Datsun 280ZX IMSA GTU race car build...

Restores, Revamps and Repairs
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Grunzter
Posts: 541
Location: Epsom, Auckland

Re: Datsun 280ZX IMSA GTU race car build...

Post by Grunzter » Wed Dec 21, 2022 8:47 pm

Thanks guys, yeh it's down to weeks now rather than years...
It will miss out on Pukekohe but only just.

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1981 280ZX #33 IMSA GTU Race Car
2012 Fairlady Z34 ST (For the son/wife...)
2007 Fairlady Z33 NISMO
(Sold) 1984 300ZX Z31 2+2 Turbo
(Sold) 1980 Datsun 280ZX 2+2

jdufour
Posts: 1

Post by jdufour » Wed Jan 11, 2023 1:54 pm

Hi,
We are considering build a 280Z race car for the ChampCar Endurance Series. It's amateur racing. We are concerned about the rear suspension. How did you configure your rear suspension? Is your rear suspension stock? Or are you using an aftermarket rear suspension? How large are your rear tires? Was your choice of tire size influenced by your rear suspension setup?

Thanks,

John

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Grunzter
Posts: 541
Location: Epsom, Auckland

Post by Grunzter » Thu Jan 12, 2023 4:43 pm

jdufour wrote: Wed Jan 11, 2023 1:54 pm Hi,
We are considering build a 280Z race car for the ChampCar Endurance Series. It's amateur racing. We are concerned about the rear suspension. How did you configure your rear suspension? Is your rear suspension stock? Or are you using an aftermarket rear suspension? How large are your rear tires? Was your choice of tire size influenced by your rear suspension setup?
Thanks,
John
Hi John,
My rear suspension uses the stock the components that have been heavily modified/strengthened.
- Rear crossmember has had inner mounts slotted vertically to allow camber adjustment.
- Rear crossmember bushes changed to solid/sleeved plastic ones.
- Rear arms were shortened and then rod ends added, so they can be adjusted in place, i.e. Left/right threaded. (in/out)... to adjust toe.
- Rear shocks/coil overs are from Koni Racing and are adjustable.
If I was to do it again, the APEX Eng. set is probably a cheaper way to go, and will offer similar adjustment. Though they did not exist when i started this project, and i wanted to keep it as close to the GTU car as possible.
If i didnt do the APEX thing, I would probably have gone complete custom rear like the GTO cars... but big bucks! :)
https://www.apexengineered.com/s130---280zx1.html

With the wide rear guards, I went with 11" wide wheels.
The original works GTU cars were running 16" x 12" wide wheels from memory.
Currently the car is fitted with 280 wide (300mm overall) x 650-18 slicks, but I will also use 295/30-18 Dot Semi-slicks (or 315/30-18).
My wheel offset is about 1/2" to far inwards, so I could have gone to a 12" wide rim, or at least 11.5"... but with two sets of wheels I'm not changing.
My tyre size is really influenced by the original car, and the amount of room I had under the guards.
Based on the average 8~10 lap race, the tyres are probably oversized for the car, but it looks cool!.
I'm only running 9" wide on the front (235 or 240 wide tyres) because my front guards are not as wide as the official GTU cars were.

We have done a few complete wheel alignments so far during the fabrication, and the front & rear camber/caster/toe all looks perfect to what you would expect (touch wood), though time well tell.

Photos below are before final powder coating.
Anything let me know, and good luck with your race car build!

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1981 280ZX #33 IMSA GTU Race Car
2012 Fairlady Z34 ST (For the son/wife...)
2007 Fairlady Z33 NISMO
(Sold) 1984 300ZX Z31 2+2 Turbo
(Sold) 1980 Datsun 280ZX 2+2

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bernjean
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Posts: 1711

Post by bernjean » Sun Jan 15, 2023 2:25 pm

It just gets better and better.
Bernie Kant
Club President

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Grunzter
Posts: 541
Location: Epsom, Auckland

Post by Grunzter » Mon Apr 24, 2023 7:03 pm

In case you don't follow the FB page, here is a few recent updates.
A few pictures of a clean white interior...
Yes, it's back from the painters a few weeks ago.

The assembly has started. Today fitted the rear lights, fuel cell, dry brake, Diff cooler pump, rear brakes, and bits & pieces.
Also test fitted for a new driver side seat.
Clutch & flywheel all assembled, and new pilot bearing made to suit the Chev input shaft.
ARP Flywheel bolts used.
Little carbon protector for outside kill switch.

Engine bay ready for the engine & gearbox. They will go in later this week.
Engine & gearbox got a good clean, and hydraulic release bearing got plumbed up.
And eyes (headlights) fitted so car can see for the first time in 20 years.

Today we got the front brakes back on, fitted the small fire extinguisher as well as a few minor jobs.

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1981 280ZX #33 IMSA GTU Race Car
2012 Fairlady Z34 ST (For the son/wife...)
2007 Fairlady Z33 NISMO
(Sold) 1984 300ZX Z31 2+2 Turbo
(Sold) 1980 Datsun 280ZX 2+2

mikec(nz)
Z Club Member
Posts: 189
Location: Tauranga, New Zealand

Post by mikec(nz) » Sat May 13, 2023 10:47 am

Love it, looking so good. This is really the fun part now, can't wait to see it on the track. You have inspired me ......

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Grunzter
Posts: 541
Location: Epsom, Auckland

Post by Grunzter » Wed Jun 14, 2023 7:35 pm

Hi Mike,
Thanks, its not far away...

Engine got a new Kameari 77i cam, Titanium retainers etc...
And body got a new seat and some decals.
Wiring all in and ready, motor, gearbox and drive line all in, as well as fuel cell etc...

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1981 280ZX #33 IMSA GTU Race Car
2012 Fairlady Z34 ST (For the son/wife...)
2007 Fairlady Z33 NISMO
(Sold) 1984 300ZX Z31 2+2 Turbo
(Sold) 1980 Datsun 280ZX 2+2

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Grunzter
Posts: 541
Location: Epsom, Auckland

Post by Grunzter » Mon Jul 03, 2023 6:48 pm

Engine finally looking ready for action...
Car getting ECU/PDM/Dash/Keypad programming ready for dyno day.
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1981 280ZX #33 IMSA GTU Race Car
2012 Fairlady Z34 ST (For the son/wife...)
2007 Fairlady Z33 NISMO
(Sold) 1984 300ZX Z31 2+2 Turbo
(Sold) 1980 Datsun 280ZX 2+2

mikec(nz)
Z Club Member
Posts: 189
Location: Tauranga, New Zealand

Post by mikec(nz) » Sun Jul 16, 2023 1:30 pm

Looking awesome, my only comment would be that Bob Sharp rocker cover just looks out of place, you should pull it off and replace with stock. I of course would be willing to take care of it for you. :lol:

Interesting going for the PDM, just purchased one myself (for the ZX) and going to be interesting to see how it all goes together, much cleaner and simplier setup than lots of fuses. Glenn used one on his 4x4 March and sang it praises.

Be interested to see how easy it is to set up and how well it works.

Is there a big reveal planned?

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Grunzter
Posts: 541
Location: Epsom, Auckland

Post by Grunzter » Wed Jul 19, 2023 8:16 pm

Hi Mike,
I recall someone on the BSR page mentioned he might make a copy of the BSR cover... It didn't get much attention as idiots like me who paid a bomb for one of the 150 that were made didn't want them to drop in value. B-Speed covers though are very nice!

PDM is definitely the way to go, super easy to wire and set up, though I've only seen it done rather than doing it myself. My PDM is nearly full if not full, but the PDM30 was a bit too much at the time. They save as you say a mess of wiring and all the fuses are no more!
If I ever done another car, I would go PDM every time!
Q: What is the 'ZX'?... :)

I will plan an unveiling. after the initial dyno tune, which shouldn't be far away. Most likely at Hampton Downs on a coffee & cars day (Auto addict)... not really sure.
The Autoaddict day is not for race cars, and a test day is during the week i think... ???
Cheers Grant

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1981 280ZX #33 IMSA GTU Race Car
2012 Fairlady Z34 ST (For the son/wife...)
2007 Fairlady Z33 NISMO
(Sold) 1984 300ZX Z31 2+2 Turbo
(Sold) 1980 Datsun 280ZX 2+2

User avatar
Grunzter
Posts: 541
Location: Epsom, Auckland

Post by Grunzter » Mon Aug 21, 2023 6:00 pm

Wow, it's nearly been a month without an update. Everything takes longer than you think.
Its back from the Motec setup, still need to double check the DBW system properly.
A new gear position sensor has replaced the old mechanical switch, as that had reached its lifes end...
Dash fitted, took a lot longer than I thought it would, but i had to move the steering column a little bit to the left and up. So should be good now. Motec keypad installed, as well as Tilton bias, just need to find some small rivets.
The digital dash will be mounted to the column, and the shift lights to the top of the dash.
Also one more extinguisher pull lever to be fitted. ...looks a bit empty without all the normal buttons and switches...
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1981 280ZX #33 IMSA GTU Race Car
2012 Fairlady Z34 ST (For the son/wife...)
2007 Fairlady Z33 NISMO
(Sold) 1984 300ZX Z31 2+2 Turbo
(Sold) 1980 Datsun 280ZX 2+2

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stevenewenham
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Posts: 148
Location: Auckland

Post by stevenewenham » Tue Aug 22, 2023 10:49 am

Getting close now! You must be able to taste it now!

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Grunzter
Posts: 541
Location: Epsom, Auckland

Post by Grunzter » Sat Aug 26, 2023 6:52 pm

Thanks Steve, yeh getting closer!

Another day off and some more progress...
Side mirrors and rear vision mirror installed, the later being one of the few original parts left.
Driver's seat rear mount fitted so that that allowed me to install the RH rear quarter window and B pillar. I needed the window out to get easier access...
I managed to get my name on the roof for the drivers side, but i ripped the passengers side one, so will need to get a new one printed next week. 🙁
Seat belts also in, just need to adjust them.
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1981 280ZX #33 IMSA GTU Race Car
2012 Fairlady Z34 ST (For the son/wife...)
2007 Fairlady Z33 NISMO
(Sold) 1984 300ZX Z31 2+2 Turbo
(Sold) 1980 Datsun 280ZX 2+2

User avatar
Grunzter
Posts: 541
Location: Epsom, Auckland

Post by Grunzter » Thu Oct 12, 2023 7:27 pm

More progress,
Windscreen is in with chrome, so is the dash, door cards, door seals, window nets etc...
The Motec dash and shift lights were also fitted to the new steering column, had to change the mount, but it looks good and is functional.

Still a few small jobs to accomplish over the next few weeks, but nothing to major such as:
- front brake ducting backing plates, inlet shroud to radiator, front splitter...

Car is booked in for engine startup and running in on November 6th!

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1981 280ZX #33 IMSA GTU Race Car
2012 Fairlady Z34 ST (For the son/wife...)
2007 Fairlady Z33 NISMO
(Sold) 1984 300ZX Z31 2+2 Turbo
(Sold) 1980 Datsun 280ZX 2+2

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stevenewenham
Z Club Member
Posts: 148
Location: Auckland

Post by stevenewenham » Fri Oct 13, 2023 11:10 am

Looks awesome!

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