jmortensen

Sure thing. I have done some funky mods to my car in this area and eventually (2015 or 2020 when I actually drive mine again) part of the plan is to actually test the difference with the crossmember and without in autox type driving. I agree that for a pure street cruiser it probably makes no difference as you said. I was thinking of taking it off because it would make diff swaps SUPER easy, and add room for the exhaust as you said.

You guys may want to consider that the crossmember holds the front control arms at a fixed distance and acts kind of like a strut tower bar does in the front. IF (and I don't KNOW) taking that piece out allows the front control arm mounts to move relative to each other, you'll be getting some funky camber and toe changes as it moves.

What are you going to do with those crappy Advance Design struts then? Just curious.

The Cannon has 3 "towers" which are rod ends that hold the linkage bar. The Mikuni has 2, and the spring pressure from the carbs acting on the linkage will bend the bar in the middle. The ratio isn't a make or break deal, but if you're racing and you are next to a car with tighter ratios and a lower rear and all else is equal, you'll lose. I made a list of the parts you need for the R200 swap here:http://forums.hybridz.org/showthread.php?t=114798

Todd has good linkage setups on his Mikunis. IIRC he puts a support rod end in the middle of the chrome linkage bar, from the factory the Mikunis only had rod ends on either end of the chrome linkage bar, and the middle would bend slightly under the weight of the return springs for the throttle plates. I would suggest with 44's that you get a ZX NA 5 speed and a 3.90 or 4.11 diff. I think the stock 4 speed and rear end would work, but you have such large gaps between the gears that you'll be out of the powerband on shifts. I had a friend with a pretty built 510 and he had the 280Z 5 speed which has similar gaps in the ratios. Our cars turned very similar lap times at autox but when we went to a big track he had to deal with the gap in the 2-3 shift and the one time I was behind him coming onto the front straight, as soon as he made that shift I was in front of him. Now a Z has more torque and a wider power band than a 510 in general, but after that incident he got a closer ratio 5 speed and we were neck and neck again.

We are comparing to the L which traps steam near the #5 combustion chamber on high hp applications. BTW looks like the OS Giken head has steam lines (or coolant passages) for all the cylinders. http://forums.hybridz.org/showthread.php?t=125186

How much is an LSx swap? I think I'd go for the one that costs 1/10th the price, makes more power, and that I can find parts for at the local parts store. Call me crazy.

You mean right handers, right? It's not a pickup issue, it's a sloshing over the jets issue. Tom Holt was nice enough to show pics of the simple solution here: http://www.classiczcars.com/forums/showthread.php?t=18948

I ran triple 44's with a stock compression motor, a medium cam, a light flywheel, 2.5 exhaust and an ACT clutch and it was a *****cat in traffic. No problems at all. It did have less power off of idle, but that was a sacrifice I was willing to live with. I also drove basically the same setup (stock clutch though) with SU's and that worked great too. I think the car was faster at autox with the SU's because my gearing was too tall for the Mikunis, but I couldn't get myself to give up the top end power of the Mikunis. They made quite a bit more power on the top end.

If you were taking that literally, you've still got 1/4 of your life left. It would be an asymptotic type of thing. I like his other one better: "I had some powdered water, but I didn't know what to add".

I called Energy Suspension and asked about grease and they said any chassis grease would work and not degrade the poly. I put zerks in the outer control arm bushings in back, and they functioned well and made a difference that you could feel when pushing the control arms up and down by hand with no spring in the suspension. Unfortunately they don't work on the inners because the bushing cap isn't tight and the grease just comes out the gap. You can also drill and tap the sway bar brackets to grease there too, and you can shim up the strap that holds the sway bar bushing so that it isn't so preloaded and tight on the bar. Less stiction should = less squeaking, and being able to grease them up is for sure going to help.

They both hook right up, no difference there. The real difference is in the ratios. The early 5 speeds have wider ratios and a shorter OD, which makes them more well suited to the 3.54 gears that they came with. This also makes them better suited to the 3.36 gears your 240 came with. The ZX had closer gear ratios and came with a 3.90 rear gear. If you swap the late transmission into a car with a 3.36 the result is a car that is a slug off the line and has a theoretical top speed of 200 mph. Seeing as how most Zs will never break 150, this is a ridiculously tall gear combination in my opinion. The short version: if you don't want to change the diff, get the 280Z 5 speed. If you want to change the diff and make the car as fast as possible, get a ZX and a lower diff ratio like a 3.90 or 4.11, depending on your intended usage and your motor's power band.

I really like Hybrid Z because the focus is on technically correct answers and modifying the Z to be faster, which is what I go to Z forums for. There are occasionally head butting type arguments there and I've been in a few, but at the end of the day it's not about telling someone else they're stupid. It's about finding the right answer to the question. My guess is that if you caught flak at Hybrid Z it's probably your own fault. For the record, I hung up my Hybrid Z admin spurs, so don't complain to me about it... Hybrid Z is not the end of the road for no BS tech info type forums. Try corner-carvers.com if you want to get a serious beat down for not bringing relevant technical info. I think the thing that annoys me most about forums in general is when people post without searching or post and title their thread "Question about Z cars" or some other nebulous thing like that. If you post "Length of stock wheel stud" or "spline count of 280Z stub axle" then the next guy can find what he's looking for when he searches before he posts and doesn't have to wonder what is in all the poorly titled posts. As far as US-centric posting goes, I wonder what percent of the users here are US based. This forum is out of Oregon, right? Am I wrong in thinking that Americans are the vast majority of the membership? If I was going to shoot from the hip I'd say 80% US. Maybe more. Is that way off? Regardless, I don't read the 240K posts and think "those damn aussies and their AU centric 240K BS" and I don't know why anyone outside the US would feel the slighted by a post I made about a LHD Z car. Similarly, while I occasionally read posts on ozdat.com I have never felt the need to complain about their australo-centric posts. My advice there: try not to be so sensitive, and people in other countries should consider the source of the info they're getting. If someone says 15/16" instead of 24mm, don't get your panties in a wad, just realize that the person who is trying to help you is in the US where we use SAE and to a much lesser extent the metric system. It's not an affront to you. Convert the measurement and be glad that someone was nice enough to give it to you.

A509's were a GREAT tire. Granted, 10 year old A509's probably aren't that great, but man I remember being PISSED when Yokohama stopped making that one, and the AVS Intermediate too. GREAT tires. I think the problem is that you have a large diameter wheel and probably a little more caster than you had previously with the poly TC bushings. I think the best solution is to either roll the fender in front or cut the lip of the fender where the tire hits it. You could go with wheels that have less offset, but Panasports really don't have that much to begin with.

I believe they were discussed at Hybrid Z with regards to reducing underhood pressure. I know they were tested in the windtunnel and shown to have a positive effect, rendering them riceless in my opinion. For my money I'd buy some "alligator tooth" style vents, which are better at reducing underhood pressure, but probably more ricey looking.

The clamshell works too and should be easy to make. Either is WAAAAY better than Nissan's original strap design and should solve the clunk. I'd get a rubber foot from the hardware store and put that on the top of the clamshell part so you have rubber on both sides of the diff crossmember.

Trying to think of why this wouldn't be so easy as to just take the front crossmember off. 4 bolts and the nut that holds the mount to the diff. Then you should be able to remove the bolts that hold the mount to the diff, replace the mount, replace the crossmember, and you're done.

Nice zombie post Mr Z. Since we're here... I know this is an old comment, but a phantom grip does not work like a detroit locker. It works like a (weak) limited slip.

I feel like I keep saying the same thing over and over, so this will be my last attempt. If you turn the halfshaft and watch for motion elsewhere, you are introducing slop into your measurement. Slop from the halfshaft splines to the side gears of the diff on the input side. Slop between the side gears and the pinion gears, slop in the halfshaft splines on the other side, a bad U-joint, etc is being included in your measurement. That is more than enough to throw you WAY off. The backlash is .005" to .008" if I recall correctly. That is a very small amount of lash. Trying to feel that through the halfshaft would be very hard to do even if there weren't all the other slop. Trying to feel it at the ring gear even takes a little attention. You have to rock the ring gear back and forth without actually moving the pinion, and moving the pinion is pretty easy to do. When you put the parking brake on and rotate the driveshaft, you also are not checking ONLY the play at the gears. Again you are adding whatever slop may be in the driveshaft to tailshaft splines in the transmission, driveshaft U-joints, the side gears and halfshaft splines, the cross pin shaft and the pinion gears, halfshaft U-joints, potentially the splines on the stub axles, plus whatever elasticity there is in the brakes during your test. There shouldn't be a lot of play in any of those places, but there often is. Another thing about measuring at the pinion: The measurement of .008" at the ring gear does NOT equal .008" at the pinion flange. The movement at the pinion is greater than the movement at the ring gear because of the cut of the gears. I think this is the number one reason why people pull their diffs, they rotate the driveshaft, are surprised when it turns more than they think it should so they assume that backlash is the problem and start pulling the diff unnecessarily. This is from a thread on Hybrid Z. This guy checked his backlash at the pinion and then went on to find out where the perceived slop was: If you want to know if your backlash setting is OK (and it probably is just fine), the way to check it is to pull the diff, pull the cover, and measure it directly. As far as bearing noises, I think whine on decel is typically pinion bearings and wheel bearings growl, and the growl changes pitch with load, so swerving side to side will help to identify if it is a rear wheel bearing and sometimes which side needs replacing. I agree that the little metal bits are probably bearing material. That doesn't mean that the whole diff needs to be torn down or replaced. For more diff noise ID: http://www.ringpinion.com/ContentFrame.aspx?FilePath=Content%2fHowTo%2fGeneralInfo%2f%2fDiagnosing_Noise_%28Part_1%29.inc http://www.ringpinion.com/ContentFrame.aspx?FilePath=Content%2fHowTo%2fGeneralInfo%2f%2fDiagnosing_Noise_%28Part_2%29.inc

Glad to hear that. I'd much rather know when I'm wrong too, but not all people share our view.

I'm not trying to be insulting, but in reading this statement I wonder if you know how the Quaife works. Here's the brief description: the drive forces drive the side gears into the sides of the case, where they push hard on it. They in turn drive all the worm gears into their pockets in the case at the same time. They also push very hard on the case. So you have gears that are being shoved against the case hard. Now when you turn the side gears have to move at different speeds. This causes all of the little gears and side gears to move. It's the friction between the gears and the case that causes the limited slip action, and it's pretty much all shear friction. You have shear from the ends of the side gears to the case, shear from the smaller helical gears into their pockets, shear from the toe of the helical gears against the case, and shear from the side gears to the helical gears. If you have a gear driven diff that doesn't have preload (yes, they can be preloaded) you can spin the tires in opposite directions with your pinky. I've seen this done with an ITSS Firebird that my ex-boss used to race. He sat there spinning it and said "I don't know why this thing works, but it does!" At the time I didn't know why it worked either, but later I worked for Randy's Ring and Pinion selling diff parts and had a demo model of one of these on my desk for several months, along with a little tiny detroit locker and an Auburn gear miniature LSD. The reason the wheels spin so freely is because the gears don't get jammed into the case until torque is applied to the ring gear. It's also why when you lift one tire off the ground the thing is completely open with no resistance (assuming no preload). With no torque to multiply, the inside tire starts spinning immediately.

Thanks for the vote of confidence. I am starting a business that sells diff parts with my brother-in-law Mat www.m2differentials.com (nothing for Z's as of yet and the site needs a lot of work). For the last six years I've sold doggie doors through my other business www.thepetdoorstore.com, so keep that in mind too. And I'm not building or repairing diffs this time around, just selling the parts. In my favor, I've built ~10 differentials (Toyota 8" and Ford 9" mostly) and completely disassembled and reassembled the R200, so I think I have a clue as to what is going on. I do like the suggestion your suggestion that they check it themselves. Eliminates all doubt one way or the other and doesn't rely on the expert opinion of someone trying to diagnose a noise or perceived slop through a post on a car forum.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=623 http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=5645

It's probably not a backlash problem at all. Checking it from the pinion is VERY hard to do accurately. If the backlash is really opened up a lot, the ring and pinion probably have a LOT of wear, and the diff is most likely junk. I have to speculate here, because I haven't ever seen one that wore out in such a way as to really open up the backlash either in person or on one of these forums. It's a red herring. Plenty of people think that their backlash is really bad because they have a clunk. I suppose it is possible, but it has not been the culprit in any case that I've ever seen.

Just a suggestion, but if I were spending that kind of money I'd try Coffey's new OS Giken clutch LSD unit. As to the Quaife, Modern Motorsports handles the R200 so I'm betting they can get the R180 version even though it isn't listed on their site.