JMortensen

If John was running carbs, then the float bowls act like little surge tanks. There is no fuel reservoir on the FI setup, so they are more particular about running low and if they suck air air gets into the system. In the carbs the air just goes out the float bowl vents and it's like nothing even happened so long as the fuel pump can refill the bowls before they run dry.

You need to learn how to heel toe if you're leaving a black stripe when you downshift, and that has nothing to do with how strong the pressure plate is. The best test for a pressure plate is to go about as slow as you would want to go in 4th gear, preferrably uphill. Then push in the clutch, rev up the engine and drop the clutch. If the clutch is weak it will slip. If it isn't it will instantly pull down the engine rpms. The Daikin is just called the "Heavy Duty" and it requires a 240mm flywheel.

Have you looked under your Z? It has IRS. The Z's all have IRS. So that's not likely to be a prominently mentioned item in the search function. You'll get a lot more from "diff swap" or "r180" or "r200" or "r230". "Straight axle" would hit big, because that would be different than what is in the car now.

Allright I think I figured out where I was wrong. The pistons and rods can pivot over to allow for the engine block to twist around the crankshaft. So I conceed that point. The engine block should be free to pivot even if the diff is locked down. Still if you run the solid front diff mount and rubber or poly in the back you're asking the narrow front diff mount to handle the lifting and the torque that goes to the diff. So it looks as though solid mounting both the front and the rear of the diff is the answer to making it stronger.

I never had any of the hole size problems, my trap doors worked very smoothly, and I don't run ARP studs, but I can vouch for the fact that you'll definitely need a 280 pickup.

Could be an alignment issue too.

Thanks a lot, BRO!!! For the record, red and silver are the only two colors it has been.

On the contrary, I'd say your motor mounts should last longer with the diff solidly mounted. Lets assume that you have a manual trans. The crank is then locked solid to the trans via the clutch, and the trans output shaft is slip yoked to the driveshaft, which is bolted to the diff. The U-joints in the driveshaft might allow the engine to move side to side, but they won't allow the engine to twist, because their function is to not allow loss in a twisting motion. So the engine might still move side to side or up and down, but it will not be able to twist, because when it tries to that torque will travel down the crank to the tranny to the driveshaft to the diff, where it hits something solid and transfers into the crossmember and into the unibody of the car. I still agree with 2126 that the torque does go through the engine, trans, and driveshaft as he says, but the question is where does it END UP? It ends up getting held tightly by the diff crossmember. So the torque either goes through to the wheels, or it starts to tear up the weakest link in the chain, which is the diff mount. Shore that up by rigidly mounting the mustache bar and now it is the driveshaft. Another way of saying it is if you could have the engine in the engine compartment with no motor mounts, the car wouldn't drive, but instead the engine would just spin (in theory). You need to control the torque of the drivetrain before it can transfer its torque to the wheels. The first thing that CAN control the torque WILL control the torque. In our example of the solid front diff mount with soft mounts everywhere else, the first thing that can control the torque is the front diff mount, because it is the only part of the system that is rigidly mounted. And the reason they get tore up is not just because of the lifting of the nose of the diff, but also because it is now controlling the torque of the whole drivetrain. In Cary's case it's a little different. He had everything rigidly mounted and still pulled the washer through the crossmember. Clearly his was isolated from the torque and failed just from the lifting, but the torque AND lifting is really going to do a number on the crossmember. I don't know how to explain myself any better, but I am pretty confident that this is what is happening.

Forget about straps. There are much better much easier ways: http://forums.hybridz.org/showthread.php?t=95128 http://www.classiczcars.com/forums/showthread.php?t=17417

Excellent point John. That single mount in the center isn't capable of handling anywhere near the same torque that the mustache bar can with it's 2' wide span and solid connection to the frame on either side.

Not sure I'm reading this right, but what happens when you have rubber or poly mounts on the drivetrain is that the engine torques, the transmission moves, the differential moves. If you eliminate the possibility of one component to move, the others still will want to, and all of that torque gets focused on the one piece that can no longer move. I think we're agreeing... Think about what you're saying. You're saying that a U-joint should absorb a twisting motion. That's exactly what they should not do. They should transfer ALL twisting motion. If that's not the case, your U-joints need replacing.

My theory on this is that this happened because the mustache bar was still rubber or poly mounted. However, even if the mustache bar was mounted in aluminum, if the engine/tranny are soft mounted you're still going to have problems. If you mount the diff solid (both mounts) and the engine/tranny on rubber the engine is still going to want to twist over when you put torque to it, but it can't because when it trys the torque goes down the engine and trans through the driveshaft and into the diff mounts. So basically you're using the diff mount to keep the engine from rocking over under power. Had this conversation on another forum, a guy had this problem and I said next time you go out you're going to bust the driveshaft. Guess what happened? Either rigidly mount the whole thing or soft mount it all. I disagree with Mikelly that this kind of stress will still occur with a poly mount, because the problem is rigidly mounting just one component of the drivetrain, then expecting that one component to control the torque of the whole drivetrain. My $.02

I ran the stock pump for years on my L28 with SU's, but finally I had issues with vapor lock at the track once when it was 105 degrees. At the end of a long straight it would just start sputtering, ended up having to short shift. Pulled in at the end of the session and popped the hood, and it would run for a minute then slow down and finally die. Wait an hour or so till the next session and it would fire right up again and run bitchin until about 2/3 of the way through the session. At the time I figured the heat was getting into the fuel through the fuel pump and the fuel rail. Touch either when the car's hot and you'll see what I mean. I took them both out, ran an electric Carter pump in the rear and a rubber fuel line across the rad support and then dead headed the SU's straight off the rubber line. Never had a problem again. Switched to triples, again no problem. Built the higher compression more hp motor, again no problem. I don't like the stock pump not because it won't flow enough fuel, but because of the heat it puts into the fuel. But that's just my take on it.

I haven't run the puck disk. I always went the other way and ran a heavier pp and a stock disk. But if the Nissan Comp disk is a 4 puck with no springs, you should be able to call those places and ask for that and they'll just throw one in a box and send it to you. I don't think they're hard to come by. The one thing I would say is that I would avoid the sprung puck style clutch. I've seen enough of the regular disks throw a spring, or you pull it out and the springs are totally loose floating in the disk. You're just asking to lose a spring on a grabby puck clutch IMHO.

Yep. That's what most of my friends have done on their 510s. A couple of them even have 240 springs and hats. Cut the bottom perch off of a 240 strut and welded it onto the ZX strut. then the 240 spring goes on with the 240 top hat. The 240 stuff is like 1/2 the diameter of the 280ZX suspension, so then you can slot the crap out of the tower and adjust camber quite a bit. It's like a cheapo sectioned strut (ZX struts are shorter)/camber plate/big brake/kinda halfassed coilover - adjust the spring perch till you get the ride height you want sort of mod. The ZX brakes really stop a 510 pretty damn good. Then throw some 79-81 ZX rear disks on, I don't know what's involved for that but not much, slot the rear crossmember and flip the washers, Subaru LSD and you've got something...

The Nissan Comp clutch disk is a 4 puck, non-sprung clutch disk. You should be able to get a similar disk from somewhere else. I believe Spec has one, as well as 10,000 rpm. If not a non-sprung 6 puck will probably work just as well. Reuse your old throwout bearing sleeve (it's the part that the bearing fits onto). Stock throwout bearing is fine.

I suggest you read all you can about those parts before you buy them. Spend hours searching. You'll be laying out a lot of cash...

That one looked like it was drawn on the pancake. I think somebody here even suggested using a soldering iron to create a $30,000 pancake. It looks to me like someone has that idea and is running with it.

Right because horrible + horrible = less horrible. Wait a minute...

Don't want to jack this thread but I'd love to see those pics. I've been a firm opponent to the solid front diff mount for a long time. Heard stories of the diff mount cracking and tearing, never seen pictures. Make another post in the drivetrain forum... As to the steering coupler, I have the delrin one and vibration isn't a problem at all. This does look to be an improvement over the usual setup. Kinda like Ross's CV adapter and how it recesses the companion flange into the adapter.

The LSD doesn't determine the gear ratio. There should be a stamp on the ring gear that says the number of teeth on the ring and the number on the pinion. The number is about 10 characters long IIRC, but its the part with the colon that is the important bit. My 4.11 says 37:9. Divide 37 by 9, 4.1111111 is the result. 37:10 is a 3.70, 37:11 is a 3.36. 39/11 is 3.54, etc.

Take the tar off. You'll see how small that section is. If you wanted to weld in a little square there, you could weld in a flanged section. But you'll find that the square is probably only an inch larger than the visible portion that you see there. At least that's the way it was on my car. Definitely do try to poke holes in it. I did on mine, and I couldn't poke any more holes in it, and I only have 2 tiny pinholes in there. If you punch a 4" square hole in your floor, then obviously you'll have to take care of it another way. But if it's similar to mine, other than the worrying thought that there is a square section of pockmarked floor under the carpet I just don't see the problem. I'm just judging by your sig, but it doesn't look like you're going for that concourse build to me.

Why is NASCAR still using carbs and pushrods? IIRC only Chevy still uses pushrods, and none of them use carbs anymore. The answer is because everybody has been doing it for the last 50 years and they all know exactly how to make the carbs do what they want. It's kinda hard to change the formula like that on everybody, they have lots of cash invested in these classes as they are written. There ARE fuel injection classes for drag racing, but the big money goes to the fastest classes. I suppose you could ask them if they thought the FI was more consistent...

Now that is just plain crazy. The mid 70's FI the L28 has is really really bad, and I believe by some accounts you can gain hp by going to SU's. Go to something like triples and you can make a HECK of a lot more power. I'll take the funky cold starts anyday vs losing huge amounts of hp on an engine that doesn't make much to begin with. If I had an LS1 I might think otherwise. If you were comparing an aftermarket EFI to carbs I'd think otherwise, but that stock Datsun FI just sucks. Really sucks.

I saw a Eclipse GSX bust a rear CV joint at an autox once. He sat on the line revving it to 6K, dropped the clutch, the rear suspension bottomed and BOOM, there went the CV. After he got stiffer springs, he still launched that way but I never saw him break a CV again...