r_seng

iTrader: (9)

what lift is that? how much? and where?

daveh

iTrader: (9)

Initial driving impressions:
I backed the car out of the garage and eased her out onto the street. I immediately noticed that the push/pull effect I often complained about was gone. Steering was crisp again like an open diff. There was still a good amount of chatter so I went to my secret lot and did figure 8's to work the oil in the plates. Things quieted down a bit and everything felt ok, so I went for a spirited drive in the hills. Again the precision that was back in my steering was very apparent. I was beginning to think that I took too much lock out of the diff because I couldn't feel it working like I used too. I had a track day the following weekend so that would be the true test of whether or not I wasted 5 hours of my life.

At the track the diff still did it's job and never spun an inside tire, but the feeling of a strong locked diff was not there. Also, my neutral to slightly oversteering car was now transformed into an oversteering monster. They say that adding an lsd adds understeer, well taking one away reduces understeer, or in my case adds oversteer to my once balanced car. Lots of oversteer. The good news is that the WPC treatment seems to have smoothed out the operation of the unit. Typically my diff gets louder after a track day. My diff actually got quieter after this event. Perhaps the plates are still wearing in an breaking in.

I decided to take the diff down again and try changing the number of surfaces from 7 to 8 or ABABABABBA. This seems to be a step in the right direction but to be honest, it feels very close to the 100% that I started with. I'll be at the track next weekend and should have a better idea then. Perhaps the 7 surfaces would have been the best along with an increase in front spring by 25lbs to bring back my neutrality.

daveh

iTrader: (9)

http://www.asedeals.com/mid_rise_lift.html

betamotorsports

iTrader: (1)

Great information. Its nice that these clutch pack LSDs can be tuned, unfortunatly its a 5 hour job.

John

iTrader: (17)

Interesting - sure it's not slipping a bit and not transferring enough torque the outside wheel?

Asterix

You know you can adjust how much a posi locks by tweaking how much slip additive is in the oil? It's a lot easier than taking the whole thing apart. Start with Redline's NS oil, get the slip fluid, then add little bits at a time until you're happy. Or, get a quart of regular (with too much slip added) and and quart of NS, then mix until you're happy.

Asterix

daveh

iTrader: (9)

Yup, know about that trick. I added some the other night to get some slip out of the 90% config that I have now. I think I've got it to where I want it.
I also have the option of changing the break away torque since I'm in the middle setting right now.

1cockyZ

iTrader: (46)

This is a really informative thread. I have a question. If left at 100% lock with the lowest initial torque setting and some friction modifier added, would it behave like it does now with the friction surfaces reduced? Also what setting would you say most closely resembles the characteristics of the stock vlsd. I actually would like to start there. And what oil are you using?

dklau33

iTrader: (17)

Nice work dave... burning the old midnight oil again huh?

daveh

iTrader: (9)

No, if you start at 100% lock, the diff will always be very strong no matter what you set the break away torque and no matter what fluid you use. To make it behave like the vlsd, you would probably want to set it at 30% lock, but then again, why would you buy a clutch lsd if you want it to behave like the weak vlsd??
A lot of this seems like personal opinion. Sport compact car had an article where they kept reducing theirs until they got to 30% lock. That seems way to soft to me. Many of the cusco owners on the board have gone with 80% and they report that it is too strong for their taste.

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

It really depends on how you want the car to handle and what you're using it for. My recommendation with the nismo for someone who does street and track would be to get the plates wpc treated and go with 80% (7 out of 9 working surfaces). You will never spin an inside wheel, still have good turn in, and not have too much chatter. For a track only car, I would do the 90% that I have now or just keep it at 100%. Tire choice also plays a role. The stickier the tire, the more lock you can use (as sport compact car also discovered). This season, I had to move to down to a 255 RA-1 so I felt like the 100% was too strong. It's also interesting to note that cusco includes in their instructions on how to change the lockup to 80% or 60%. I think the nismo should have the same.

saberphx

iTrader: (5)

Wish I read this a week ago when I had the lsd awaiting install. Oh well

daveh

iTrader: (9)

Track update:
the 90% config worked out well for me at thunderhill. I was able to dial out the remaining oversteer with shock adjustments and the lockup was ok, if not a little too strong.
I would definately recommend the WPC treatment to the clutch plates. The LSD stayed smooth all weekend long and isn't any louder than it was before the track time. Engagement still happens, just without the audible 'broken diff' sound. That's all for now.

hippie

iTrader: (9)

Hey man, I may be wrong, but the 2nd pic in your #4 post looks like the diff is set up 1way.

The shaft that supports the spider gears has a flat side and a round side. In a 1.5way the flat sets against the sloped edge of the side plates and the round side sets against the flat edge of the side plates (the notches the spider gear shaft sets in)......lots of spreading under accel and some spreading under decel.
Your pic looks like the round edge is against the slope and the flat edge is against the flat part of the notch.....no spreading (plate friction) under decel.

I only noticed it b/c I just finished setting up my new cusco rs for install......1.5way, 80%




mike

edit for pic

daveh

iTrader: (9)

You're making me nervous here. This is a picture of what it looked like when I took it off of the car. It is set up as a 1.5 way from the factory. I don't think the pin is reversable in the nismo because it houses the break away torque setting adjustor. I believe the way it works under decel is that only one side of the clutch pack is activated, hence the half strength under decel. It worked that way when I moved it by hand while it was apart.

Also curious what cusco considers to be 80%. I'm assuming it's 7 out of 9 friction surfaces, or the way I had mine set the first time aroune.

edit: if you look closely at the picture below, you will see that the notches are separated from each other and contact the pin at the rounded portion. The cusco has the flat portion of the notch touching the flat portion of the pin, hence no outward force, or locking)

hippie

iTrader: (9)

I didn't mean to make you nervous......It just looked different from what I expected since cusco makes the nismo.(I think) I see what you mean in your edit. The side plates in a nismo are farther apart and contact the rounded edges of the pin, not the flat.

The cusco has 10 plates on each side (like yours) so the adjustment should be the same. The order for 100%.......TsTsTsTsTs
80%.......TsTsTsTTss

I'm curious......Does the breakaway adjustment preload the clutch stacks from the outside of one of the spider gears? The cusco has small springs between the two halves that sets the preload. I'm wondering if changing those springs would work the same as the nismo adjustment.

mike

daveh

iTrader: (9)

The breakaway adjustment sits in the middle of the lsd. When you adjust it, it basically expands (maybe .25mm) and adds more pressure to the plates. It is the equivilant of adding a spacer but without the need for a breakdown of the diff. I've never seen the inside of a spring loaded diff but I would think that changing the springs woudn't actually change the breakaway torque, it would just change the speed at which it locks. I would venture to guess that adding a spacer/shim to the cusco would be the way to change the breakaway torque.
Here's some good reading on breakaway torque.
http://www.gordon-glasgow.org/lsd4.asp

hippie

iTrader: (9)

I'll have to do a little bench test before Installing the diff. The springs are putting pressure on the clutch stacks.....the question is how much.

interesting link

ZSpectrum

iTrader: (4)

How effective will an lsd clutch or gear type be for autox/ road course racing. Benefits as well as disadvantages. Also which ones do you reccomend.

vaughn1576

iTrader: (3)

The benefit is greater grip when exiting the corners. I don't know of any disadvantages for autoX.

ZSpectrum

iTrader: (4)

Ok thats what I was thinking, but was wondering about any disadvantages. I was also wondering which type would be best for a daily driver, and which one of that type. Like gear or clutch and then brand. I have a base btw. What all would I need to install it?