Sharif@Forged

iTrader: (92)

Ok, I know this has been a long time coming. We have been sitting ont he ATS carbon LSD and DSS Level2 axles for a couple months, as some other projects and events took priority. To my knowledge, we are the first people to install the ATS Carbon LSD on a 350Z in the USA, for street usage.

If you arent familiar with the ATS Carbon LSD, it is claimed to be the world's first carbon LSD. Like their excellent line of clutches, the carbon clutch packs in the LSD provide a very smoother transition between lock and unlock, and they claim it minimizes noise and chirping during low speed turns. Keep reading to find out the results.

I'll also review the installation of the Drive Shaft Shop Level 2 axles that we installed at the same time.

Installation of the axles was relatively straightforward. I had my tranny guy do most of the install, since he does this stuff about 15 times a day, and can pretty much do it blind, and in about 1/3 the time it would take me. To install the axles, you just unbolt them from the differential housing, and unbolt them from the hub. With a hammer, you just bang them out of the hubs, and thats it. we also had to remove the sway bar mounting bracket to get some clearance.

Now comes the messy part. You have to remove the stock inner CV from your stock axles and install it on the new axle. It's not a difficult process, just very messy with all of that nasty poop-like bearing grease. Here is a pic. The reason that stock inner is resued, is becuase its been track tested to 800whp without failure, so DSS doesnt even bother replacing it as well.



There is a snap ring that holds the outer in place, and a color and some ball bearings that makeup the interior of the axle. THere is a C-Clip that holds this together, so its just a matter of stacking in the reverse order, and reinstalling everything. The axles include new grease and press clamps to secure the boots to the axles.

Removing the differential housing is a straightforward process as well. Several bolts mount the carrier to the chassis, and thats about it. The drive shaft just slides out. Once the carrier is out, my tranny guy broke it down, cleaned everything, swapped diffs, installed the new bearings and races, and checked the lash. Amazingly, the backlack was PERFECT with the ATS LSD, and right in the middle of the OEM range. So no shimming or adjustments were needed.

Here are some additional pics:








Hold on....please dont post until I get the review up. THANKS!

Sharif@Forged

iTrader: (92)

After loading up about 2/3 of a gallon of ATS LSD oil, I began the break in process of the LSD. ATS recommends driving at about 15mph in "figure 8's" for about 20-30mins. If anyone has tried this, they know that after about 4 mins of this, you will feel the need to vomit. So I opted to do figure 8's for about 10mins, and then did the rest of the break-in on the street. ATS also says that a street driven break-in is fine, but just takes longer. You should not beat on the LSD or load up the drivetrain until the break-in is fully completed. Roughly 200miles of city driving, or 30mins of figure 8's.

After the break-in, you should drain and refill the differential with the ATS LSD oil. Unfortunately, I don't have enough left, so I have to finish up this process next week.

The first thing I noticed is right off the bat, I was expecting the diff to be pretty noisey and chirpy. To my surprise, the ATS Carbon LSD was very quiet and only had mild chirping during the most extreme of turning angles. I have driven a lot of other metal based LSD, and the difference is night and day. In a straight line, the LSD makes no additional noise or vibration whatsoever. During turns, with throttle, you can definately feel the diff lock, but its a relatively progressive feel, and does upset the chassis or cause unwanted barking of the tires. Now, don't expect this LSD do be as normal feeling as the stock LSD, or a Quiaffe gear driven LSD....as those are seamless in nature. I will say this is the smoothest clutch style LSD I have ever experienced.

The ATS Carbon LSD comes preset from the factory in 1.5 way or 2.0 way. You can change it later, but it requires you to purchase some extra parts, and remove the diff again. 1.5 way diffs lock on acceleration, but not on decel. 2.0 way lock on both decel and accel. The one we have installed is the 1.5way. It's lock is 99%, according to ATS. Personally, I like 1.5way for street usage, and the drifters tend to like the 2.0way. It is entirely personal preference....so that statement is just my opinion.

My overall assessement of this LSD that it has completely transmformed my driving experience. The level of grib and precesion in corners has improved dramtically. Gone are the days of inconsistency between right and left turns, and completely smoking a tire, and overhearing the factory diff during turns. The rear end just feel incredibly planned, yet the backend can stil be coaxed out of line. The great thing, is that the correction is almost instaneous, vs. the lazy corrections of the stock LSD. For instance, with the stock LSD, if the rear end stepped out, it would be very challenging to reset your line and correct. With the locked LSD, the correction happens almost immediately.

Straight line drag starts are far superior, as it's now much easier to get clean launches off the line, and the power is being applied equally right and left, without the stock diff overheating, and causing excessive tire spin on one wheel.

Technically, I need to drain the fuel and add fresh ATS oil after the breakin. They claim this will reduce the noise and chatter. If that is the case, I can only imagine how smooth this thing will be after changing the oil. Becuase right now, I think its already very smooth and quiet.

OK, that's about it for now.

John Sutton also purchased an ATS Carbon LSD from me, and I am hoping he can provide a "track guru" review. For those of you that don't know John, he is a track instructor, and road racing nerd in his spare time, so he is more qualified than myself, to give a track impression of this LSD.

Thanks everyone! oh.....price on the ATS Carbon LSD, in case anyone is working, is $1295 shipped.

zillinois

iTrader: (6)

Thanks for the reviews. Very good write ups. I have been wanting the ATS diff for some time now. I just bought a driving suit and safety gear so I'm tapped. But, I can't wait to hear John's review of the LSD on the track. Those axles look messy!! How much for would installation be on either?

g356gear

iTrader: (12)

Sharif, a few questions for you. Does the ATS oil come with the diff? Exta cost? Does this diff need periodic adjustment? Life expectancy of the carbon friction plates? Thanks.

Sharif@Forged

iTrader: (92)

ATS oil is extra, and its $97 shipped. We ship both the LSD and the Oil in one box to keep the shipping costs down. Both items weigh 32lbs shipping costs tend to be a bit high. AS always, we include shipping the price of nearly all of our products.

The diff shouldnt need periodic adjustment. The preload is set from the factor. The life expectancy of the carbon clutch packs is at least as long as metal disc, and likely much longer. It is unlikely this LSD with need replacement or repair, within reason. Just make sure to periodically change the gear oil. You can tell it needs to when the diff gets noisier than normal.

Oh, sorry didnt mean to scare everyone with the greasy photo. Here was what the Level2 axles looks like, in comparison to stock.

rednezz

iTrader: (1)

Great write up! If I only had the money.

imoz

I want this LSD.

I have a 350Z Base. It would be cool if I could get this preassembled in a pumpkin with the 3.9 FD from 350EVO so it is a simple swap. How hard would it be for a tranny guy to install this if I went out and bought the stub axles and other parts needed for the Base? From the photos it doesn't look too difficult to install.

Sharif@Forged

iTrader: (92)

The differential will not work with the 3.9 gears, from what I have been told by ATS. I havent confirmed this with anyone else.

The job is worth about $300 for the changing the diff and installing the axles..about 3.5hours of labor.

If you need me to do some more research on everything you would need to install this on a base, just shoot me a PM.

Z1 Performance

iTrader: (564)

I wonder why they say it wont work the 3.9...does not make sense to me off the bat

you are spot on about a good diff transforming the car....I remember being among the first to do the Cusco RS in my own car, and like you said, it was like climbing into a totally different car

Do they provide a means to adjust the lockup via re-arranging the carbon disks like you do on the metal disk ones?

mchapman

iTrader: (1)

ATS mention two adjustment tools on their website. One attaches to the wheel hub and you use a torque wrench to adjust the diff.

http://www.a-t-s-usa.com/ats-products/tools-lsd.shtml

BJ / Downshift from 350evo says the reason why the auto final drive wont work on the ATS diff is because the offset of the ring gear is different between a manual and auto rear gear.

Is the offset between the 350EVO ring gear and the stock manual ring gear different?

BJ went on to say that 3.9 FD works in aftermarket LSDs when I asked if it would work with the ATS.

Sharif@Forged

iTrader: (92)

I will double check with everyone on Monday after calling ATS. I know it doesnt work on the auto diff, and he mentioned you needed stock 6MT gearing. I will confirm shortly.

Righy on Adam...these cars with LSD's are like driving a completely different car. Its utterly amazing. The more I drive it, the better it feels!

daytona350z

iTrader: (19)

i may be wrong on this, but i though 1 way locks on accel only, 1.5 lock on accel but also on deceleration at only 50% of the force, and 2 way is full lock on acceleration and deceleration.

Sharif, can you answer a question for me? i know carbon clutches take time to heat up and really "clamp" when they are hot, does this hold true for their diffs as well?

very nice write up and review. now get that fluid flushed and really start to hammer it the difference is exponential as speed and drift angle/steering transitions increase. i am very curious how the ats performs against the clutch type lsd's. i know the ats carbon disks would probably last alot longer.

it would be cool to do a little comparo between the two.

Brandon@Forged

Is it both 3.9 gears? (Central 20's and 350EVO's) Great write-up Sharif, looking forward to seeing the write-up on the axles. (unless this was the review for those, I didn't see you mention the change in launching due to the axles or noise impressions from driving)

Do you still suggest the Quaife over the ATS or has your position changed?

Sharif@Forged

iTrader: (92)

The axle write up was included. There is no change in noise, or anything else due to the axles. They fit just like stock, just much stronger. I havent really done any hard launching just yet, since I am still letting the diff fully break-in. I trust they will not break.

Details on the Quaife are still sketchy. I have heard it is going to be designed to work with the open diff cars only....rather than the factory LSD cars.

The Quaife is a helical gear driven LSD. They are excellent. The reason some people dont race with them, is becuase if the outside wheel lifts in a turn, then the LSD becomes an open diff, essentially. The main benfits of the gear driven LSD's are lack of noise, chirp and they are essentially seamless in operation. However, after using this carbon LSD, its incredibly smooth, and I really the overall feel. The other drawback to the Quaife is the cost. They will likely be $1500 or so. We are also Quaife dealers, so as soon as they are formally launched, I will try to recruit someone to test it, and get some additional detail on it. If anyone is interested in getting one test unit....let me know. I have a feeling both the ATS carbon LSD, and the Quaife will be excellent options.

In regards to the 1.5 way vs. 2.0. To my knowledge, I havent seen 1.0 way diffs...only 1.5 and 2.0 for the 350z. The 1.5 does have some locking on decel..but it is very minor...I havent really notived it on decel.

In regards to the heat and carbon, the same hold true for the diff. They do grab more aggresively once warm, but again, I havent really pushed it enough to determine the feel. Shortly, a thorough thrashing will be applied to the diff and axles...stay tuned.

MR RIZK

iTrader: (7)

The tin of oil that you ordered how big was it? Since you mentioned that you did not have enough to flush the diff and refill? Just to know when I order the unit I will order extra.

xswl0931

It would be great if you had some 1/4 and track times for a comparison to stock (and eventually Quaife).

Sharif@Forged

iTrader: (92)

The oil comes in a 1 gallon container. We used a little under 2/3 of a gallon to fill it. If we could get every drop of oil back into the diff, you could probably do two changes with it. However, invariably, oil is lost in the transfer, and ends up on the floor. Probably a good idea to order two gallons, and then you will have more than enough for 3 oil changes.

Also keep in mind that ATS recommends only using their oil, especially for the breakin. It "might" be possible to save a few bucks by using a different type of gear oil for subsequent changes. For me personally, I am sticking to ATS, and its not worth a few bucks of savings in the oil. ATS uses its own friction modifiers, which are designd to work with their diff. Not sure how much of this is marketing fluff, but who knows.

This is a great idea. Unfortunately, its very difficult to replicate power and setup conditions precisely, in order to get a valid comparo. There are just too many variables to dial in, so a comparison may not be entirely accurate. Swapping diffs is also a messy chore, so I would need another car to really get a test like this going. As time goes by, we compare my times to Phunks, as Phunk has an OEM diff, IIRC. I believe he is also running BFG Drag radials on the track.

MR RIZK

iTrader: (7)

Thanks for the follow-up on the oil, and yes we will be sticking to the ATS fluid.

350zzzzzz

iTrader: (2)

for a base z do u need to buy any other parts to put an lsd in.

imoz

Yes, you need to buy new stub axles, bearings and seals.

edit: This has me wondering, is there something like an online ETK for the 350Z?