Datsun Roadster: 2020 Challenge Build

In reply to wheelsmithy :

I deserve that hahaha.

A few more hours this morning, total 120 so far. Finished the last piece of the structure. So sans final welding of the joints, the frame is complete!

Had my kids come out for some glamor shots.

Next I started working on seat placement and mount.

After some sitting this was feeling pretty good to me.

The seat already has plenty of holes! So I picked a few that look like they will work, and started drawing and CAD.

Next I went to work on my sheet metal bender:

Another hour, up to 121. Beautiful morning here in Chicago!

I got my straps to a place I was happy with:

Also seems to continue to work after test sit.

De-rusted, un-painted, ready for tacks:

Today I only had a little more than 30 minutes, but I'm not going to start counting minutes so that'll round up.

First I "captured" some nuts.

Then I put the seat in place, did one final test fit, and tacked everything into place. 

I did remove the seat and put it back just to test all the bolts still thread in no issue. They do. Woohoo!

Next up, final cleanup and welding.

She's gonna have the ride quality of that Radio Flyer down your neighborhood hill.  Love it!

I suggest a thick butt pad.  I have a gardening kneepad that i got at menards that's about 1.5" thick for my cars with aluminum seats, and it works great and the handle hole is a perfect pass through for the anti submarine belt

In reply to Fladiver64 :

Sorry to thread jack but the contact page didn't work....

if no one else has already claimed, I'd be interested!  Can you email me at username at yahoo??

btw, awesome build.  Shocked at how fast it's coming along.  I generally employ a 1:1 thinking:working ratio

RACEC4R said:

She's gonna have the ride quality of that Radio Flyer down your neighborhood hill.  Love it!

Wait, your radio flyer had Hoosiers! Today I learned my childhood was depraved.

In reply to Patrick :

Good idea!

In reply to jfryjfry :

Thank you! I'm impressed with how much can get done in an hour each morning. And I'm certainly enjoying seeing it come together too. Long way to go still however.

In reply to jfryjfry :

Stampie jumped in already.

123 hours. Seat bottom mounts done. 

Next up, pedals and steering wheel.

Didn't post anything yesterday but that's because I didn't take any photos. I basically just drank coffee and looked at the pedal setup until I developed a plan. This morning I started implementing it. 125 hours.

Here's the pedal setup. Very clean and simple setup that allows adjustability for different height drivers with a fixed seat. Twin brake masters so balance can be controlled. I'll plan on keeping those features and not reinventing the wheel.

It could fit sort of like this

Cut away the extra metal and start mocking into position.

I'll do a crossbar under the pedal rails basically at the back of the a arms. Then that should be good for now.

So, that's gas and brake and clutch by hand on the shifter?

wheelsmithy said:

So, that's gas and brake and clutch by hand on the shifter?

Correct. Current plan is that clutch is on the shifter handle. That will allow me to use matching motorcycle clutch lever. Also I'm going to put the shifter on the left side, since that gives better line of sight from shifter handle to shift lever at engine, AND anyone who rides a motorcycle will have the left hand muscle memory needed to work the clutch. 

I'm not sure yet, but I THINK that with intelligent part sourcing I can get a functional quickshifter and a slipper clutch which would then allow fully clutch less up and down shifting. Just like F1 the clutch would be required only to get moving in 1st gear.

In reply to Robbie :

Most motorcycles I have ridden really don't need the clutch past getting into first and moving. Just slam the gear.

java230 said:

In reply to Robbie :

Most motorcycles I have ridden really don't need the clutch past getting into first and moving. Just slam the gear.

This!

Although, to be a bit more precise, Ya preload the shifter, dip the power momentarily, and she slips in the next gear! On the street, I drop power with the throttle, but racing, we put a momentary kill switch in the ignition for a split second. Red set up a air shifter to preload each gear and reset; Reggie just tickled the thumb button for each upshift!

Yeah I'm familiar with the shifting. Basically you can clutch-less shift, as long as you relieve the pressure on the trans for a moment. Hence dipping the throttle or using a quickshifter or button to cut ignition for a moment. But on downshifts it's the opposite, you need to blip. A slipper clutch allows the rear wheel to spin faster than the engine - so if you do one to many shifts and would normally overrev the engine and slide the rear tire(s), instead the rear is allowed to freewheel. Anyway, that's a little bit away. 

Today, I got a solid 4 hours in and have the pedals done and should have the steering done shortly too. 129 hours.

First the pedals. Made some cuts, did some grinding, cleaned some rust and paint. Test sat.

Welded in. 

Next I turned my attention to the steering. I cut the steering column mount off since I'll be relocating it.

Also, whoever did this amazing work of welding was obviously not the person who welded most of the original chassis.

The bottom is not even connected...

Also, I learned a big part of the slop in the steering is due to a missing roll pin on this u joint.

So I took the off the u joint. Amazingly, the shaft fit perfectly inside some old conduit I had in the shop. Perfect for mocking up.

I got the length where I wanted and bent the rack mount to match. Dialed in the length, and then looked for a suitable middle. Turns out, there was a bar on the original chassis between the two rear wheels that had a perfect ID and was long enough. I don't have any pictures but I got it cut to length. I'm trying to decide if I try to drill holes in it to attach with roll pins or if I just weld it in.

In reply to Robbie :

I would scrounge a collapseable section from ann aircooled VW and weld it in some where in the column, or make some method of you own. This chassis is fragile enough to push the column far back with a relatively low speed crash. 

It's late tonight but I'll look in my scrap bin tomorrow, I think I have a couple dumpster-dive collapsible sections with u-joints. If I still have them, they're yours.

A collapsible column is a good idea, angry if you've got one laying around I'd really appreciate it.

Today I kept trucking on plan A for now however. I started by drilling my shaft for roll pins. I knew that they needed to be pretty exact and I wasn't sure if I could pull it off or not, especially with my 100% wobbly drill press. I figured however that if it didn't work I could always fall back to welding.

Dunno if you can see well from here but I only missed it by a tiny bit. The other side was even less off. I gave myself a pat on the back and grabbed my file.

After I took this photo, I got smart and removed the inner shaft before actually filling anything. After a few minutes of adjustment, both roll pins went home.

New steering shaft isn't perfectly straight, but it's close enough to work I think.

Here is it on the car.

After a bit of playing around and test sitting, I think I established a good spot for the support. I got a crossbar going.

Similar de-rust, de-paint, tack, check, and weld process later, and the car has functional steering again.

132 hours.

In reply to Robbie :

PM'd

I've only done a lot of standing around and looking and thinking since our last update. I did mock up the shifter location. I thought about shifting.

I thought about the floors. I thought about the gas tank. I thought about sheet metal work.

My next big job however is either fitting the body (and thus doing floors), or mounting a real engine and test firing.

I should probably do the shoulder harness bar and seat back next. And then maybe a final weldup on the frame (I'd like to roll it over to do the bottoms).

133 hours.

134 hours. Now that the seat, pedals and steering is in, I can confirm the location of my shoulders for harness bar locating. I sat in the car and put a level on my shoulder. The nhra rule is at shoulder level or up to 4 inches below. I'm aiming for 2 inches below to accommodate people both taller and shorter than me.

It turns out, that puts the bar right at a pre-existing node, so that's cool. This will be the most complicated notch I've done by far however.

Also, not short term by any stretch, but I learned that air cylinders and solenoids are very cheap on amazon... So that gave me all sorts of bad air shifter ideas. Combined with a small Arduino with an rpm input, you could do all sorts of fun stuff. Like fully automatic upshifting at preset rpm, maybe downshifting too. Imagine launching on the drag strip and having the computer rattle off 3 or 4 perfectly timed upshifts all while just leaving the throttle matted. Like I could probably make that happen for $60ish.

In reply to Robbie :

Having tried the air shifter thing on an FSAE car, I'd recommend taking the time and money you would have spent on that and using it to practice your launches and shifting instead- you can flat shift by preloading the shifter and letting the rev limiter do the "throttle lift" for you, and with the right technique (easy to teach a human, hard-ish to teach a computer) it's fast and repeatable.  There's a lot of "just pull a little further until you feel it" or "ooh that's light under this load/engine braking/whatever" that you do pretty naturally when shifting a dogbox manually, which translates into a lot of false neutrals and crashy shifts when you try to program a computer to do it.

Looking great, like the air shifter idea. What would you use for an air source? I was thinking a high pressure bottle and regulator would be expensive.