SATAN

Wait, you wanna pull your open R-200 diff and replace it with another open R-200 diff? Why don't you just pull one of the input stubs and count the splines. If it is 29 like the z31 turbo cv shafts, then I don't see why you couldn't just plug them in. I don't know much about the s30's and 130's but I'm pretty sure the reason you need adapters to use the z31 cv shafts is because they don't bolt up to the wheel side, not the diff side. IF this is the case, then swapping differentials will do absolutely nothing for you unless you are possibly looking for a different gear ratio.

You sound like you know what you are doing. Good luck

You sound like a dealer for Turbonetics. Like none of their turbo's have ever broken either. On that note, I like my Borg Warner turbo. Truth is, all turbo companies are having turbo's that blow up. If you look around the interweb's, you will find someone bashing any company you can think of. Then you will find others getting all pissed off cause someone bashed the brand they are running. It all comes down to... These are not normal cars. We beat the **** out of our cars and sometimes **** goes wrong. If you cant afford to play... GO HOME.

That sucks dude. What size engine are you running? I would think a 35r with a .82 A/R hot side would be plenty large enough for an L series engine. Maybe your IC/pipes/throttle body is too restrictive and the engine just cant ingest the air fast enough because of this? Was the surge worse before the .82 swap? After watching the video in your sig, it says 3" IC pipes. That doesn't sound restrictive at all. You can definitely see it surging when you look at the boost gauge though. That's pretty strange. Did the surging ever seem to go away in higher RPM's? I did not notice.

I was like "Ooooh, I wanna see the difference!" Then I was like "I want that 3 minutes of my life back..."

It sounds like you are already in the process of replacing the filter element. I had a similar issue (actually, exact same issue). I pulled the element and could not even blow air through it, that's how clogged mine was AND it was less than a month old. Although, this would not explain how temperature effects the situation. That is the only thing that confuses me.

If you are looking at something comparable to the Aeromotive... I run Magnafuel. Granted, I run one of the largest pumps they make but... None of their pumps require or even recommend running a voltage regulator. I have run mine for up to an hour at a time and it runs really cool, not even warm to the touch. Again, no voltage regulator required. The 044 and the Walbro are good pumps, but are not on the same level as the Aeromotive or the Magnafuel pumps. The only reason I suggested them is because that is the level you started out with in the discussion.

So I posted this in the fabrication forum, but realized it should probably go here instead. Either that or everyone has seen it and it's just not as cool as I thought it was LOL. Mods, please feel free to delete in out of the Fabricaton forum. I decided to do my own quick spool valve since Sound Performance wants a whopping $500 for them ON SALE! Anyways, you aren't supposed to put them on divided manifolds, but I worked mine over so it will work. Valve is closed, exhaust gas is diverted to passenger bank. A/R ratio on turbo is essentially cut in half causing quicker spool 6lbs of boost is built and valve opens. Normal flow resumes when valve opens. The flow isn't the greatest going into the passenger bank, but I am sure it will be adequate with low flow like it is designed for. Everything goes back to normal once the valve opens. http://www.youtube.com/user/satanz31

Hmm, that is bizarre. I don't know what the debate would be about. In my opinion the CLSD is better than the VLSD. The CLSD is less likely to be worn out, it is rebuildable, you can modify it to be stronger, it is less likely to wear out, and it doesn't require any special half shafts. I would go the 87 turbo LSD that you mentioned. Oh and as far as the wheels spinning the same direction or not. Someone said only if the car is out of gear. I don't know why you would try with the car in gear but... On a CLSD, both wheels should spin the same direction. If they don't, then it most likely is not a CLSD, or if it is, then it is somehow broken (doubtful). If you are looking at the z31 series, then anything with a finned aluminum diff cover has a CLSD, as long as someone didn't just put a finned cover on to be cool. The 88ss... If you have the time, the car is worth picking up for $800. If you are looking at parting it out, go to z31performance.com Obviously lots of z31 guys there. People love them some 88SS's.

I decided to do my own quick spool valve since Sound Performance wants a whopping $500 for them ON SALE! Anyways, you aren't supposed to put them on divided manifolds, but I worked mine over so it will work. Valve is closed, exhaust gas is diverted to passenger bank. A/R ratio on turbo is essentially cut in half causing quicker spool 6lbs of boost is built and valve opens. Normal flow resumes when valve opens. The flow isn't the greatest going into the passenger bank, but I am sure it will be adequate with low flow like it is designed for. Everything goes back to normal once the valve opens.

I guess I will answer my own question. The HKS box will not work (or should not be used rather) with the Hayabusa/aem pencil coils as it is an inductive box. The Hayabusa coils are designed to work with a true CDI box only. The HKS works on coils with the igniter built in, like LS-1 coils.

So... I have an AEM EMS, mistubishi 3000gt igniter, hayabusa coils, HKS DLI ignition box. I have read that you cannot run the HKS DLI to the hayabusa coils, as those coils do not have an igniter built in and you can over head the ignition drivers on the AEM. Instead you have to run a true capacitive discharge box like an MSD or a Autronic or M&W or Motec. The HKS is supposed to be for three (or more) prong coils... coils that have a built in igniter. Although, If I have the 3000gt igniter wired in with the hayabusa coils, then does it make it ok to run the DLI? The HKS DLI is not like every other CDI box. There is no input and output like on an MSD or any others. Anyone got an idea?

If it is an R200 then it will work. Long nose/short nose does not matter. What matters is the ring gear/pinion shaft combo. You have to keep those the same. If it is a short nose case, then you need the short pinion shaft and mating ring gear to go with it. If it is a long nose, you need to have the long pinion shaft and accompanying ring gear.

Ok, one more question. I am using the Red Line shock proof in my LSD. I was just told that this is a no no. That I should be using 80/90w with LSD additive. On that note, should it be synthetic or conventional? I just want to get the best performance out of this thing.

LOL, ok. I was freaking out. Glad to know it is normal. I will add the friction modifier and hope that it helps it out.

VLSD uses standard gear oil just like the normal open differential. The viscous coupling inside is sealed with it's own fluid inside of itself. Thank you guys for the suggestions on the friction modifier. I have some on the way. That is also what others have been telling me. So the consensus then IS that the sound IS normal until you add the friction modifier? Also, Cannonball55- If that is a true 89 turbo (Not a conversion), hang on to it. They made just over 200 of the 89 turbo's, they are VERY rare.

I performed the 6 clutch mod on my 88 turbo CLSD. I added the appropriate number of shims to equal roughly 70-75lbs of break away. I added redline fluid (cant remember which kind right now). Situation: Severe clunking in the rear end. Clunking is only while mildly accelerating and turning at the same time. Time on the diff since the swap is roughly 100 miles. Driving straight the diff acts normal. Attempts to fix: I have pulled down the differential and tore it all the way down to the clutches to inspect it. Upon inspection there was no wear at all. I inspected all clutch disks on both sides, entire ring gear and entire pinion shaft, along with anything else that was apart. No wear at all. I have also swapped out CV shafts to different units with no change. I also mounted a camera on the bottom of the car to film the rear end to see if control arm's were clanging around or something. The vid showed nothing other than suspension behaving normally. I have had people tell me that the sound is normal for the mod performed. I wish that were true however, it is extremely violent and I am having a hard time believing it is normal. But again, I cannot find any wear. The car is a 1985 300zx with solid crossmember mounts and solid diff mount. This probably amplifies the noise. Here is a vid of me driving the car. You can tell I try to take it easy around the first turn to avoid clunking. But when I have to turn around you can hear it very well. It worries me... http://www.youtube.com/user/satanz31 Basically, I am just looking for some input from people who have performed this mod. Does that sound along the lines of normal, or is my intuition correct in feeling like something is terribly wrong.

Holy crap dude... Eric, don't die on me man. I'm glad you are ok. I still have yet to tell Niki about this. She is going to cry for you when she hears what happened. The car is looking sick. I Decided I wanted to do a turbo LSx some time in the future as well (didn't know they made iron one). Thought it was funny I came over here to look for some cars running turbo LS engines and came across yours very first. That turbo is a monster. I have the s374 and it is huge at 75mm. 80mm man... sweet christ all mighty in hell! At 20lbs on the LS you are going to be looking at what... 850whp or there about? You are going to have to learn how to drive all over again LOL. I'm curious to see the torque curve of this engine. Again, glad you are ok. You are making very quick progress with your car.

Lots of information here, but it is very hard to read due to the spelling, grammar and run on sentences. Looks like there is good info here, but just hard to make out. Correction though. The Q45 differential is NOT an R230 like the twin turbo differential. It has a 200mm ring gear and will fit inside the R200 case from an 88 300zx.. I have personally done it with pictures to prove it. However the splines ARE larger than the z31 series and the s130 series differentials. Along with almost all other R200's for that matter.

If you look at the viscous coupling in my post from a 1990 Q45, you can see there are NO access ports of any kind. It is NOT a serviceable unit. The same goes for all 300zx VLSD's if I'm not mistaken.

I am writing this because there are people that do not understand what a viscous limited slip differential (VLSD) is. There is nothing wrong with that, but let me clarify. A VLSD is different from a CLSD (Clutch Limited Slip Differential). The CLSD has actual clutches that engage when the rear wheels turn at different speeds from each other. The VLSD while performing the same task, does not have clutches. I am not going to go into the EXACT differences of the two diff's. You can research that elsewhere if curiosity gets the best of you. Instead I will give you a somewhat simple idea. The VLSD has a viscous fluid inside of a coupler. This coupler is part of the internal working of the LSD much like the clutches of a CLSD are. Obviously they are not the same though. Instead of clutches engaging when the wheels spin at different speeds, the inside and outside of the viscous coupler spin at different speeds from each other (this will make sense when you look at the picture).There are two sets of plates inside the viscous coupling. When they spin at different speed, the thick fluid inside is forced to try and catch each set of plates up with the other. When driving in a straight line, they are both spinning at the same speed, when turning a corner, one wheel spins faster than the other, in turn one side of the viscous coupling is spinning faster than the other. Below is a picture of the viscous coupling out of my Q45 VLSD. This is essentially what all viscous couplings will look like. Sadly you cannot see the inside of it because it is a sealed unit. This is one side of the coupler... And this is the other side. In the second picture you can see where the splines of the input shafts are. Then you can see the track where the planetary gears ride on the outside. You will notice that the spline section and the track for the gears are two separate pieces. These are the pieces that are allowed to slip differently from each other. When they do, the fluid inside tries to catch both sides up again, creating your LSD effect. Now some things to know about viscous LDS's... It has been noted that you CAN burn the fluid inside the viscous coupling by over heating it. If this happens you can damage the fluid and change its viscosity. When this happens, it is no longer able to catch the two pieces of the coupling up with each other like it should. Essentially, your coupling is burned up and needs to be replaced with another working unit. I do not actually KNOW of anyone this has happened to, but have heard of it happening. Changing how the viscous unit locks up by changing the fluid inside... Sorry but, you can't. You cannot change the fluid inside of the viscous coupling. It is sealed, you cant get in there without destroying it. Keep in mind this is NOT the same as changing the differential fluid, (which will still have zero effect on how the coupling operates). What some people do is actually shim the viscous coupling tighter. This doesn't really change how fast the unit locks up, but it does sort up wedge the coupling in place and causes it not to spin in the first place. Some people do this wit burned out units to try and help get their LSD effects back. Kind of a kludge fix. How do you know if you have a VLSD or a CLSD? Again if you refer to the pictures above, you will notice a washer in the center of the viscous coupling. This is to keep the longer input shaft from stabbing all the way through the viscous coupling from the wrong side. If this happened you would actually lock both sides together making a solid diff. Now before you get any brilliant ideas about doing this to lock your diff by knocking that center washer out... there is more to it than that due to the differences in the two input shafts. But I will not go into that here. So, looking through the holes where the input shafts plug into is one way to tell. You will see that washer in the center. Another way to tell, is to look at the input shafts them selves. One of the splined sections on one axle of VLSD input shafts, will be substantially longer than on the other axle. This is so it can plug all the way into the viscous coupling. On a regular CLSD they are close to if not the same length splines. The third and hardest way, is to take the diff apart and visually inspect it. I hope this clears up some questions and common misconceptions about the VLSD. Hopefully someone will sticky this so the information is easily found.

Spline count wont tell you if it is a V or CLSD when it comes to the 87-89 300zx lds's, they are both 29 spline. The way you can tell is to look through the input shaft holes. Look at the picture I posted of that viscous coupling. You see that washer that is inside it? Essentially a barrier to keep the axle from going to far (although I don't think that would happen anyways). If you look at a CLSD, you can look straight through to the other side. There is no washer like that. Another way you can tell is to look at the actual input shafts them selves. One will be a lot longer than the other due to the fact that it has to plug so far into the diff in order to reach the viscous coupling.

It's pathetic really. I troll the drivline forum in hopes that people will ask questions about the R200 or R230, just so I can hopefully answer them.

Are you talking about the viscous diff still? You cannot change the oil in the viscous coupling. It is a sealed unit and has to be replaced once it goes bad. The only way to stiffen it up, is to shim it. But then you are not really stiffening it up, but more just wedging it in place to keep it from moving. This is one side of the viscous coupling... And this is the other. If you look at the second picture, you can see where the teeth of the gear ride vs. the inside of the coupling where the splines are. These two parts spin differently from each other. When they start to spin the fluid inside heats up and expands locking them together to give you your LSD effect. As you can see, there is no way to get in there and drain the old fluid out and put new in. As far as the viscous coupling burning out... I don't know of anyone that has actually burned one out. But I usually talk with z31 guys who mostly run the CLSD not the VLSD so...

The CLSD can take WAY more abuse AND you can rebuild it. Not only rebuild it, but rebuild it and make it stronger by adding more clutches. If you abuse the VLSD to much, you can cook the fluid inside of the viscous coupling. This would essentially turn it back into an open diff again. Then it would be useless for any kind of track use.