JMortensen

Confirmed 7/16-20 threads on seatbelts.

All done and painted. As soon as it dries I'll put the seat in permanently. Anyone happen to know if the seatbelt holes are 7/16-20? I think they all are, but when I tried putting a bolt in there it wouldn't go. Could just be paint on the threads but wanted to verify before I ran a tap through them.

Welding went pretty smoothly. One tip I'll pass along is don't try to beat the floor up against the subframe connecters. What worked much better was a jack with a piece of plywood. Just jacked the floor up to the mount and tacked it in. Had to jack the floor on both sides of the SFC. Then took the plywood and jack out and stitched it. Got in and I'm thinking that the seat is slightly turned towards the driver's side but not enough that I want to redo anything. Also because of the layback there is less footroom on pass side, which might be a good thing as it will make it easier for people to jam their feet against the floor to keep from flopping around over there. Tomorrow: Seat back brace.

I am working on putting a passenger seat in my race car. Driver's side is on a slider and the mount on that side is totally different but thought I'd share how this non-adjustable pass side is going in. First thing was removal of the stock mount. I had done this on the driver's side 10 years ago or so and remembered it being a big PITA. I did not remember wrong. I really hate trying to get all the spot welds loose. I tried a spot weld cutter and ruined it after successfully cutting about 10 spot welds. Unfortunately there are a lot more than 10 spot welds holding the stock mounts in. After that I tried air saws and other tools, but finally ended up with the tool I hate (and use) the most: 4.5" angle grinder. I used a cutoff wheel and hacked the stock mounts out and ground down as much of what was left as I could. Pro tip: I had been using ear plugs but figured out I could use my new bluetooth over ear headphones to listen to music and podcasts, and I could hear my phone ringing and customers on my website chatting with me, etc. Huge upgrade. I cut the stock mounts out and stuck the seat on the brackets in the car to figure out where the seat mount would be fore/aft. Then I measured from the seam in the floor behind the seats to where the seat bracket would be. I drew a line on the floor where the rear of the rear mount tube would be, and another one 2" in front of that. I had already figured out that there was going to be 6 1/8" between the front and back tubes, so I measured another 6 1/8" and drew another line across and another one 2" in front of that. So now I've got 4 lines across the floor marking where the front and back of each tube would be. Then I cut long strips of 2" tall cardboard, and trimmed them to match the contour of the floor. I then traced them onto the 2x2 tubes and used an angle grinder with cutoff wheel to shape the ends of the tube. Getting the front and back templates lined up correctly is kind of a pain because the trans tunnel isn't straight, so line them up on the outside where they hit the rocker. and leave a little extra on and then grind to fit. On the driver's side I cut into the bottom of the mount tubes to clear the little hump in the middle of the floor. On this side I cut the hump in the floor. I think cutting the hump is easier. After the tubes were cut to shape and fit reasonably close to the contour of the floor, I welded in two 6 1/8" tubes to connect the two and spaced them to fit right where the subframe connectors are. Next I needed to locate the seat laterally. I put the mount in the car and set the seat on its brackets on top of the mount, and figured out where I wanted the seat, then drew lines on either side of the brackets. Knowing where the nuts needed to be to bolt the seat in, I cut square holes in the top of the tube. Then I cut 2 x 2 pieces of .100" sheet and welded nuts to them to bolt the seat brackets to. After that I bolted the 2x2 plates with nuts to the seat brackets and set them on top of the mount and tack welded them in place. I unbolted the seat and brackets and finished welding the plates in. Next I'll weld the top ends of the tube to the rocker and the trans tunnel. I'll stitch the two longitudinal tubes to the subframe connectors. I used a LOT of heat on the driver's side and melted through the floor to get good penetration into the SFCs. My floor was pretty bashed up when I got this car, so the floor doesn't fit perfectly on the bottom of the 2x2 tubing. Plan there is to beat the floor up to the tubing after the mounts are welded on the ends, then stitch across the front and back of the tubing to attach the tubes to the floor. That's today's project. The mount on the driver's side was as long as the slider for the seat, so more like 12". Like I said before, much different on that side.

Second on Dutchman. Best axle supplier I used when I was making stuff. It was done right, first time.

You can't get around the limitation of a 1.250" stub axle no matter what CVs you use. IMO you're never going to keep the stub axles from breaking at that power level. Time for backhalf or an IRS solution that allows for larger diameter stub axles. I'd look to an 8.8 if you want IRS. Might as well upgrade that too while you're in there. The diffs are cheap and readily available, lockers and limited slips galore, wide range of gear ratios, there are very strong CV options for them, etc.

You can specify the site in your google search this way: whatever you are searching for site:forums.hybridz.org

Is Tokico still in business? I thought they were, but they aren't offering these for Z's anymore. Might see if they can fix it. I remember a lifetime warranty when I bought mine in the 90s

Not sure why you'd want inboard brakes on a 9" rear end, but looks like this guy pretty much has the rest covered: I think that car is the best that I've seen. I love it. There are a couple things I would change, but not many. I do like what I did with my own with the 15x14 wheels and slicks, but I'm sure he would smoke me on an autox course and road course wouldn't even be close as he's got an extra couple hundred hp on my L33 truck engine which should put out ~350whp.

To be fair, I have read of some people losing the control arm bushings on a hard launch. Seems to me Jeromio did that about 15 years ago and posted here, and there might have been another one. I'm not going to go looking for it now though. The point, for me, anyway, is that if the bolts are tight, the tube in the control arm already does this job. IIRC the way that happened to him is that the bolts came loose and the control arm slid out of the bushings under hard accel.

Ok then. Obviously had that wrong. Seems like it's not necessary so long as you keep the big ass bolts on the control arms tight. Probably have to sand down the bushings so that you can actually bottom the bolts out. Hardly anyone does that though.

If I'm looking at it right, this goes between the lower control arms in the back, connecting the bushings. There is a piece for that in the stock suspension. Looked at their site, and it appears that they use a different brace mounted higher, which would allow for the use of a finned cover with a bigger sump. I guess you could use this piece and their other brace together? Not sure that would really improve anything. I dunno. The more I'm looking at it the more I'm not sure what it is. Can't figure out why you would want the brace up higher and this one too, since they both do the same thing.

One thing occurs to me. If they slotted the holes on both sides, you could adjust the toe with this. You'd need to pry the arms instead of using a turnbuckle like the Poor Man's Toe Adjuster that many of us have made, but that's not such a big deal if you're doing an alignment every couple years.

There is already a link there that ties those points together. This one looks cooler, but I think that's the only benefit.

I would suggest that you consider what you're going to want for camber and work from there. If you want more neg camber than plates will get you, then I'd make the LCAs at least as wide as the stock ones at full compression. With this setup you'd have 5/8" adjustability before you fell afoul of the 1.5x rule. I can't really tell you what plates and stock LCAs will get for max neg camber. I suppose it depends on your ride height. I don't think you can go farther than about 2.5 degrees (would be good to have someone else verify that), so if you are running newer radial slicks or Dot R tires you might need more camber to make them happy. Bias slicks don't need much camber by comparison. Also keep in mind that there is not a lot of thread engagement in the tie rods, so if you add a bunch of width there you'll need to deal with those too. That's easier now as there are aftermarket ones available.

The scrub radius issue is a problem. I've got ridiculously wide 15x14 wheels on the front of mine. Had to use spacers to clear the bumpsteer spacers on the tie rod. Car has about 6" scrub, which is a lot. I did this after talking to Tony Woodward of the custom steering rack company and he told me that it really wasn't that big a deal and he had seen plenty of fast cars with 6" scrub or more. I think his experience was more to do with circle track though. You would want the camber plate as far in as you could manage to minimize scrub. The imaginary line from the top of the plate and the ball joint and through the tire contact patch is where the scrub radius is measured from. It's the distance from that intersection with the ground and the center of the tire. Tube80z was looking at a dual LCA system to work with the strut to alleviate the scrub issue on this thread: He kinda stalled out on that and I don't have software to figure it out, but that's an option if you have the software or know someone who can help you out with that. Otherwise, I think SLA is the best solution and you can solve other issues while you're in there, like adding more camber gain, fixing bumpsteer, using 5 lug hubs and bigger brakes, etc.

Looks like I saw a year old post there. Oh well. Probably missed caperix but might help someone else down the line...

This is incorrect. Many of us have held this erroneous opinion at one point, including myself. BlueovalZ explained it to me maybe 15 years ago: the control arm doesn't need to be level to start losing camber, it needs to be perpendicular to the strut before it starts losing camber. This is basically impossible, unless you're running really tall tires and trying to scrape the frame on the ground. 24" wheels or something ridiculous would be required to get there. There is a really good thread (IMO best thread on this site) started by Tom Holt and with lots of info from Dan McGrath, aka 74_5.0L_Z, where he takes on all the suspension kinematics. The Z has a very flat camber curve. It just doesn't have enough gain to offset the roll with soft springs. Here is the post where he diagrams the camber curve:

Agree with Leon. I have to wonder if there is a measurable difference in a 6-3-1 vs 6-2-1 design. I would think if you grouped the primaries so that you got an exhaust pulse every 120 degrees on the 6-2-1 you'd get roughly the same effect as the 6-3-1. The main thing is the primary lengths, and according to Vizard, even that is secondary to not having as many bends in the tubing on a V8. You see some people go to great lengths to get equal length primaries, and I think especially when they use a lot of really tight bends to make the rear cylinder primary as long as the front, they're probably losing overall.

I believe there are differences in the pedal assemblies, although I can't tell you what they are. The pedal box is the same between stick and auto, just use different pedals, so if you could find a 280 brake and clutch pedal you should be good to go.

I did. Haven't yet sprayed oil in there, but that's the plan. I am going to use Corrosion X when I eventually do it.

I think you're right about creating a space for corrosion, but if you look, the whole chassis is built by layering sheet metal and spot welding it together. My 70 is pretty rust free... except for all of those areas. I just cut the pass seat mount out. Rust between the seat mount and the floor. No rust anywhere else on the floor, as I fixed it years ago. That's the story for the whole car. My take is that trying to get the rails perfectly sealed is a fool's errand. For frame rails and hollow cavities, I think the best thing to do is shoot oil inside of them after welding. This is what Krown rust prevention in Canada does: https://www.krown.com/en/ I suppose you could spray oil everywhere there are overlapping sheet metal panels too, but there are a lot of them inside the cabin, and you'd have to dig out the seam sealer to get access. It would be messy.

I think it's a matter of running the right compound that still functions at high temps. Back in the day katman had a thread where he was talking about running 2 3" ducts to the front brakes to keep them cool. I looked for it and couldn't find it. Joe Demers was making a heat sink that fit between the piston and brake pad, might be a tight fit on a 14" wheel. Found it: http://www.coolshims.com/coolshims-technology.php. John Coffey talked about adjusting drums in between sessions. Heard from several people that ditching the AL rear drums and running the cast iron ones off of a 510 is an upgrade because they can take more heat. If brake recirculators are allowed that would be a biggee, as this would protect against boiling fluid: http://www.colemanracing.com/Brake-Recirculator-P3775.aspx

Coilovers are a better solution, but no problems with cutting. I ran my first Z on cut springs for quite a while. My friend who cut mine also ran 240 springs and perches on 280ZX struts in his street 510s. He cut all of the springs, and again, never had any issues. There are a lot of rednecks that cut them with a torch, or just heat the spring up until it sags to the proper height. This takes the temper out of the spring, and can cause the spring to fail. If you cut them with a cutoff wheel the heat is very localized and doesn't cause a problem IME.

Terry sold his Z and bought a Manta, which he did up to an even higher level than the Z. It's just awesome! http://www.fototime.com/ftweb/bin/ft.dll/pictures?userid={7DC317B0-8EDB-4B2E-A837-F708D07C9769}&AlbumId={B0B466A9-4204-4F78-BC4C-DEBD9966B5B9}&GroupId={E9BD2EDD-A388-43BD-B264-DFF5CB43B8E2}&nt=a I still see Pete posting from time to time. Katman was moving away to focus on engineering on more modern racecars, E36s at the time. I assume if he's still in it he's probably working on newer stuff than that. Mike Kelly sold his Z after several failed attempts to put an engine in it. No idea on Denny. I miss Coffey. We emailed or FB'd with each other on a weekly basis. As to miata.net, they allow for the newbie questions over and over. I haven't seen the antipathy that you describe towards those posts. Seems like there isn't a "protect the searchability" drive like we have here. I know when I got my 99 I searched and found so many threads on my particular issue that I posted again and immediately got an answer with no admonition to search. Turns out coils were dead, killed precat, killed cat. PO had replaced coils and left it like that and I had to go through the exhaust to fix.