Datsun Roadster: 2020 Challenge Build

Yesterday I cut a couple of pieces of scrap to make part of the rear engine mounts.

Then today I started in on bracing stuff. In the continuing spirit of "use every single piece of the buffalo", here are some radiator bracket folded sheet metal corners I cut out of the engine bay long ago.

They are now gussets!

I also need to make a pretty substantial mount for the inside of the rear suspension mount to the chassis rail. I have a piece of leftover roll bar tube, but I don't have tons of it. Certainly not enough to be wasting any with poor mockup.

So I got out the scissors and tape.

Then paint pen and more tape.

Now I can adjust the fit many many times until I like it and then I can translate it back to the metal.

739 hours.

Well, I still managed to screw one of them up, even with the templates. 

However, I persevered and got these done and am happy with them. I had juuuuuuust enough metal to make them. Still need to finish some welding, but holy moly was that harder than I thought it would be. 

Cleaned and started welding.

Even did the other side!

742 hours.

Same as everyone else, when I wake up in the morning I put my pants on one leg at a time. The difference is, after I put them on I want MORE TRIANGLE!

And the other side too

743 hours.

Triangle = strength.      Carry on!

More mounts are becoming tacked in!

744 hours.

Next was mocking up the diff mounts. I already had a plan but yet I still spent a lot of time in this phase just looking and thinking and measuring, etc. Also, lasers.

Once I was happy with everything, I just had to drill and tap a ton of holes. 

Oh, and make some neat little brackets. For these brackets I used scrap angle that was one of the first things I built for this car but then discarded. It was scrap from the f500 and I used it to attempt to make a gsxr motor mount with it. Then I discarded that idea and it became scrap again and just now I decided to make it into these neat little adjusters. Meta.

And here's the idea (this is where I left off yesterday).

Today I decided it was all good enough to go forward. So I started making it so.

And, (use all parts of the buffalo), I grabbed this front sheet metal that I cut out from the grill opening and hood hinge support area.

Cut it down a bit.

Then clean up the rust near the weld areas and tack it into place. (I was also test fitting the chain).

And boom. Drumroll please, REAR INDEPENDENT SUSPENSION:

This all was about 9 hours over the past 2 days, 753 total now.

Magnifico!

I like it.  I do think its gonna have a good moment on it, especially when you're launching.  Has that been looked at?  Dan might've run it through some calculator already.  If he hasn't, is there any way to tie it into the upper frame?  Something roughly like the below?

Top two lines would be either or, with the lower one probably being a good suggestion even without.

In reply to Mr_Asa :

Well, it is currently just tacked in and I can already lift the rear of the car with it. BUT, I like where you head is at. I have a plan that involves a piece of metal that is hilariously oversized for the job, but I'm running out of tube choices from the in budget scrap I have laying around (stuff from the Datsun body and the f500 frame).

Tacks can hold a surprising amount of weight.  Launching is likely an order of magnitude greater than that.  You knew that, though
Big ole sheet of metal across the whole thing?

Its too bad I didn't get a receipt for the ~6 year old tubing I was given from the FSAE team.  The year before I joined they ordered 1" tube w/something like 1/4" wall, and it is hilariously oversized for an FSAE car, so they gave it to me after I graduated but kept coming back to help out randomly.

You want me to ship you some bedframes?

I'm certainly no engineer but I was also wondering if you don't want some lateral support for this. Sorry if I've missed it in your plans. 

This is the kind of thing I mean. 

Either way, this is incredible. Awesome work. 

The Datsun radiator support is perfectly shaped for the task and good enough in geometry, but I question the strength due to the tissue thickness (thinness?) of Datsun sheet steel. Upper braces only to substitute for lower brace. Lateral strength will be OK here.

AxeHealey said:

I'm certainly no engineer but I was also wondering if you don't want some lateral support for this. Sorry if I've missed it in your plans. 

This is the kind of thing I mean. 

Either way, this is incredible. Awesome work. 

I was thinking the same thing but only on the "short" "passenger" side

Alright, I know you are all been holding your breath, but here's my hilariously oversized upper support. Bonus points if you can guess what it's made out of.

Remove weight and tack it in. (Gussets will be replaced later).

And finally drilled 2 holes at the back and found some bolts from the ol buckets of fdat bolts - I think they are 2 of the 4 that were holding the vfr engine to the chassis when I got it - to put in the holes. I tacked the bolts in so only one wrench is required to loosen the fasteners.

5 more hours! 758.

Yeah, that'll do it.

Does remind me, though.  Every FSAE car had a chain guard to prevent the chain from launching if it came loose.  Can't remember if the first iteration had one, but you might want to look at it, you've got most of it there already with that, you'd just need some sheet metal along your tube to prevent it from heading somewhere dangerous like your noggin.

TurnerX19 said:

The Datsun radiator support is perfectly shaped for the task and good enough in geometry, but I question the strength due to the tissue thickness (thinness?) of Datsun sheet steel. Upper braces only to substitute for lower brace. Lateral strength will be OK here.

Measured today, and it is 16 gauge (.060). Not sure if that's thick enough or not! Haha.

In reply to Robbie (Forum Supporter) :

Wow! I would have guessed it was .048 or less. I think I would go with it. Engine support pieces are swimming pool blue, but the bent tube? Still pondering...

Three more hours and two more supports built. 

Need to figure out the shifter mount, and then I think I can start finish welding everything up. 

761.

The bent tube was someone's roll hoop

TurnerX19 said:

The bent tube was someone's roll hoop

Ding ding ding! This one, in fact.

It took me longer than it probably should have just staring and thinking, but once I had the idea implementing it was quick.

Even better, I only had to remove material to mount the shifter! And I get to reclaim the janky bracket into the scrap pile.

763 hours

Couple hours Wednesday and couple Friday. 

First I added some more triangles to the diff mount and the rear engine mount.

Added plate between frame and diff mount tube, as well as diagonal from horizontal engine mount bar all the way down to the left frame rail.

Also did similar diff mount on other side but with tub instead of plate.

Next I turned my attention to fixing the seat. The existing seat is from a kart, and is, suboptimal. I happened to get a kirkey seat in a deal by trading the free rx8 seats for a parts lot, including this seat.

This seat will be a lot better, and it even comes with a cover! However, it will need some massaging to fit. Mocked it up on the wall to get an idea.

Also found an opportunity for weight loss. The old seat mount can go, as well as this giant rear subframe mounting plate.

Woof! 10+ lbs removed!

Next up, mounting the seat!

767 hours

Ok, got a bit behind on my posting here. Few hours on Sunday got the new seat trimmed and fully mounted. It is a big upgrade, for free!

I was able to re-use the bolts from before, and I used the Datsun door hinge backing plates to make the tabs to weld to the frame. The backing plates were already the right thread. In fact, the bolts for the seat may have been door hinge bolts originally. Who knew?

The seat cover will require just a few cuts but will wrap around the bars to provide extra elbow and knee protection.

I also got out a harness and made sure I had good locations for all the straps. Done!

Next I looked at shortening the exhaust and mounting the muffler. Over the years I've mounted this to many different things, but it has always been way up high. The tubing is titanium, and I cannot weld it, so I've been hesitant to modify. But now that the engine is turned, the muffler ended up not only way up in the air, but also pointed at an angle and off to the side. Aaaand much too close to the gas tank for comfort. 

So I grabbed the band clamp I traded to stampie like 2 years ago (for a Datsun wiring harness), and got to work. 

With only a band clamp, basically my option is to shorten a straight section.

I found these stampings in my scrap pile, they are originally trunk lid support structure around the hinge mounts. 

And now they are muffler supports!

Muffler is lower, straighter, still not centered, and much further from the fuel tank.

And here's the band clamp where it ended up.

772 hours.

I don't know if you saw but registration for the test and tune just opened.   It's what 3 weeks out?  You got this!!

Robbie I'm sure will be along to explain this in more detail but for brake rotor mounting a imported wheel spacer needed sacrificed.  Since Robbie doesn't own a lathe he had it shipped to me to make the modifications.  

I chucked up the part and got to lathing.  

Halfway there. 

The openings on the ID won't matter because the part is clamped by the rotor and the diff.  It will make sense once mockup occurs.  

Next to it's unmodified brother. 

It weighs about 1/4 of what the unmodified one weighs, the aluminum is probably 1/2 the weight.  

+1.5 hrs and like 2 oz of WD40 for cutting fluid.