Zmanco

I'm looking to purchase an OBX LSD for an R200 from http://www.racingpartdepot.com. However, they have 5 separate listings for R200 LSDs each with a different part number. Sadly, none of those match up with the one that was discussed in the FAQ sticky which is LSD10528. I've emailed them for clarification but so far haven't heard back. The 5 part numbers on RPD's website are OBX465 OBX3642 OBX1873 OBX2590 OBX1496 There's another seller on eBay offering part number LSDAJE28. Can anyone who has purchased one recently share which one they bought? FYI, I'm planning to use the stock 280Z stub shafts that came with the diff.

Just checked with a bathroom scale and the T5 weighs ~20 lbs more than an 81-83 ZX 5 speed.

You can d/l the software from the LC1 website. Cable is a 1/8" male miniplug to DB25 male for laptop, IIRC. It's simple to confirm/change the output mode.

Did you free-air calibrate the O2 sensor when you installed it? If it has been a while you might want to pull the sensor out of the exhaust pipe and do it again. Also, under Tools in Tuner Studio there is an option to load the AFR table (I'm going from memory for what this is called as I don't have my MS tuning laptop with me). If you have updated the MS firmware and didn't reload the table, then you may notice that the O2 sensor behaves as if it was a narrow band - e.g. it only reads either full lean or full rich. One more thing - in extreme case where you have lack of combustion (e.g. no spark), even though we would describe that as "rich", the O2 sensor will read lean since there is so much O2 left in the exhaust (along with a lot of unburned gas as well). Probably not your issue right now, but something to keep in mind as the O2 sensor will be reading the opposite of what you expect so might be confusing when trouble shooting.

The T5 does not weigh 70 lbs more than the NA tranny. I have both in my basement but am on the road so can't weigh them. I'd guess the difference is more around 10-20 lbs, but that's just going from memory. I've been running an 81-83 NA tranny with 4.11 and loved it when I had a NA L28 with moderate cam. But it turns 3100 rpm at 75 rpm which is a bit busy so a 3.9 might be a better choice for the street. 3.7 is probably good with the NA cam that runs out of steam by 5500 rpm. Experiment with this to see how changing transmission, diff, and redline all affect your speed in each gear. After a year of running a turbo the tranny is starting to fail so I'll be swapping to a T5 and 3.54 or 3.7.

Let me clarify what I'm looking to do. I currently have an R180 4.11 with Powerbrute LSD and a NA 5 speed behind a turbo L28. I'm planning to swap to a T5 and hence need to change the diff ratio to 3.54, or perhaps 3.7. My plan has been to source a 3.54 R180 from a 240Z automatic, but so far am not finding anything local. The idea was to swap the LSD from the 4.11 over to the new diff. With regard to the Xterra diff, given I'm going to swap the LSD carrier into it, then do I care about the output shaft splines, etc? Aren't those part of the LSD assembly? Sorry for the dumb question, but it has been years since I installed it and the pictures in my head are fuzzy. Also, I seem to remember a discussion regarding 10mm vs. 12 mm bolts used to secure the ring gear. As it's not convenient to drop the diff to open it up, can anyone venture a guess which size I currently have and what I'm likely to find in the Xterra R180? FWIW, my current 4.11 came from the front of a Nissan 720 pickup. Lastly, even if the owner of the Xterra off roads it, isn't the weak spot on the R180 that they only used 2 pinion gears? Spinning a wheel would seem to be likely when off road and hence the weakness people see with those diffs. Given I'd be replacing the open carrier, none of this matters to me, correct?

Thanks Jon, I was thinking that the output shaft splines might be different. I heard back from the seller and it's the front diff, in which case it won't be worth the trouble and cost for an open diff. Also turns out that there is a lot of discussion on the Xterra forums about breaking the R180 up front when off-roading. Apparently it's common to swap to a bigger diff which is probably why this one is for sale.

http://www.edmunds.com/nissan/xterra/ It's available in three trim levels: X, S and Pro-4X. The first two are offered in either rear- or four-wheel-drive versions, while the Pro-4X is offered in 4WD only. Can't tell if it's 4x4 - I've got an email into the seller.

I'm looking for a 3.54 R180 for my 73 240Z and found one from an 08 Xterra X trim. Before I drive up to take a look I thought I'd ask if after all these years, will a modern R180 drop into our early Zs?

With that brake setup, unless you go with a pad material for the rear with a higher coefficient of friction, the brakes remain front-biased (fronts lock first) even if you open the rear proportioning valve fully. On the track it means you can't optimize the front/rear braking balance. It's not as much of an issue on the street where you'll want more front bias for safety. Of course, the stock drums would also be fully adequate for the street, but they obviously don't look as good.

Huh? What does his name have to with whether he is an American or not? And what does that have to do with his car? From the HybridZ Rules: 8. While we are on the subject, we want you to stay off of your religious or political soapboxes as well. Religious or political topics should be avoided. Any posts that stray into the realm of politics and religion will be closed and/or deleted. This is a car website, so let’s keep it focused on cars.

That approach uses the two holes to the left of the radiator - routing across the front of the engine allows one of those holes to be used for a cold air intake.

What is a rain visor?

Let me summarize: - Engine was rebuilt. - Driving with either the original or new non-OEM thermostat causes it to overheat and blow out freeze plugs. - Removing the thermostat solves the overheating issue. - You have verified that both thermostats open in hot water. - You have verified that the thermostats are properly installed. - When engine overheats, top rad hose is cold, bottom is hot. The symptoms don't add up to me - cold top hose suggests lack of coolant flow. That's usually due to the thermostat being installed upside down or having failed closed. I suppose it's conceivable that you have an air pocket that is blocking coolant flow with the thermostat in, but that purges itself without the thermostat? Doesn't sound likely to me and I've never done anything special to purge coolant on an L6. Did you look at the water pump during the rebuild? Any damage to the impellers that would reduce flow? Anyone else care to take a stab? Like I said above, the symptoms don't add up to me.

It sounds like you did have it properly installed. You said you checked the thermostat and that it was opening. How did you do that?

Knocksense Has some issues with false detects, but it's inexpensive insurance. I had what I thought was a conservative tune done by ear, but the first run with it installed showed me otherwise. A simple test of pulling timing across the board 5 deg under boost eliminated most of the detonation events, suggesting that they were indeed real. Even if you don't tie it in to the ECU, the bright red LED will warn you that you may have a timing issue. Tie it in with datalogging, and you can see if perhaps the mixture is spiking lean, or if it's near the torque peak and needs some timing pulled.

If the thermostat was open, the top hose should be hot. You removed the thermostat and then it did not overheat. Sounds like you have the thermostat installed backward.

Think twice before you go with a non-webbed intake manifold, and make sure you include the heat shield too. There's a lot of heat from the turbo and it's not hard to heat soak the fuel rail and injectors on hot days. The fuel will heat up becoming less dense and the O2 correction may not have enough range to compensate. Hot restarts can be more difficult as well. Nissan added the FI fan on later models to address this, even with the webbed manifold and heat shield. You'll need to choose form vs. function.

Wasn't the stock factory 280zxt limited to 7 psi boost, albeit with the P90 head? It did not use an intercooler. I'm sure you can make it work at 10 psi, the question is how much timing you will need to pull in order to avoid detonation, which will reduce power. I know others have experience with this approach so maybe they can chime in here. BTW, what engine management system are you running? A programmable one would allow you reduce timing only at higher boost levels. I don't think you have that option with the factory ECU. But could you add the factory knock sensor and rely on it to pull timing only when it detonates? Again, I never ran that so perhaps others can chime in.

Go back to physics basics: f=ma. Assume that z-ya's car can generate 1g under braking. Then the total force across the 4 tire contact patches is ~ the weight of the car. With weight transfer due to braking, the fronts will generate more of that force vs. the rears. There's some further force multiplication (leverage) since the lever arm from the contact patch to the strut tower is longer than the TC rod connection to the strut tower. Seems like the TC rod takes most of the load in the lateral axis - hard to imagine the spring providing much lateral stiffness - hence each TC rod probably absorbs a load close to the half the weight of the car. Does that make sense?

Do you remember what year and car the mat was for? I'd be surprised if they still have 1973 (or even 1978) cars in their listing.

When I went turbo I already had a shaved P90 from my NA car so started with that on a stock L28ET block with dished pistons. CR was 8.4 IIRC. As I went beyond 1.5 bar (~7 psi boost at sea level) I found I was retarding the timing more than others with the stock non-shaved P90 which of course hurts max power. I had a stock uncut P90 so I tried that dropping CR to ~7.5. Initially it felt like I had lost top end power, but after retuning to use the extra advance possible with the lower CR, I suspect I have at least as much, if not more, top end power. This setup definitely detonates less, especially on hot days, at the track, etc. The issue is balancing the tradeoff of CR against the ability to run more advance. The general consensus is that you'll make more max power with a lower CR if that allows you to run full advance. There is a small but important difference for what you're proposing: in my situation I am using dished pistons which I would expect don't quench as well as flat tops would. So you may find that you don't have to back off the timing as much as I did. In the end, the difference for me between the two setups was pretty small, and even the low rpm response of the engine isn't much different. There's no doubt that all else equal, a larger CR is desirable. In the real world with tradeoffs, I think perhaps people put too much emphasis on bigger CRs instead of focusing on the entire engine. I suspect you can take either path and will land up with similar results in the end if you take the time to properly tune.

Would you post a few pictures?

No

I ran the LC1 straight to the MS and used one of the gauges in TS to show AFR. Not sure why you would want to log the LC1 output separately unless you were troubleshooting it.