JMortensen

Looks like it ended July 31.

I would warn you that you might need to extend the mounts to get the bar higher, as the valve cover is higher than the strut towers. In other words, the CAD drawings are great, but go figure it out on the car before you commit to having a bunch of parts machined. Also, if you're redesigning the whole thing, you might make it double shear and have the attachment point right in the middle of the strut tower so it is best positioned to handle the stress it will receive. With double shear I'd go back to a rod end. Also, the braces back to the firewall are a decent idea, the question is where to attach them and have it be strong enough to really make a difference. Pull the cowl panel and take a good look at the firewall and you'll see what I mean. There isn't much back there. bjhines did a good job reinforcing his cowl to deal with the stresses from the strut tower bar, but without that reinforcement I'm not sure how much good those will actually do (and I say that having had a similar set up on my car for years).

Caught this on a different forum. Really really really good explanation from 1938.

If you read up, screens and socks are supposed to be the MOST restrictive. ITG style is the best, K&N and similar with the metal cap is in the middle.

I'd love to see the brackets behind the air dam.

Nobody knows the answer to that question, because nobody has ever tried to get the widest tire that would fit without flares. And if they did, they sure as hell wouldn't have posted that information here before. It's a good thing too, because if it were posted here previously, you might have to actually search to find it, just think of how sucky that would be. Searching is for nerds and bookworms.

I have mine valved differently than most. I was talking to a guy who does shock valving in OR and he suggested that I worry about the unsprung weight instead of the sprung weight, the idea being that what is important is to keep the wheel on the ground and what is not important is to make the car ride smooth. If you have lots of rebound damping it controls the oscillations of the car body (more comfortable, feels more stable) but it also tends to pick the tire up off the ground and reduce traction on corner exit. My Bilsteins are valved 100/100. I'm quite sure they would beat the piss out of me if I intended to drive the car on the street, but I won't. My Z will go to the track on a trailer, so I have no concern for ride quality on the street whatsoever. I was starting to second guess my valving choice until I got into this discussion over at corner-carvers.com: http://www.corner-carvers.com/forums/showthread.php?t=41374 If you see holes in my analysis of the BMW vs my valving let me know, but I think it looks at least similar in concept, and I would expect the Z has more unsprung weight, so could use a little stiffer valving... I want to say that Konis are not gas charged, I think that means that they do not extend all on their own. I'm not sure what to make of Howler Monkey's bit about "purging" air. Where does the air go? My struts are sealed, air doesn't come out of any vents or anything. Plus the picture shows compressing the strut upside down. I don't think the original Z struts were actually sealed. They just had a (leather?) seal at the top of the housing. I've never had a problem with compressing the struts upside down causing trouble with the strut's operation. In fact, this article says to turn them upside down and right side up and check for dead spots: http://findarticles.com/p/articles/mi_qa3828/is_200309/ai_n9278028/ IME, if the shock has a dead spot, regardless of whether it is right side up or upside down, it needs to be replaced.

Ladder frames and subframe connectors aren't very good in torsional rigidity. They might help, but having braces to the strut towers in 3 dimensions is the way to increase rigidity. If you search for "chassis stiffening" you'll find some good ideas on the subject. Or for a basic rundown read Chassis Engineering by Herb Adams. To the OP, the strut tower bars will help a lot in terms of improving handling, they just don't control the up and down movement of the strut very well. Don't take that as a knock on the idea though, it's just that a strut tower bar is the wrong tool for that job.

Vacuum advance is for mileage. I'd disconnect it and set total advance for somewhere in the mid 30's total advance after all the mechanical is in, which is probably 2500, so if you set it in the mid 30's at 3000 that should be it. The 280Z distributor has a lot of mechanical advance which is not good for low end power. You could get a 280ZX distributor and use it because they have less mech adv, or you could go to some sort of crankfire setup like megajolt. I think crankfire is the way to go if you're going to spend money on ignition. No point in spending hundreds of dollars on a Mallory distributor when it is still a distributor and has the slop in the gears at the crank and the potential for failure in the cap and rotor and wires. If you're going to spend a lot of money get rid of of the dizzy and go crankfire.

Operating temps for the Yokohama slicks I was running were 190-220 degrees. That was part of my problem, I could never get them to operating temp. Stiffer springs will put more heat in the tires.

Bilsteins are much looser in the housings, no need to grind paint off or any of that. Here is the gland nut:

We've done this argument before, but the strut tower brace is VERY weak in the axis that the joints allow movements in. If you want to keep the struts from moving up and down in relation to each other, a thin long bar attaching the two is not the way to do it. I would go so far as to say that your typical strut bar is next to useless at preventing this kind of movement. For this design I like Cary's clevis idea but it's not as snazzy looking, so most people would rather have a rod end in there.

They should be 2" shorter than stock. I think the Konis are 1 5/8" shorter, so you'll probably need a spacer front and rear. They do come with gland nuts, but they're the wrong ones. See earlier in this thread for the correct part number. They should work fine with stock valving, which really wasn't that far off from what guys were having them revalved to. No idea on the Koni vs Bilstein comparo question.

Beautiful car. Are you going to run without rear quarter windows? I'm not sure I'm on board with your driver's door bars. I would finish the X at least, but the point of cutting out the door is so that you can put the bars into the door, thereby getting them farther away from you. There is also a difference in strength between bars that bend into the door vs bars in a flat plane. If they're in a flat plane and the car takes a hit to the door, it's basically just the welds holding the bars away from your body, and the bars themselves are in tension. If you have NASCAR bars, or an X that bends into the door cavity or anything that angles away from you, then if the bar gets hit it transfers that load to the A pillar and main hoop in compression, which should be a lot stronger. Now it's true you can point to a lot of cars that have flat X's in the doors (rally cars being a major one) and say "no biggee" but after I learned a bit more about it, I was glad that I had my driver door bars bend into the hollowed out doors.

That looks like the same die that came with my Speedway bender. I had a roll bar fabricator bend up the main hoop based on Dan's .gif you have there and it worked out perfectly, and then I did all the other bends with a basically similar bender: http://www.speedwaymotors.com/3rd-Generation-Hydraulic-Round-Tubing-Bender-Assemby,6614.html

Most racing organizations demand that you remove the backing plates and I ran my Z on the street for years in all kinds of weather without issue.

All-thread is the name of the stick of threaded metal.

Brawndo mutilates your thirst. It's got what plants crave.

You should have no problem at all with 44's on a basically stock engine. Mikunis are EASY compared to Webers as they have a lot fewer adjustments and seem to hold a tune better. According to most they are a lot less finicky. I'd suggest you pick up "How to Modify Your Nissan/Datsun OHC Engine" by Honzowetz. It has good info on Mikunis. You can also download the manual from the Downloads section here: http://forums.hybridz.org/showthread.php?t=122217. At least you'll know what jet affects what. I'd focus on pilot screw setting first because it will take you 5 minutes and should make a noticeable difference. Turn them all in till they stop (might be interesting to count the turns here). Don't crank on the screw against the stop, just turn them until they touch the stop. Then back them out 1.5 turns. Don't mess with the screws again. If it's too rich at idle, get leaner pilots. If it's too lean at idle, get richer pilots. Most Mikunis I've seen have pilots that are way too lean. Aftermarket Mikunis are race carbs and come jetted small because race engines have large cams, so there is more intake stroke time to pull gas into the cylinder. Running them with a stock or mild cam necessitates larger jets. You can get jets through Todd @ Wolf Creek Racing, he's a good guy and I always got the right part the first time.

Mikunis are usually very easy to start in cold weather. 2 pumps on the pedal and turn the key and it should fire right up, pump the gas a little once it starts until it warms up a bit and you're there. I never bothered with the chokes in SoCal or Seattle. As far as shops to take a car to for Mikunis in the LA area, that's a tough one. The only one I can think of is Top End Performance in the valley, but their rep is a little shaky. Do you know how to work on the carbs at all? Might check things like synch and idle screw position. Seems to me like something would have to be pretty screwed up to get the problem you're describing.

My douchebag name is Alex????

Search "chassis stiffening". Bad Dog rails are one part of a bigger solution.

No. In order to do that properly you'd have to have spring rates that wouldn't allow bottoming (often) within the available travel. I don't have an idea of what that would take, but I'd imagine 1000 in/lbs or more. Then of course you'd need the chassis to work with those spring rates and shocks to control it all.

If you wanted to run the WRONG springs and struts for that height, you might try some 200/225 in/lb springs and Illumina struts. That would be stupid though.

I had the WRONG springs and shocks for running that height. To run that height properly you need really insanely stiff springs, and it would still be completely undriveable on the street. Why? Because you couldn't get in or out of driveways, you'd high center on speed bumps that were 3" tall, might even hit the chassis on the ground if you hit a big enough pothole. I did that at that autox venue because it was totally flat concrete.