ANOTHER Datsun Z/LS3/T56 Swap Thread

[Ironhead]

1 hour ago, jpndave said:

Other than a little reinforcement and a few gussets aren't the front subframe rails pretty much stock? They should collapse at a more or less stock rate. I would be more inclined to keep the strength you have up there. Just my opinion though. I would keep in mind the collapse in an accident but you want all those bits to stay rigid and aligned. I think you are headed in the right direction and progress looks great. 👍

 

Thanks!

[Ironhead]

Finished the bumper/splitter mount.  I know it looks like an over-engineered monstrosity, but it actually weighs less than 10 pounds.

 

My plan is to bolt a piece of 3/16" aluminum to this framework, which will follow the contour of the bottom of the bumper to reinforce it.   The splitter will attach to this aluminum plate, not sure yet what the splitter itself will be made of.

 

I want to do it this way because the splitter will obviously be prone to damage, and I wanted it to be as simple and cheap to replace as possible.  Also, the car will see some street driving, and ...I dunno....driving around with an aluminum knife blade sticking out the front of the car seems maybe a bit...uncool.  Finally, the splitter is bound to exacerbate problems with speed bumps, curbs, etc.  Basically I wanted the splitter to be easily removable without having to take the entire front of the car apart, and only have it installed for track events.

 

I wanted to use carbon fiber for these large sheet parts....but if you have ever priced 3/16" CF roughly 30" X 70"....you will understand why I went with aluminum.

 

 

 

 

Edited January 26, 2020 by Ironhead

[LooseRocks]

Aren't you worried about ground impact with your splitter?

[Ironhead]

6 minutes ago, LooseRocks said:

Aren't you worried about ground impact with your splitter?

 Very much so....

 

The car is going to have ground clearance issues already, and while the splitter won't be much lower than other parts of the car, the further forward it is from the front axle, the bigger clearance problem it will become.  One of the reasons I only want it installed for track events.

 

Unless I don't understand your question....?

[tube80z]

The one recommendation I have is to make the splitter frame movable.  In the past I've used either hinge points or support rods that allow movement of the splitter blade upwards.  As you have a rigid frame I'd make some provision for it move like this.  It will also help if it grounds when you corner.  This way you don't unload the corner weight when you really don't want that to happen.  Your splitter life will be much longer this way.

[Ironhead]

25 minutes ago, tube80z said:

The one recommendation I have is to make the splitter frame movable.  In the past I've used either hinge points or support rods that allow movement of the splitter blade upwards.  As you have a rigid frame I'd make some provision for it move like this.  It will also help if it grounds when you corner.  This way you don't unload the corner weight when you really don't want that to happen.  Your splitter life will be much longer this way.

 

Sorry...having trouble visualizing.  If the splitter could hinge upward, wouldn't the bumper have to move upward equally?  And the fenders?

 

You have any photos of how you tackled this?

[tube80z]

I looked through my photos sure I had taken pictures of how we did this on a friends Z.  Good thing we didn't bet on it because I would have lost.  Every time I do this it's a little different.  For just the splitter blade (flat piece, whatever we want to call it) we fabricated what was essentially a outdoor gate latch as the rear pivot and cables connected the to a frame that was mounted to the blade.  This allowed you to lift up the front or side if it hit anything but still connect to provide downforce.  As we had no idea if this would hold at 150 MPH the frame was very basic and light so if it folded under or came off it wouldn't hurt too much when ran over.  To seal to the airdam edging material was going to be added that would mount outside of the bumper cover/airdam.  At speed I figured the leakage would be minimal.

 

My FP car had an airdam and one-piece front end (hood, fenders, grille) and separate airdam with floor (no splitter) that was reinforced with a metal frame.  The front end was held down with hood pins that floated on springs so there was some movement allowed.  The airdam had a frame behind it and that mounted to a tube that connected to the stock bumper bracket location.  I used only the rear bolt hole and it was mounted so it would move up or down and there was a bracket that connected to where the stock hinges were that captured this tube.  It was L shaped and the bottom limited the bumper bar from going down and there was an upper limiter on top that used a valve spring to keep some pressure on the tube in the downward location.  I don't know if that was needed or not but I had seen a similar setup on a wrecked Ferrari challenge car.  The used this for allowing splitter movement.  The airdam mount was was tubing that slid over a pin and held in place by a spring clip.  I had to be able to take it off to load and tie down the car.  Previously it was all connected to the front and and couldn't be removed without much effort.

 

My new car (if it's ever completed) will use a setup like almost all the current Trans-Am and GT1 cars do.  That's a seperate frame that hold the splitter, airdam, radiator and front ducting that bolts up to the car. The lower connection is in a cup that allows it move forward to a degree but not rearward.  So if ground a corner the body can lift up a limited amount or like loading on a trailer.  Since this will replace the core support being able to remove the engine will be easier too.  I don't know if the attached image will help or not.  Happy to try and draw it out a little better.

 

Cary

 

 

 

[Ironhead]

Thanks much for the input.

 

I'm not too worried about the edges of the splitter hitting in a corner and unloading the front wheel, just because the outer edges of my splitter plate would not be supported by anything more than fiberglass.  If it hit the roadway the splitter edge /fiberglass would flex upward before significant "unloading" of the tire could take place.  My "rigid" support structure would only be supporting the splitter more under the center of the car.  But I have no doubt in such a contact with the road the splitter would be bent/possibly destroyed...

 

Just so I understand....you are talking about mounting the splitter plate on a hinge, and only connecting it to the bumper with some sort of flexible material to block the wind?  So the splitter could hinge and move upward with any impact, while the air dam/bumper remain stationary?

[tube80z]

23 minutes ago, Ironhead said:

Thanks much for the input.

 

IJust so I understand....you are talking about mounting the splitter plate on a hinge, and only connecting it to the bumper with some sort of flexible material to block the wind?  So the splitter could hinge and move upward with any impact, while the air dam/bumper remain stationary?

 

You've got it.  At first it was for easy on/off when loading/unloading from the trailer.  But it worked well when jumpings curbs, various offs, and occasional high angle track entry.

[Ironhead]

Moving forward at a glacial pace, but I did manage to add an aluminum stiffener to the bottom of the air dam, to tie everything together and keep the fiberglass parts rigid.

 

This plate was going to be the attachment point for a splitter, but I have a nagging feeling given my intended use, a splitter might be more of an PITA than it's really worth.  Ground clearance is going to be an issue already.

 

 

 

 

 

[Ironhead]

Hood pins/latches and vents installed:

 

 

 

 

 

[LLave]

well, those aren't going anywhere. Looks great. 

Again, thank you for sharing. 

[Ironhead]

Trying to wrap up a long list of small tasks to get the car ready to start painting...

 

From the time I first assembled the fenders/bumper, the gaps circled in the picture below have kind of bugged me.  I kept telling myself...you know..."fiberglass front end"...."racecar"....and other excuses to try to just live with them.  I knew fixing them would be a bit complex because simple trimming or filler would not do it.  Also, this time of year (cold) the fiberglass is taking a long time to adequately cure for sanding.  After a couple people looking at the project said "what's with those gaps?" they started to haunt my dreams and I knew I had to get off my lazy ass and fix them....

 

 

I ordered some 1/32" G10/FR4 and bonded it to the inside of the fender as sort of a backing:

 

 

 

Then carefully sanded down the outside of the fender to make a gradual taper to "zero"....to provide a place for the fiberglass to bond to:

 

 

 

Then added four or five layers of fiberglass:

 

 

After sanding and trimming, I'm happy with the result and glad I did it...I think it looks a lot better.  I honestly don't know if this was the "correct" way to extend a piece of fiberglass, but it seems like it worked and the result is quite rigid and seems as strong as the original edge:

 

 

 

As can be seen, I also modified the fiberglass to allow the use of the stock headlamp buckets.  This was kind of involved as once the flat panel is cut out to allow the buckets to fit in place, the outer section of fiberglass prevents access to the screws to fasten the headlamp retaining rings.  The only solution I could conjure was to sand out the divots/recesses in the fiberglass to serve as ports to put in the screws.  This required greatly thickening the back of the part with layers of fiberglass in each spot, or the "divots" would have cut through the fiberglass and been "holes".  I suppose this would have served the purpose, but it would have looked like shit IMHO:

 

 

The headlamps are Morimoto Super 7 LEDs.  They are kind of interesting in that there is no high/low beam circuit.  They are always "on" full bright, but when on low beam there is a metal shield on a servo motor that moves and covers part of the LED to provide a low beam pattern and prevent blinding oncoming traffic.

 

I realize the turn signals won't win any style points.  But...I needed to include them....and couldn't come up with any clever/stylish way to incorporate them....so I just sort of "did it".

 

 

The light bar probably won't be installed most of the time.  It is easy to unbolt, and might lessen incoming cooling air somewhat.  But this will be a street legal car, and I thought it might come in handy for nighttime canyon drives...or something.  I have one of these on my DD Subaru, and once you have used them on dark roads it is hard to be without one.  The light they put out is incredible...

 

 

Thanks for looking.

Edited February 15, 2020 by Ironhead

[DREW RBZ]

What make are the good vents?

[Ironhead]

11 minutes ago, DREW RBZ said:

What make are the good vents?

 

Trackspec...the larger outer ones are part #U5512SHL, the smaller inner ones #U412SHL-B.

[Max_S]

I get that it's probably too late now, but in case you ever change something about the lights, wouldn't 7" Motorcycle-headlights (think harley-aftermarket) work?
Round, high beam, low beam, and indicators all in one unit (per side).

Either way, I'll keep following this.
Far from legally possible where I'm at, so it's even more fascinating.

[Ironhead]

44 minutes ago, Max_S said:

I get that it's probably too late now, but in case you ever change something about the lights, wouldn't 7" Motorcycle-headlights (think harley-aftermarket) work?
Round, high beam, low beam, and indicators all in one unit (per side).

Either way, I'll keep following this.
Far from legally possible where I'm at, so it's even more fascinating.

 

That's kind of what these lights are Max...they are the same standardized 7" lights like you see on motorcycles...although they do lack the indicators.

 

As far as legality, the USA is kind of funny that way.  Other than emissions laws, which this car is old enough to be exempt from, there aren't really that many laws that apply to one-off custom cars built by the owner.  Almost anything can go on the road, there are very few laws that apply, and most of the laws that are there never get enforced. 

 

Basically I need headlights, brake lights, turn indicators, windshield wipers....I think fenders...and not too much else.

 

Edited February 17, 2020 by Ironhead

[Ironhead]

So...I am using the Skillard rear spoiler...and also a CF rear hatch.  The Skillard wing uses adjustable turnbuckles to hold and set the angle of the spoiler.  The turnbuckles are designed to attach to the stock hatch sheet metal, which is probably up to the task.  The CF hatch however had paper thin CF in this area, that would flex with the slightest finger pressure, and I didn't think it was strong enough to support the aerodynamic forces pulling on the turnbuckles.  At best I figured it would flex enough to crack the paint.

 

So I started by adding six or seven layers of fiberglass to the portion of the hatch involved:

 

 

This didn't seem like it added enough rigidity, so I made this contraption out of aluminum plate and spacers:

 

 

 

It spreads out the load on the turnbuckles to the aluminum and to the hatch framework, so hopefully there will be no issues down the road.  It also doubles as a panel to fill in the hollow portion of the hatch.  I figure I will paint it satin black.

 

 

 

 

 

[Ironhead]

I got the rear hatch bolted in place to check fit.  It went on OK, but the panel gaps quite frankly suck.  I knew this was going to be an issue, because when I received it I took measurements and found it to be roughly .25" smaller than the stock hatch.  So the fit is predictable....it "works" but there are huge (roughly 10mm) panel gaps.

 

This all kind of pisses me off.  I know CF can shrink during the curing process, but shouldn't the builder know this and compensate?  If the common sense expedient of just making the part .125" or so over-sized was followed, the part could easily be sanded to fit.  But by making it .25" too small....what the hell can be done to address the fit?  There is no practical way to enlarge it over the entire perimeter.  I mentioned the under-sizing to the seller ("Datsmo") and was soundly, completely, and entirely blown off by him....his only response "take it up with Restored.jp" (the maker of the part).  The only reason I was dealing with Datsmo in the first place was because Restored.jp would not respond to emails and could not be reached....and Datsmo was the only seller for these parts I could locate. Once the problem surfaced, he was unwilling even to contact Restored on my behalf.  Datsmo had his money, why should he care? 

 

Meh, the Datsun parts aftermarket can be frustrating to deal with.  I imagine I will just suck it up and use the hatch, panel chasms and all.  I guess it isn't a huge deal.  At any rate, no good alternatives....  

 

 

 

 

 

I made some rear fender liners, using 1/16" ABS made with patterns utilizing Cardboard Aided Design.  This was pretty simple, and I found IMHO that the 1/16" ABS was pretty much an ideal material for this task.  I mainly just didn't want crap getting thrown up between the fiberglass "over-fenders" and the car body.

 

The fronts will be a bit more complex.  We'll see how that goes.

 

 

 

 

 

 

Edited February 27, 2020 by Ironhead

[grannyknot]

That is seriously undersized😬  If you don't mind going back into body work you weld a 1/8th" welding rod to the inner lip of the hatch opening all the way around with tack welds then fill and sand.  Not ideal but only another Z guy would notice it.