I just love the Z and will get my hands on one soon. I was considering of whether I should get the base model and get some track wheels with the money I'll save from the enthusiast. Should I? I won't be hardcore racing, just those little freeway encounters, and the car will be my daily driver. Anyways, what are the benefits of having the limited slip differential? Yay or Nay? Thanks.

 

You may lose a few horses , is all .I have the base , it's great . The horsepower loss will only occur on some surfsces . You'll have all 287 most of the time . There are aftermarket limited slips if you want it later .

 

Loose horses? Have 287 most of the time? Do you even know what a limited slip differential is? hehehe

For ICYBLUE1203, a limited slip effectively balances power output between your rear wheels. With a standard open differential like what is on the base model the tire with the LEAST amount of traction will get all the power. Therefore, if you try accelerate hard you will find one tire spinning while the other just sits there. If you get hard on the throttle in a corner and try to swing the backend around (create oversteer) the inside tire will just spin and the backend will not come around as expected. The limited slip differential employs a clutch pack that engages when one wheel tries to break traction and move faster than the other wheel. Once the clutch engages the axels turn as one solid piece and both wheels have equal power applied to them. On a car like the 350z I would not consider owning it without a limited slip differential. If you're not into modding then definitely get it from the factory. If you're planning to mod then you may want to consider holding out for a Nismo or other aftermarket setup. Aftermarket units will be considerably more expensive than the factory option but will likely be stronger.

I hope that at this point it has become painfully obvious that limited slip differentials do not have anything to do with how much HP your car makes. Sorry FrankieZZ, dont mean to be a butthead but you were more than a little off with your explaination

Hope this helps.

 

My $.02. I had originally ordered a Base with side airbags, and then changed to an Enthusiast without side airbags for a difference of $1400. I am VERY happy with my choice. I think a 287 HP RWD car REALLY needs the LSD. Also, I think the TCS might keep my out of an accident some day -- I would rather stay OUT of an accident, than have the MARGINAL extra protection of side impact airbags when I am IN an accident. I think those two items alone are well worth more than the $1400 extra that they cost me -- and I don't believe you can get even an aftermarket LSD for anything close to $1400. Finally, I LOVE the xenon headlights. The color of the light is really cool, and they put out tremenous amount of lights for low beams -- without blinding oncoming drivers. Beyond those three things, the bells and whistles of the Enthusiast are nice, cruise control, aluminum petals and the Homelink (although I have not yet programmed it). I would strongly recommend going with the Enthusiast.

 

Japanparts.com has a LSD for around $800.

Jason
NJ

 

the VLSD does not employ clutch actuation, but uses a viscous fluid that changes properties when heated. In the case of the Z, when one wheels spins, the fluid heats and changes and somewhat transfers power to the wheel with no grip. It is important for your question to note that the axle does not act like a solid piece, but ATTEMPTS to. The LSD in the Z is not that great and its abilities are limited. I have even launched the Z with only one wheel slipping, and only giving me marginal power transfer.

I guess to answer your Q, the LSD is no big deal. But I think the real reason to have the enthusiast are the zenons, Homelink etc.

 

From a dead stop, the stock limited slip seems to allow a bit of spin before "locking up". Around corners however, I've been able to easily rotate the rear end by applying throttle, which makes it seem like the LSD works better once the car is already in motion.

I can't say for sure, but if you are looking mainly for fun on the streets (stoplight racing/twisty road driving), then the LSD does not seem like it will make much of a difference.

I think FrankieZZ was trying to say that it is easier to get all the power down to the street with a limited slip because it helps eliminate wheelspin. I don't think he was saying that the engine itself makes more horsepower, only that you can actually use more of it.

-D'oh!

 

yeah I did a burn out, and both tires were spinning, this is good and bad tho, you REALLY lose traction if you do this. but thats besides the point.

LSD=good, specificly if you dont think youll ever swap in another one. another thing is the reason it doesnt totally lock up is because on a turn, your wheels spin at different speeds, the LSD has to allow this to occur or you cant turn worth crap... thats why we use a LIMITED SD, not a locked diff. I believe drag racers use a locked differential.

personally, more important than all this is the xenons, and homelink, lighted vanity mirrors, that sorta stuff, the little stuff. stuff you would or could never add to your car. obviously this stuff by itself isnt worth the price difference, but with the LSD it sure is.

 

This LSD is a mechanical LSD that will not endure the heat-soak that our VLSDs will. If you want to modify, go ahead and get the base. If you don't, better go ahead and take the next level up.

 

yeah but apparently you can get an LSD for 800, which still allows for room to get the rims if he wanted both. HOWEVER, in retrospect the TCS has been on during some spirited driving and may have saved me (I hit a wet patch I didnt see and was accelerating out of a turn, the TCS light blinked and cut power WAAY faster than my reflexes could have allowed!)

 

Took the words out of my mouth. The LSD on the Z is like the LSD I have on my 200SX SE-R, it is a viscous type and sorry to say it is the shitiest of the LSDs. It is at the lowest rung of LSDs to put on a car. I really doubt that it prevents more than 25% of slippage. The best LSDs are the mechanical type LSDs (Helical, Quaife, Torsen).

The Sentra SE-R Spec V has a WAY better LSD than the Z does. The Spec V has a mechanical helical type LSD. That is the LSD that the Z should have had. It is a shame that Nissan went cheap with the LSD and installed a "shitty viscous," to quote a Nissan engineer.

I race my SE-R (not the Spec V) and now I have a Quaife LSD instead of the Viscous in the tranny. It is way better than the viscous. Also, mechanical LSDs doe not wear out like viscous and clutch based LSDs.

I hope that Nissan will equip the Z with a mechanical LSD in the future. It is amazing to me that the cheap (17K) SE-R Spec V has a mechanical LSD and the (30K) Z has a viscous type LSD

 

I have read this thread with great interest. I understand the differnces between viscous and mechanical, helical I've never heard about. When you guys agree the viscous diff is inferior to mechanical or helcal, where and under what conditions is it inferior? Is it inferior to the others on the drag strip or a racetrack like Laguna Seca or Road Atlanta?

What about its behavior in every day driving, like on the highway driving in rain, snow or other places. Would I be advised to be concerned, or is this inferiority present only under race conditions?

Boomer

 

mostly race conditions where it can over heat. for regular driving you wouldnt ever use the LSD. unless you try to spin a tire then it does nothing(9 out of 10 cars dont have a LSD)

for rain, it wont matter much, for snow, if one tire slipped the other would get traction rather than one tire spinning all around and the other sitting steady on the ground. could keep you from getting stuck.

 

Agreed. A big majority of cars come w/o an LSD. For every day driving you do not need it and you will not notice it. To feel your LSD here is what you do. Park one rear tire of your Z on wet asphalt and the other tire on dry asphalt. Turn the TCS/VDC off. Then launch hard. You will feel the LSD working. Since power takes the path of least resistance w/o an LSD the Z will simply spin the tire on the wet asphalt. W/ an LSD the slippage is limited to the wet tire and power goes to the dry tire causing more traction and allowing the car to move.

Most of the time LSDs help in hard cornering. Why? because when going into a corner the inside wheel will lift. W/O an LSD the power will go to the wheel in the air and it will simply spin. you will lose precious 1/10 of seconds that way. W/an LSD the inside wheel that is up in the air will spin less and power is diverted to the wheel on the outside that has more traction. With more traction you move faster out of a corner and gain precious 1/10s of seconds.

Mechanical LSDs are best at transfering power to the tire with most traction. Why? because they have gears in them similar to those in your tranny. Power transfer through gears is more efficient than through liquid (viscous) or clutch packs. So the response of a mechnical lsd is way better than the viscous or clutch lsd. The downside of a mechanical lsd is that it is a bit noisy. It chatters. I can hear the mechanical lsd on the Spec V when I drive it.

If I want to rank order differentials I would put
1. Mechanical (Helical, Quaife, Torsen)
2. Clutch Pack
3. Viscous
4. Open diff. no LSD.

since the Z is a RWD, then the LSD resides in the rear axle and not in the tranny, so it should be much easier to repalce the viscous with a mechanical lsd, if that a unit becomes available.

 

This means that installation should be much cheaper, correct? Goodie

 

I am assuming that Nissan did the easy thing and put the LSD in the rear axle/differential. If that is the case, then yes it will be cheaper to install a mechanical lsd. when I installed mine in the SE-R we had to open the tranny, remove the gear clusters, remove the stock VLSD, mount the quaife on the final drive ratio, put everything back together CORRECTLY and reseal the tranny. But that is the way it is in FWD cars.

 

You guys are a little specific for this point of view, for me the difference between LSD or not, is very little, I race a Track from a stop 5 times and the spinning are very similar, but if you planning to put the Z in more than 400 rwhp you most be thinking for the LSD.

Just my opinion!

 

You are talking about drag racing. I am talking about road racing. The LSD is more helpful in road racing than drag racing. You can use the TCS for drag racing. But if you use it for road racing, unless it has F1 electronics, it will slow you down. TCS/VDC tend to be set to interfere on the early side in stock cars.

I drove my race car w/o an LSD, w/a VLSD, and w/a quaife. I will tell you that there is a difference. Given equal cars and drivers, the car with the mechanical LSD will have an edge on the car w/o an LSD on a road course.

 

Thanks for your explanations. I learned a lot about differentials I have only guessed at before.

Boomer