Jump to content
Sign in to follow this  

Persephone '81 280ZX

Recommended Posts

DatsunMotorSports Project Persephone 


This is Nathan's (AKA Gollum) old 280ZX.





I purchased the car from him back around Nov of 2014 and have been caring for it since. The timeline here will be a bit fractured but hopefully not disorientating. 




I came with a few buddies, and we shoved an L28e in it, and drove it back the same day!


Ive made progress, and stepped backwards more than a few times, and I dont expect that, I will find myself on the same path I am on now in the future with this car. Though the point of this car is that I have a backup car of sorts. But being one of my cars, I tend to go overboard. The car is still in the smog system here in Ca so I am also limited by that factor. 



I got as far as to get the L28e in and the car smogged, and then the head gasket on the L28e blew out. The engine had been sitting for many years prior to me using it so it was not unexpected.


So I installed an L28et. 
Smog Regulations allow me to install an 81 turbo as a replacement in an 81 car that had that option!

I also installed a Chinese Aluminum radiator and dented my hood!





I converted the car to a Z31 ECU at some point in time, I dont recall exactly when, but it was maybe 6 months after the L28et went in. I was having nothing but issues with the first turbo engine, and I was beginning to suspect a bad hole. I lost power and #5 went dead prior to the big turbo swap. After moving to Sacramento I just assumed the engine had had enough abuse so I installed a second engine I had around and it ended up being a mistake! I had installed a set of Doctor Injector Flow tested and cleaned injectors


Thanks to Marc Pickering for this Wonderful Writeup for the Z31 to a L28et




Turns out #5 injector took a dump, so it was off to Doctor Injector under warranty. 

But it was time to escalate again!



I opted for a Nistune with an 89 Z31 ECCS ECU and the Feature Pack to include E85 Flex fuel as here in Sacramento Ethanol stations are everywhere!





Yes, I installed a front mount intercooler! Many other small changes have been made. You will note the TechnoToyTuning camber plates, you will find T3 coil overs and adjustable tension rods under there as well. The lack of a power steering pump should also be apparent. A 78/79 S130 Manual Rack has been installed. It was interesting to note that a S30 RHD rack is the same part number! However S130 rack bushings are extremely difficult to find! A 1" Nissan BM50 MC has been installed to replace the stock 15/16" MC unit. The Ignition Coil and Ignitor will also stick out, but this last picture still shows the NGK plug wires which ended up being a huge source of ignition headaches! The coil is a GM HEI from a 96-99 Chevy Votech Truck engine, and the ignitor is a Nissan PRW-2 ignitor. 


"For the 280ZX Turbo dead ignitor:

Here's a better ignitor upgrade than the now common Chevy HEI swap. The non-Z31 VG30 and VG33 (Maxima / Pathfinder / Quest / QX4) engines use a PRW-2 ignitor that wires up almost the exact same way as the 280ZX Turbo and Z31. These can be easily found in the junk yard (in front of the distributor base) or parts store.
Step 1: Run the 280ZXT BLACK WHITE STRIPE wire direct to the coil positive.
Step 2: Run the 280ZXT YELLOW wire (ECU signal PIN5) to the right wire on the PRW-2 (GREEN RED STRIPE).
Step 3: Run the PRW-2 GREEN left wire to coil negative.
Step 4: Run the PRW-2 BLACK center wire to body ground.

Alternatively you can use the Z31 ignitor, the only wiring difference is the ground and ecu input signal wires are swapped. So on the Z31 ignitor the BLACK ground wire is on the left and the GREEN BLACK STRIPE input signal ECU PIN5 is in the center.


XenonZcar PRW-2  "

Credit to Marc Pickering







I Had Troy Ermish machine the stock 5spd Bell Housing for a KA transmission, modified the stock mounting member, and shortened the driveshaft.




I installed the tripod axles, and eventually pulled the whole sub frame out for a later 83 turbo with the late model brakes and control arm geometry prior to Z31 initial EFI swap. 



Upper is 82-83

Lower is 6/78-81




And Eventually Z31 CLSD went in just after NISTUNE was installed.




Keeping an old L28et working well on a stock stuff system was becoming a royal pain the butt. With the Z31 ECU swap in place and NISTUNE on the way it was time to address the TURBO!

And honestly the Garret T3 I was using was from a 85 Z31 with water cooling and it was starting to show its age. But when you have a HKS GT3037 (a big compressor version of the Garrett GT3076R) just laying around because it was too small for another project, why not use it?



I got online and went to ATP and ordered up a .48 Turbine housing with a swing gate housing and a few other mockup parts. I plan on Changing the Turbine housing out once more to a .83 as of current.


A stock T4 housing next to the big one.





Mocking up the turbine housing, I was forced to use a 1" SS spacer. The manifold was ported, and the studs removed. 






Notice the stock down pipe is still on there.


Next was the Fuel System


Palnet was kind enough to put a rail together to my specifications.


Dual Feed in and center out on Denso 440cc Injector 11mm O-ring.




This was mocked up on a spare L28et. I have 5 of those for this one car.



Accell 9.5mm custom wires with MSD ends.



The stock FPR wasnt doing it.

Nismo FPR!



It was here that I finally realized that the stock fuel pump was hitting a wall at 4500rpms at 10psi of boost.

So while in Perris Ca while down for the 2016 MSA Show I located a Bosch 300LPH@5Bar fuel pump and hunted down all the needed hardware with some help from TonyD, JeffP, Frank280zx, and Silvano! 



A couple pictures at Tony D's Driveway




On the way home from Tony's place though trouble struck. The car was having heat issues on and off even on the E85 the whole time I was down in socal. It pegged out on the grapevine. 230F. I was able to slow down and coast it cool, but by the time I hit the bottom of the grape vine it was 110F outside and the car was refusing to cool below 210F. I cruised the whole way home(hours more), making only one stop in Kettleman city for food and to attempt to cool down again. It did cool down, but it was for a but a few miles and the car was back at 210F. The plan was to use this engine as a mule anyway so I was not concerned to much. It would be a few more weeks before I was able to figure out that the radiator had plugged up with rust from the block! I ended up flushing everything and installing a new radiator. The cars normal temp with 100%Dexcool is about 165F under load and it was finally back there. Sadly the engine survived but 1 more week and one trip to work 2 miles out and the head gasket blew and shoved all 2.5gal of coolant through 3 and 4... that was a smelly cloud! The coolant system was under 25psi of pressure!

I cleared the cylinders out on the side of the road, and limped the car back to the shop! 

Turns out all that extra heat and a sub par block decking took its toll. The bearings, pistons, and head all checked out fine amazingly.

Well except this quench pad




That damn coolant port in the center got me good.


So Im prepping the next engine




It was time to modify the coolant passages in the head though.






Yep drilled down through the flash casting!


I warped the old exhaust manifold so I started working a new one.








The car as it sits for now.


The Engine components are all at my machine shop currently for a fresh build. 

I have many more plans, I just bought a S13 rear sub frame, S15 front spindles and a some cheap mockup coil overs. 


Stay Tuned for some epic disaster or lots of fun!

Edited by rayaapp2

Share this post

Link to post
Share on other sites

I took some measurements, I have a rough plan in place. I have to have the subframes shipped up to me from SoCal. After seeing all that JeffP went through to keep his stock subframe in, and all the mess that is getting the geometry correct on the stock subframe... not to mention a total lack of options for brakes and stuff... Im over the S130 setup. I already have all the Z31 outter hubs, axles, and the vented rear brakes all collected for the stock sub frame and Im probably going to give them to a friend of mine that could still use them. Franks Z31 axle writeup has some issues, he doesnt mention in there that he is using Euro stuff! Its not the same. JeffP figured out the mess of parts needed to make that all work together using US model parts at least. Anyway, here are some pictures of where I am at... Just gutted the rear out.








Im thinking I can drill out the spot welds that hold this box frame to the rockers, and the floor. Ill leave the box frame under the tunnel and console, so Ill have to cut straight down through the box frame on both sides. Ill have to make a new panel to the floor from the new position of the box frame. Ill work out the re-informent of the center tunnel after I position the new sub frame mounting pins in. 





Edited by rayaapp2

Share this post

Link to post
Share on other sites

Some inspiration/research









That is an effective way to do it... easy too, but not how Im going to do it.










Guy is listed right here in Sacramento. I wonder if he is still around.


Not exactly how I would mount mine at all. Those mounts would simplify this greatly and reduce chances of error in squaring it all up! 






Rims seem to suite it well.

Share this post

Link to post
Share on other sites

I stripped most of the car out.















I also took the time to start measuring the front suspension stuff for new parts. 

So out with the old 




In with the new to me.



S15 Spindles on crappy coil overs(change for Stance later).








I got underneath and took a look around to see how the sub frame is laid out under there for myself with a tape measure.




Last time Ill have this stuff under this car so I napped some pictures.


And then I really dug into it... checking how deep the entire cowl went... which as it turns out is a lot farther than I thought.





Tar Removal...





Rust located... pencil sized hole.





Transmission back out



A real mess now...




These brakes are much larger... but still clear the Rota 15x8 Grids I have. I checked. I am unsure what the final wheel that goes on after will be. 






Bat Sheet Wild Much? I hope not.









My phone gets drunk often and takes blurry pictures... 



Lovely right?


Well, I got the paint in...





So Im off to choose a good epoxy primer. 

Share this post

Link to post
Share on other sites

I would love to see you put those mounts in. I'm at the limit where I can either put an s13/14 subframe in or just do the late model swap like you did. 


I took some measurements Turns out those mounts are not going to be the best solution. The sub frame is approx 23" center to center on the rear mounts. After getting the tape measure up there it appears the box frame that incorporates to the the floor frame rails up to the rear box frame structure where mounts are needed is the same width apart and 3-3/8" wide. So these C channel mounts would require that an ear be cut off, and without knowing that the C channel is precisely the same ID of 3-3/8" it seems like a tremendous waste of nearly $200 and that starting from scratch is a much better idea. I know several guys cutting up S130 chassis right now, and Ive ask 2 of them to remove the front sub frame pins, and cut the mounting box for those pins with plenty of meat for me. So with any luck Ill be re-using the stock parts from the donors, but Ive also contacted a local fastener company that says they an get me a M20 bolt in fine thread if needed. As I understand it the fronts should be 5" long and the rears should be 6.5" long, but I have yet to get the sub frame in my hands. My buddy is still packaging it for shipping. 

Share this post

Link to post
Share on other sites

Transplanted a rear S14 subframe assembly years ago for a race two seater S130 and the biggest problem by far was not being able to get the assembly high enough. It's a race car so low is good but it's not a disaster, it's done quite a few laps and drives great. So what I'm saying is don't worry about the detail, it will sort itself out as you go, but get that subframe as high as possible which will involve cutting, patching and welding whatever gets in the way, not just some hammer massaging.


No kit needed, if you can't do it without a kit then seriously you don't have the necessary skills and equipment to do such a job.

Share this post

Link to post
Share on other sites

I hadnt considered how far it would drop from the frame rails(seeing as the stock sub frame hangs no lower than the rails). Thats good to know. Ill have to take some measurements. Im still waiting to get my sub frames shipped up from down south. 

I have no interest in paying the money that kit wants. Its not that I cant fab up a mount, I totally can, but the to do so vs just buying something thats is well built sometimes wins. I ended up plasma cutting out the whole rear deck box frame with studs from a donor car for mockup purposes. I might chop it up and pull the pins and mounts from that as they are super clean. I also salvaged a nice cowl area for my car from that donor.

Share this post

Link to post
Share on other sites

In hindsight some of my posts are not the best but the one above says it all and deserves thanks. My avatar car, S14 suspension front and back.

Do you have any pictures of your work?

Ive been working on the motor lately and havent got back on the rear suspension yet. My main goals at the moment are to get the wastegate plumbed up as Im running an external. But Id love to see another version of how the rear sub frame was swapped. Thanks

Share this post

Link to post
Share on other sites

No pics taken of mine during the build, it's been a running car for years now so the diff, axles and all the other stuff under there obscures the build detail.


S14 subframe into a two seater, rear S14 mounts match up to an existing body X member, fronts are narrower and a bit back from the OE mounts. So basically you do what is fairly obvious, reinforce where the S14 mounts are going to sit and bolt them in through the floor. Detail will only confuse, you know that something like a suspension subframe needs to be solidly mounted so that's what you do. If you can weld, make brackets and so on then go for it.


The good thing now is that dropped rear spindles are available to help keep the proper rear suspension geometry correct if the car has to be lowered more than the S14 suspension should be.


Nearly forgot, be careful with measuring everything to make sure the rear suspension is square with the rest of the car. I just used the usual measuring tools, when the wheel alignment was done the machine showed .01* out of square when new cars can be several degrees out. A bit lucky of course but it shows what can be done with care.

Edited by 260DET

Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

  • Create New...