Some of these aftermarket LSD's make alot of noise and can be aggressive for street action (ie. Nismo). Do a search. There's some good threads with info on some the others.

 

Here is a good article that shows some of the disadvantages, along with remedies.

http://www.sportcompactcarweb.com/pr...t_2/index.html

Also check out my thread on rebuilding a clutch type lsd and getting the plates treated for smooth operation.

 

Thank you very much for the link. Where can I find the how to on rebuild.

 

lsd does slow down ur acceleration by a lil. thats what i read about how different lsds work

 

I can see how they would while turning, but going in a straight line I cant see why they would.

 

I have done one track day with an open diff in my base model Z. I had no problems with 1 wheel spinning and I got the car sideways multiple times. At this time I'm not concerned with spending my money on a diff. LSD's may be effective on an autox because of generally being tighter corners, but in my personal experience, they are not necessary on a racetrack WITH stock power. I am far more concerned with getting wider wheels and tires right now.

 

I too don't have much problem with the stock vlsd without the ABLS to help it, at the track. I run 275 RA1 so there is still plenty of grip.

But driving on the street with street tires, the vlsd has a hard time controling wheels spin. HP are just wasted in wheels spin...

 

In the real world, LSDs improve lap times and 1/4 mile times.

Well, if lap times are not a concern, then I agree. If lap times are important; I've seen a 5% improvement in lap times going from an open diff to a LSD and I've seen 1 to 3% improvements in lap times switching from various types of LSDs.

 

With a basically stock car, I didn't have one case of 1 wheel spinning while at Shenandoah. I could induce oversteer as needed. I'm no expert, nor even experienced at track driving since I only have one track day under my belt, but I didn't feel I could have benefited from an LSD. Maybe in the future.

 

In that case, maybe it's not an issue of the car having stock power but more one of the driver just learning a new art ?

No offense intended. We all start at the rear of the "track pack" and slowly progress forward at our own pace.

 

If you plan on future track days or even auto-x you will eventually want an lsd. If you had to induce oversteer you have alot to learn about going around corners. Practice and more track days will help you improve your drving skills. The more you improve the more important the lsd will come in handy as you try and carry your speed through the corners.

 

Possibly, and no offense taken. I did get oversteer pretty much at will though. I'm running on puny 225 width tires on all 4 corners also. My next purchase will be some 17x9 wheels and Nitto NT-01 275/40/17's. As it were, I was sliding around most of the corners at Shenandoah only using throttle inputs to control my rotation around corners. Understeer was only an issue in the slowest corners, the car felt very neutral and oversteer was way more common.

 

It actually took some time for me to get used to driving my car with the nismo lsd to get its full potential. It takes a slightly different drivng style. You can get on the gas sooner and control the balance more with your right foot. Point and shoot with foot to the floor at the apex..

I would agree with betamotorsports that a 5% reduction in lap times is reasonable with a good lsd. The ability to apply the throttle sooner and added the traction out of corners is very helpful on the track. The added car control and stability is also noticable at 10/10th's driving.

I realized this when driving someone else's track model with VLSD. If I drove it like my nismo equipped car, I was spinning inside tires and not able to have the at the limit balance that I enjoy with my nismo. Again not noticeable if driving at less than a race pace.

The downside of an lsd on the track is that your rear tires will generate more heat. Driving style and car setup can help this though. Another downside is that a little bit of precision is lost in the steering wheel but I think that this would be more noticable in an autox situation more so than road racing, and the diff can be built with different lockup percentages to aid in this as well. I also believe that ultimate skid pad grip is lost a bit with a strong diff. The traction out of corners more than makes up for this though.

 

How loud is your nismo lsd on the street and what lock do you have it at.

 

It's pretty much silent now with the WPC treatment. It is currently at 90%. Check out my recent thread on my rebuilding process. If you're buying a new nismo, re-stack it 80% before installing it.

https://my350z.com/forum/autocross-road/274357-rebuilding-nismo-lsd-and-plate-treatment.html

 

I autocross with a Quaife and love it. I had an open diff and had traction issues on corner exits my first event. I suffered with the open diff for a few months and developed a nice soft touch with the throttle. When I got the Quaife, it took a little over a second off of my 43 second test-and-tune time. (A time that I was always within a couple tenths of every month.)

It's also great for daily driving. No noise and smooth, always-there traction. (There's no lag time for "lock-up")

If you have a factory LSD the improvement will not be as big. But I have driven stock LSD and my Quaife back to back, and can say the Quaife it better than stock. I have no experience with clutch type LSD's though, so I can't compare the Quaife with somethong like the Nismo.

 

How many of you have an after market LSD, what % do have for the set up and what do you think it was your gain after installed?

 

Here's a writeup from me that might be helpful.

https://my350z.com/forum/showthread....ight=nismo+lsd

 

Are you looking for opinions on what to buy? Or do you already own a clutch type and need help setting it up?

I have a Quaife LSD and it's awesome, but it doesn't use plates so I have no info on setting up a clutch-type LSD.

 

I have a Cusco RS set to the usuall 1.5 with 60% lock.

Works great on track and on the street. Would buy it again if I had to.