Tube-frame 1968 Datsun 510 - Slowest moving project ever!

[JDM510]

epic!!!!!!!!!!!!!!!!!!!

+2!!!!!

 

this things bad ass.. and your pretty much sitting in the back seat now!!

[blueridgespeed]

So, with the suspension pickup points placed by choice rather than the constraints of the stock body, the "car" has a wide range of ride height options. Everything was built to be easy to adjust, so it's fun to just play with it.

 

I lowered it all the way down, then started cranking it up 'till it looked good to me.

 

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This is what I feel is a nice, reasonable ride height.

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People keep telling me "oh my GAWD, it's too low....what would you do if you were driving and came across a piece of wood in the road?"

 

Well, fear not! I grabbed the first piece of lumber at hand in the shop - some "5/4-inch decking". The car EASILY rolls right over.

 

NOW, AS LONG AS I DON'T COME ACROSS SOMETHING HUGE LIKE A 2x4" - it should be no problem.

 

What, am I crazy? I mean, c'mon people, let's get real, Huh? I don't want to have the car all "jacked up" like an off-road truck!

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[datto510]

Are they crazy? Thats the perfect ride height! :lol:

[XeroX]

WOW i think this sets a new standard for ride height! hahaa

 

duno if this has been covered but what are you going to run for wheels? you planning on running whats on there now?

[Duke]

The ride height is PERFECT! I love it. Makes me feel funny in my pants... :blink:

[datto510]

The ride height is PERFECT! I love it. Makes me feel funny in my pants... :blink:

 

[blueridgespeed]

WOW i think this sets a new standard for ride height! hahaa

 

duno if this has been covered but what are you going to run for wheels? you planning on running whats on there now?

I'll run the Watanabes for now. This is a staggered set, 14x6.6 rear and 14x6 front. My aesthetic preference is somewhere between 14's and 15's. This is a light set, and I already own them, so this is what I'll do for now.

[Farmer Joe]

oh... muh gud!!!! :thumbup:

 

thats is fucking sexy!! excuse my french, but that is just awesome!!

 

this car is full of win!!

[greengo]

i have a 72 dime and i only dream of something this cool but your making it true .. all the hours and blood and sweat you put in it will be worth it when you sit in your car and go for a drive.. and if you ever plan selling it... im here ill sell my body for it..lol.. nice car for sure ... love the build

[Bears510]

I don't know...seems a bit high to me. can you say...JEEP?!?!

I kid!! I kid!!! Actually it's perfect!! not to mention, it is still totally adjustable so you can roll it however you want to! Sweet work! keep it up!

[blueridgespeed]

I got the steering rack back from the machinist. It is now narrowed exactly as desired. The rack was mounted, and steering column mock-up was investigated. The "intake tube" that connects the turbo to the intake manifold was kinda in the way, so instead of adding more complexity (and U-joints) to the steering, the intake was rebuilt using smooth mandrel-bend tubing. This opportunity was taken to eliminate a few unnecessary bungs, and make a straighter tube (less bends and less sharp bends) It isn't as good as an intercooler, but it should help flow. The short intake tube was part of the "instant boost" response that our Japanese engineer bretheren were after when introducing the 300zx turbo (z31) to the market.

 

[blueridgespeed]

I've always wanted a set of Tilton reverse-mount pedals. For a long time. About a decade I've wanted 'em. At this point in the tube-frame project, I could deny myself no longer! It was meant to be. The pedals and steering column mounts are done.

[bonvo]

almost there! keep it up

[thisismatt]

Rack looks crazy far forward. Just curious if you calculated the geometry or just winging it?

[blueridgespeed]

Rack looks crazy far forward. Just curious if you calculated the geometry or just winging it?

HA! Yeah, the rack looks pretty far forward. Keep in mind the engine is pretty far backward, if that's a reference you're looking at. It's set up with many considerations indeed. Plenty 'o head scratching for several of us involved in the project.

 

I was pretty sure what I THINK needed before I took the rack to the machinist, I can tell you THAT!

 

I built a camber gauge for all the suspension setup which is very accurate, but to measure TOE CHANGE (which is what's happening with bump steer) I'll need a different tool. I do have a dial indicator kicking around somewhere so I'll probably make a bump-steer gauge with that.

 

Of course the location of the steering rack can be adjusted a bit, and we may make some adjustments to optimize bump-steer.

 

I've got a lot else on the list of things to do (floors? who needs floor?), but when I get to that I'll post what kind of bump-steer numbers I get at that time. It's definitely set up with the basics needed to avoid a disaster (effective tie rod length and pivot locations matching the lower control arms - that was why the rack needed to be narrowed 5 inches). Also, there will be no toe-out during the compression/bump arc. The toe curve (rate of change) is what's yet to be precisely measured.

[thisismatt]

How about ackerman angle?

[fisch]

I've always wanted a set of Tilton reverse-mount pedals. For a long time. About a decade I've wanted 'em. At this point in the tube-frame project, I could deny myself no longer! It was meant to be. The pedals and steering column mounts are done.

 

Totally jealous of the room this creates! If I ever do a VG swap in my '59 I will be looking into this set-up. I almost bought a wilwood reverse setup on ebay, but realized there are many more things I need to get before I can think about that too hard.

 

I love everything about this build!

[blueridgespeed]

How about ackerman angle?

Keep me honest, Matt! Ackerman was considered as well- more head scratching and consulting folks who know stuff- opinions are numerous! I pulled 240z steering knuckles, 280zx steering knuckles, and even studied the (rear steer) 510 arms. By the way, I believe Ackerman with a steering box and crosslink setup like the 510 is different because of the swing from the steering box and idler arms, but with a rack and pinion, it's a little more intuitive.

 

Drawing an axis/imaginary line from the tie rod attachment point on the end of the steering knuckle, through the steering axis (which is generally in the region of the balljoint on the bottom of the strut in a McPherson Strut application) - to an intersectin point between the rear wheels (center of the differential) - is the way I was taught to build in Ackerman. This allows the "inside wheel" to track a tighter arc in a turn, which is the best way I can simplify a description of Ackerman.

 

So that's the theory. What I learned when looking at the 240z and the 280z and the front-steer 280zx is that there's almost no Ackerman. We called a chassis designer (actually, he owns and runs a shop dedicated to automotive alignments) -and he said - "duh! Don't put in any Ackerman if it's a strut!" We told him the anticipated camber setups, and the caster we were looking at, and he said not to worry about it. By the way, he also helped advise us on caster settings.

 

I don't know if any pics show it, but we fabricated the "steering knuckles" for this project. They were made about 8mm shorter than the stock nissan units on purpose to quicken the steering a bit. This was somewhat arbitralily chosen while drinking a beer and remembering that the "fast steer" early 240z arms are 10mm shorter than the later cars, and are supposedly the hot setup. ANYWAY, my fabricated knuckles are otherwise very similar to the stock units - including the lack of "splay" which would give ackerman. Mine are "straight"

 

If it makes sense, the "straight" axis knuckles that are on there now are almost parallel, as opposed to intersecting at the rear center.

 

If for some reason I learn different and decide I want ackerman, it's as simple as fabbing new knuckles. We even thought about leaving room on the knuckle ends for alternate "ackerman holes" but darn it- I just couldn't stand how it wouldn't "look cool".

 

Once this beast rolls and stops, I anticipate we'll have a WHOLE SLEW of chassis stuff to test and sort out, so I'm just making my best calculations and leaving options/adjustability when possible.

[denveratsun]

Blueridgespeed.....your build is very top notch. clearly very well thought out..or it would be called the fastest moving project ever. ;)

 

The rack angles seem to be a little too far forward from the stand point of their relationship to the rod ends and not to the suspension.

 

If an imaginary line were drawn from tierod to tierod across the rack body, it does seem as if the rack could have been mounted a weee bit further towards the rear of the car. Now....from the looks of it the distance from the rack to the crank pulley isn't very large, so it's pretty clear how and why that mount would have been established where it was. This is even more clear if you have already dropped the motor as far back and down as possible to maintain your very low COG.

 

There are like 200 things that I totally love about this build.

One is that you weld very well.... :cool:

Another is that you have a great body of people gathered around you to oversee the concept. Your not just flying by the seat of your pants on any step of this process.

Another is that the "end game" has been pretty clearly the focus for the entire time....very little of the "oh yeah...what if we...?" along the way.

I truly look forward to seeing the next update as you build. Its lookin really good man and it is going to work SICK when it gets on the road. Keep it up man. :)

[blueridgespeed]

The rack angles seem to be a little too far forward from the stand point of their relationship to the rod ends and not to the suspension.

 

If an imaginary line were drawn from tierod to tierod across the rack body, it does seem as if the rack could have been mounted a weee bit further towards the rear of the car. Now....from the looks of it the distance from the rack to the crank pulley isn't very large, so it's pretty clear how and why that mount would have been established where it was. This is even more clear if you have already dropped the motor as far back and down as possible to maintain your very low COG.

 

 

 

Yeah, I'm definitely up against constraints at this point. The whole build, the whole engine placement, the whole PROJECT has been SLOW MOVING in part because of careful thought trying to minimize these constraints.

 

At this point in the completion, I'm really quite pleased that more barriers haven't come up. We'll just have to see how the design works out vs. reality with the rack.

 

You're right about the engine vs. rack placement - they cannot occupy the same space. We've got a little wiggle room, but not much. Not only does the engine need to clear it in place, the engine also has to come OUT! _Um, er, remember that it's tucked under the cowl about 7 inches? THAT was a big challenge, and part of why the engine mounts were designed the way they were. There wouldn't be room to lift the engine "up off" standard engine mounts since it's up so tight against the (sectioned) cowl.

 

I've had design ideas prioritized on paper, and that's the only thing that has helped me decide when one or the other has to give! For example, cutting the sheetmetal and flaring the fenders would have been much easier than narrowing the rack, adjusting the front lower control arm mount points, shortening both 1/2 shafts, making a narrowed rear subframe (to hold the diff and mount the rear LCA's) and mini-tubbing the rear wheels - but I like to do things the hard way, I guess.

[VQ260z]

Man this is SOO COOOL!, excellent work.

[blueridgespeed]

ThisisMatt, I don't have any data yet for you on the steering performance, but the column has been secured and new precision SWEET (brand) u-joints were exchanged for the less expensive ones I initially purchased.

 

FWIW, I'd recommend avoiding large stainless steel steering U-joints like are sold by Speedway. I though I could get by with a non "top shelf" piece, but I soon regretted it. The joints are so chunky they won't tighten down on the splines or double-D's. Also, the allen bolts that cinch (well, don't quite cinch) don't fully clear the steering shaft, so they would have required grinding/notching to clearance. No prob on the shaft, but I wasn't going to grind on the spline of my new steering rack. Ordered the Sweet Products needle bearing U-joints ($70 each, but aptly named - they are Sweet, and slipped right on like a dream.

 

SOOOOO, the car now not only ROlls, but it STEERS. It can go Left and Right.

 

 

And, it can STOP!

 

We plumbed the brake system yesterday, with one temporary line that will be rerouted after interior sheetmetal is done. I'm liking the dual reverse-hung master cylinders! A split system is nice for bleeding! And the resevoirs sit right in front of you where you can see 'em. I hope I'll never experience it, but IN CASE of a brake failure (leak) you MIGHT get some warning by seeing the levels in the resevoir going down.

 

I dunno, just minutia, but such is my mode.

 

Suspension, Brakes, Steering - That's a lot of a car! (of course there's a lot to go).

 

I'm going to drag the project to the Mitty this weekend on a trailer. Trevor Harris (chassis engineer for BRE and others) is going to be there so I'm hoping to get his input)

[bonvo]

will you still be able to see the resivours after making a dash?

[blueridgespeed]

will you still be able to see the resivours after making a dash?

hmm, good question. It could go either way. I think I'll probably leave them exposed for service reasons, if anything. There's no danger of the car ever appearing stock at this point! ha! There are quite a few dash ideas, including a bare simple race panel, but I'm kinda partial to a simplifed "shell" of the stock dash, if it can work.

[blueridgespeed]

So the hulk is back from the Mitty, where I got lots of encouragement and the project has been boosted along again!

 

All those Datsun's were motivational. I believe there were 34 510's in attendance, including of course the BRE fleet.

 

Anyway, the big news on my project front is that the engine "ran" in the car for the first time last night. It was neat, after so many years. We got about 75% done making a subframe to mount the radiator. The separate mount is due to 2 things: 1 (non-stock radiator without side flanges). 2. Ease of front sheetmetal removal - I've "gotten used to" being able to acess all that stuff with no front sheetmetal on, and it can all come off with 6 bolts now, so we decided to make a system that didn't connect the radiator to that.

 

Pics to follow once she's a little more photogenic!