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Everything posted by Ironhead

  1. Ironhead

    Nelsonian 240z

    Lookin great dude....thanks for the update pics!
  2. Ironhead

    Tig Help

    I too just now saw this post.... The most common problem for beginning TIG welders is overheating the part by moving too slowly and "heat sinking" it. This is particularly an issue when welding thin stainless. It takes very little time for this to happen, and you wind up with grey welds that have lost their stainless properties, I think primarily from the chromium cooking out. It is sort of a balancing act between using enough heat to quickly get a weld puddle, then promptly getting moving so the part is not overheated. I saw a video on "Welding Tips and Tricks" where he did some tests with TIG welding, and the amount of heat absorbed by the parts being welded had far more to do with the speed of travel than with the heat settings on the welder. When I welded my first stainless exhaust....I simply did not have the experience/skill to move the puddle fast enough and was overheating all my welds. I finally managed to come up with a workaround, just clamping thick copper pieces to the parts to serve as heat sinks. That buys you a bit of time, but really it is an issue of just needing more practice.
  3. Looks like a great project, congrats! Some of the things that have been done to old race cars always intrigue me. I wonder why they added the framework under the driver and passenger floor? Seems like it would add no rigidity but a lot of weight....
  4. As the title says....I am just starting the teardown on a '74 260Z that I am going to strip, media blast, cage, and swap in (probably) an LS3 and T56 6-speed. Here are pics of the car in its current form: The car clearly has had some cosmetic restoration work done to it during the course of it's existence, and some have expressed to me that it is "too nice" to do to it what I have in mind. But it really isn't all that nice. The paint job looks OK from 20 feet, but in reality it is a cheap respray with over spray on bumper rubber, glass rubber, and many other places. Also, the engine is just....tired...and it feels like it is putting out about 80 RWHP. And finally, it is an automatic....and I have trouble believing that first gen Zs were even sold with autos....so out of character for the car. In a nutshell, I have no hesitation to strip it down and start over. The plus...I cannot find any rust...anywhere. I think the car spent it's life in the Mojave desert. The plan (subject to evolution) is to make it into a pure track car that is still street legal (barely). I will try to keep regular updates. I have just started dismantling it.
  5. I spent my last few days of shop time conjuring a mounting system for my steering column and bias bar pedal system. I am using electric power steering, which occupied some of the room for the pedals, and the pedal assembly was not compatible with any of the stock mounting locations, so I had to cut it all out and start from scratch. The steering column mount was easy...it just consists of two heavy duty 1.5" tubing clamps welded together at 90 degrees with a short section of tube between them, then bolted to the dash bar and column. I was a bit surprised that a 45 year old Japanese car used 1.5" tube for the steering column...but that is the case and it made things easy. The mount is so rigid I have no doubt you could lift the car by the steering column and the mount would not shift. I wanted it really beefy because the mount supports the weight of the power steering motor, which is cantilevered a foot or so outward. The motor for the electric power steering wanted to interfere with the pedal assembly...so it took some dicking around to figure out the best way to mount everything and have it peacefully co-exist. Just one of those jobs that is simple in concept, but time consuming to actually implement....at least for me. Thanks for looking.
  6. Calling the cage done, at least from the dash back. Also hit the tubes and welds with Scotchbrite so they are ready for primer.
  7. Hard to make recommendations...colors are so personal. For track cars I like saturated non-metallics...pastel easter-egg type colors.... Like the colors Porsche offers in the GT3 RS. I would like to see a "Z" in Porsche "Signal Green"....for example.
  8. Just a small update... In trying to finish up the cage, I thought I had planned sufficiently and left adequate access to 360 degree weld up all the joints. But with the bases of the main hoop...no matter where I stick the welder, I could not get the angle/visibility I thought I needed to lay down a decent bead. And I knew if I fucked it up....getting a grinder in there to redo it would be a nightmare. The easiest approach wound up being to cut weld portals in the fender. Sounds like a bit of poor planning, but it worked out OK. Started assembling the rear hub uprights from T3. I found that the way they were machined, the stock Nissan axle seals would not fit. I perused the 'net every which way, trying to find a seal that would work....but found nothing. So, I wound up having aluminum bushings machined to press in so that the OEM seals would work. Maybe overkill....I dunno...since the wheel bearings have their own seals. But Nissan (Infiniti) used the axle seals in the OEM application, and I figured they must have had a reason.....so I went with "better safe than sorry". Thanks for looking.
  9. Ironhead

    Nelsonian 240z

    It's kind of funny...with that stitch welding....I found it was easier to just do everything than to decide where there might be a benefit and where there wouldn't. As long as you do it slowly and don't overheat things....there is no way a stitch weld can really do harm...so....you know....go for it. Project looking great dude.
  10. 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. 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. I was pleasantly surprised, the bearings actually looked pretty good. No pitting or signs of significant wear on the races. 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.
  11. I know T3 currently sells front struts wherein the entire thing....spindle included....is manufactured/machined for them. No OEM Datsun parts used at all. I presume that would make them a bit stronger....but not sure.
  12. 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. 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. Thanks for looking.
  13. Ironhead

    Nelsonian 240z

    Nelson, do you have any estimate as to how much of the flares will be filled up with the 275s? I suppose without your drivetrain mounted it is pretty hard to guess.... I am "thinking" (still a ways down the road) of running 315s in the rear....and I was wondering if the YX flares would fit them....or if I would have to go with the IMSA kit....
  14. Ironhead

    Nelsonian 240z

    It looks like you are pursuing the same basic vision as I am...you are just much further along. Looking really great. What do you think of the basic quality and fit of the Ztrix parts? I am torn between the IMSA kit, the YZ kit (like yours), or the Pandem kit. I like the looks of the pandem kit the least, but being Japanese it is probably of very high quality. Do your strut tower bars tie into the dash bar, or ? And do they eliminate the possibility of using wipers? I still haven't decided how I am going to handle doing that portion of the cage. I admire the dedication of your fab guy doing the stitch welding for you. I did it on my own car and thought about killing myself a few times. It really is a sucky job, particularly if done thoroughly.
  15. Hoke provides driveshafts now too huh? That will be good to know down the road. Project is looking great! It kind of reminds me that in many ways a pure track car like I am building is so much simpler....no messing with getting a decent stock dash and all that!
  16. 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.
  17. 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.
  18. 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.
  19. 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.
  20. 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.
  21. 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.
  22. 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.
  23. 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.
  24. 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.