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drivendaily
drivendaily New Reader
2/28/16 1:51 p.m.

An History of Things

(alternatively, THIS IS NOT A DATSUN)

I've been putting off starting a GRM build thread for awhile, but I suppose there's no time like the present. It all started in 2014, when I raced in my first hillclimb race

... no wait, it started before that, in 2013, when I volunteered as a safety worker for my first hillclimb race

... no ... wait, that's wrong too. It all started when I realized I like cars.

After a long chain of events, I bought my fourth Datsun s30, a sad 1975 280z with an l28et under the hood. The first thing I do with any car is sell off all the cosmetic 'stuff' that makes maintenance more difficult, as long as it doesn't make the car faster.

In this case, it meant the body kit went away for $500.

The Borg-Warner/Nissan t5 went away for an additional $500.

... and I put that money toward a Megasquirt3 setup for the l28et.

I quickly realized that I wouldn't have this thing ready for the first hillclimb, event and bought a bone-stock 1.6 Miata that I raced for the next two seasons (2014 and 2015). They say Miata Is Always The Answer, and it treated me extremely well. With a few modest upgrades, it carried me through both seasons to win my class. However, I never quite fell in love with it, and decided it was time to finally sell it off and put some real focus into the Datsun.

I tinkered with the Datsun off-and-on for awhile, but mostly planned out what I really wanted to do with it, and saved up my pennies.

Rear End Decisions

When it became time to 'get serious', I decided the Chapman suspension in the rear, coupled with the open long-nose r200 differential, and u-joint axles just wasn't going to cut it. I mean, that differential is held in place with (I kid you not) a leather strap. It's a bit of a mess (sold that assembly for $500).

Eventually, I settled on the Nissan 240sx rear subframe and suspension (purchased for $250). It gives a very tuneable multi-link design, gobs of aftermarket support, a much easier-to-lsd short-nose r200, good axles, and the subframe just has 4 simple mounting points (simple to tie in to a cage). Mocked up, I found that it was pretty wide, compared to stock.

Front End Decisions

In the front, the Datsun comes with an OK Macpherson design, but the aftermarket support is both limited and expensive. All four corners use a fixed strut cartridge design, so coilovers require a fair amount of fabrication, and even after that, the geometry isn't quite ... right. Plenty of people have made it work extremely well on plenty of race tracks, but hillclimbs are more like rally courses than typical racetracks. The surface can be very rough.

I searched and searched and searched, trying to find a good front-end donor. The Miata front suspension is kind of a work of art, but that spider-like subframe makes install difficult. The s2000 and FD3s would be great candidates, if they weren't a bajillion dollars per bolt. Circle track parts are well suited ... but I wanted longer travel than a typical setup would allow, and front suspension is complicated to re-engineer. After a long, long time, I came to a decision: New Datsun (Nissan)

I called Dave up and asked if he was up for a salvage yard run, and we picked up an Infiniti G35 front end for $1100 (less than a front coilover conversion, with a better steering rack, steering column, and brakes included!). We hauled that up to where the chassis now sits ... which we'll get to in a moment.

Squishy Human-Meat-Compartment Decisions

After I decided to get serious, I looked back on the progress I had made on the Miata while I owned it. The Miata is very simple to cage, but I spent a lot more time and energy on it than necessary, and I still wasn't totally and completely happy with it. I decided to drop it off with a fabricator that I know and respect (Joey Kale, near Burlington VT), who primarily works on rally and hillclimb Subarus (which means he sees the same cars every two weeks, because something's ALWAYS broken) ... kidding! I'm kidding...

By this point, Joey had finished most of the cage structure, and things were starting to look good. That's Joey on the left, who is enjoying the long process of recovering from Mono.

Engine Decisions

I wasn't happy with the l28et decision, even though I had invested time and money into making power with it. You see, I care far less about power than I do about ease-of-maintenance and size-weight. The l28et is pretty bombproof, and easy to rebuild on the rare occasions when it needs it, but that weight was just killing me. I put so much energy into getting the chassis right, and the suspension right, that I needed to outfit something lighter and smaller to it. I sold the l28et, and explored other options.

I started with the Ford 5.0, which makes sense in every way. It's reasonably light, makes torque for days (even if it's less powerful than the small block Chevy engines, it has better packaging and better low-cost manual transmission options), and is super inexpensive. I picked up a pair of blocks with rotating assemblies, blueprinted them, and started mocking up their fitment. Everything looked good, until I started looking at hillclimb classification, and I didn't like where it would place me.

Dave stepped in again, and after some chatting, I ended up with a pair of 4port 13b turboII engines and transmissions a few weeks later. One went into the back of a truck, and ended up in Burlington with Joey.

He quickly had that mocked up, and I can't describe the difference in size and weight.

... so here are some photos instead.

Deadlines

Our first hillclimb is May 20, 2016. That's 82 days, including weekdays/holidays (23 weekend days). It's a technically challenging hill, and I'd really really like to shake the car down before I head up there. As you can probably see, there's a fair amount of work left to do, though.

Here's the rough to-do-list:

  • Mount front subframe
  • Plumb brakes
  • Mount fuel cell
  • Plumb fuel
  • Get the engine running (OEM EFI, Megasquirt3, or VEMS are all on the table)
  • Convert 4-lug 240sx hubs to 5-lug to match the g35 front end)
  • Pass inspection to make it street-legal
  • Buy wheels/tires
  • Add floors
  • Make fenders/flares
  • Buy a driveshaft
  • Make an exhaust
  • Mount/plumb cooling (oil cooler, radiator, and intercooler)
  • Add rear coilovers
  • Fix all the issues that come up as a result of building a whole new car

How hard can it be, right?

Budget

Some people get excited about budgets, and buying specific things. I've been detailing this year's budget in a simple spreadsheet that lets me know how sad I should be about this. 2016 s30 Budget

Ryed
Ryed New Reader
2/29/16 3:43 p.m.

Is it still at Joey's shop? Looking forward to seeing it at the hills. What class will you be in?

drivendaily
drivendaily New Reader
2/29/16 4:16 p.m.

Dave and I just dropped the front subframe/suspension up there. I'm really happy with everything that's done, at this point ... but there's still a lot that isn't done. I'm trying to wrap up all the body work on my end, so I'm not the one holding him up once everything else is done.

Mostly, I'll be trying to train my brain to go 16% faster (the difference between my time and Bill Hudson's time at Philo this year), so I'm not going to be looking at the rest of the class. Just learning what it's like to use the brake pedal once in awhile.

The goal is street prepared 4, but I'm not sure I'll be able to swing that with the intercooler. That means I'll be in SP2 with ... hmmm ... let me check ... a ridiculous turbo vr6, a ridiculous turbo crx, and a ridiculously fast Camaro. Speaking of a ridiculous turbo vr6, how much damage did you end up with at Philo?

crankwalk
crankwalk Dork
2/29/16 5:05 p.m.

Hey its a 130Z.

I've messed with both of those engines (L and 13b) and they both have their merits. In a hillclimb with good cooling, I'd expect a pretty good life out of that 13b. Rotaries like to be beaten on and this would be a good use for an all out racecar. Changing the taillight panel out?

Good luck!

Ryed
Ryed New Reader
2/29/16 5:54 p.m.
drivendaily wrote: Speaking of a ridiculous turbo vr6, how much damage did you end up with at Philo?

I consider myself very lucky. I was able to source a used bumper beam, bumper, and passenger door (color matched!) from a guy in Hartford, CT all for $100. Very minor tweaking on a frame machine. New radiator & starter, intercooler mounts re-welded and unit sealed, cv boot kit on the almost brand new axle. That's it! Haven't driven it yet, and suspect I may need an alignment. But all-in not bad at all for my 1/4 roll and frontal impact.

Fitzauto
Fitzauto HalfDork
2/29/16 8:45 p.m.

Following with much interest. I love seeing s30s get turned into ridiculous racecars.

drivendaily
drivendaily New Reader
3/1/16 7:21 a.m.
crankwalk wrote: Hey its a 130Z. I've messed with both of those engines (L and 13b) and they both have their merits. In a hillclimb with good cooling, I'd expect a pretty good life out of that 13b. Rotaries like to be beaten on and this would be a good use for an all out racecar.

I don't have any (immediate) plans to build the 13b at all. I'll probably go with a front-mount intercooler because the top-mount is difficult to duct on the s30. I think I'm going to try to swap to a more standard td04 turbo as well, since the stock turboII is so non-standard (and mine is pretty tired to boot).

crankwalk wrote: Changing the taillight panel out?

The tail lights that were on it when I purchased it were essentially trailer lights (or c4 lights? is there really a difference?) with janky wiring. There was never any doubt that they had to go, so I'm going back to one of the OEM sets I have, but probably with some 12v LED strips in them.

Fitzauto wrote: Following with much interest. I love seeing s30s get turned into ridiculous racecars.

I keep telling people:

"If I drive it to work every day, it's not a race car."
Definitely not an all out racecar.

Ryed wrote: I consider myself very lucky. I was able to source a used bumper beam, bumper, and passenger door (color matched!) from a guy in Hartford, CT all for $100. Very minor tweaking on a frame machine. New radiator & starter, intercooler mounts re-welded and unit sealed, cv boot kit on the almost brand new axle. That's it! Haven't driven it yet, and suspect I may need an alignment. But all-in not bad at all for my 1/4 roll and frontal impact.

So it was an expensive off in terms of time invested, but not in terms of money invested. That's kind of hard to complain about.

java230
java230 HalfDork
3/1/16 9:31 a.m.

This is going to be GREAT! Cant wait to see it done.

Ryed
Ryed New Reader
3/1/16 11:55 a.m.
drivendaily wrote: So it was an expensive off in terms of time invested, but not in terms of money invested. That's kind of hard to complain about.

No complaints here. Based on the other two "offs" on Sunday, I'll thank my lucky stars...

drivendaily
drivendaily New Reader
3/7/16 1:38 p.m.

Nothing new to report yet, I've just been doing a lot of math on turbo sizing, suspension geometry, and cutting templates for the fenders. I think this project finally has a name, though.

MazDatsuNissan 130z-t

Have I covered all the bases there?

  • Mazda
  • Datsun
  • Nissan
  • 1.3liter
  • z-car
  • turbocharged
drivendaily
drivendaily New Reader
3/28/16 7:51 p.m.

This weekend was a lot of math. I already knew that the g35/350z front subframe would be wider than the stock 280z subframe. I also know that the 240sx rear subframe is wider than the stock 280z rear subframe.   The stock front and rear subframes are designed to be the same width. 240sx width compared to 280z width   After math-ing, I came up with the following:

  • Original hub-to-hub distance: 53"
  • g35 hub-to-hub distance: 60.8"

That's 3.4" wider on each side

But wait! There's more!

The original Datsun wheels were 14x5 (15" diameter by 5" wide), and I'm bumping up to 17x8" (8" wide) for street wheels. I need to accommodate 17x10" race wheels, and my math suggests that I'll have around 6" of those wheels outside of the hub (per side). That's 5" more 'wheel' outside of the hub than stock.   At the end, this all means I'm going from a fender width requirement of 55" to 72", which is 17" wider, or 8.5" wider than stock, per side. This car-shaped thing is starting to show how ridiculous it really is.

My fender plugs just keep growing and growing. It's starting to get ridiculous. Fender plug

drivendaily
drivendaily New Reader
3/31/16 3:05 p.m.

I suppose it's time to start talking about what's going under the hood. The current engine is a test mule, something I picked up off Craigslist that may or may not run. A friend of my fabricator happened to have a 13b that had been sitting on a shelf for a little while. I made an offer on it, and just barely squeezed it into my budget ... but this solves my "will it run reliably?" problem pretty completely. It's a ported 2rotor running on VEMS that's already been tuned, and is ready for whatever I want to throw at it ... as long as I'm throwing lots of fuel and oil at it.

Driven Daily s30 2016 13b Driven Daily s30 2016 13b

According to the dyno results on this engine, it should be good for better than 350whp. Sometimes, you get lucky and the right deal comes along at the right time. This was my time.

It's going to take some time to get it in the car, get the harness wired in, and build the body harness for it, but I'm in full-on thrash mode now. 14 weekend-days left before the first event.

drivendaily
drivendaily New Reader
4/5/16 7:22 p.m.

No real update, but I can drop this off as a reference of scale. The engine will probably end up slightly farther forward than this, but I think it can safely be called 'mid engine' 13b 280z fender

drivendaily
drivendaily New Reader
4/10/16 4:57 p.m.

Because the new engine is going in, I now have the 'leftovers' of stuff that isn't going into the car in my shop. That means cleaning, organizing, and storing needs to happen (before the car shows up). This is unacceptable:

I started by shuffling some parts around, and making room in the 'engine room'. Because I know I won't using OEM EFI on this car, I decided to tear all the extras off of the assembled-spare 13b.

I started with this and a beer:

And ended with less clutter, and no beer. Here's the mockup housing assembly next to the 'assembled spare' block.

The turbo goes on the 'spare turbos' shelf. If there's any kind of market for it, I'll happily sell the harness/ecu/manifold/turbo/lines off to whoever is interested enough to make it worth putting them in a box. I have no idea what it takes to convert n/a to turbo, or if any of this is worth anything. 13b turbo

One interesting discovery I came up with is that these two engines apparently have different rotor housings. Otherwise, they appear to be identical.

One with no markings on top 13b housing markings

The other with licensing markings on top. 13b housing markings

As for accessories, here's one of the spare transmissions (I now have three turbo2 transmissions), and two of the intake manifolds (again, I have a total of three right now). 13b accessories

That emissions block-off kit is really disappointing. It's so thin that I can't use the stock studs. I can either draw up a DXF (just put these on a flat-bed scanner and scan them 1:1) and have Big Blue Saw cut out some proper plates, or pull those studs and use bolts instead. Generally speaking, I find that steel studs in aluminum don't come out as easily as I'd like. I'm leaning toward slightly girthier blockoff plates.

Billy_Bottle_Caps
Billy_Bottle_Caps Dork
4/10/16 7:38 p.m.

Great build

jimbob_racing
jimbob_racing Dork
4/10/16 9:01 p.m.

Wow. Hardly any original car left.

drivendaily
drivendaily New Reader
4/11/16 8:52 a.m.
Billy_Bottle_Caps wrote: Great build

Glad you're enjoying it. I get so much inspiration from other peoples' builds, I'd feel guilty if I didn't try to share in kind.

jimbob_racing wrote: Wow. Hardly any original car left.

Well, if they had just engineered it the way I wanted from the factory, I wouldn't have to do all this work!

I'm slowly realizing that I'm building a tubeframe platform that should be able to fit under pretty much any body, using mostly-production-parts from various donors. I want to make sure that if/when I chuck it off the side of a mountain, I can just keep iterating on this design and end up with something even better.

akylekoz
akylekoz Reader
4/11/16 9:21 a.m.

Do you have any leftover Turbo II trans mounts, I have a friend who is looking for one.

Looks like fun, makes my bolt on weld on projects seem so normal and uninteresting.

drivendaily
drivendaily New Reader
4/11/16 9:30 a.m.
akylekoz wrote: Do you have any leftover Turbo II trans mounts, I have a friend who is looking for one. Looks like fun, makes my bolt on weld on projects seem so normal and uninteresting.

I don't, I haven't ever seen the OEM crossmember. I just see transmission mounting points and required fabrication.

If it makes you feel any better, I'm $12,088.44 into this project so far. There are a few parts left to sell off, and the v8's still need to be sold off. That'll recoup SOME costs, but I'm guessing I have another $2k or so left before it's even driveable. Street legal will be another matter altogether.

sachilles
sachilles UltraDork
4/11/16 10:52 a.m.

The more I think about this Jesse, and given it's current location. I think you need to get a subaru part integrated somehow.

RossD
RossD UltimaDork
4/11/16 11:05 a.m.

Awesome work! I love it.

drivendaily
drivendaily New Reader
4/11/16 2:13 p.m.
sachilles wrote: The more I think about this Jesse, and given it's current location. I think you need to get a subaru part integrated somehow.

You know, I was thinking the same thing. I did some research on my rear differential though (short-nosed 240sx r200), and found that all of the r160-r230 differentials are made by Fuji Heavy Industries. I was looking at potential upgrades (the unit I have is a viscous limited slip, I believe), and that led me to Subaru rear diffs. They have slightly different stub axles, but use the same carrier and internals.

Fuji Heavy Industries

The design for those diffs came Fuji Heavy Industries. A little bit of digging on Fuji Heavy Industries, and I came up with their logo.

Fuji Heavy Industries

Mission: Accomplished.

Now I need to find some Honda part to throw into this.

crankwalk
crankwalk Dork
4/11/16 6:14 p.m.

Oh man, lots of info out there on R180-R200 Nissan/Subaru LSD guts. Back in the day I'd buy S14 "SE" parts cars to resell the differential and the unexploded airbags. S13 LE's have a LSD as well. If you are ever in a scrap yard and find an S13 with leather, it should have a LSD.

sachilles
sachilles UltraDork
4/12/16 8:00 a.m.
drivendaily wrote: Now I need to find some Honda part to throw into this.

You have those, I left two boxes of them for you at the shop!

petegans
petegans New Reader
4/12/16 2:26 p.m.

Holy E36 M3 this rules! I laughed at the difference in engine size from above photos. Gotta love rotaries.

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