Datsun 280ZX IMSA GTU race car build...

mikec(nz) · Post by **mikec(nz)** » Tue Oct 17, 2023 6:37 pm

Woo Hoo, excellent. What's your plan for running in, just on the dyno or something a bit more detailed?

Grunzter · Post by **Grunzter** » Fri Oct 20, 2023 5:28 pm

mikec(nz) wrote: ↑Tue Oct 17, 2023 6:37 pm Woo Hoo, excellent. What's your plan for running in, just on the dyno or something a bit more detailed?

Just on the dyno.
Hopefully it goes more or less first time... and then want to run it for say ~1 hour non-stop at 1500~2000 rpm to run the cam in.
Thats what Kameari recommended, I'll put a break in lube on the cam before startup.
We will also get oil pressure by turning over the dry sump pump before start up.
Will use some BP7ES plugs for the initial running in, and have some colder ones for when it gets more serious.
After the first hour I will do what the experts say...

Grunzter · Post by **Grunzter** » Thu Nov 23, 2023 6:41 pm

Well its pretty much done.
A few under bonnet things being corrected, and some minor jobs being finished now.
So will get a wheel alignment next week fingers crossed, and then oil priming & water leak test before the big day!

stevenewenham · Post by **stevenewenham** » Fri Nov 24, 2023 11:11 am

Wow- exciting!
It's looking a million dollars!

mikec(nz) · Post by **mikec(nz)** » Sat Nov 25, 2023 9:41 am

Truly understand how much time, effort and racecar dollars (which are not like real dollars) go into these projects. Can wait for the dyno results and to see it in person. Well done to get to the finish line.

Grunzter · Post by **Grunzter** » Tue Nov 28, 2023 7:31 pm

stevenewenham wrote: ↑Fri Nov 24, 2023 11:11 am Wow- exciting!
It's looking a million dollars!

Thanks Steve!

Grunzter · Post by **Grunzter** » Tue Nov 28, 2023 7:33 pm

mikec(nz) wrote: ↑Sat Nov 25, 2023 9:41 am Truly understand how much time, effort and racecar dollars (which are not like real dollars) go into these projects. Can wait for the dyno results and to see it in person. Well done to get to the finish line.

Yeh, very true... you need to start by digging a big hole, and when done, make it deeper.
Then prepare to fill it with $$$, until its full. And then you have a race car. Lol...
Yes, will share results as soon as i have them, be it good or bad or indifferent...

Grunzter · Post by **Grunzter** » Tue Dec 05, 2023 7:12 pm

Even closer now.
Running in oil (Penrite 10tenths) added and pump primed and run so oil is everywhere but the cooler due to the oil thermostat.
Looks like it takes around 10L of oil!
Water added for now but will be drained out later and replaced with motorsport coolant/corrosion inhibiter.
New water thermostat housing top looks a bit odd, but works perfect

Power steering fluid (Redline) added.
Cables under dash tidied up and brake lines tightened.
Brake & clutch fluid (endless racing) added and all working!!!

Final tasks are:
Set ride height and do full wheel alignment to adjust front & rear camber/caster/toe...
Complete DBW relocation.
Ready for 'Start'!

Grunzter · Post by **Grunzter** » Wed Dec 06, 2023 6:07 pm

Ok, nearly as exciting as what the engine will produce... here is the weight of the car with all fluids and 20L of fuel:
1153 kg (2540 lb's)
I assume weight difference at the rear is due to the Dry-Sump oil tank being pretty much over the top of the LH rear wheel.
The front I guess is all down to the motor, as the ancillary items would not make much of a difference...

Also ride height is set, and alignment complete.
Next up Dyno time...

stevenewenham · Post by **stevenewenham** » Thu Dec 07, 2023 10:33 am

Were you sitting in it when weighed? If not that will swing the bias from left to right.
When you say alignment complete, did that include weight jacking , or is that still to come?

mikec(nz) · Post by **mikec(nz)** » Thu Dec 07, 2023 4:12 pm

That is a light car, wdll done. Fun with I assume 250-300hp it should fly.

I too assume you (or driver ballast weight was not in it). Since you have all the adjustable suspension might be worth chasing cross weights with driver weight.

There is a good video on it here

https://youtu.be/jpuztcGQM9k?feature=shared

Grunzter · Post by **Grunzter** » Fri Dec 08, 2023 6:41 pm

stevenewenham wrote: ↑Thu Dec 07, 2023 10:33 am Were you sitting in it when weighed? If not that will swing the bias from left to right.
When you say alignment complete, did that include weight jacking , or is that still to come?

Not sure what it's called, but yes, alignment was undertaken by the Koni Racing Shock suspension guru, not just a 'wheel alignment' dude.
He had to keep the sway bar link removed from one side as he tested the set up etc.

Grunzter · Post by **Grunzter** » Fri Dec 08, 2023 6:52 pm

mikec(nz) wrote: ↑Thu Dec 07, 2023 4:12 pm That is a light car, wdll done. Fun with I assume 250-300hp it should fly.

I too assume you (or driver ballast weight was not in it). Since you have all the adjustable suspension might be worth chasing cross weights with driver weight.

There is a good video on it here

https://youtu.be/jpuztcGQM9k?feature=shared

Hi Mike, yeh my bum was not in the driver's seat.

But overall happy with the weight and balance so far.
As for power, will know in little over a week, it's booked for the 18th.
It should have a minimum of 300hp at the flywheel, any less and I'll be disappointed, anymore and I'll be grateful

The plan is to do that when I'm down their next time but looking at the numbers it's not far away with luck.
Dwane Bicknell of Bicknell Autosport & Engineering is doing it, he basically does a lot of the motorsport shocks in NZ (He does all of George Stock's work...).

stevenewenham · Post by **stevenewenham** » Mon Dec 11, 2023 10:30 am

We await the magic number with baited breath! I am sure not as baited as your breath!

Grunzter · Post by **Grunzter** » Fri Dec 15, 2023 5:57 pm

stevenewenham wrote: ↑Mon Dec 11, 2023 10:30 am We await the magic number with baited breath! I am sure not as baited as your breath!

Thanks Steve, only a few days to go... If it all goes quiet, don't ask...

Datsun 280ZX IMSA GTU race car build...

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