Datsun Roadster: 2020 Challenge Build

Just caught up on most of this. 

You're rapidly approaching, "Carving a race car out of scrap metal" territory. 

Well done!

Robbie (Forum Supporter) said:

1. This weekend is taken - I have a funeral to attend.

My condolences.

The following is probably implied, but I thought I'd bring it up... just in cases.

Robbie (Forum Supporter) said:
So, no more messing around. Time to focus exclusively on things that need to be done before this car can drive again. I believe that list to be:

• [Make Body Fly in Formation]
• Nut & Bolt Check
• Add gas
• Air tires
• Figure out trailer (long story)

In reply to Robbie :

Do think long term. Vintage racing will be a good long term place to have fun and with your challenge budget in mind  it will be very affordable.  
     For you  VSCDA  and SVRA rules will be what you need to comply with.  VSCDA  tends to be fairly relaxed  and I have no doubt you could use alternate engines etc. at first ( although check)  your fellow racers will encourage you towards more originality  but I don't think anyone would complain if ( for instance) you were to upgrade it to 2000 specs.  

We'll, if you're reading this you might have guessed I didn't make the test and tune. It was actually cancelled, but I wasn't even close to ready anyway. 

I'm finally back at the fdat! For the last week or so I've been working quite a bit,. It really just organizing the shop and cleaning up. And selling junk. Today I had a good chunk of time to dive back in.

I decided to switch up my plan a bit. Instead of mounting the cowl first, I decided to tack the doors in to make sure the body was spaced out correctly. Lots of prep, but ultimately they came out good!

Passenger first:

Next I did the driver's side, that door had some Bondo on it (the rear quarter on that side has a lot more) and it didn't fit as well. But still came out ok.

After that, I went back into the project scrap bin. This was the very front of the f440 nose cone support.

That'll do!

I got both sides cut and tacked in. The body will bolt to the square tube part.

7 hours today, bringing us up to 472 total.

Feels good to be back in the saddle!

Still gonna be able to lift the body up with that setup, or have you crossed that off the list?

I may have asked this already

In reply to Mr_Asa :

I'm planning to make the body removable still, just not sure if it will be "easily removable".

From the work I did yesterday, the body still tilts up quite nicely. And actually now that it weighs so much less, it's actually pretty easy to lift.

In reply to Robbie (Forum Supporter) :

As someone who has lifted that body, good.

Can't wait to see if the suspension stuff starts working out better!

*Got your package just after posting that, lol

Yesterday I only did a couple of cuts with the grinder, but the discard pile is growing!

This morning I started laying out pieces for the floor. Here's the big piece of aluminum that made up the f440 floor for the most part. 

I drilled out the rivets and also reclaimed some nice aluminum pieces that can be reused.

Then I made measurements which led to a plan and then an engineering drawing.

473 hours.

I've done a few things since last post, but a lot of thinking about how things will come together. Sometimes the thinking is important...

Any, while I was thinking I busted out the nitrous kit I got a few months ago to start testing it.

Ewww, gross battery pack. But yes this nitrous system was fired by 8 AA batteries and a single button.

After some cleaning and tracing and hooking up to a better battery - I can confirm both solenoids fire and using my own lung power both solenoids open and close correctly with the button. 

However, current boss noss kits use Bernoulli to pull fuel with the flowing nitrous. This doesn't look like that is the case on this kit. So I need to figure out what "pressurizes" the fuel. I know for a lot of mc systems it's just gravity, and that may be the case here too but I need to confirm.

Next, I put the body up in the air to prepare for rocker fabrication.

475 hours.

I bet you could rig up a motorcycle or lawnmower carb to use the flow of the nitrous to pull and mix fuel

Well, I just called boss noss and the guy who answered (Jim) was VERY helpful. He told me that with my old kit, they used to use engine fuel pressure (which mostly would come on from a vacuum fuel pump on a 2 stroke snowmobile) and they have a fuel needle in-line that the user would have to tune the fuel with. He said they moved away from that because too many people would lean it out too far and blow up their motors. 

He also said they would sell me a new NPFI (nitrous powered fuel injector) or two and that those would work with my system. That may be the easy button for this year so I might take him up on that, especially because he was so helpful. But theoretically I should just be able to run a separate electric carb fuel pump - and I happen to have one in budget already since one came on the f440 - and then I just have to tune it myself. 

A third option (though seems dubious to me) is that a lot of motorcycle 'dry' kits aim the nitrous right across the air temp sensor to trick the ecu into seeing colder denser air and injecting more fuel. 

maschinenbau said:

I bet you could rig up a motorcycle or lawnmower carb to use the flow of the nitrous to pull and mix fuel

yeah but you don't need a throttle, so it's a LOT simpler! Just need a tube for nitrous to go through and a port on the side where the fuel would come in. What's harder is knowing the size of the hole...

Was able to spend some time thinking and eventually came up with a plan I like. 

This roll bar is already in budget and I'm already at max recoup. (and very few people seem to be clamoring for a Datsun roadster rollbar anyway). So why don't I use it?

Now it's still a rollbar, just much less effective.

And you can see my plans here. Still need to final trim the transverse pieces to the correct length (and cut them nice and straight). 

This is the final part I was thinking about until this idea finally clicked it my head. I debated and debated with myself over where to attach this tube. But the rollbar fits so nicely in this stub square, and I get to tie more things into "nodes". And it will make for an excellent starting point for my diffuser action.

476 hours.

Robbie (Forum Supporter) said:

This looks vaguely familiar

How close is the new rocker width to the old side pod width(original floor)?

In reply to gumby :

What you mean familiar because it is what you told me to do 1.5 years ago when I was picking it all up? Haha.

Regardless, the width of the floor is about 2 inches wider than the f440s sidepods. Because I am making this car and I get to choose where I put the rockers! (The Datsun rockers want to fall a bit wider than that even). But I want to use the nice aluminum floor piece, which means I want the edges of the floor to fall in the middle of the rocker square tube. The 2 inches will be made up by 1/2 of the 2x2 rocker on each side.

A couple more hours got me here:

478 hours.

Got the other side done too.

Then curiosity was killing me so I put the floor about where it will end up. 

Nice. Next was to start fitting the body to the new rockers. Draw a straight line...

And then add to the discard pile!

Finally I removed the paint (and quite a bit of Bondo from both sides) in preparation for the massaging that will be needed next.

Woof. I need to sweep the shop.

482 hours.

That's a lotta zap zap. You could probably just stitch it and Bondo the rest. I also see some swiss cheese...you have some patches in your future.

You mean you see speed holes?

Also, I'm trying to keep this body removable, so the current plan is nutserts into the square tube and then a hex cap screw every 6 inches or so. But that may change.

Robbie (Forum Supporter) said:

You mean you see speed holes?

Also, I'm trying to keep this body removable, so the current plan is nutserts into the square tube and then a hex cap screw every 6 inches or so. But that may change.

Nutserts sound like a pain to get the first one or two aligned.  Maybe a channel or clips welded to that square tubing to hang the body on, then you just need to move it left or right to get the holes lined up?

Today I swept the shop and did a lot of thinking. Also, I quickly put this temporary support on the cowl so I can lose the block of 2x4 that I had precariously balanced instead.

483 hours. 

I'm actually swinging toward making the body permanent now. I may not do it quite yet, but it's starting to look quite attractive.

There are a lot of places where I will have "close interaction" between the "body" and the "frame". And I'm not sure I'll be able to neatly make all those interactions happen with any sort of quality if the body still has to be able to tip up. 

I do think tipping the body up is a cool trick. And I think it was worth concour points for sure. BUT, the loose body was also probably the biggest impediment to performance in the autox at the same time. 

I need to spend more time looking and thinking.

You could weld the square tubing to the body and make a perimeter frame, which could neatly bolt to the frame cross members protruding from the sides. That keeps everything stiff but still removable if you have a tight spot job.

I think you're definitely going to need to be able to remove the body if necessary, if not then there will be a fairly wide variety of things that need to be modified in order to do maintenance and repairs.  I like the perimeter frame idea, should allow you to be able to lift the body straight up instead of tilting it. 

Just think, you could get some removable air rams and have it setup so that you unbolt the bolts holding the body frame to the chassis frame and then pssssshhhhhh its up for maintenance.  I think that would be budget neutral as well considering it wouldn't be on the car on track, only a maintenance item like a jack or jack stands?

While I'm waffling, last night I decided to finish up some welds that needed finishing. For example the bottoms of the square frame I just made. I hate welding above my head.

Then I worked on the doors some more - and ran out of shielding gas. I knew I was low, but I wanted to use it up before getting a new tank. So hopefully I'll be able to run out and grab a new tank this afternoon.

Finally, I pulled the valve on the nitrous tank I have. Glad I did this.

No siphon tube, and the o ring that was in there was cracking. Easy to fix when the tank is empty...

485 hours.

LOL, lessons learned in second hand nitrous acquisition...test that E36 M3 before you get to the challenge...

- Oct 2019, Holey Spirit

Looking so good man, sorry I'm not there to help you make a mess in your shop.