JMortensen

Not a problem. The driveshaft is fine. I believe the stubs that go into the sides of the diff (the part that the halfshaft bolts to) are different between the 180 and 200. So you need the stubs from the 200 The halfshafts should be OK. Strut bearings??? Now you're talking about rear wheel bearings, but those shouldn't have anything to do with the diff swap. You should have the stronger stub axles, due to the fact that this is a 280. The wheel bearings are kind of a PITA, so search and find some threads about grinding away the peened nut on the inside of the stub axle before you dive in.

I've done that many times with an iron block NA L6... Suppose it depends on what type of racing you're talking about though. It would be a lot harder to do in a drag race than autoxing or time trialing.

That list is written to include EVERYTHING a person could possibly need. If someone were to buy an R200 out of a Z31, they would need everything on the list. If they bought the diff out of a 280Z, it already has most of that stuff on it. 1.Yes, you need the mustache bar. 2.The yoke is the part of the differential that the driveshaft connects to. So if you bought a 77 R200, it would have the correct yoke on it already. For those who are installing the 300ZX diffs, they need to find a yoke from an earlier R200 and put it on their diff. 3. The rear cover from the 77 will work. 4. The stub shafts I think need to come from the R200, I think the R180 has smaller stubs with less splines. I haven't verified that personally, but I'm pretty sure. Diff mount needs to be flipped around and the crossmember and rear transverse link will work fine.

I think it's just a bad bit of casting, don't think it will hurt anything if removed now. If left in it could break off and that wouldn't be a good thing.

The purpose of the tubes from the hoop to the strut towers is to provide another load path for the door bars in case of a side impact. I guess I'm not following the second part. Can you draw it for me? EDIT--Just clicked, don't need the picture. The curved plate part had me confused because I was thinking you meant on top of the tunnel. Yeah, I suppose I could do that. I'd have to cut more holes in the rear deck, and they might be going straight through that thicker plate there. I'll have to work it all out and see where everything ends up. Thanks for the idea.

No, you convinced me to do a full cage. The original plan was to do a bar, but now I'm going for broke.

I've been pretty well set on doing Cary's X design for a long time. He and I have discussed it at some length via email, and he's done some modelling of various different designs and found that it really made a big difference in the stiffness of his models. With the spring rates and tires I intend on running I think it's going to be worthwhile. I figure for ~10' of tubing at about 1.1 lb per foot for this thin walled tubing, it's going to be worth it. I didn't really feel like I was doing the right thing on this control arm stuff, which is why I wanted to get more opinions from everyone. But I do feel my latest idea comes with an absolute minimum of weight added and should keep the control arm mounts from tearing out. I'm looking at doing a pretty thorough cage, and at this point my goal is not to leave any stone unturned. I'd rather overdo it now that the thing is on a rotisserie than underdo it and have to tear it all apart again.

Think I have it. The tunnel is already reinforced in this area, so I think this will work. Weld the plates in on the floor to strengthen the mounting to the chassis as originally intended. Run a small 1x1x.063 square tube gusset from the floor to the side of the tunnel. Do the X as I had previously intended. Also added in the shoulder bar in blue just to clarify the plan there.

Not trying to rain on your parade, but there are several issues with an aluminum block L series (or a DOHC head--the other mythical L series mod that is always just about to be figured out): 1. Cost 2. Illegal in just about every racing class except the "open" classes 3. If you're going to be make the car illegal for a given class and run "open", you can make a hell of a lot more power with a whole different engine, and the cost is MUCH lower, eg V8 swap. I'd be curious to know what you think this aluminum block will cost, what it will weigh, and how much benefit could really be obtained by using it. Then compare that to say a LS2 swap with a brand new engine and transmission. Compare weight, power, cost, etc. It'd be interesting to see where that would end up...

From http://forums.hybridz.org/showthread.php?p=708798#post708798

Russell, the yarn test has been done. The air goes INTO the engine compartment. The base of the windshield is a high pressure area. The base of a spoiler that you put on the hatch is a similarly high pressure area. There are a bunch of other aerodynamic threads on this site where these topics have been covered pretty thoroughly. OTM's yarn test with the chase vehicle has been tried as well. Let's not let this one get too argumentative or redundant. What is interesting about this thread is the drag information. If you want to talk about downforce or upforce or vented hoods or spoilers or any of that, try one of the other threads.

Thanks for those Justin. There will definitely be a shoulder bar across at the kink. I have been waiting to get a tubing bender for that one. I need the bender because the brace behind the driver's seat needs to bend back to allow the seat to slide all the way back. I just had a tubing bender delivered, but they sent the wrong one. The second picture with the straight bar all the way across the bottom is a good idea, and I had that option when I put the control arms together, but opted against it just because I didn't want to have to try and remove the original frame rails and then have to build another front diff mount. It might have been the "best" answer, but I just didn't want to have to hassle with it. The bar from the top of the hoop to the back corner is something that I've seen in older racecars and on some Japanese cars, but it's purpose is the same as the diagonal bar in the main hoop, mainly to keep the hoop from folding in the event of a rollover. So that one is a bit redundant. The ^ from the shoulder bar down to the control arm mounts is a possibility.

Yes, you need a new yoke from a 280Z or 280ZX with an R200. It is a simple part to change if you have an impact gun. Take the old one off, put some red loctite on the nut and put the new one on. The torque spec is ~150 ft/lbs, so I usually just put my gun on 5 and lay into it. The R200 does not use a crush sleeve so overtightening the nut is practically impossible.

It totally depends on the rest of the engine. Triples work best with a much larger than stock cam, and that works best with high compression. I figure I gained about 40 whp by putting them on in place of SU's. I think Dan Baldwin had similar results verified by the dyno. Just slapping big carbs on with a stock cam isn't going to get as big an increase, and you also have to figure that they need to be tuned to be optimized. Tuning them isn't really that hard on Mikunis, harder with Webers, but you'll find a lot of people chase their tail trying to get them running right. Tuning is somewhat expensive because of the cost of the jets as well, so factor that into the cost of upgrading.

I don't suppose there is a reason why that BRE idea couldn't be done this way...

You can also do an external surge tank. Several people have gone that route. Tim240z had a pretty good post on his a couple years back if you search you'll find it. Basically works just like you said, doesn't need to be big, and just uses a carb type fuel pump to fill the surge tank with a fill and return nozzle at the top and the fuel feed to the engine at the bottom. Oops, I see now that you had already considered an external tank... Why do you think it's going to take up a lot of space??? 12 oz of fuel in the surge tank should be MORE than enough. The surge tank on carburetors is the float bowl, so it really doesn't have to be a large container at all.

Well I suppose just in terms of mounting everything in a stronger way just welding the plate to the floor and plug welding to the bottom would make the control arm mounts less likely to tear out. Maybe I should just do that and then concentrate on the X...

Let's have fun laughing at the idiot and not get political, alright?

You can see from this picture where the strong part of the frame rail ends: I suppose I could run a small piece of tube or a gusset from the SFC to the bearing holder area here. I don't think I'd physically have enough room to weld it in all the way around.

The area of stronger, reinforced metal where the bearing holders are attached to my early Z car is actually very small. It only extends maybe 1" on each side beyond the area where I've welded in the bearing holders on the bottom, and then it also attaches to the reinforced area in the trans tunnel as well. To the sides of the bearing holders the frame rail changes, and goes from .108" thick to .035" thick (guessing on the thinner stuff, but it is sheet metal thin). This small area of the chassis isn't only subjected to side loads, it also handles all of the upwards torque from the nose of the diff as it tries to lift. I have an alternate diff mount, but it still puts that torque into the chassis through the diff crossmember, and that means directly through the bearing holders. I suppose I could have done the Ron Tyler diff mount, but I've already put a lot of time/effort into the one I made previously, and don't just want to switch it out now. The point is, there really is a lot of upwards stress on the chassis right there. What I'm really worried about though is the fact that with NO rubber in the suspension there will be NO damping of any shock loads going into the chassis. That's why I'd like to make this area as stronger. I've already redesigned the uprights in the back to make them stronger, and the footprint of the uprights is probably 300% larger than the original design, so I'm hoping that will keep things intact in the back. I would like to do something to prevent damage in the front here as well. If the supports from the main hoop were straight up and down, that would mean that they would not be terribly good at dealing with side loads. They're not, though, and by coming in at a 45 or so degree angle they should be able to handle some side loading with too much trouble. For these braces I'm going to use 1.625 x .065 tube, which is about 1.1 lb/ft. So while I will be adding weight, and I'm trying to figure out the most efficient use of that weight, it won't be as bad as the main cage structure which is 2 lbs/ft. Lastly, I do think there is some value to adding more support back here. I'm going to be running some extremely heavy spring rates, taking a cue from those wackos down in Oregon... They seem to be having really good luck with spring rates over 500 in/lbs, so I'm expecting that I'll probably start out somewhere in that range. Not to mention I'll be on very wide slicks. If I use the previous slicks I was using, they're basically 10" wide, but I may go wider than that. I haven't decided yet. All of this translates into some pretty severe loading of the chassis, and that's why I'm looking to do all of this seemingly unnecessary support structure in the back. I'm not averse at looking to the bottom of the chassis to see what bracing can be done there as well. In fact I'll probably run out there and take a couple shots just to get an idea of how I could brace to the SFCs on bottom as well. I had already planned on welding gussets in the corners of the frame rails, and between the frame and rockers as well.

I think a lot of people run out and buy a "high performance" clutch to go with their basically stock engine. This isn't really a good idea, since it just makes the car harder to drive, and doesn't really give you any benefit at all. I'd guess that was the case with 2ManyZs. If you can't tell the difference, then you don't need anything more than an OEM replacement. That's not all that surprising considering your own usage. A really potent ITS engine puts out what 200 flywheel hp? We're talking about engines putting down over 200 whp and the situation does change at some point. I had a little bit of slippage shifting into higher gears at WOT, but not bad, when I was running my engine with SU's (estimated 200whp). When I switched to triples the clutch just would not hold the power down. It wouldn't hook up when you left the line and it wouldn't grab when shifting into the higher gears. 3rd to 4th shift at WOT had the clutch slipping for 4 or 5 seconds before it would finally grab. I think if I were building an ITS race car that never saw the street I'd be inclined towards a stock pp and a puck clutch. Should be no slippage and it doesn't need to be street friendly. Plus the pp isn't strong enough to tear the fork apart like some of the aftermarket pps. In general I think the Centerforce clutches don't have a very good rep for L series engines, and that is the only one that I would really go out of my way to avoid. That's kinda weird, because everyone I know with an American car swears by them.

Ground Control sells them, I think I paid something like $10 for a pair. I'd guess that most other places that sell camber plates would have them too. I'd just ask for a bushing for a MR2 that you're installing plates on.