JMortensen

Prepping for track days next year. Should have something for you in about 6 months...

I think the easiest way to reduce front lift is to duct the radiator to the front of the car, so that all the air that goes in the nose has to go through the rad and can't go under or over the rad support. Even better would be to take the air out of the rad and send it back outside of the car, either to the sides or out the hood. I also think that a wing shape under the crossmember could potentially work, but the front end of the Z packs so much air into the engine compartment that you'd have a hard time accelerating the air with your foil, as it would exhaust into the high pressure area under the hood. In other words, it probably won't work much or at all without first dealing with the huge amount of air that's packing into the front of the car. None of the cars tested in the windtunnel had a radiator duct, unfortunately. They did close up the hole in the nose to varying degrees, which is better than nothing, but I think they left a lot on the table in that respect.

I believe I have an extra set if you need them. Dunno what they're going for, but I'll offer them for $50 and cover shipping. PM if you're interested.

Stock bushings need to be pressed in. If they're loose, that's not going to work. Probably the wrong bushing. Poly should be tight in the control arm. The idea of poly is that when you tighten the bolt down, the sleeve that goes through the middle of the bushing gets pinched in the crossmember and stays stationary, and the poly slides on the sleeve. IME the Z bushings are way too wide, so that when you bolt it all together there might be 1/8" or 3/16" of bushing sticking out past the sleeve. If you tighten the bolt down enough to pinch the sleeve in the crossmember, the way it should be, the bushings are so compressed that it makes it damn near impossible to move the control arm. What would really help here is taking the bushings to a belt sander and removing some of the extra bushing material.

Increasing track width increases grip on that end of the car, so widening the front end should help with understeer. I suspect your problem with the hump is bumpsteer. I had a similar issue with a hump right on the exit of a corner. My Z would do an emergency lane change kind of maneuver as a result of the bumpsteer (running really low with 3/4" bumpsteer spacer, but no other bumpsteer mods at that time). I fixed the bumpsteer by slotting the front crossmember and moving the lower control arm pivots up about 7/16". One issue that might arise with an offset spacer is ball joint wear. You're increasing the leverage on the ball joint. Not sure if it's a big problem or a minor one, but theoretically should be different than stock.

Not usually necessary, but a dirt cheap and easy way to do it is to take a piece of 3/8" hard fuel line, pinch the ends in a vise, drill holes and attach to existing holes in the chassis and fender. I had to do a brace on zredbaron's car because he barely had clearance between tire and fender and then bent the fender just a hair. When he turned the wheel the fender hit the tire. Took about 10 minutes, worked great.

I have a suggestion: DON'T make a super strong support that comes off of the strut towers. If you are reinforcing the chasis for stiffness, end all of that at the front swaybar mount. Everything forward of that doesn't need to be super strong, and if you make it strong and get into a minor accident, it will take out the strut towers and make repair more difficult. If you haven't reinforced the chassis then you need the stiffness up front as that helps to keep the upper and lower frame rails in alignment. Just don't overdo it and run back to the strut towers. Not necessary to attach to the strut towers to support the weight of the rad, intercooler, ac condensor, whatever else you decide to put up there.

The popular one is the Subaru rack. If you search "subaru power steering" I'm sure you'll find some threads. The electric is the go to now, but I'm not convinced it's the best answer. I've heard racers complain about dead feeling steering, and that is certainly the case in my Kia which has it. If you just want to steer in parking lots, it's an easy out. I have a custom Woodward rack. Was expensive and required lots of fabrication to the front xmember, but I love the way it feels and I love the 75% faster than stock ratio I ordered with it. I can go through entire autocross courses without having to move my hands on the wheel. Here is my thread on it:

I would add "cheap" to your light, simple, and beautiful characteristics. Cost was the main reason I bought a Z - bought it for $1500 - and the 6 cyl was the reason I didn't buy a 510. I am an autocrosser and started the sport just after the Miata hit the market, so the Miata has been ever-present and always appealed to me. When I finally bought a 99 midway through building my Z, I had a moment where I considered selling the Z and building the Miata instead. From a stock vs stock comparison, they are both slow in a straight line but the Miata is WAAAAAAAAAAY more capable and fun to drive, and you can do the same sorts of things like engine swaps, etc. I sold mine when I was short on cash, but I would like to have another. The prices are starting to creep up on Miatas already though, so I may miss the window of opportunity. That 350Z is nearing the zone as well...

Have you seen this one? Posting GT2 race times in home built 350. https://www.turnology.com/features/car-features/video-homebuilt-350z-sets-118-at-mosport-rivaling-alms-gt2-times/

There are a lot buried in threads here (and many many many dead links), but easier to look through my photos on FB: https://www.facebook.com/Jon.E.Mortensen

Working on getting mine track-worthy: oil cooler, brake ducts. After that, it's aero and fire suppression, maybe trans and diff coolers. At that point I'll have a pretty potent weapon, and since it's LS based I can swap in a bigger motor or add a turbo pretty easily if I feel like the ~370whp it has now isn't enough. This year I got it out and autoxed quite a bit, and I have to say, it's getting pretty close to where I would call it a dream build. Every time I go into my shop I stop and think: "What have I done?" in a really good way. The thing makes me smile.

Based on your couple sentence description, it sounds like the crosspin is coming out (failure imminent). R200s are not that hard to find. The turbo might have a different pinion flange, I'm not sure, but if it is different you can just swap the one from the current diff to the new one. Needs red loctite and very tight, I think the spec is something like 150 - 225 ft/lbs. I just put my impact on 5, drain the compressor so it fills back up, then nail it to get it as tight as I can. If you don't have air compressor/tools, you can probably rent an electric impact gun locally. Or, just find a diff out of a 280ZXT. Here's one on ebay: https://www.ebay.com/itm/1982-280zx-Turbo-R200-Differential/283474896273?hash=item42006ba591:g:WywAAOSwO7Ncz2aY

Yeah, I think the problem is that you'll run out of room moving the stock spring in there because it's wider than a 2.5 ID spring. As far as camber plates that actually adjust a decent amount go, outside of TTT, AZC, and GC, there is the "biscuit" style which doesn't require cutting, but I think you'll need the smaller diameter springs to get enough movement for the track. https://www.dpracing.co/datsun-z-front-suspension-1 It's really not that hard to piece together a coilover setup with threaded adjusters, top hats, and springs if you want to get the camber. DP has everything, so would Coleman Racing or similar circle track supply houses.

Plates > arms > bushings. I would suggest you get a good set of plates. The plates that come with some of the cheaper coilovers only allow for 1/2 or 3/4" of movement. That's enough to even it out side to side, but not enough to get enough camber for racing. A set of "good" plates (Ground Control, TTT, AZC) has a large range of motion, I'd have to go measure but I'd guess 2+ inches. Arms work, but when you adjust you drastically affect toe so that's a lot more hassle, makes it much tougher to make changes in the pits. Also there isn't that much extra thread in the stock tie rods, so if you adjust a degree of camber in with arms, you might need longer tie rods for safety. Add in an adjustable tie rod and you're coming pretty close to the cost of the good camber plates. TTT sells a pair of camber plates for $250. By comparison their front control arms are $400, and then you're probably going to need the tie rods in addition, which are another $150. You could piece together the rest of a coilover setup like was commonly done just a few years ago, where you would modify the stock strut tube to use the coilover adjuster, or you could buy BC or similar cheapo coilovers that weld on, and use the better camber plates on them to get the camber you need. Either way is better than arms and tie rods, IMO. Camber bushings in front are not a good idea IMO. The bushings don't allow for fore/aft motion. The arm needs to follow the TC rod which moves in an arc, that means that something is giving every time the suspension moves; probably flexing the crossmember sheetmetal. Also adjusting the camber with the bushing adjusts bumpsteer. It's a bad idea to use these in front. They do work in the back, but I found that I had a very narrow window where the toe was set correct, so I couldn't get the camber I wanted and the toe I wanted in back with them. As far as building your own strut tower bars, you can buy turnbuckles from circle track parts suppliers or chassis supply places cheaper than you can buy the materials to make them through someplace like mcmaster.com. When I built my first set I didn't know much about this stuff so I bought "tap tube" and LH and RH taps and did it all by hand. This is a much easier option: http://www.colemanracing.com/Tie-Rod-Aluminum-P4199.aspx