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Ironhead

ANOTHER Datsun Z/LS3/T56 Swap Thread

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Yeah...the dash that came with the car is trashed...and I am not really bound to maintaining any sense of originality anyway.  All I need is a place to mount a digital dash.

 

I was taking stock today....other than the doors and body shell...there is really almost nothing OEM Datsun that I will be reusing.

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More roll cage nonsense....

 

The diagonal roof bar is just wedged in place and is coming out for a redo.  I can tuck it a bit tighter to the roof if I change some of the angles.  I don't think I have ever gotten one of these bars right on the first try.  Kind of frustrating being an idiot...lots of wasted steel...although a lot of it can be cut up for smaller pieces....and/or used for welding practice since I am a noob welder.

 

Thanks for looking.

 

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I had to postpone finishing the roll cage...without more critical parts on hand to mock things up too much chance of welding in a tube where it will end up interfering with something.

 

So I started working on a structure to support the fuel cell.  The cell is a 15 gallon, with an integral surge tank and in-tank fuel pump.  I am going to wind up making it a bit beefier than necessary to support the tank and fuel, just because it seems like it would be a good idea to include some crush protection in the event the car gets hit from behind (or crashed backwards).  I am using .095" wall tubing, so it is pretty sturdy (also, sadly, fairly heavy).

 

This is where I am so far.  Just need to include some more bracing and a bolt on "lid" then I can work on welding it into the car.

 

Nice doing some welding on a work bench for a change, rather than contorted inside or under the car.

 

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Edited by Ironhead

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Finished the fuel cell mount.  Once welded in place I am going to skin the outside with 18 gauge sheet metal.

 

I realize it might be a tad over-engineered, but in addition to the safety aspects, I am going to weld a rear jacking point to the bottom of it, and probably mount a diff cooler pump, possibly a diff cooler, and probably rear exhaust hangers as well.

 

Thanks for looking.

 

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Drove up to T3 today and picked up most of what I need to start mocking up the rear end.

 

I tell ya, if this T3 stuff works as good as it looks, I will be damn happy.  Appearance wise, it is pure porn.  Almost too nice to let it get dirty.

 

A few parts seem like they might be needlessly heavy.  The hub carriers are made from something like 1" thick steel....seriously beefy.  I suppose they know what they are doing, and I imagine potential liability plays a part in the design as well.

 

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Edited by Ironhead

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Welded in the T3 adjustable camber plates.  This was a more fiddly and time consuming job than I expected...I was obsessed with getting them at exactly the right angle, alignment, spacing, etc....and it is not easy to come up with precise, easily accessible, accurate measuring points.  I think I got it pretty much dead on though.  They are perpendicular to the centerline of the car...within .30 degrees of the same angle....and within 1/16" equally spaced fore and aft.  Probably far straighter than my chassis is anyway.

 

I also tidied up my welds with a grinder...which I don't usually do...I just embrace their ugliness.  But in this case the beads were above the flat surface of the camber plates and would have caused problems with my plans down the road....so I went to town with the grinder.  At least now I know none of the welds had any porosity.

 

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Edited by Ironhead

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I love the results keep it coming as I am getting completely motivated for my build with each new update you put out. How are you planning on filling the fuel cell? from the stock location on the passenger side or something custom behind the license plate? Trying to make sense of the last pic showing the canted spout on the top of the cell. I am now committing to a fuel cell and frame much in line with yours and the over built route.

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6 minutes ago, Nelsonian said:

I love the results keep it coming as I am getting completely motivated for my build with each new update you put out. How are you planning on filling the fuel cell? from the stock location on the passenger side or something custom behind the license plate? Trying to make sense of the last pic showing the canted spout on the top of the cell. I am now committing to a fuel cell and frame much in line with yours and the over built route.

 

Thanks much!

 

I would like some sort of remote fuel fill...I am thinking I might just put a fill cap in the stock location, connected to the fill neck on the cell with a 2.25" filler hose.  But, I plan to enclose the top of the cell in an aluminum bulkhead (as required in SCCA rules for cars without an enclosed trunk area), so ideally the fill hose would also have to be enclosed in the bulkhead...which would be complicated.  I could just run the fill hose through the bulkhead...which would slightly compromise the safety aspects....so I dunno.

 

You have a good eye...I have both a direct fill plate for the cell and a remote fill plate....because I keep going back and forth as to which approach makes more sense.  I might just encase the cell in the aluminum bulkhead, and put a remote fill cap on top of the aluminum.  Then I would have to open the hatch to fill up, but not open a trap door to get inside the enclosure to access a direct fill cap.  I spend a lot of time pondering these details....

 

I am also not decided on which fender flares I am going to use...as the full blown IMSA style flares completely cover the stock fuel port IIRC.

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I hate the aspect of lifting the hatch and filling inside the rear of the car, but want to be legitimate for any beginner/amateur  track related use I would be starting in. Trying to plan accordingly and from what I have seen from other builds here it is imperative to have a trap door cover and if I'm correct only fill from that in rear car location. My car is primarily going to be a street driven with plans to occasionally canyon carve/beginner autocross and be a beginner occasional drag car. I was originally going to modify the stock tank with an in tank pump  and I already have the top ring, but I like the track legality and roll over safety of the cell. Been looking at Fuel Safe and Radium engineering surge tanks lately. I definitely want the largest cell I can put in (15 gal?) as I plan on using 91 premium and E-85 which will be consumed voraciously. 

Edited by Nelsonian

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1 hour ago, Nelsonian said:

Trying to plan accordingly and from what I have seen from other builds here it is imperative to have a trap door cover and if I'm correct only fill from that in rear car location. 

 

I honestly don't know.  The way I read the SCCA regs, the cell itself has to be enclosed/partitioned, but it doesn't specifically mention remote fill points one way or the other.  Maybe someone with experience wheel to wheel racing will weigh in.  Since the one way fill valve is in the cell itself, it doesn't seem intuitively that a remote fill cap outside the enclosure would greatly increase the hazard....but what do I know?

 

I know SCCA regs allow fuel lines to run through the driver's compartment (as long as they are braided steel or hard lines) and those contain pressurized fuel.  It seems like an 'empty' fill hose would be a lower risk than that?

 

I don't plan on ever having to pass tech with my car....I just think following the safety regs is a good idea.

Edited by Ironhead

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4 hours ago, rossman said:

Awesome build!  I'd recommend something different than the T3 front differential mount.  That type of mount is known to move around under load.

 

Thanks...I can see where it would be less than rigid.

 

Is there a better design available, or is it a matter of fabbing something up?  The diff will be a short nose R200.

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Got a bit more done on the cage today.

 

I put in the diagonal bracing in the plane of the braces to the rear strut towers, rather than in the plane of the main hoop.  I have a very far rearward seat position, and a diagonal brace in the main hoop would interfere with some of my seat placement options.  The rearward diagonal braces as I have done are allowed in the SCCA regs in place of a diagonal brace in the main hoop, I presume for the same reasons I chose to do it...room for seat placement.

 

I am looking for opinions...virtually every "Z" cage I have seen done has used a horizontal bar between the rear strut towers.  I am thinking that in my case, with the rearward diagonals...the horizontal bar would be wasted weight and bulk.  I don't see how it could do any more to brace the strut towers than the bars I already have in place.  What do you all think?  It is tempting to include all sorts of bars here and there to increase rigidity, but it definitely becomes a decreasing returns thing at some point...and needless weight.

 

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Edited by Ironhead

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Got the door bars done.  I still need to add a harness bar and a dash bar (I will do those after dropping the cage and welding the awkward spots), and some gussets, but other than that I think I am calling everything from the dash back to be "done".  I can think of additional bars I could add that might stiffen things up a bit, but IMHO I kind of feel most of it would be diminishing returns.  Everything has been a trade off of adding stiffness and chassis integrity, while still allowing decent access in and out of the car.  I think I am at a decent place to stop.

 

Thanks for looking.

 

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Edited by Ironhead

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On 2/26/2018 at 6:44 AM, mr.mike said:

This is my favourite build thread. Keep the pics coming. Cheers

 

Thanks much Mike, glad you are getting something out of it.

 

I got the cage dropped to fully weld all the awkward joints up by the roof and other body panels.  I thought this would be kind of a hassle, but it went fairly smoothly.  I wish I could do prettier welds.  I can do OK on a bench when light and position etc are perfect....but welding up the cage...with all the contortions and awkward positions, is a different story.  I know the welds are all structurally sound and are not coming apart...at least.

 

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I also permanently welded in the base structures for the main hoop.  Probably overkill, but I also welded a support inside of them out of a piece of tubing...since it added virtually no weight and should make them extremely robust.

 

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Thanks for looking.

 

 

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Posted (edited)

I had a bout of flu and took a couple of weeks off from working on the car...

 

When I returned to it I decided to tackle the rebuild/assembly of the CV axles, using the T3 shortened axle shafts.  Early on in this project, I purchased the entire rear end assembly of a junked 1994 Infiniti Q45.  This included CV axles, but I had some doubts about their condition because it was apparent that all of the parts had simply been sitting outside in the elements for many years.  The wheel bearings and many other parts were shot.  So, I also ordered a cheap set of CV axles for $70 each from a major online parts retailer.  That price, when the OEM Infiniti axles are around $1K each....should have been more of a warning than it was....more on that later.

 

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Trying to disassemble the axles, the "inner" bolted portion came apart without issue.  But the other end, where you have to basically knock the CV bearing off the end of the splined shaft, over a snap ring, simply would not come off.  I beat on the thing until I was hating life, and even tried dropping it inside a piece of 2" tube, but it would not budge.  Since I was not going to re-use the shafts, out of desperation I wound up taking a cutoff wheel to the shafts, cutting them as close as possible to the CV joint.  This allowed me to pivot the CV sufficiently to take out the bearings, then remove the cages.

 

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I was pleasantly surprised, the bearings actually looked pretty good.  No pitting or signs of significant wear on the races.

 

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I also dismantled one of the new $70 CV axles....just to compare.  It was immediately obvious the cheap replacements were crap.  The machining of the parts, the tolerances, everything....was clearly vastly inferior to the OEM Nissan components, so I decided I would just clean and re-use the junkyard parts.

 

Along the same lines, I had some "universal" CV boots that I ordered online to use on the rebuild.  Here again, the aftermarket parts had little in common with the Nissan parts....the aftermarket boots for example were about 1/3 as thick as the OEM ones....and I had major doubts about how long they would last.  So I managed to track down some CV joint rebuild kits from Nissan and used them....which of course cost about 6 times as much as the generic boots.

 

So I wire brushed and painted the junkyard parts, then it was just a messy/greasy job re-packing everything and putting it all together.  I wound up using the crimp-on style boot clamps (the OEM Nissan ones work differently) just because I happened to have the proper tool for crimping them.

 

For grease, I used Redline synthetic CV joint grease....mainly because I have trememdous faith in all Redline products.

 

These Q45 axles are pretty beefy....I figured since they came on a RWD car that weighed twice as much as what I am building, they were the best bet for withstanding the LS3 torque.

 

Thanks for looking.

 

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Edited by Ironhead

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Love your work so far, fabulous fab work.

 

Think you are correct regarding the cage, a bar between the rear strut towers will add some more strength, but its barely going to be noticeable over the cross brace you already have so better not to add the extra weight.

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