Jump to content
HybridZ
Jethoncho

1978 Datsun 280Z RB25 Restomod

Recommended Posts

Hello All,

 

And so begins the epic journey to go from rough unloved 280Z to a resto-modded RB25 equipped super car.  I realize I’m not blazing any trails that haven’t been traversed so I will benefit from anyone’s input as this project progresses.  I’m starting with a ‘78 280Z and a series 2 RB25.  With the size of the project I’m sure I’ll be all over the place in the beginning until I can get a solid plan worked out.  My initial plan is to get the current L28 running so I can sell it and the 5-speed tranny as operational component.  Once I have the engine running I’ll pull the engine, all associated wiring and ECU and transmission to make room for the RB25.  I have already acquired the RB and started the process to convert the forward sump oil pan to a rear sump.  Once the rear sump conversion is complete I’ll drop her in to mock up mounts.  I know there are kits out there for this but I prefer to utilize factory RB mounts so I’ll mock up new engine stands for my subframe.  If possible, I’ll also look to move and modify the existing transmission tunnel/rear body mounted structure aft to permit a more symmetrical rear crossmember/mount.  Once the RB is mocked up in the body I will switch my focus to restoration of the body.  I plan to go with retro-spec Carbon Fiber front fenders, headlight buckets, hood, BRE style front spoiler, cowl, rear hatch and BRE style rear spoiler.  I will also retrofit 240z bumpers with no rubber or overrides.  

 

I have no illusion, this is a huge project but with support I hope to get through it.  When I purchased the 280 it appears to have been sitting for at least 25 years and it’s mostly unmolested.  It has some rust in the usually spots but is not a total rust bucket.  I believe I am starting with a base car that is worthy of this project.  I’ll post a couple pics and try to do regular updates but I travel a lot for work so I’m sure there will be times when updates are further apart.  For now here are some baseline photos.  I look forward to loads of input from experts here!

BDA1BD09-7BC2-4CFF-B09A-ABAE78845F63.jpeg

B6020C9E-9F4B-41A3-9C04-4844845027F1.jpeg

EB28792E-8160-4950-8DB8-9B49D1281790.jpeg

Share this post


Link to post
Share on other sites

So I started a couple repairs/mods to the body.  

  1. Removed the 280Z tail lights and modified body to mock up 240Z tail lights.  Still have loads of metal work on this item.  I intent to cut out the old 280 tail light mounts and fabricate new mounts to properly accomadate the 240Z lights but they look so much better.  The 240 light in the photo is just for mock up purposes as I intend to go with JDM lights with amber turn signals.
  2. stripped the left rear quarter, found an old body damage repair completed in true hack fashion, holes drilled in the panel when there is pretty good access to the reverse side, this damage was in addition to the crease that is visible in the before photos.  Spent a couple hours massaging it and it’s starting to take shape.
  3. Rust damage to the left side of the upper core support was cut out and new part fabricated, just waint to get my MIG machine home from the airport to install.

 

AC0D6258-7A63-422C-B1E1-F3631C570E29.jpeg

2DFF2BEB-A0C2-4F1E-86C6-7EAB09231FA4.jpeg

Share this post


Link to post
Share on other sites

Okay, I been bouncing all over the place.  Here are some of the issues I have been addressing.

 

1. Since my rear quarters had some previous minor collision damage that was poorly repairs I attempted to massage out this damage and was fairly happy with the result.  That being said they had some minor rust too so I switched gears and decided to replace both rear quarters with replacements from Wolf Steel, I've cut the left quarter off and fitted the new panel.  This too some work but ultimately I think I am going to be much happier with the final result especially since I intend to go back with 240Z bumpers and the new quarters have recesses for these bumpers.  I am still working on the inner structure behind the left rear wheel as there was a two small areas of rust, one has been repaired by cutting out the damaged area an butt welded a patch panel in place, I also shaved the existing hole in this structure that had an existing rubber grommet in it.  I can't think of what this hole's function might have been but its now sealed with a but welded patch panel.  I have attached a couple of photos of this work in progress.

 

2. Cut out left door skin where mirror mounted and but welded in a new patch panel I intend to go back with factory 240Z mirrors and there were extra holes due to the variety of mirrors that have likely been installed over the years.  Now I have a fresh surface to mount the factory mirror to.  Didn't take a photo of this yet.

 

3. Driver's floor pan had some rust under the rear seat mount structure.  I removed the rear seat mount and cut out an area approximately 6"X16", now I have to form the beads in the patch panel, then butt weld back into place...this is still a work in progress, photos to follow.

 

4. Rear panel above tail lights...know rust area and my 280 is no exception.  Just ordered the replacement panel should arrive today.  I started removing the old damaged panel and found so rust in the structure above the tail lights as well.  This is fine cuz I am replacing this structure anyway to accommodate my 240Z tail lights that I have mocked up in place.  Gonna try and get this area cut out over the weekend to assess it further and get a plan to repair the structure so I can weld in the new panel I got from Tabco.  Photos and update to follow.

 

5. There is a small area of rust under the wiper cowl where the inner mount of the front left wing/fender bolts in place.  Cut the area out about the size of a quarter but decided to go a little further to ensure all corrosion was removed.  Started fabrication of a patch panel once completed it will be butt welded into place.  

 

My goal is to get all metal repairs addressed on the left side then turn her around in the garage and take care of the right side.  I'll keep this thread updated from time to time.

IMG_7281.JPG

IMG_8667.JPG

IMG_1434.JPG

IMG_7457.JPG

IMG_5326 copy.JPG

Edited by Jethoncho

Share this post


Link to post
Share on other sites

Looking good! When you talk about the hole with the rubber grommet, are you talking about the hole on the top of the fender where the red meets the metal that you've welded in? If so, that was for an antenna, but I deleted that as well on mine. Either way killer job on that rear quarter! That is dang seamless!

 

Also, did you buy the car from a guy who has a bunch of Zs or what? I noticed the other cars in the photo are also Zs.

 

Share this post


Link to post
Share on other sites

Hey, thanks for the kind words and support.  No, I shaved the antenna hole as well but I’m talking about a hole that existed behind the rear quarter (in the structure that faces the fuel tank), if you look at the photos it the one the shows a couple bare metal spots with an area that I need a smaller sanding wheel to finish dressing the weld. The rubber boot/grommet looked like it was meant to allow a small harness to pass through, since none existed I shaved the opening.

 

Yes, I bought the car from the guy in Georgia that bought someone’s collection...some of what he has is total junk others are worthy of resurrection.  Mine was a pretty solid base with some what I would call minor rust here and there but certainly not a basket case...it was fairly unmolested and what I consider a good base for a project like mine.  I have stripped the left side of the car of its rather horrible paint and it now sits in bare metal awaiting a good coat of sealer.  

12D14AA3-D40C-4462-A1E5-4EF009E91D01.jpeg

Edited by Jethoncho

Share this post


Link to post
Share on other sites

Removed the gas tank to inspect and modify to accept an in-tank EFI pump for the RB swap, upon inspection of the tank’s interior it confirmed what I already knew...the car sat for many years.  The car appears to have been parked with nearly 1/2 a tank of fuel given then level of the gum/varnish in the tank.  I cut the hole for the EFI pump in the area near the center of the spare tire relief.  This gave me a 4 1/2” hole to access the tank’s interior.  I moved the fuel filler port (more on this later) and removed the existing fuel pick up, feed and return lines from the tank’s interior.  I cleaned the varnish I was able to reach then took the tank to a local radiator shop, he cleaned the balance of the varnish and the surface rust that was in the tank then coated the tank’s interior with a sealer called Red Kote.  Now the tank’s interior is super clean and ready to continue service.  I brought the tank home removed all exterior paint and surface rust then recoated with POR-15  to emulate the original factory coating (this was my first time working with this product and I applied it a little too heavy in a few areas so it almost looks like a crinkle finish in a few areas, fortunately, this is on the top of the tank where it can’t be seen once installed.).  I then installed a FITech retrofit in-tank EFI fuel pump.  The tank is now restored and ready to install except for the sending unit which I am still restoring and the mods to the sparewell that will be necessary to allow the routing of the new fuel supply and return lines.

EA6AE1A5-264C-4C5D-9FF8-942A5FFC5341.jpeg

EEE4A682-9110-4C91-98CE-76E41EB23265.jpeg

649D7EA2-BFBA-43DC-B50B-EA19D3D1EF83.png

Edited by Jethoncho

Share this post


Link to post
Share on other sites
12 minutes ago, pochie45566 said:

Im really excited to see this build! I’ve been thinking about buying a beater car so I can start my RB25 swap. Though I love using my 78 as a daily. Tank looks awesome, glad to see that you aren’t cutting any corners on this build. Ill be following it! 

Thanks for your kind words, I’ll be updating this thread as progress continues...

Share this post


Link to post
Share on other sites

Yesterday’s project was removing the structure that the 280Z front bumper shocks bolted to and fitting a 240Z grill.  Took the existing grill attachment brackets off the removed bumper shock mount structure, relocated to the removed brackets to the remaining structure that was under the 280Z bumper shock structure which appears to be the same as the 240Z.  Fabricated two upper grill mounts, welded the four mount brackets in place then installed the grill for mock up confirmation.  Haven’t decided if I’m gonna restore this 240 grill that I pick up or go with the Skillard billet grill.  I’m leaning toward restoring this grill since it’s in pretty decent shape and I already spent money acquiring it.

0D85F821-F7F3-48CB-ADB6-161EE777744B.thumb.jpeg.bcb4384ce21187a3b304b99034823534.jpeg

I realize it doesn’t look like much but it was a fair amount of work.  Still have some welding to do to repair the holes left behind after the spot welds were drilled out to remove the 280 bumper mounts.

Edited by Jethoncho

Share this post


Link to post
Share on other sites

Latest project was to start the rust and panel repairs to the rear of the Z as well as making permenant panels to go from the 280 to 240 rear lights.  

  1. I started by removing the upper panel under the rear hatch (known rust area),  I found the areas above the tail lights also had rust so these areas were cut out and new patch panel are yet to be fabricated.  I can’t reinstall the upper panel till the rust repair panels are fabricated so this remain a work in progress...upper panel installed on 28 October, I decided to bond it in with 3M panel adhesive to prevent moisture ingress which likely caused the original rust issues.
  2. I then removed the rear lower valence...not due to rust but more due to damage caused by the removal process of the 280’s body to bumper filler panel that was removed to facilitate installation of the 240 bumpers.  I also want to replace the rear valance with the 240 valence to permit the installation of a twin pipe exhaust (taller exhaust cutout in the 240 valence) further along in the project.  The replacement valence arrived and to my surprise (not really surprised) the panel was completely straight from left to right even though the car has a slightly round feature across the back.  I took the replacement out to the airport where I have access to a shrinker/stretcher and shrank the upper flange to create a slight radius on the panel.  I haven’t completed fitting it so this also remains a work in progress.
  3. Next, I cut the body out around the left rear tail light then fabricated a replacement panel specifically fitted and shaped to accept the installation of the 240 tail light while closing the areas from the back up light portion of the 280.  I’ve welded in the left side and I have to say I’m pretty pleased with the outcome, next I’ll tackle the right side and the project will be fully converted to use 240z tail lights.

Sorry, I didn’t get any photos, had to go make the doughnuts, Friday I flew from Ft Lauderdale to LA then Honolulu, Saturday back to LA now here till Tuesday then home on Tuesday.  I’ll be back on the project on Wednesday and get some photos up then.  

2B334229-19B5-44EE-8416-31ACBF18CD8D.jpeg

08E2F014-9503-48ED-BAAA-A50DF996F58B.jpeg

93081A55-0528-435F-8BEA-B1284A47A967.jpeg

Edited by Jethoncho

Share this post


Link to post
Share on other sites

Yesterday’s project was to mock up the front suspension upgrade, S14 spindles with 5-lug hubs and BC coilovers.  Started by removing the factory S30 struts, brakes, spindles and steering knuckles.  Then installed the S14 spindle (left on right and vice versa) this was necessary due to the location of the tie rod connection on the S14 spindles.  I was pleased that once I removed the S30 steering knuckle the S30 lower ball joint bolted right up to the S14 spindle.  I am waiting on new Techno Toys Tuning lower control arms and tension rods but the S30 stuff works for now.  Installed the BC coilovers which bolted right in except for a little modification to the upper body mount due to the 4 bolt mount on the new coilovers...the upper body mounts will change when I get my weld-in camber plates from Techno Toys Tuning.  The BC coilovers are custom order for this application (S30 upper unit and S14 mount), BC quoted me 4 weeks for the custom build,  I received them in 4 days, great company and outstanding customer service.  Then there is the issue of the steering...the S14 steering knuckle turns in where the S30 was straight.  This has was temporarily solved by removing the S30 outer tie rod ends and cutting a 37mm section out of them and welding them back together...don’t worry I won’t drive it with those but it works so I can roll it around until I come up with a permanent solution.  I’m thinking I’ll go with the outer tie rods that Techno Toys sells, they are available in two lengths and I believe their shorted set will fit my needs.  I temporarily installed a borrowed set of 300zx wheels with 205 16R 60 tires, vast improvement over the stock S30 stuff!  I’m holding off on buying new wheels and tires till I get it all mocked up and can do some proper measurements (not to mention the car is a long way away from being on the road).  The S14 brakes will be a nice upgrade to the front of the S30.  As soon as my stuff comes in from Techno Toys Tuning I’ll get the rear mocked up too (S14 hubs, brakes, axles and VLSD differential).  

 

 

0AD44B95-A7A6-4C8C-9AC8-83206DE454FC.jpeg

BE0FDC1C-10FB-4B15-B529-4FAC489AE8F3.jpeg

Edited by Jethoncho

Share this post


Link to post
Share on other sites

Been working on the rear valence for the past couple of days.  Let me start by saying this replacement part is much heavier gauge than the original part but it was delivered in a nearly flat condition and the rear of the car is not flat so it takes quite a bit of massaging to get this panel to fit.  And, the only part available is for a 240 so this creates more work too.  The 280 bumper brackets (behind the valence) were bolted and welded to the chassis (genius), they are totally different than the 240 so these had to be cut off the chassis.  Then I fabricated new ones to be welded back in place.  Then the only indentation in the 240 valence falls right on the rear chassis crossmember so it had to go as well.  Now Im ready to move forward with final fitment before I weld it in place.  This piece is a lot of work but should be a vast improvement over what was there.

Share this post


Link to post
Share on other sites

Jumped back on the left rear quarter panel.  Started butt welding it in place but it’s slow work trying to prevent excessive warpage, plus I have a couple areas where I have an excessive gap between the weld area so I ordered a magnetic copper backing plate to back these areas up to aid in bridging the gap.  I’ll get some photos up ASAP.  On a different note, my rear end conversion kit from T3 arrives today so i’ll Probably get sidetracked from the quarter panel to mock up the new rear suspension and BC coilovers. I’ll keep you posted how it goes.

Share this post


Link to post
Share on other sites

As predicted once the T3 candy showed up I couldn’t resist.  Plus, I’m waiting on some welding aids to continue the left rear quarter so I unpacked all the T3 odds and ends, unforturnately a couple of pieces were damaged in shipping but as soon as I let T3 know they immediately shipped new parts.  I was able to remove the stock left rear suspension and install the T3 control arm, hub adapter and BC coilover. The BC coilover was a weld in unit but T3 was kind enough to sell me their mounting tabs.  My welder is not high enough amperage to weld the 1/4” plate tabs so they are only tacked in place until I can weld them up with a stronger TIG welder.  I am quite pleased with the result,the rear end is lowered by about 3” on the initial setup...keep in mind these are only mocked up and will need final setup once they are permanently installed in the car.  Next week I’ll get the right mocked up and lower the fronts to a move level attitude.  

 

 

512BB6B4-E7B9-4126-B5E8-05A0CBD53450.jpeg

Share this post


Link to post
Share on other sites

Okay on a different note, I have been following Ivan and Hung’s (Vintage Dashes) work on their fabrication of a new reproduction dashboard for the 280Z.  Well, I received notification today that they are ready to start selling these and since I’m on their waiting list I was qualified to buy in their first offering.  I paid their selling price immediately so I should have a new dashboard in 6-8 weeks!  I’m excited at the prospect of getting rid of my seriously damaged dash for a new pristine dash. I’ll make sure I post when I receive it and install it.

Share this post


Link to post
Share on other sites

Well I went back to my metal work...this past weekend I fabricated the aft driver’s side floor, there was a small area of rot but I ended cutting our a section approximately 6” long and the full width of the driver’s side.  This required me to remove the rear seat mount. I also had to purchase a bead roller to roll reliefs/stiffeners in the replacement floor to allow it to fit properly over the aft section of the frame rail.  All in all it came out pretty good.  Still have a little welding to get this repair finished. It’s not very photo worthy but once I get the rear seat mount reinstalled I’ll snap a photo or two and post to this thread.

 

Still have to get the driver side rear quarter welding completed but it’s on the list.

 

Also spent some time over the weekend removing all the OEM rear drivetrain and suspension then installed all the T3 candy, both rear control arms, drop down mounts, mustache bar.  It’s all in for mock up purposes but excited to see it in there just the same.  I also installed the T3 front control arms.  The quality and fitment of the T3 stuff is phenomenal... I highly recommend their stuff.

 

i’ve posted a couple photos, please keep in mind this is only mocked up to ensure fitment, please excuse the condition of the bottom of the car...it’s on the list;-)

C50F2F40-AD7B-4915-BF00-375398949FE7.jpeg

64EFD516-2D6F-4063-89D6-3807D715740D.jpeg

Edited by Jethoncho

Share this post


Link to post
Share on other sites
On 11/17/2018 at 6:17 PM, Jethoncho said:

Okay on a different note, I have been following Ivan and Hung’s (Vintage Dashes) work on their fabrication of a new reproduction dashboard for the 280Z.  Well, I received notification today that they are ready to start selling these and since I’m on their waiting list I was qualified to buy in their first offering.  I paid their selling price immediately so I should have a new dashboard in 6-8 weeks!  I’m excited at the prospect of getting rid of my seriously damaged dash for a new pristine dash. I’ll make sure I post when I receive it and install it.

Post up pics when you get it! I'd love to see what it looks like! I restored mine and I'm pretty happy with the results but I'm not even sure I'll use it moving forward ha, we'll see!

 

52 minutes ago, Jethoncho said:

Well I went back to my metal work...this past weekend I fabricated the aft driver’s side floor, there was a small area of rot but I ended cutting our a section approximately 6” long and the full width of the driver’s side.  This required me to remove the rear seat mount. I also had to purchase a bead roller to roll reliefs/stiffeners in the replacement floor to allow it to fit properly over the aft section of the frame rail.  All in all it came out pretty good.  Still have a little welding to get this repair finished. It’s not very photo worthy but once I get the rear seat mount reinstalled I’ll snap a photo or two and post to this thread.

 

Still have to get the driver side rear quarter welding completed but it’s on the list.

 

Also spent some time over the weekend removing all the OEM rear drivetrain and suspension then installed all the T3 candy, both rear control arms, drop down mounts, mustache bar.  It’s all in for mock up purposes but excited to see it in there just the same.  I also installed the T3 front control arms.  The quality and fitment of the T3 stuff is phenomenal... I highly recommend their stuff.

6

man I am so jealous! I can't wait to start going through my suspension pieces! T3 makes some superb stuff, share some pics of yours when you get a chance! 

Share this post


Link to post
Share on other sites
12 minutes ago, Jboogsthethug said:

Post up pics when you get it! I'd love to see what it looks like! I restored mine and I'm pretty happy with the results but I'm not even sure I'll use it moving forward ha, we'll see!

 

man I am so jealous! I can't wait to start going through my suspension pieces! T3 makes some superb stuff, share some pics of yours when you get a chance! 

I back on the road for work but I get home Thursday. I’ll get some photos up when I get home.

Share this post


Link to post
Share on other sites

I finished the initial mock up my rear suspension and came up with the following approximate measurements.  

 

The suspension consist of:

  • Full T3 rear end swap kit, minus the T3 coilovers.
  • BC Coilovers with T3 tabs welded to the BC lower mounts...this allows the BC coilovers to be bolted to the T3 hub mounting plates.

The resultant clearance is in the drawing attached.

 

Given these dimensions I believe I should be able to stuff a 9.5" wheel in the well but its going require a positive offset of approximately 40.  I may be able to adjust the lower control arms in a bit to get this down...I'll have to take a look at that.  

IMG_0028.JPG

Share this post


Link to post
Share on other sites

I see you're thinking about welding on T3s tabs on your BC Coilovers. I had the same idea since I wanted to run their rear upgrade with my BC Coils. I actually contacted them and the end result was that it would not work.

 

This is what Gabriel at T3 told me

"The backing plates we can sell for $550 the pair. The weld on tabs $40 the set of 4. Yes, the mustache bars and LCA's are in stock. 

 
For the rear backing platses our setup is meant to work with our coilovers specifically. We've had only marginal success adapting other brand coilovers to it.
We've tried many times to adapt coilovers like the BC stuff, but invariably, the fatter lower tube causes problems with the CV Boot and puts the coil spring into the inside of the strut tower. It tends to kick the camber to positive and require slightly extending the lower control arms as well.
After having to re-do things 3 times on some kits, we no longer offer the service of welding our tabs onto other brand coilovers. We'll sell the tabs, but from there out it's on the customer to try and get other brands to fit. If you want a no hassle install, then I would suggest our coilovers."

Share this post


Link to post
Share on other sites

 

34 minutes ago, Kevlars30z said:

I see you're thinking about welding on T3s tabs on your BC Coilovers. I had the same idea since I wanted to run their rear upgrade with my BC Coils. I actually contacted them and the end result was that it would not work.

 

This is what Gabriel at T3 told me

"The backing plates we can sell for $550 the pair. The weld on tabs $40 the set of 4. Yes, the mustache bars and LCA's are in stock. 

 
For the rear backing platses our setup is meant to work with our coilovers specifically. We've had only marginal success adapting other brand coilovers to it.
We've tried many times to adapt coilovers like the BC stuff, but invariably, the fatter lower tube causes problems with the CV Boot and puts the coil spring into the inside of the strut tower. It tends to kick the camber to positive and require slightly extending the lower control arms as well.
After having to re-do things 3 times on some kits, we no longer offer the service of welding our tabs onto other brand coilovers. We'll sell the tabs, but from there out it's on the customer to try and get other brands to fit. If you want a no hassle install, then I would suggest our coilovers."

 

Thanks for the heads up, I’m not trying to reinvent the wheel here but I want to try to keep to BC stuff on all four corners.  Right now the car is mocked up with the T3 tabs on my BC coilovers.  So far camber and clearances look fine but I’ll have a closer look after I get the axles mocked in.  

Share this post


Link to post
Share on other sites

 

On 12/3/2018 at 11:50 PM, Kevlars30z said:

I see you're thinking about welding on T3s tabs on your BC Coilovers. I had the same idea since I wanted to run their rear upgrade with my BC Coils. I actually contacted them and the end result was that it would not work.

 I did this very thing. The deal to get the strut tube to clear the CV boot is to kick the bottom slightly to the rear. The strut isnt perpendicular to the ground anyway and leans slightly towards the front of the car at the top, so kicking it out at the bottom isnt a big deal. If you see in my picture, the strut is threaded way down. The way it is now, the car can be lowered way further than the stock BC setup. I might redo it in the future and slide the tube higher so I can weld it differently. You have to be careful not to put too much heat into the strut tube as to not warp the threads. Mine are still pretty tight due to the warping. I am not a pro welder, so a pro welder might do a better job at minimizing the warping. I dont have any clearance problems, but that may be due to making my own tabs to place the strut in a better position. I oversized the upper holes to give me some camber adjustment and the camber plates are now at center at ride height with 0 camber. 

 

On another note, I think if I used a TIG welder, the results would be better.

 

20170904_192242.thumb.jpg.9905ee3e3123a3d74f2e50c414eba61e.jpg20170828_165935.thumb.jpg.6b296a1ba3fac065586a6dd5faa9b4cc.jpg20170829_123553.thumb.jpg.e0c24e67d7278004d1c659796efb1c52.jpg

20181027_222022.thumb.jpg.2843addbfd612e6dc57ef9acfd4dbad0.jpg

Edited by winstonusmc

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×