell breaks loose. It's aggressive and gutteral, but with all the sharp edges removed.

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  • 2 weeks later...

Just got back from a 10 day stint in Grand Junction, Colorado, where an unexpected family emergency took command of all my attention, as well as my wallet. Whatever grandiose plans I had for the Z are going to be on hold for a while. Thankfully, I already set aside the money for the Powdercoating, so I can finish my exhaust system. And when I got back home, my last amazon order was waiting for me on my doorstep. So I have stuff to keep my busy for a while.




Last night, I installed said amazon purchase. An analog style AEM wideband controller/gauge. After getting the 14point7 controller installed, I made the difficult decision to replace it with this one, because I really wanted a dial to look at instead of a wandering numerical display. Easier to get at-a-glance info with a big fat red needle to look at. The 14point7 unit DOES have an output for a simulated narrowband signal, but it felt weird to have two gauges. Finally, I found this AEM stepper motor gauge with the UEGO controller built in. Price was steep, but not horrific. Once I learned that you can set the backlighting to green, the decision was made.




Since the factory clock is non-op, I decided to gut it, and install the AEM gauge in the clock housing. Happily, it fit with a slight mod to allow the cables/connectors to fit through the housing. 


Gave it a first test drive a few hours ago, and I am very pleased. Amazing how a good data visualization can give you immediate insight into esoteric processes. For instance, I never realized just how lean the exhuast can run at idle. I can actually SEE how the fuel mixture affects the power band. I can see WHY the DOCEs stumble off-idle, sometimes. And I can see WHEN the main jets kick in... and how well-tuned they really are. Pretty sweet!



Oh and finally... Since the AEM kit came with it's own O2 sensor I now have a completely functional 14point7 wideband controller kit sitting here on the bench with nowhere to live. Anyone interested? Drop me a line. Comes with everything you see here. Part of this complete breakfast. 
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  • 4 weeks later...

Xmas came early this year! Picked up my exhaust from Amerikote this afternoon. Tonight is going to be a BLAST! I spent the last few days changing the head gasket, cleaning the HECK out of the engine compartment, and getting ready for this badboy to go back in. Was going to wait til i had it out in the daylight before posting, but i'm like a kid on Xmas morning right now. Couldn't wait to start unwrapping my present!  :D



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  • 2 weeks later...

Big update today!


I can't remember ever saying this before, at any point in my life. This car is running SO GOOD that i'm stopping here for the rest of the summer. It tracks in a perfectly straight line.No wobbling steering wheel. No driveshaft vibration. Minimal valvetrain chatter. No sputtering. No backfiring. No dieseling. The only blip in performance is that off-throttle bogging of webers that is just part of owning webers. I've had my hands on every last last thing under the hood without actually blueprinting a new engine config (which i still plan to do in a year or two), and made it my own. Readjusted the valve timing, and did more tuning on the ignition map. My last motor (destroked with a stage 3 cam) was certainly faster, but I've NEVER owned a Datsun motor this healthy until now.


On top of all that... you can eat off this thing.



It's at that point now where your eyes are drawn to the outlying dirty components, like the timing chain inspection plate, the fuel & brake lines, the yellowed plastic on the master cylinder. We've reached the next phase!  :D


There was one big hurdle a few weeks ago, however. After the head gasket job, the valve timing was completely screwed... to the point that it was shooting fire from the carbs. I even called Leon at one point out of frustration because it seemed like no matter what i tried, it wouldn't go away. In a desperate moment, i considered that the timing chain might be off by a tooth, and I tried advancing and retarding +1, +2, -1, and -2 teeth. Still nothing. Played with the crank sensor position and the offset within the megajolt software. Nothing. Compression was great on all 6 cylinders. Was starting to pull my hair out.


The experienced folks here probably already know the answer. Somehow (and i seriously have no idea when or how it happened) the firing order was wrong on the coil pack. It was running when i took it all apart, and i normally never take the plug wires off the coil pack. Usually i pull those off as one unit and set it to the side. I want to say a friend of mine did it when helping me clean the parts, but it was probably me. The only reason i didn't notice it earlier is because it's not the 1-5-3-6-2-4 i'm so accustomed to on a datsun distributor.  :unsure: As soon as I switched the wires back, it fired right up and instantly ran like a champ.




On the bright side, I found issues inside the timing cover when i tore it all down. The curved timing chain guide was loose, and the chain had quite a bit of slop in it. This ended up being the source of the valvetrain noise I was hearing. Now, everything is running really quiet under the hood, and the timing is all centered. The slots on the crank wheel have the same amount of adjustment in either direction now, too. But I doubt I'll ever need to touch it again, because there is so much adjustability in the megajolt software.


My good buddy who I worked with at ALLDATA for many years is an expert tuner (a turbo volvo guy) and came over to help me look at the timing map. He sat in the passenger seat with the laptop, while i went up and down the powerband on a straightaway, conveniently close to my house. 


Here is the "before":


10 degrees of starting advance (the big green number), 36 degrees under load from 3000 up... It felt really good at low rpm, but seemed a little "uninspired", under load. 


Now here's the after (blue outlines the changes. SHADED blue appears to be a mistake. Gotta bump those up a few degrees):


Basically the car just kept taking everything we threw at it. If you look at each column, we tried making the curve more gradual. And across the board, everything got a good 2-5 degree bump. It feels GOOOOD, and we never even heard it ping. Could proabably benefit from a few more degrees, but I'm kind of thinking of getting a cheap standalone knock sensor (like KnockSense) to help find the safe edge.


The only weird thing, is that when I apply gradual power, from a cruising speed, the wideband gauge drops somewhere between 10:1 and 11:1 AFR. My friend seems to think there's another 10-15 horsepower hiding in the midrange here, and that I should experiment with jetting, or add more advance in the midrange to start burning that fuel a split second earlier. Open to opinions here! 



Oh and that titanium colored exhaust coating? Loving it. The headers are GORGEOUS under the hood (the engine appears to be developing a "metal on metal" color scheme), The muffler almost matches the tail light panel color, and it's understated. No exhaust tip. just a 2.5" outlet with an even titanium color that should never rust or change color (much). Also used Mr Gasket copper collector gaskets on the final install. It sounds spectacular, and the ground clearance on the resonator is ideal. I've gone over some pretty tall speed bumps and it never scrapes! My god... I DO want to drop it another 0.5"-1.0" in the front, but DO I???? Come on now... this is almost too good.


Here are a few more pics from the build phase:


protecting the paint from overspray (cleaner and engine paint)


11218871_462531447234850_797693601278734Before scrubbing it down with a toothbrush. I was able to flush a whole bunch of chunks out of the water jackets. No more external oil leak! I suspect there may have been TINY bit of leakage between water and oil. The oil never got milky, but the radiator fluid felt a little funny to me. No matter. It's tight as a drum now.



Terrorizing the neighborhood...



... while trying to maintain a philosophical high ground.



When your wife does this, it's a telltale sign that you need to spend less time shopping for car stuff, and more time shopping for house stuff.  :P


That's it for now! Just retorqued all the bolts yesterday. Next stop... Cars & Coffee! 

Edited by Swami
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Blackhawk Cars & Coffee in Danville. Sounds like it's a morning thing. Have you been before? Curious what is the best time to arrive.


Been there more than I could count. Ideally, you would want to be there early. My friends and I usually get there by 7:15 am. Earlier if you want to get into a premier spot, but then we're talking about 6:30 am, already at Blackhawk :P

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Nice job!!! Sounds great!!!!!


Fine tuning the dip in a/f ratio on carbs. is very difficult, it's the nature of the beast. It's easier to tune out on the TB set ups, but with the volume of air and fuel at once, it takes a second for combustion to equalize. I'm going to spend one more dyno session for the low end, where we had no time. Just going to trim it out a few % and call it a day.


It's fun to have a running Z car. I have a small battery drain somewhere, but I keep forgetting to plug in the battery tender.

Hmmmmmm....maybe I'll go out with my son today. I only drive it when he's with me.


Hope to see you at the next Cars and Coffee.

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