JMortensen

Yeah, you're right. Which got me thinking, how the hell did they make that work? So I searched for a picture, and found one. Looks like the front doesn't need the flare at all, and the rear is going to cut the tire, just like all the people running ZGs today. So ZGs never really worked correctly for the intended purpose. https://dattosankureiji.wordpress.com/2013/12/02/some-datsun-racing-history-goodness/ Thanks for piquing my interest. Always a pleasure.

The purple car above, and 99% of the ZG flares people install have this problem. The have the tire all the way out to the lip of the flare in hella flush style, and because of the shape of the flare there is no way for the suspension to move an inch without the tire hitting the flare. On ZGs in particular people tend to mount the rears too low and not cut enough of the fender. I think this is because the flares were originally useless: the old 70s Japanese Zs that ran them had wheels and tires that fit into the stock fenders anyway. Why they put them on in the first place is beyond me, but I don't bolt fake vents or scoops on my cars either. https://www.sportscarmarket.com/profile/1972-nissan-fairlady-zg [img]https://www.sportscarmarket.com/wp-content/uploads/2016/08/1972-nissan-fairlady-zg-drivers-front.jpg[/img] Looks like putting the image tags in doesn't work, but there's a good shot of an original ZG at the link and you can see that the flares are totally unnecessary. If you were inclined to go hella flush, I'd suggest you run a huge stack of packers and a big foam bumpstop so that the suspension rode on the bumpstop all the time and the packers kept the suspension from compressing so far that you'd smash the tire into the flare or cut it on the not trimmed enough original fenders. Lots of newer cars ride on the bumpstops all the time, or as soon as there is any body roll at all. You can do that pretty well, surprisingly.

There is a similar video of the Janspeed car with the hood blowing up like a balloon: Love the duct idea, did it myself. Louvers work too, if you can do that too...

I have the front crossmember 2.5 inches off the ground and the pan is slightly higher. I made my mounts so if you're using off the shelf stuff YMMV. My goal is to eventually run a paneled bottom. I had to raise the drivetrain because the T56 was hanging down below the frame rails (Bad Dog SFCs). 280 rails are taller so there is a little wiggle room there.

I did the 2.66 Woodward rack. I don't drive it on the street, but I would. I don't think it's too sensitive, although you might be in trouble if you were leaning down to get something off the floor and weren't paying attention. Much nicer in slaloms. I also did the Holley 302-2 and and Improved Racing baffles and a 3qt Accusump. I have a 30 lb low oil pressure light, haven't seen it come on when autoxing on 14" wide slicks. More info on my swap here:

I was out of town, thanks for posting this info Arttu. I have this end: https://www.ebay.com/itm/381257941708 which came off of a sway bar for an E46 that I bought used for an extremely good price. Here are some details on my blade end from Hoerr Racing Products: "The GC1042 blade is a 950L blade which is the longest one we offer. The .310 thickness is a bit heavy for a 1 ¼” dia bar, a .270” blade would be more ideal. Let me know which direction you end up going with, I’ll be glad to help out if you choose to buy new items." So that would be 7.75mm thick, tapers more dramatically, and is also shorter at 190mm. Now I'm mulling selling and buying the thinner .270 blade which is 6.75mm thick, or just making an adjustable bar end and leaving it be. I'd love to have the in cockpit adjustability, but not sure how much effort I want to put into it.

What size blade are you running, on what size bar? I bought one used and am debating running it or reselling.

Return them and get steel, then chop the ends and do boxed sheet?

I got my bar from colemanracing.com, but aside from spline count variations they're basically the same idea, and my understanding is that we can buy arms from other suppliers like Speedway and as long as the spline count is the same, they'll fit. Coleman sells a 48 and a 49 spline, mine are 48, FWIW.

Different material but I tried bending the steel ones with BFH and got nothing. Put in my 12 ton press and was able to deflect the end about 1/8" before I gave up for fear of my life. Then found a machine shop with BIG machinery and they put the arms in a 50 ton press and bent them easily. Your standard auto shop press ain't gonna cut it. The double shear end link mounts are so that I can use a clevis and not have to worry about the clevis leaning in the hole. Pro-tip: if you're making them double shear, take a piece of plastic from the last tool you bought, or a razor or anything that comes in a blister pack, and put that between the rod end and the arm. That will give you an extra .005" or whatever and it allows the rod end to slide easily into the mount. Last time I did this I didn't use a spacer and it was a real bitch to get the rod ends into position for the clevis pin. Will probably clunk a little, but hey, racecar. I think AL is stiffer and more brittle. Someone mentioned spring rates, and the higher the spring rate the less sway bar you need, so you can get away with less strong arms as a result. Before I decided to make boxed arms, I had an engineer friend I used to autox with 20 years ago suggest milling down the arms to 3/8" thick so that they could be bent more easily. That would be another way to fix and would reduce weight. The strength of the arm as delivered is more than capable of withstanding the thickest sway bars that you would use on a 3000 lb dirt track car with soft springs and (WAG) 7" of travel, so a lot more force on those arms than what they'll see in a stiffly sprung ~2500 lb car that moves a couple inches at most.

My impression is that you don't want the backing plate to cover the face of the rotor as that prevents the heat from dissipating as quickly, which is why my mine fit into the center of the hat. I'll leave it to Keith to comment on that. His setup was for a solid 240Z rotor with different considerations, but IIRC he moved on to E36s after he left the Z scene so I'm sure he'd have some other race cars to draw from.

FWIW, I have a similar style bar and Cary and Richard suggested making boxed sheet arms for it. Those freakin arms are HEAVY. It's on my list of things to do. Idea is to cut an inch or two after the spline and weld the tube arms to that. I think it will be pretty easy to drop 10 lbs. Maybe more. Was surprised that my tubular bar with the solid ends was a couple lbs heavier than the 1" MSA solid bar I was using before.

I made some a couple years ago and still haven't redone the feed tube into them, which interfered with the sway bar. Supposed to be on the schedule for this winter...

I agree with you guys and think it's the pushing back that makes the urethane ones sag in the middle, not any pushing down. Likewise I had a fiberglass airdam with a rubber piece about 3" tall on it, called a Flex-dam. Made in CA in the 70s and 80s. Anyway a friend of mine snapped a pic on the front straight at Buttonwillow, which is not that fast, and the rubber was flapping up and letting a good amount of air under the car. Replaced with plastic lawn edging to fix. Whatever you do, test to make sure it works after you've done it.

Can't really see what you're doing on the bottom, but also blocking off the entire area between the front valance and the rad support helps to minimize air that goes through the grill and then down under the car. I expect you're aware of this already.

I assembled the suspension without springs, used a ratchet strap around the A arm to compress, then I think I measured from the hub to the fender.

Looks like Onesight1 and I are late to the party, but I think the main thing is that you want the suspension to have as much bump travel as possible and simultaneously want the rear tires to not hit the insides of the fenderwells. If you line the flares up with the bodyline like most do, then you will not have enough clearance for the tire, particularly if you have taller tires or run the car lower, or both. Taller tires and lower ride height seems to be the thing to do these days. Mounting the flares high enough to allow for the tire to move means installing the ZGs at a pretty awkward height, unfortunately. John Coffey had a good thread 20 years ago about Amir's SR20DET powered Z, and how he had to move the flares up to keep it from eating tires. I also shared my experience cutting and then redoing it to get enough clearance for 24" slicks with gigantic IMSA flares. I don't remember whose car this is, but it's an example of what NOT to do IMO.

Why do you have to pull the hubs? Bracket goes all the way around? Just cut out the bottom section and bolt it on.

Oh wait. You meant a skirt at the front of the splitter. I had that idea about 10 years ago and emailed Simon McBeath and he wrote me back and said don't. Also emailed Glenn Bunch with the road race Challenger, because he had pics of his on the track with a splitter with a dam on it, he gave it a thumbs down. I shared all of that in page 2 of this thread.

Yes, I did run a skirt. I have it set up on a pivot on the back and was going to run cables in the front, but as it turned out it didn't allow for much movement when installed and there was some other problem I can't quite remember so I ended up using AL fuel line smashed on the ends to make struts for it. Passes the "stand on it" test. 1/2" birch. 3/4 would be really heavy. I just went to Home Depot and found a flexible white plastic that I think is used behind showers or something like that to waterproof. Easy to trim to fit. Have a small 1/2" AL angle section on the splitter, and then it's screwed right to the fiberglass. It looked pretty nice before I drove it, but after the splitter hit a couple times the plastic warped and buckled. Oh well. Race car.

Guessing he found it when he was searching for "splitter." FWIW I ended up making one out of plywood. Didn't want to do it from CF and then break it immediately. Kinda glad I did. It has rubbed once or twice. I've been autocrossing with a club that has 3 classes: FWD, AWD, and RWD. Since the rules are wide open I've been thinking again about doing diffusers and all of that. Have a couple other projects going though, so nothing planned for the immediate future.

You can weld the skin. Just drill out all the spot welds and remove the old roof, weld the new skin in its place. Another option is to cut through the pillars and weld back together. There are differences in the 240 and 280 chassis. Not sure what if anything is different about the pillars. Should be dimensionally the same as the hatches, doors (some lock issues but size and shape the same), quarter windows, and windshields swap. I have a friend who built his roll cage this way, cut the pillars, did the cage, welded the roof back on. A lot of people were poo-pooing this at the time, but I think if I were doing another cage that might be a good way to go. Probably want to stay away from the leaded joints so that you don't make a mess, or melt it all out with a torch and deal with it.

There used to be a good variety of bubble flares that weren't bolt on. MSA had a couple different varieties IIRC, I had some from a company called MAS, Jim Cook Racing had some, there were others. You should NOT buy from this guy, has had a terrible reputation for decades, but he still has the pictures stolen directly out of MSA's old catalog showing some of the bubble flares: http://showcars-bodyparts.com/240z.html

I think I figured out the turn part. You're just saying the MN is superior because it has the port at the same level and the valves lower. OK. Point taken, but again, you're starting with a head with smaller valves, so one might have a better port shape, the other has bigger ports and valves... ???

I agree, it's good to keep hashing it out, although since switching to LS I don't care as much as I used to. It got pretty heated in those threads 20 years ago. I remember being particularly pissed off when Mack said something to the effect of "I can go half throttle and not have any pinging." LOL Here's a different angle: if it's not a race engine (at least a weekend warrior), then why bother bumping the compression up to the bleeding edge? If it is a race head, then why start with a head that has smaller valves and ports and liners when you could shave/shim and end up with something very similar and then have a better starting point to go crazy from? Re the turn from the port to the cylinder, it's not affected at all by shaving the P90, because you're shaving the bottom of the head, and the turn takes place in the port. Might change the distance from the valve seat to the piston, but IIRC the P90 has a deeper chamber and shorter valves, so you'd probably be returning that to a place where they would be more comparable. I think the MN valves would still be closer to the piston. I suppose that's going to matter most when the cam is big enough to put the valves into the pistons, at which point need some flycutting. If someone were building a race head though, ideally they'd raise the port roof and work on the short side radius, and you would do that on either head. Not sure if one has more meat there and can handle more porting, but you'd start out with more to do on the MN, plus installing bigger seats and valves, blending the bowls would require more work, etc.