JMortensen

I don't think anyone would hold it against you that you can't share your results, but obviously the whole idea becomes more attractive to the rest of us if we can benefit. I wouldn't be interested at all in a subjective "this works and this doesn't" sort of analysis. I'd rather have the numbers for the things that you all can share numbers for.

Is anyone testing a flat bottom? I have a couple ideas for that...

One benefit of carrier bearing preload is that it prevents the ring gear from torquing away from the pinion. IMO our R200s don't have enough. Most diffs require that you beat the carrier into the housing with a dead blow hammer. My R200 carrier just fell into the housing. That said, I didn't mess with it because problems with the gears are so rare, but it is different than most others. The best way to test pinion bearing preload is with the carrier out. A new seal will dramatically increase pinion bearing preload, and IIRC the FSM even has a spec for with a seal and without a seal. Checking it with the LSD installed means that you're adding in a whole bunch of other stuff, gear friction etc, so I'd test pinion preload by itself and I wouldn't bother testing it at all with the carrier installed. I would try and get it shimmed back closer to what it was previously. If you have the diff at .008 and ran it that way for 100K miles, then you move it to .005, you might find that you get a gear whine out of it, because they're now wearing in a different spot. FWIW, the few that I've done were all .005 or thereabouts.

The hatch does have a bow to it. Have you held it up to a hatch to see if it is a problem?

On my arms I recall that what I did was to compress the suspension and check the position of the strut shaft in the camber plate hole. If it was forward, then I shimmed it back, etc. I was using 12mm strut shafts and 5/8" monoballs, so you could see if it was shifted forward or back.

FYI, if you compress the suspension with no spring in it, you can see where the shim really needs to be. It's not going to be as misaligned at full droop, but it gets worse as the suspension compresses, so checking it on the bumpstop is probably the way to go. I used bumpsteer spacers from a circle track kit to figure it out on my first attempt at adjustable control arms. I'm guessing TTT is sending out something similar.

Is your point that you can test airflow with a shop fan in your garage, or that those vents work, or that it would work as well as an open vent, or that the area behind the wheel isn't a turbulent low pressure area of the car? We can prove that it is a turbulent low pressure area by using the photos from the last test. Since we know what the flow looks like there, we can make some assumptions about what kind of vent to put there. FWIW, I wouldn't put a NACA there either. http://i51.photobucket.com/albums/f380/rontyler/WindTunnel/PICT0288.jpg http://i51.photobucket.com/albums/f380/rontyler/WindTunnel/PICT0570.jpg http://i51.photobucket.com/albums/f380/rontyler/WindTunnel/27HoodVentsUntaped.jpg This spot needs a big open hole to let the air out. Here is a good example: http://www.google.com/imgres?imgurl=http://upload.wikimedia.org/wikipedia/commons/a/a8/Pikes_Peak_Toyota_Takoma_709762748.jpg&imgrefurl=http://commons.wikimedia.org/wiki/File:Pikes_Peak_Toyota_Takoma_709762748.jpg&h=1200&w=1932&sz=343&tbnid=5wb2fz0ZQklvKM:&tbnh=90&tbnw=145&zoom=1&usg=__G27RsXV_8DRVjXfk6LAgf6JvHVM=&docid=-C1StHtprmh-mM&sa=X&ei=vK6iUb_lG4PUiwLYpIDACA&ved=0CDMQ9QEwAQ&dur=356

Mike C has mentioned GM 12 bolt before. There are 12 bolt car and 12 bolt truck diffs, but I'm not sure that he ever specified which one (might be the same, can't remember). If you go down to your local gear shop the probably have a wall full of shims and you can just look and see what is closest. I would think that the 44 shims would work fine.

Shortnose. I think the issue as Jessie states is that you get some leverage on the mount for the shortnose diffs. I think the answer is a bolt in cradle above the diff. If anyone local wants to take up that challenge (or do any other diff mount figuring), I still have the diff section of a 280Z tub that I cut out of a parts car. You can have it free of charge.

What diff was Clive running? The other option is welding the mount in.

Those vents are meant to be used in smooth airflow. You'd do better taking them off, as they essentially cover 90% of the hole, which is positioned in a low pressure turbulent flow area, as you can see in the 27th test of the last wind tunnel outing.

I thought you weren't going to make the results public because of Matt's race agreement. Does that just apply to his car?

They did a test of this airdam on splitter idea a couple months ago in RCE. Unfortunately the air dam was still pretty high off the ground, so IMO it functioned to spoil the air going under the car more than to create a low pressure area. I still think this could work, particularly at low speeds.

The clutches are slipping and then grabbing again. It's just stiction.

It shock loads the CVs and stubs, but you've got everything upgraded, so I don't think it's likely to harm anything. I know guys who didn't run friction modifier in their rock crawlers because they wanted their LSD to be more aggressive. Just put in another tube and your problem will be solved.

Every LSD is a compromise; the Torsen/Quaife/helical options sacrifice too much grip for comfort for my liking. A nicer CLSD would have friction material on the clutch disks and not have as much chatter. The popping noise happens when the clutch pack slips and the clutches slide past each other and then grab again. Add more friction modifier or reduce preload or both. I think overcoming the little bit of chatter you have there will not be difficult.

Get something shorter and put a spacer underneath.

They did change the model name in the US in 2006. It was Miata before in the states and MX-5 everywhere else. Now it is MX-5 everywhere. Look at an NC and you won't see "Miata" on it anywhere. It's just an easier way to differentiate for people who aren't familiar with NA, NB, and NC.

I bought a 99 Miata (10th Anniversary model) last year, and I love the way it handles, but it badly needs more balls and I don't want to get into serious mods on it until the Z is done. Aside from minivans blowing my doors off on freeway onramps (no joke) it is without a doubt the funnest car I've ever driven. The factory Bilstein suspension leaves a lot to be desired in terms of ride, but when you turn the wheel the thing just turns in, which is something you really have to fight a Z to get it to do. I've driven an MX-5 and it had a LOT more power, although nothing like my triple carbed Z had, but didn't turn in quite as well as my 99. Don't know what tires he was on though, and I've got the super sticky 195/50/15 Toyo R1R's. Sending the shocks back to Bilstein pretty soon and I'm hoping I'll have better handling and ride with a lower ride height and be able to dial in some more neg camber when I get them back. I had to cut some foam out of the seat, Miata guys call this a foamectomy, in order to be able to put my helmet on under the soft top. It would be a lot nicer car to drive with seats that are 2-3 inches lower. I'm 6' 185, BTW. Left knee can't fit between the steering wheel and the door panel either. It's cramped.

Sounds about right. I've boiled fluid on the track more a few times. Brake once OK, brake again OK, next time might be a little squishy, next time no pedal whatsoever and you go shooting off the track at 90 mph.

There have been many different attempts to improve this area of the car. Most involve braces from the bottom of the upright to the mustache bar or frame. I've never seen another car with so flimsy a setup, and I'm not so sure that I buy into the idea of building in weakness so that it bends there instead of somewhere else. Compliance there is going to result in toe out on the outside wheel under load. I reinforced it a bit and made a toe adjuster for the back. bjhines did similar. Terry Oxandale made a large aluminum plate to mount the diff and then incorporated the toe adjust mechanism into his as well. Search and you'll find various solutions.

If you get some of the super racy street tires, Toyo R1R, Hankook RS3, BFG Rival, etc, their 225s are ridiculously wide. I was at an autox the other day and there was a guy with a common set of Miata wheels and the Toyos. I said: "Those must be the 8" wide rims, because they fit the 225s perfectly, he said they were 9" rims and that he compared the Toyos to a regular old 225 and it was about an inch and a half wider. Did you section the strut housing to fit the insert? If so, that is your problem. Saw a 240 last season autox and the guy was spinning all over the place. He had sectioned the strut to fit the insert instead of using a spacer, and then jacked up the preload to try and fix. It still looked like it was dragging its ass, but it wouldn't remain pointed in the right direction for more than a turn or two.

I don't believe you will ever get "good" bias out of that setup. Maybe if you put more aggressive pads in the back. I had the same setup, Toyota in the front and early 280ZX rear disk, and I couldn't get it even close no matter what I did with the prop valve.

If you're searching, you won't find a lot on "calibers" because it's the wrong word. "Caliper" is what you want.

Bubble flares =/= inverted flares.