Hello drifting world, long time no see. I hope some of you still remember Aardvark, my ’76 Datsun Z that is being turned into a Drift / TA / generic mayhem vehicle. More than a year has passed since my last update, but the project hasn’t just quietly died away. On the contrary: we’ve made huge progress. Then we made nothing for a while, only to restart in a different direction. But now we do make progress – and we have a deadline to meet too. Please check out this new video walk-around above if you will, and the more technically minded of you might want to read the build write-up as well, and have some laugh at our misery.
OK, so how come you’ve posted a nice shiny race car a year ago, and now Aardvark is a mere skeleton again (and a rather skinny one at that, too), I hear you ask. The reason we went for a full tube frame instead of further modifying the original front end is that adapting the (rotten) original would have been way more complex.
This is how the decision-making project went:
I already had a set of Driftworks S13 coilovers, a full set of adjustable racing arms and several other goodies.
This meant that we had to use the S13 platform. With hindsight, starting from scratch, I’d choose the S14 rear subframe (slightly different geometry with less anti-squat, hence better traction, and same abundance of racing parts). For the front, considering how far we’ve drifted from the S30 roots, now I’d go for a double wishbone setup with a much nicer camber curve than any pimped McPherson. Anyway, due to the parts I had to re-use, my hands were somewhat tied. You may call it an extreme case of automotive leftover cooking.
So the rear seemed all set, and the transplant of the complete S13 subframe and all associated arms, knuckles and struts was finished long months ago. That is until I realized that the subframe angle was wrong and that the whole assy hadn’t been set higher in the chassis the way we had agreed previously, but was at its factory height relative to the under-body. That’s all wrong, because that way, after dropping the body, you end up with wishbones pointing to the cloudy skies giving piss poor geometry.
So the subframe mounts were cut and re-adjusted, and I bought a set of Driftworks rear uprights that fix the geo. Just the way to burn money by mistakes. So that’s where the rear stands now.
In the front the only thing we knew from the outset was the necessity of the front-steer setup. Seeing how many people have successfully transplanted VQ-s while retaining the original Z steering, we could have (and probably should have) gone along that route. The PCD would be good, the mounts of the S13 coilovers and Wilwood big brakes could be modified to fit and we’d preserve some authenticity.
So why ditching the Datsun front end?
1: power steering
In a drift car PS is a huge boon (not a strict necessity, I’ve spent 6 years wrestling a manual AE86), especially as you start shortening steering knuckles to increase lock and effort
2: the freedom to fail
With the venerable Z parts out of the equation, we are free to screw up in modern and innovative ways
3: the original uprights got lost
So after deciding on ditching the factory solution while sticking to the sweet but primitive strut, we had to find an upright that would fit the bill.
First it seemed that an old school RWD Ford item would do fine, but eventually we decided to give BMW a chance. It turns out that the E46 uprights are acceptable, if not perfect. Since I lack the skill, the money and the bravery to design a custom item, I went with the Bimmer instead. This brought with it the E46 steering rack, which has OK throw and decent directness. It’s certainly not racecar quick, but much better than the unassisted Datsun rack and somewhat better than the S13 original. And we can always speed things up by shortening the steering knuckles, which we won’t, for the sake of driver longevity.
The most important factor of the rack selection was length: I’m terrified of bump steer. Aardvark has a much wider track now, and with the super butch 90.7 in wheelbase of the S30 (that’s the same as the Fiat Panda, for the record), it has the handling fundamentals of a real snappy, twitchy beast.
To keep bump steer down, we must have perfect harmony between tie rod and control arm. The width of the E46 rack allowed us to have the adjustable lower control arms right were we wanted them. Of course the LCA inner pickup points had to be custom fabricated to position the roll center at a suitable point in space, but thanks to our tube frame, this posed no further problem.
The BMW upright somewhat limits the position of the strut tower: sadly, the cast upright has a ring that the strut tube goes into, which means that we can’t change steering axis inclination without messing up the camber, as we could with a bolt-on upright like the S13 has.
All this meant that I had to relocate all the suspension hard points as compared to the factory spec, which in turn meant that it was easier to cut the whole bent and rotten mess of a car away, from the firewall forward.
That’s how we ended up with a tube frame front. All this struggle for two lowly struts, Colin Chapman would surely laugh.
Anyhow, now we are busy tying all those tubes together to regain some chassis strength. The front X-brace holding the radiators will be removable to help servicing and trackside fettling. If the structure seems to be too weak, we’ll have some sheet metal added to turn some tube triangles into shear plates, we’ll see if that helps.
Oh, did I mention that fixing the rear and properly designing the front suspension also meant that those super beautiful fat widebody fenders that OMG Visuals put hundreds of man-hours into producing didn’t fit any more? So a new rear FRP fender was drawn up, this time somewhat wider and more suited to the very low static ride height of the car. I think that the end result is just as pretty, and now the wheels can actually travel up in bump without ripping off the plastic buttocks.
This also means that I can’t use the first set, which is suitable for cars 6 feet 1⅝ inches or 187 cm wide. This was it, in its full glory:
I hope the new fenders will be just as great, but in order to tell that, we need to finish the frame and the suspension first, so that Aardvark can actually stand on its own feet again, after all these long months.
Thank you for reading, hope to meet at a racetrack soon.