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Ironhead last won the day on June 30

Ironhead had the most liked content!

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About Ironhead

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  1. I have been planning this stage a lot even though I am not there yet... I am using the 525 HP LS3 and as of now am planning to have a "Y" pipe right behind the tranny where the system merges into a single 3" setup. The way I read exhaust research, there is absolutely no difference to the engine between a single pipe setup vs a dual pipe, as long as the total volume is equivalent, and you use a well designed X,Y, or H section. I think the vast majority of performance oriented cars have way more exhaust (combined pipe diameter) than the engine requires, just because it looks cool. If you have been under your Z (which I'm sure you have) you will see that this fashion is not really a good option as there is not a lot of room for exhaust, at least not if you want decent ground clearance. I built a very complex dual mandrel bent exhaust for my prior track car, and the one tool which I found invaluable was a disc sander with a very coarse disc. You can cut the tubing pretty well with just a hand grinder and a cutoff wheel, but the disc sander is invaluable for facing the tubing joints so that they fit together well and can be welded decently. This is absolutely imperative if you will be tig welding. I bought this Harbor Freight unit: https://www.harborfreight.com/12-inch-direct-drive-bench-top-disc-sander-43468.html It is very inexpensive and it has been completely up to the task. Then buy 36 grit sanding discs from McMaster Carr (the ones meant for stainless steel) and you are good to go. This setup will really dress the ends of the tube quickly.
  2. Thanks dude. I freely admit to having a tendency to over-engineer parts a bit. I was going to make the mounts out of aluminum, then reasoned the weight difference would only be a pound or so, and I already had the steel lying around, so I just went that route. Plus I avoided having to confront my fear of welding aluminum. Got the steering rack mounted today. Had to have custom outer tie-rods machined due to the combination of threads I am using with the new rack, the T3 parts I planned to use would not work. Woodward power steering machined the tie rods for $35 a piece...which seems like a smoking good deal. Most machine shops won't even chuck a part into a lathe for less than $100. On the advice of Tony at Woodward, and other stuff I have read, I moved the rack backward so that it sits roughly 1" behind the point where the tie rods pivot on the steering knuckles. This apparently improves the Ackerman and general steering geometry for a performance oriented car. Time will tell if the change also introduces bump steer or other undesirable characteristics, but since everything on the front suspension and steering setup is completely adjustable, I am confident I will be able to sort out any problems that might arise. I am not super familiar with the principles of steering and suspension geometry, so this part is proving to be a bit of a learning curve for me. I am also wondering if the engine will interfere with the steering rack...again...time will tell and I will deal with it if it does.
  3. I am running a clutch type LSD with this project, and the manufacturer of the LSD in their documentation recommended the differential gear oil be changed after every race or track event if a diff cooler was not used. Since that would be a huge PITA, I decided early on to include a diff cooler in the build. I spent the last week or so figuring out what would go where and fabricating mounts for the cooler and the fluid pump. There is not much room under the back of a Z, and I could not come up with a mounting scheme wherein the cooler would both be somewhat protected from road hazards and also get decent air flow. So, I decided to use a couple of 4" Spal fans instead. The setup will be wired to come on at a preset diff temperature, which will turn on both the diff oil pump and the fans. Below is my progress thus far. I have plumbed in the supply line, but haven't totally figured out yet where I will route the return line. Thanks for looking.
  4. Ironhead

    Best LS Swap Kit?

    I'm using the Apex cross member with the Hoke engine mounts, but I had to greatly modify the Apex cross-member to work with them (weld on mount bases similar to the Hoke ones). I hope that is what you meant...or I have an unpleasant surprise ahead of me....?
  5. Ironhead

    Best LS Swap Kit?

    Funny...I bought the Hoke kit but ended up just using a small part of it. Not that there is anything wrong with it...I just found myself going in other directions and needing to fab a lot of my own stuff.
  6. Just a bit of scattered progress... I was planning on relying on the fill port on the rear diff cover for a return line from a cooler...but there wasn't clearance...the T3 support blocks for the control arms were too close. Same for the threaded plug I welded on the other side for a diff temp sensor. So I had to weld on new fittings. Not a big deal, but the whole "welding aluminum" thing is still kind of a mystery for me. Sometimes it goes OK, sometimes it doesn't, and I never know why. They don't look great, but I got them welded on...don't think they will leak or fall off. Mocked up the front brakes, just to make sure everything fits as intended. I drew up the hats and caliper brackets with a CAD program, then had them machined and anodized locally. Seems like everything fits as intended, but I initially drew things up with the discs sitting too far inward, where the caliper brackets would have interfered with the steering arm. There were a variety of reasons I did not want to go with one of the assorted "bolt on" BBKs that are available for the Z, but getting this setup done was enough of an expensive PITA that I should have. And finally, got the door hinges stripped and rebuilt with new hinge pins and bushings, then painted them. In the photo the paint looks a weird greenish color, but it is actually just a medium gray that I am going to use for the interior of the car. Thanks for looking.
  7. Installed the Apex Engineered cross-member and braces today. Seems like a good product, although I am kind of dubious how much rigidity it will add, since the front and rear control arm mounts are directly on the frame and are very close to each other. I do like the multiple adjustable pivot locations the setup provides. I have no idea whether the LS3 oil pan and other ancillaries will clear these parts. I am just going to have to drop in the engine and find out. It took a fair bit of grinding and brute force to get these things to line up, but considering Apex has to produce a "one size fits all" product to fit 45 year old cars, pretty amazing it goes on at all.
  8. Thanks! Wish I had seen that link a couple of weeks ago. That mount looks quite a bit less beefy than mine, so if that car has an LS swap and the mount has held up, I should be sitting pretty.
  9. Yeah I have the big washers, just haven't been using them when mocking things up... Is that your car in the picture? Just wondering how that mount has held up. Regarding the strength of the bolt, I did some math. A grade 10.9 bolt is rated at 150,000 PSI tensile strength. In other words, a bolt with a cross sectional area of one square inch would fail at that load. An M12 bolt has cross sectional area of .17". So, .17 X 150,000 = 25,500 pounds of tension, or just shy of 13 tons for the bolt to fail. And that of course is for one bolt, and the mount uses two. If that isn't enough for us, an ARP stainless bolt is not only pretty, but is rated at 180,000 PSI tensile strength....which without doing the math I'm guessing would knock us up to between 15 and 16 tons of load per bolt. So you could lift a small-medium bulldozer off the ground with one of those bolts. And those ratings are minimums, so it might actually exceed those figures by a fair bit before it broke. So whatever might fail here, I'm not really worried about the M12 bolts. Thanks for the input.
  10. Thanks for the input.... I am definitely going to use what I have made, particularly now since the cross-member is part of it. I am just considering whether to add some bracing similar to what New Zed sketched as insurance. By my thinking, it shouldn't matter much whether the steel supports are above or below the diff tabs, unless there was a chance of the diff snapping the two grade 10.9 M12 bolts holding it in place (I don't think there is...). But what was sketched would add even more strength and rigidity by introducing another chassis tie-in location. I just cannot decide at this point if it would be overkill or not....
  11. Yeah, I was looking over things today and I think I am going to do something like that. The area NewZed is referring to is more or less dead space, and installing a vertical brace up there should provide good insurance against having to re-do all this crap down the road. I would rather do a little extra work now that the car is stripped and not risk having to worry about it later.... Anyway, here is Diff Front Mount V2.0. It should be pretty dang rigid now....as all the forces are now spread out and secured by eight M10 bolts and 4 M6 bolts. Still....better over-engineered than under engineered, so I think V3.0 will be coming soon......😐
  12. I pondered doing something similar to what you describe, because there definitely would be a significant advantage to having bracing directly over the diff mounting tabs. What dissuaded me was that I didn't think it would install from the front when the diff was already bolted into the rear mustache bar mount. In other words, it would have to be bolted to the diff then the entire assembly raised and installed....hard to explain....it just seemed like it would greatly complicate installation/removal of the relevant parts. I have already partially welded the cross member to my mount, and I am convinced this setup will give immense rigidity.
  13. I was pondering my "design" today, and even though it seems sufficiently rigid on its own, I am concerned about the ability of the four OEM thread locations to absorb the torque from the mount itself wanting to twist. Particularly the rearmost pair, as the captive nuts are secured in very flimsy looking sheet metal brackets. So, I think I am going to weld the mount onto the OEM crossmember/control arm bushing mount. This will tie the whole thing in with four more bolt locations, and should add vastly more strength and rigidity with no additional weight. I didn't really want to do this, because it will probably require removing the whole mount whenever the driveshaft is removed or attached. But, not a big deal really, and how often does one need to remove the driveshaft anyway? I want to get this right the first time, even if it involves some over-engineering, rather than having to dick with a flawed design down the road after the car is finished and painted.
  14. Clearly most of the twisting torque from the engine would be absorbed by the rear diff mount, which I am sure is why it is about three feet long, to give it a degree of "leverage" to counter any tendency to twist in place. But the rear mount would have almost no ability to stop the front of the diff from flipping up and down with acceleration/deceleration, so I designed the front mount (hopefully) to address that. The T3 mount is so flimsy, I am surprised they haven't received sufficient negative feedback to change the design.
  15. I am planning to use the original cross brace/front control arm pivot. The two "U" shaped cutouts on the sides of the mount I constructed provide clearance for the cross brace. The pinion flange sits approximately 3" behind the cross brace and perhaps 1" higher up, so the driveshaft should clear well above the cross brace. At least I hope I haven't miscalculated. I am running into multiple interference problems that need to be sorted. I am planning on running a diff cooler, but there is almost no room between the diff fill plug and the rear control arm pivot mounts to install a threaded fitting....so not sure what to do. Does that answer your question or am I not understanding...?