JMortensen

I think "flush" is trying to get the rim even with the fender and usually incorporates stretched tires. Hella is a word I punched myself in the gonads for uttering about 10 years ago. As I became aware of it I thought that it was a pot smoker NorCal adjective that basically means "very". Hella good, hella awesome, hella lame, etc. usually followed by the pot smoker laugh.

As soon as I saw the Porsche's license plate I knew it was going bad. All I could think was: Got 2 tickets to see Dr J Front row seats IT'S FREE no pay Radio in had, snacks by feet Games about to start You're kicking popcorn to the beat Finally wake up Doc's uptown Round his back through the hoop And you scream "TOUCHDOWN!" http://www.youtube.com/watch?v=-vaAlnR-LeA

I think it would lower drag. I also think that if lowering drag is your main goal, you should start with a different car. We know the base of the windshield is a high pressure area. How much would downforce be affected by lessening the angle of the windshield is probably similar to asking how much downforce would be affected by lessening the angle of attack of a spoiler. The Primadonna Z's have the center of the base of the windshield moved out quite a ways, so it wouldn't be the first time it was done though...

I'm assuming you went with the 10" springs because you want the car low. So what I would do and have done on my Z is to put the spring on, hold the spring against the top hat and hold the coilover (adjusted all the way up) against the bottom of the spring. Mark where the bottom of the coilover sleeve is, and that's where you weld your ring on.

I guess I'll be the stick in the mud and suggest a minivan. I actually argued FOR a minivan, and ended up buying a Subaru Outback when my wife got pregnant because she didn't want to drive a minivan. The Subaru is a fine car and the AWD is great when we get snow here. That doesn't make it a good kid carrier. For the first year you have to have the kid facing rearward in the car seat and even in the relatively large Outback that couldn't happen with the car seat on the passenger side of the car, so it had to be stuck in the middle between the two seats, and even there I had to scoot my seat forward for clearance. Try getting a 20 lb baby and a 10 lb carrier/car seat thingy into the middle of the car over and over and over. It's a pain in the back. Once my kid turned one and we could flip her seat around the situation became a lot more tolerable, but now my wife has her heart set on a minivan. She's probably thinking ahead...

I suppose it depends on what kind of mounts you're using. If you're using a RT mount and poly bushings, there might be enough movement to cause problems, but I think it's a sure thing if you're using stock rubber. How about notching the brace, or plugging the stock vent and drilling a different hole in the cover and running the vent somewhere else?

Is that the NA diesel? If so, don't bother. I remember going with my dad and uncle to a lake pulling a LIGHT 14' fiberglass boat and aluminum trailer with a 6.2 diesel blazer. The trailer and boat had to weigh 1/2 or less of what your car and trailer will weigh. Foot to the floor, puking out black smoke, we climbed a minor grade at 27 mph. Check the specs in the page below: A whopping 140 hp and 255 ft/lbs of torque. http://consumerguideauto.howstuffworks.com/1990-to-1998-gmc-sierra-6.htm Look at this "awesome" build up of a 6.2L diesel, complete with turbo. With the upgrades it still makes less hp than your race car, and if you have any mods like a cam the car probably has more torque too. http://www.dieselpowermag.com/tech/chevy/0554dp_62l_buildup/index.html

Traffic - Dear Mr Fantasy

John Coffey (http://www.betamotorsports.com) makes a conversion bracket to run dual master cylinders, one for the front and one for the rear brakes, without a booster. Some others (me included) have modded the stock pedal box to mount duals. One thing to take into account is that the stock pedal box was designed for the booster, so the brake pedal leverage ratio is something like 3:1 (going from memory here so cut me some slack if that's not exactly right). Most non-power brakes run 5 or 6:1 leverage ratios. That may not sound like a lot, but it is a big difference. Also, running a larger master will require MORE force on the pedal for the same force at the caliper. If you really wanted to run manual brakes, you'd want a smaller master cylinder for the same pedal effort, or ideally a different pedal leverage ratio and then similar to stock sized master cylinders.

I like the covering of the front of the front tires and integration of the flares into the airdam. Does it have a duct for the radiator, or is it just blocked off in front to allow less air in? Any reinforcement under the hatch for the wing? I've always been a bit worried that a big wing would just flex the hatch.

If your plan is to get the car really low you really don't want more travel. More down travel means that you could potentially hit the chassis on the ground before the suspension bottoms. So to prevent that you'd have to run bigger bumpstops, which would mean you would be reducing travel with the bumpstop, so why bother with the extra travel in the first place. If you're going to lower a car you should increase the spring rate (a lot) to keep it off of the bumpstops and try to have enough travel so that you can drive without constantly having to worry about bumps in the road, etc. If the weight of the car is the same and the spring rate goes up, it stands to reason that the car would use less actual motion on the strut. For example if you have 500 lbs per corner and a 100 lb spring on there, the car will sag 5 inches. If you put 500 lb springs on, it will sag 1". Likewise, it will move less when hitting bumps with the heavier springs. IMO, rebound travel should be roughly the same as the compression travel, but having a LOT more rebound than compression doesn't make a whole lot of sense. If you have 6 inches of travel but your car is running 4" of sag, then what you really have is 2 inches of compression travel and 4" of droop on the strut. You don't need a huge amount of droop travel on a Z (again, especially one running stiff springs), and in fact it might be worse to have it then to not have it from a handling perspective. Search "droop limiter" and you'll see some other interesting conversations on this subject. When you get a Z really low you start screwing with all of the geometry, roll centers go underground, bumpsteer get's really extreme, you will have pro-dive in the front, etc. You might take a look at all of those factors too before you get too excited about getting it as low as possible.

I think roostmonkey had a run of mounts that had the hole in the wrong place. I know mine has the hole in the wrong place, even though I haven't installed the diff yet. Not a big deal to drill another hole. I really don't think the bottom mount is needed. The ES mount has an interlock feature, so it's not going to come apart, and the amount of torque that the diff gets while decelerating is quite a bit less than when accelerating, so in my opinion the stock mount is just dead weight with the RT mount.

FMIC seems to make sense on a Z since they have a long engine. There is plenty of room on the right side of the motor, but it's a long skinny space so the trick would be plumbing and getting an intercooler that would work in that space. I can visualize a big huge NACA duct and an outlet through the fender near the battery or something like that, but for all the hassle a FMIC sure seems easier.

The quietest backlash setting is going to be right where it was when the gears were originally run in at the factory. In the future any time you take a diff apart, measure the backlash before disassembly and try to match the same setting when you reassemble. If you've run the thing with the backlash opened up for years, it will be damn near impossible to find that setting by pattern, you'll basically have to play with it if it matters that much to you. I would not run it tighter than factory spec. It will get hot and possibly ruin the gears. In general longnose R200s are not quiet differentials, and I think the other guys are right that mounts are probably the most important thing you can do to quiet them down. The softer the mount the less noise you'll get. I again agree with the other guys that your harmonic issue is more likely a driveshaft angle problem than a differential problem.

Yup. It sounds like you need to flip the mount. All the Z's can use the R200 mustache bar and the front should mount up. I was wondering if you had erroneously had someone modify the front crossmember.

Can you restate that? I'm not following.

I'm not sure how much movement you can get with camber plates and stock springs. If you do camber plates, it would really make sense to go with coilovers too. I don't think it makes much sense to do one without the other. Coilovers give you a lot more freedom to try different ride heights and roll centers, and change spring rates cheaply. It's the way to go if you can afford it. You can section the struts and use any spring you want, you just have to find a spring that fits. I had friends with 510s who would section their struts and cut the spring perches off of 240 struts and weld them on, then use 240 springs, for example. I'm not sure if you could use the 280Z Tokicos with sectioned struts. From the pictures I've seen, I think the 240 springs would DEFINITELY coil bind. You need springs that have enough travel if you section to hit the bumpstop before they coilbind, but the advantage is that you would be able to run the car at the same height or lower with more suspension travel. Reducing the rear toe would decrease understeer and increase oversteer as a general rule. I just used your conversion calculator that you had put in the download section to put the alignment into inches, and in doing so it looks fine to me, so I would retract my statement. Looks like you have .145" total, which is not excessive in my opinion. Probably is excessive in others' opinions, but that worked OK for me. There isn't a good book on tuning that I've found. You'll find lots of books on theory, but they don't really say "Try X and if that doesn't work, try Y". I think you'll get better info on a forum like this one than you will from a book. Only problem is you're following the leader for the most part, so you need to know when to listen to me or John and when to try something different.

If you just want to look at the oversteer problem, I'd focus on the rear bar. Mine was an MSA bar and it was bound up when the suspension went through it's travel. Take the rear springs off and push the suspension through its motion by hand and see if the bar hits anything. I think your 73 has factory sway bar mounts, and mine had the bar bolted through the floor with the supplied brackets, so it may be different, but it was a problem for me. My car plowed really bad on most corners, and then occasionally would whip the back end around on corner entry when I first started autoxing. Sound familiar? I worked on the front end and added caster and camber and that helped a lot to get the front end working better. Even right at the end before I moved to WA after years of screwing with it (albeit with a VERY limited budget), I was still fighting plow and oversteer. The car was a lot faster than when I started, but the problems were the same (tough to see the understeer, but there is quite a bit on the slower corners): http://videos.streetfire.net/video/2000-autox-indisde-and-outside-I-think-my_8051.htm I didn't do too much with the rear, just added stickier tires and those oversteer problems mostly went away because of that, but then when I took the car down I realized what a problem that rear bar was. Stickier tires will hide a lot of bad handling traits. With those soft springs I wouldn't put the Illuminas any higher than 3, maybe 4 at the most. Even with 250 in/lb rear springs I never ran them on 5. It was just ridiculously stiff. If you want stiffer, get stiffer springs and run dampers to match. I think you could run springs in the mid 200's low 300's and get a reasonably comfortable ride and better performance with a better set of struts. I would do the following: Caster and LCA - this will require getting rid of the camber bushings MSA rear sway bar - I'd check it for binding. I bet it does, and if so replace with the rear mounted Susp Techniques bar. More neg camber - Plates are the way to go IMO, since you can easily move the plate for more camber at the track, and then back after you're done for the day. Stiffer springs (coilovers preferably so you can swap springs cheaply) Section struts Reduce rear toe - possibly G machine bushings if you don't want to do control arms

I'd follow John's advice and get the Suspension Techniques bar. I had a bar like Owen has, bought it from MSA, and only after years of driving did I realize that the bar was hitting the frame rail and binding up badly, which is not good. I agree that the rear bar is an absolute must on anything but the stiffest sprung Z cars. Especially when you get sticky tires on the car, the harder you push, the more body roll, the more loss of negative camber you'll have.

When they say one alloy is easier to work, I think that generally means bending and forming. You likely aren't doing any of that, just cutting and welding. That being the case, I'd go for the stronger.

3.90 was really common in the 280ZX. 4.11 from the 200SXT, 4.38 from skylines (I think). You have options, but the 3.90 is going to be close and by far the easiest to get a hold of.

Sounds like Tom Holt's solution he fabbed up for his autox car: http://sth2.com/Z-car/rear-upper.jpg

I wouldn't haul an engine in a van or SUV if I could possibly avoid it. If you get in an accident you're likely to be killed by your engine. I'd get a pickup. Should be pretty easy to find an old pickup for a good price. Japanese truck if you aren't carrying a lot at a time, if you are, then an full size American truck should do nicely. Nice thing about a full size is you can tow a car too if needed. Yes, you can do it with a small truck too, but in my experience it's a lot less strain on a GMC 1500 than a Toyota Hilux.

http://www.thezstore.com/page/TZS/CTGY/PSDC08

The problem is that the stiffer you make them the more they impart a side load onto the strut shaft. I haven't got any testing to say this stiffness is OK, but that one is unacceptably stiff, but my general impression is leave it alone or if you want something stiffer get a camber plate which has no give, but still allows free range of motion without binding or side loading the strut, via the monoball. John Coffey has posted about strut failure issues when using the MSA poly pieces.