JMortensen

This should be non-tech as it isn't Z related at all. Moving...

I checked with the guy who ordered my cam for me way back when, he isn't 100% sure that this is the same company because he thought it was American Cams too, but he thinks this might be them: http://www.americancustomcam.com/

Sorry for the error guys. I thought the VLSD had the viscous part sealed in the middle of the side gears. I guess there are two viscous units one on each side gear...

Here's a pic of a VLSD from Warren's album: and another from Z-Monster:

Looks like a 4 pinion open diff to me. I think some of the later shortnose R200s came with open 4 pinions, but none of the Z31's as far as I know. I haven't seen one apart like this, but I just don't see anything in yours that limits the slip.

The larger the tubing the thinner the wall needed for the same stiffness. If you're worried about crushing the tubing when you bolt something in why not weld in a sleeve for the bolt?

I don't believe that they are. I think the spline count on the end of the pinion is different on all of them. Haven't got any proof of that, but I think it's right.

Cutlass, please do some searching, and then if you still feel you need to ask your question, post it in a different thread. This one is specifically for struts and we want to keep it on point.

They shouldn't be that expensive to buy at an auto parts store. If you don't want to do that then you'd have to look at brake swaps, and there isn't that much available for a ZX. I've seen Wilwoods before, but they don't incorporate an ebrake.

I don't think the valving is proportional as it relates to the spring rates. When you talk to someone about custom valving they'll have questions about spring rate, but also about sprung weight, unsprung weight, motion ratios, etc. If the only thing that changes slightly is the spring rate and the rest of the variables don't change then I don't think that the valving will be really all that different. I'd run them with the stock valving or do the 300/100.

No, the guys I'm talking about were in LA. It's been ~10 years ago since I got my cam, maybe they're no longer in business.

Gauges under the gas filler door don't make much sense to me either. I'm thinking Ron will set us straight on why the gauge is in the gas filler area, but if I had to guess I'd say it's probably because the original BRE car didn't have a diff temp gauge, and he is trying to keep it original looking.

4wds with really excessive U joint angles sometimes run CVs or dual U-joints which work like a CV. They're pretty big because they need to be, I don't think I've seen it done on a car but I see no reason not to. I think the CV's will eat up a bit more power than U-joints if the angles are kept correct, and the only reason I can think of to use them is if you couldn't possibly get the angles right. I didn't read this page, but it looks like it has a lot of the info you're looking for: http://www.pirate4x4.com/tech/billavista/PR-shaft/

The 280ZX calipers are notorious for binding. Sounds like yours is stuck. Replacement will fix, you could probably disassemble the caliper and clean and lube all the parts and fix it that way too.

I think maybe there are two different subjects going on in this thread. One is talking about how to get the most from a given tire, and the other is trying to put as much tire under the car as is possible with a limited rim width. Again, I ran an 10" slick on an 8" rim and it worked. It didn't kind of work, it worked. The downside was that the tires were really floppy feeling in corners. I think that tire would have performed BETTER on a properly sized rim. I do think there is a limit to forcing a tire onto a narrow rim. 285's on an 8, unless its a narrow 285 or a wide 8 seems really retarded to me, unless its a cantilevered sidewall. But I'm sure the idea in that case was that the class rules limited that car to an 8, so they were trying to get the most tire they could under the car. As to whether a 285 or a 315 would perform better on this 10" rim, I'd guess that the 285 would, especially given the small aspect ratio of the tires in question. To counter the Grassroots Motorsports story, Tom Holt was running an 11" tire on his 10" rims, and then changed back to the narrower 9.5" tire because it handled transitions better (I searched and couldn't find the thread where he said so). I don't think there are any limitations on rim widths here, so I'd put the tire on the correct width rim. If you got the tires cheap and just wanted to stick them on that's fine, that's why I did what I did. When you go to buy a full price set of tires, you'll get the most from the tire if you get one that fits the rim correctly. If you want bigger tires, start saving for bigger rims (and flares).

I also don't know the history, those two diffs could have been run out of oil or something. I don't think the later case is immune from pilot bearing issues, but that doesn't mean it's worse.

Coffey did some testing in this regard and found that he got the best lap times with a tire .5 inches narrower than the rim as I recall. He also quoted Hoosier as saying the same. So I'm guessing he'd say put it on a 13" rim. That's a road racing or autox recommendation, not drag racing, but I think the idea that the rim should be at least as wide as the tire tread is legitimate. A related thread: http://forums.hybridz.org/showthread.php?t=129535 I think that this car would really put the power down better with more sidewall, but the current style dictates that sidewalls are ugly.

That's interesting. The two bearing failures I've seen in person were with the 87-89 R200 LSD diffs, so I would assume that they are the later versions.

I don't know about the safety issue, and to be honest I kind of doubt there really is one. What shoving a big tire on a narrow rim does is give really sloppy handling, and as the picture above shows it pinches the tire in so tight that the edges sometimes don't touch the ground as Bartman says. I know I had that problem running a 250 on an 8, and the lower profile the tire is the worse contact patch you get when you put a wide tire on a narrow rim. I wanted to run that tire on a 10" rim, but could never afford the rims. For a 315, I'd use a 12, as 315/25.4= 12.4, assuming the width is what the tire manufacturer says it is.

Smaller wheels, taller tires and a width that is appropriate for the rim might help your traction problems.

I had something comparable to the Schneider stage IV and that worked really well on the street. It was great for SU's, when I went to triples I wished it were a little bigger. I don't know how a stock EFI manifold will relate to my experience to be honest. My cam was .490/280, but with a fairly aggressive lobe shape as described by American Cams. A lot of it has to do with the lobe profile which is hard to determine from just the lift and duration, but just by the numbers I'd be looking for something around the specs of .500/290 or .500/300. I think duration (really its the overlap and a narrow LSA) is more important than lift in getting the car to run on pump gas without pinging.

I would think you could get in and out of the roadrace intermediate without detaching the wheel. Mike might be able to give you a better idea since he has one.

I thought Delta had larger grinds than that. I would go bigger. Delta isn't the only grinder around either. Might try American Cams or someone else and see what they have available.

E Mod and time trials are where it's at for me. Yeah, I might not compete with a Lotus 7 with a Hyabusa motor, but I'll have fun and I'll spank 95% of the other cars in the field with something I built in my garage.

I think you're understating my position a bit. I really don't think that one should base current or new attempts at aero mods on what people were doing 35 years ago. We have so much more material to pull from and so much work has been done since that time that to rely on those fledgling attempts to improve things is to limit oneself. Look at them, understand them, and then move on.