Zmanco

Update: I went with the ATP studs and distorted thread nuts and so far they have remained tight holding the turbo to the exhaust manifold. However, after the last track day one of the bolts holding the waste gate housing to the turbine fell out (again!), and another was loose. I think it's time to add a flex pipe and my muffler guy has one ready to install. My question is: where should we put it? FYI, the down pipe is all one piece and a few inches after it levels off we installed a 3 bolt flange. From there the exhaust runs to the rear of the car. It's supported in 2 places: at the rear of muffler in the stock location, and just in front of the rear axle in the other stock location. I figure it either needs to go in the middle of the down pipe, or after the flange under the car. Also, any recommendations on length? He has a 4" and 6" available. I'd prefer shorter, but not sure if that will have enough flex when the exhaust expands as it gets hot.

Match the drivetrain to the cam. For example, 300 WHP isn't hard with a moderate cam that makes lots of torque from 3k - 6500 (torque peak in the 4.5-5k range). Match that with a NA 81-83 280zx transmission with a 3.9 or 4.11 diff and once you're above 25 mph there will always be a gear where the rpm will be >3k. Just don't be afraid to rev the motor and use the shifter

If your issue is that the L28 intake manifold's throttle linkage doesn't reach the "holder" on the firewall, I solved this by using longer bolts and a bunch of 1" flat washers to move it about another inch closer. I've run like that for a few years now. It's not the cleanest or prettiest, but it's functional. An alternative would be to go with a cable linkage. Some options for you to consider...

Keep in mind that the appropriate size for the cold air intake and the intercooler piping will be different. For a typical ~300 whp L28, you probably don't want to go any smaller than 3" diameter for the intake. For the intercooler piping, at that power level 2.0 - 2.5" is about right depending on who you listen to. Based on the guidelines in Maximum Boost, I went with 2.25" as it was easier to fit and should easily support 300+ whp with little pressure drop.

There's a fine line between brave and stupid... Did he even have a helmet on? Doesn't look like it in the picture. But I'll bet he got some amazing footage.

Turn the air pressure regulator on the compressor down to the wastegate opening pressure + 5 psi and then test it. I wouldn't put all 100+ psi of pressure directly onto the WG - that would probably damage it.

Ah, I didn't enlarge the picture, saw the rectangular air cleaners, and just assumed they were DGVs. Still, what is the benefit of going this route vs. getting the SUs set up properly? Unless the throttle shafts are leaking, it's very simple to rebuild SUs.

What are your plans that cause you to think the SUs will not be adequate? One of our local Z guys has a Rebello 3.1 stroker running with SUs, albeit enlarged by Rebello. The point is that the SUs are more than adequate for street L engines, or can be enlarged. They aren't harder to tune than any other carb once you learn how and there are numerous posts that take you through it step by step. You can also get the Z Therapy video if you prefer to learn by watching instead of reading. The Weber DGVs in the previous post are fine, but are not an improvement over the SUs from a performance point of view. Some will argue that the since they are downdraft, the extra bend required in airflow will only make them breath more poorly than SUs on an L engine. My own experience with them is that once set up properly, they were equivalent to SUs. They were not easier nor harder to tune, just different.

An inch off?!!!! That's an awful lot. I was imagining maybe 1/8" or less. Something else is wrong.

If the block wasn't wide enough then it might not have pressed the tensioner all the way in, and hence there isn't enough slack in the chain. It should have been a tight fit pressing the block in. FWIW, with my old high mileage engine I never had any problems, but on my new one with essentially a new chain, guides and gears, I had to make a new wider block and it was pretty tough to push in. Even then, it was still difficult to fit the cam gear onto the dowel. You might try using a large screwdriver in place of the cam bolt to try to apply some leverage to pull the cam gear up. Obviously you don't want to get carried away and damage the threads. I used a large philips head as it had a round shaft without any edges. Other than that, I'm afraid I can't add anything further. Perhaps someone else has some suggestions?

Did you put a spacer between the chain inside the timing cover to keep the tensioner from popping out before you took the cam gear off? If not, plan on removing the timing cover - not fun, I know. FWIW, some say they have been able to get the tensioner to go back in without removing the cover.

That's what happened once to me and caused the speedo to appear to be "dead". Seems like a reasonable way to test if there's a problem with the cable and speedo.

This has been discussed a few times here, but in brief that's correct. The rest of the story is that some 73s were built with the rear brackets installed without a bar. Mine was built 2/73 this way so I was able to mount a 74 bar using those brackets. I had MSA put together a custom kit with a 73 front bar and 74 rear bar and appropriate bushings. I just had to source the cover piece for the bracket which I found on ebay. There may be an advantage to NOT using the factory brackets if you plan to lower your car more than 1" as the MSA rear bar can hit the undercarriage and limit suspension compression. I haven't had that issue, but others have.

With the engine at TDC and the dizzy pointing to #1, pull the valve cover and make sure that both the cam lobes for #1 are pointing up and not depressing the valves. The most common problem is to mount the dizzy 180 degrees off. Just making sure that it points to #1 when the damper shows TDC won't catch this and you'll never get it started.

MSA has a 1" front 7/8" rear setup for the 240. I run those with Tokico springs on my 73 and it's a nice safe setup for the street, but with stock suspension settings there's too much understeer for the track. I added the TTT adjustable front LCA and TC rods to the front and finally got rid of the understeer, but as the saying goes, be careful what you ask for, you just might get it. It's a good idea to decide on what your goals are for the car as that should influence your choice here. If I was to do it again, I'd go with stiffer springs (~200 lbs/in vs. 140/160) and probably a slightly smaller set of bars.

I'm just speculating here ... I'd start with verifying that the cable is still in one piece. In other words, that when it turns at the transmission end, it also turns at speedo. Also, make sure that the cable itself is fitting properly into the speedo gear at the transmission. One time the end of the cable on my car was pushed so far into the cable housing that it didn't engage the gear. I just pulled it out half an inch and was careful to insert it gently and the problem was solved. Again, when you pull the cable off at the transmission, I expect this will make more sense. After that, I don't have any more experience with it - but it's a pretty simple system so shouldn't be too hard to figure out where it has failed.

The speedo gear is mounted in a cylindrical piece that has an O ring to seal it in the transmission hole. There's also a small O ring on the speedo gear shaft IIRC. I don't have any pictures unfortunately but if you look at the transmission you'll see what I'm describing. I'd check both of those to start. I think MSA has replacements if you need them.

You might try searching for just TO4 turbo. I found the one I mentioned here in the for sale forum, but it needs a rebuild .... Good luck!

Wow, I think you are going to have a really tough time with your car if you can't answer that by just looking at it. Sorry if that hurts your feelings, but if you play around with the throttle for a few moments it will be obvious that it is adjustable, and you'll see where the adjusting screw is located. BTW, I tried in my first response to give you a gentle hint that you should give us a more complete description of what you have and what's going on since none of us are mind readers. This is another example where we're having to pull important information out of you. And just so we know what's going on, what were the results of checking the engine timing against MS? Were they off, and by how much? One last thing: I'm assuming the PO set this all up before you bought the car. You might want to check the idle with the main electrical accessories on before you change it. Headlights, cabin fan, engine efan (if it has one) all on at the same time could drop the idle 100-200 rpm or maybe more.

Is this the boost control valve you're using? What's controlling it? I didn't think MSnS could manage BC. That might be the source of the boost fluctuations you saw, at least i wouldn't rule it out without checking further. I thought I saw a T04E for sale either here or on ebay last week - might be worth checking out, although buying another used turbo might not be such a good idea if you don't know the seller. I feel your pain and frustration - hopefully with a little time it will lose its edge.

What your goals for this car? AC can be added to an early Z for about $1300, not cheap, but a fraction of what you'll spend fixing rust if you buy the wrong car. Grungedude42 is pointing you in the right direction: the condition of the chassis and the maintenance history should matter a lot more than the presence of AC. Plus, there are a lot of tradeoffs between 240s and 280s in terms of weight, chassis stiffness, etc. It's not that either is better, but you should spend some time here searching as this has been discussed before. Of course, if you're just buying it to drive as-is for a while and then flip it, then it sounds like you've already decided that AC is the deciding factor. Otherwise, assuming they are both clean of rust (which is unlikely at those price points), I'd vote for the turbo 240. For me, fun-to-drive would trump comfort.

While I haven't experienced this with an electronic distributor, I don't see why a weak spark wouldn't still allow the engine to free rev and yet wouldn't be strong enough for proper ignition of the air/fuel under load. So I don't think you can rule out the ignition. If I've got a good picture of the ignition system, the only thing you haven't changed is the distributor. Do you have access to mechanical points version? You might swap over to it as I'm guessing you're only concerned with the car running for the weekend so the benefits of electronic ignition (better cold starting etc) don't really matter. Don't forget to add the ballast resistor back in, or at least never leave the ignition on when it's not running. The only other thing I can think of is to make sure you have the proper insulator between the mechanical fuel pump and the head as that transfers a lot of heat to the pump and hence the fuel. But the fact that you ran it without a hood and still had the problem makes me doubtful it's a fuel temp issue.

You didn't say which version of MS Extra you are running ... If you don't already have it, add ignition advance to the megatune screen so you can see what MS thinks the advance is, and then measure it with a timing light. If they're not the same, then find the screen in megatune where you can adjust the crank angle/offset so what MS and your timing light are in agreement. It shouldn't matter if it's idling or 3k - it's important that what's set in MS is the same as what you measure with the engine running. If it's more than a few degrees off, then you may have to move the distributor to get them close and then fine tune in MS. But since you say it has good power with 18 at idle and you're not saying anything about detonation, it sounds like you should be pretty close. Assuming you have the timing correct, I have to ask the obvious question why you don't just adjust the idle speed?

Double check that the inlet needle/seat combo in the kit matches what you're taking off the carbs. When I rebuilt mine I didn't notice that those in the kit were smaller and it took me a long time to figure out why I had a WOT high rpm miss ...

You just told us what the timing spec is so you're obviously concerned that it's no longer set correctly. Why not measure it and let us know? It would be a lot easier to help if we knew that instead of having to speculate. Also, let us know how spark is being controlled. You mentioned MS - Which version of MS are you running and is it managing spark+fuel or just fuel only? FYI, significantly advanced timing can increase idle speed. So can a vacuum leak ... Being more clear on your end will make it easier for us to help.