1970 Nissan Laurel project

[KC30]

Thanks again everyone! Man... I keep pondering JCCS now, but we'll see, gotta take care of some other things and I'll have to figure out a way to tow it.

 

Anyways, the turbo outlet elbow came in today.

 

Out of focus above it is the 2nd O2 bung that I'll be getting added on. Once that's done I'll start sorting out the exhaust also. That's going to be tricky and expensive. I'm looking to run 3" all the way out, but I have very limited ground clearance. Lucky I've found a few places that produce oval exhaust and the required transitions, so I'm planning on using that from the turbo to behind the rear subframe, then 3" muffler and out. Just have to figure out a good muffler that will fit and I'll like the sound of... I think that'll be the trickiest part.

[Rob W.]

Super sweet ride. I see you are in NM, what part I wouldove to see this thing in person. Anyways keep up the good work.

[KC30]

Rob W.: I'm down in the Las Cruces area, and thanks!

So I had some time to tinker this weekend. When I was looking at the O2 sensor and turbo elbow stuff, I realized that the MAF looked a little odd. I had one with a 90* plug, and not the straight one that I'm used to seeing. So I started researching and found that I had a CA18DET MAF. Not sure how I didn't catch that was what I was given during the install, but I was pretty rushed at that point. Luckily for me I have a friend waiting on his wise harness for his S13 SR and he let me borrow his MAF... what a difference! So I'm hoping that what I thought was fuel system problems was just the MAF sensor being wrong. First here's a couple of pics of the MAF difference in the SR and the CA one I found I had installed:

 

As you can see, not only is the sensor different, but the SR one is slightly larger opening. So I've got an S13 SR20DET MAF coming to replace the CA one since I borrowed this.

 

Next, I started working on mounting the new fuel surge tank. I got it all setup, just waiting on the final install it until I get the fuel line in and installed. The best location for me to mount it is where I currently have the Walbro 255lph fuel pump, which under the rear driver's side (RHD) seat.

Just to refresh, this is where the Walbro pump is installed (the pre filter is no longer there, it was temporally installed due to debris in the fuel tank):

So I dropped the Walbro out of the way and started with a couple of initial mount brackets. I was going to use the mount brackets with the kit, but I had some clearance issues and had to come up with this using L-brackets:

Next, I needed to tie the two L-brackets together, which also gives me something to clamp the surge tank on. So I riveted a cross brace on:

And a test fit of the surge tank mount bracket on the car:

Here's the final test fit with the surge tank installed on the bracket. I also had a sheet of teflon that I picked up several years ago in Japan. So I wrapped the tank with that to prevent damage from the rivets on the bracket and minimize any vibration:

Here's the surge tank and bracket setup as it'll be used:

Here are some other less interesting pics as well:

Teflon wrapped fuel surge tank

Surge tank installed on bracket in car

Surge tank on mount bracket 1

Surge tank on mount bracket 2

[Jester]

Great progress and pics. Hope to see you continue with the pics on the fuel line hook up on that surge tank. I haven't gotten that for on my research yet and look forward to learning.

[Tomakze]

I love a good thread with tons of pics! I never remember to take pictures as often as I should.

 

So, I guess I don't understand the difference between a surge tank and a regular fuel return line...

[KC30]

Tomakze: The surge tank is basically an inbetween tank (the engine/main fuel tank). It's there to have fuel ready for when the main tank is unable to supply fuel (when the tank gets low and sloshing prevents fuel from remaining in the fuel pickup area). Most street cars don't have this happen as there are baffles in the tank to prevent sloshing... but when on the track during long sweeping corners (or on highway long curving ramps) the fuel has enough time to slosh past the baffles and starve the fuel pickup. Or in my case, I have a fuel tank with no baffles. The surge tank is there full of fuel for those times (mine holds one liter) so that when the main tank is in that condition where it has no fuel to supply, the fuel starts to be used from the surge tank. Then when the main tank can supply fuel again it refills the surge tank.

Here's a diagram of my setup:

Also, this takes the pressure load off of the first pump (in my case the Walbro 255lph pump). Which without a surge tank, it has to pressurize the engine fuel feed line and flows about it's rated 255lph at stock fuel pressure and voltage. With the surge tank, it doesn't have to build any pressure (since once the fuel surge tank is full the fuel just feeds back to the main fuel tank), so I researched and found that it should flow about 325lph due to 0 pressure. More than enough to keep the surge tank full with the Bosch 044 fuel pump supplying the engine. And the fuel return from the engine just goes back into the surge tank to help keep it full.

 

Hopefully that all makes sense. The part I'm trying to figure out now is the wiring... With just the Walbro it's running off of a 20amp fuse. But now adding the Bosch, I'd like to wire them off the same power wire (not independent), but not sure what rated fuse I should switch to. Plus I need to upgrade the power supply wire.

 

 

[Rob W.]

That's a bummer you're so far away.

 

The fuel pumps should give you their amp draw either on the pump or in the specs add the 2 together and get a fuse just a bit larger than the total.

[Tomakze]

Wow, thank you for such a detailed response. That is an incredible idea!!! I am going to add that to my wish list... I was just at the track the other day, and a guy with a 370z was having that problem. Below half a tank, he was having fuel starvation issues. I wish I had known about this, I would have recommended this idea to him!

[KC30]

Tomakze: Yeah, a friend of mine in Vegas with a 370z was just telling me that same thing and looking for info about this setup. Fuel starving on long rt hand sweepers just below 1/2 tank.

 

 

Today I picked up the turbo outlet pipe after the 2nd O2 bung was added. Yep, the brand new Megan racing outlet needed some modifying. The new one is on the right:

Here's an inside view:

Here it is with the 2 O2 sensors installed. For now it's the stock skinny one for the ECU and a fat one for my Apex'i TT. Down the road it will likely get a wideband O2 sensor... but there's lots of things to do before that. In the meantime this should be a good basic setup, the Apex'i TT and the same sensor is what I had in my Skyline (I miss it SO much!), and it was pretty accurate.

Here's the setup ready to go in... and yes, that is all it has for an exhaust right now! I tried to get the exhaust done before, but I couldn't get the 3" I wanted due to ground clearance. I've considered a Y-pipe with two smaller exhaust pipes running back, but the forward curve is too soon for that to work. But I finally found a place to order 3" round to oval curved transition, then it'll be 3" equivalent oval back to behind the rear subframe, then back to 3" round, a muffler and out:

Here's the new turbo outlet installed:

Again, here are some less interesting pics:

New and old turbo outlet 1

New and old turbo outlet 2

New turbo outlet with 2nd bung, side view

New turbo outlet with 2nd bung and skinny O2 adapter

[HRH]

Hella sweet Laurel! Welcome to Ratsun, I'm jealous of your car!

[KC30]

Thanks!

 

 

Today I finished wiring in the 2nd O2 sensor, so that's ready to go. I started working on the fuel surge tank again, getting it plumbed in. I've got it in, and forgot to check the fuel level, which was near full... So yeah my stupid self got soaked with fuel.

I still have to mount the Walbro pump in it's new spot and do it's plumbing. Then do the wiring for both pumps.

Here's the fuel hose arrangement I ended up doing:

[KC30]

Thursday night I got the surge tank fully installed, with the Walbro pump moved towards the fuel tank and both wired in. Here's a pic of the tank installed, not much to see though:

I tested it out, and surprisingly it was leaking from the electrical studs. But I was able to put on a little RTV and it's good now. I still have to upgrade the fuel lines, waiting for the parts to come in. I also won't have the SR20 MAF until tomorrow. Now that I'm able to read the AFR, it's definitely rich, I'll see what the new MAF does. But even without the correct MAF, just the new turbo outlet and fuel system... it's running MUCH better!

Since I was able to get out, I got a couple of new pics:

 

 

[KC30]

Today the new MAF came in. Now since I've had the second O2 sensor for the AFR, wow what a difference. The CA18 MAF that I had would closed loop idle at 10...! It would run rich and after holding constant throttle the ECU would slowly adjust to 13-14. But having the right SR MAF, it's holding 14.2-14.3 constant. It's so nice to have it running right.

[KC30]

Argh... So I thought everything was running right... Until I hit about half a tank, it started running very lean! Max'd out the gauge at twenty and could start hearing the surge tank pump. So something's wrong in the main tank. Starting to wonder if the pickup in the tank broke, because it started doing it after a few months of doing fine.

[KC30]

So, this last weekend I finally got the Laurel back on the lift to change the fuel lines between the surge tank and the engine. It now has 5/16 feed and return lines. Next is to do the lines to the fuel tank and between the tanks.

Here's a pic right after it was on the lift, you can see the surge tank (white, on the middle right side) and the rear coil overs.

 

[zerow]

I love your car's ass...no homo...

[KC30]

Well, since last post I've been for a drive in the mountain. The car did great, but it was VERY loud... I need an exhaust. Also, if you haven't seen in the electrical section, I'm having some problems with my headlights dimming under WOT/high RPMs. They seem to be the only thing effected and my volts don't drop, though I don't know what my amps are doing. Originally I was thinking it's an amp issue, so I started the Nissan Quest 125A alternator upgrade. Here's the old and new alternator:

 

 

To fit the lower mounts, the holes had to be drilled out for the 10mm bolt the SR uses. The upper bracket has been removed, and I'm waiting for the last parts of the new upper linkage to finish the install. Here's the alternator in, waiting for that:

 

 

Since I've started the upgrade, I'm now wondering about the headlight relay since it was brought up. So I'll finish this install and see what happens, if the problem's still there I'll start looking into it.

 

Also, I've had problems with the dash light bulbs going out and just being too dim. And the original headlights are dimmer than I'd like as well. So I've ordered LED bulbs for the dash and new brighter headlights.

[KC30]

So I've been running the new alternator for a week, and it's made a huge difference that I didn't expect. As I mentioned above, I'd have an issue with the engine running lean on occasion. In trying to sort it out, I've added a fuel surge tank with a second pump, replaced fuel lines, and still the engine would run lean/start stuttering once the tank got near 1/2. This was something that started a few months ago, I originally noticed it when it was at about 1/4 of a tank. But that was a new change since I originally had it running/shipped with hardly any fuel. Even more recent after all the changes to try to sort it out, it was starting to run lean randomly even with a full tank. I was last attempting to find a way to install an in-tank pump or change tanks.

Now, in deciding to upgrade the alternator while trying to sort out an odd electrical issue, I didn't expect to find what seems to be the source of my fuel issue. Since I've replaced the alternator the engine hasn't has any readings of running lean and so far I've been able to drive it down to 1/4 of a tank. My old alternator was always reading good volts, but as I was wondering about, it seems that the amps were low.

 

Now I've been frustrated with dim instrument lights and seen something about upgrading to LEDs. So I ordered them and did that yesterday, what a difference! It seems like I had the original lights in there as well, with the old Toshiba script on them:

Here's a view of what it looks like now, finally some actual light. Before, the brights indicator was hardly even visible, now it's very noticeable.

[Tomakze]

Love watching the progress!!! It must be fun to just worry about the details. That is my favorite part of working on old cars: Tinkering! I am still in the "I need this part to get closer to driving it" faze. That is not nearly as much fun, lol! :cool:

[KC30]

Thanks. Despite how it looks, I've got a lot more than the details to worry about, but it's only the details that I could afford to do. I'm trying to prioritize some things. Front suspension rework, radiator and intercooler, exhaust, there's more... but that's all I can think of right now.

 

Tonight I was out getting some pictures of the nearby mountain fire (started by lightning), while I was out I got a pic of the Laurel in the garage. (Sorry, it's a messy garage)

[KC30]

Unfortunately haven't done anything new to the Laurel. Had to ready and do a long road trip in my slow Isuzu this month, to that was priority. But I made it back Friday night and drove the Laurel out to White Sands National Monument to so the hot air balloon fest. Here's a couple pics of the Laurel there:

 

[jun]

What a beaut!! :D

[Jester]

I'm trying to prioritize some things. Front suspension rework, radiator and intercooler, exhaust, there's more... but that's all I can think of right now.

 

Maybe take out the lift blocks in the rear and put them on the other side of the spring. That would be cool.

 

EDIT: It's so weird. I look at the two pics above and the top one looks like a '70's hot rod all jacked up in the ass, then, you look at the lower pic and it looks level.

[SSS510]

Thanks. Despite how it looks, I've got a lot more than the details to worry about, but it's only the details that I could afford to do. I'm trying to prioritize some things. Front suspension rework, radiator and intercooler, exhaust, there's more... but that's all I can think of right now.

 

Tonight I was out getting some pictures of the nearby mountain fire (started by lightning), while I was out I got a pic of the Laurel in the garage. (Sorry, it's a messy garage)

 

SWEET RIDE!!! :thumbup:

[KC30]

Thanks everyone! The ride height/stance is something I've been torn/pondering on. It's got the 70's stance alright, but it does look different depending on the angle you're at. I can't get the tires into the fenders until I get custom front control arms. I still need to get the new front coilovers that will be a little taller also, then maybe taller tires... closer to the stock Laurel tire height. Once I get the front sorted I can decide how the rear will sit. But for now, it's fun to sport the 70's raked stance.