Lets talk Difs.

[decathect]

I'm talking a 2004 RS differential, LSD from the factory. Cheaper than $1200.

 

[Ludachris]

I'm going to try and source a rear Evo 8 diff if I can find one cheap and send it off to Shep. I really think this should be something that we add to a suggested Handling mods guide, especially if cioc has done it and noted how well it worked. Not terribly expensive if you can source the rear diff cheaply.

 

[TSiAWD666]

PM me and I can give you a line on a couple cheap EVO 8 diffs. I ran across them because I just picked one up myself, $600 for the low mileage diff + the cups, shipped. Dirt cheap deal I think I have a line on another for a similar price.

I might recommend based on reading about Evo's and how they play with the diff that you look into adding up to four more plates to the eight plate diff. That's my plan based on the positive results I read about on evolutionm.net

I had thought about a Carbonetic rear diff but I've read they require very frequent fluid changes and for me I just didn't want to deal with that. I did not read any back to back comparisons between that an an Evo 8/9 diff with extra plates, so it might be light years better and worth it to some, but I figured I'll just try the Evo 8 diff for now.

edit - this was directed at Ludachris.

 

[Ludachris]

So are we basically taking the Evo 8 guts and stuffing them into a DSM rear diff case? Or are we using the entire case? Trying to wrap my head around what would have to be shipped out to Shep.

 

[TSiAWD666]

I assumed you knew since you brought it up.

You stuff it into the dsm case, so you'd need to send him a core to work with.

 

[Ludachris]

I assumed you knew since you brought it up.

You stuff it into the dsm case, so you'd need to send him a core to work with.

That's what I figured from what I read but wanted to confirm.

 

[cioc]

Send your pumpkin and an evo 8 diff, and get ready to smile upon its return.

 

[TSiAWD666]

Send your pumpkin and an evo 8 diff, and get ready to smile upon its return.

and Evo 8/9 inner cups unless you want to pay $300+ for each axle new (unless Shep is lucky enough to have some laying around, a bit unlikely).

 

[TSiAWD666]

So I found info about an additional upgrade to the evo 8/9 rear diff, the Max Lock 12-disc kit from Weir Performance:
http://www.weirperformance.com/maxgriplsdkits.html

I've just ordered it and sent it over to Zimmer so he can use it with mine. Reviews say lots of chatter but that's fine by me since this is a track car. Results are more power-on oversteer as opposed to push in the stock evo 8 diff setup and seems to be welcomed by the road racing and auto-x folks. Looking forward to it.

 

[Mike1992]

Any more updates on this? I'm soon to be installing an Evo 8 rear diff in my non lsd 2g.

 

[daplatano91]

What can be done for the rear diff of us auto guys?

 

[TSiAWD666]

Well, what do you want to know about it? I ran it last year for one weekend, so I only have street driving and three days on the track.

 

[Mike1992]

Auto guys can use this as well, as you must swap the ring gear from THE original diff to have the correct gear ratio.

I'd like to know if the swap was noticeable for a dd. Also launching, does the car seem to have more grip and go?

 

[Ludachris]

I still haven't found a good deal on an Evo rear end. If anyone comes across one for under $500 let me know!

 

[TSiAWD666]

What I have is the evo 8 diff with weir 12-disc upgrade using the evo oem spring plates and Heavyweight Shockproof diff fluid.

About the only commentary I can make about it on the street is that it makes a lot of noise during low speed turns. This is from the plates locking and unlocking as you've now got a very high initial torque before the plates will slip. People may ask if your car is broken. It's not a big deal to me honestly, but you might be annoyed.

I did recently add some Redline Friction Modifier to my diff fluid which quieted it down tremendously.

I don't really drive fast on the streets in this car because of the splitter and that I am a cop magnet heh, so I can't say how it will handle in spirited street driving. The Evo guys love it for auto-x because they say it really makes power oversteer easy and I believe that will be the case for a DSM as well. Why? Well, it really does make power oversteer easier especially on a car with street tires. See, I drove with this thing last year on 285 wide street tires in a time trial event. Turn 3 going maybe like 80 I can usually get on the power at the apex and power through with a stock diff. With this I immediately noticed the rear wanting to come around. Then later after a high speed uphill esses section that ends in a right hand turn I'm going 120+ and I usually can be mid to 2/3 throttle at apex but when I did it this time boy did I pucker as the rear starting coming around. I was definitely counter steering and drifting and it was scary! Same thing happened seconds later on the next turn.

Takeaways from my track experience?
1) Might just need to re-learn to drive. This diff might be making things faster as it is, but I'm not so inclined to believe that. So next option...
2) Lessen the initial torque. I've done research and it's actually common to experience this much oversteer from an upgrade like this, and the ways to work with them are many: stickier tires, more rear downforce, decrease lockup torque by disabling some of the plates (flipping a few to deactivate their friction surfaces), adding some different spring plates to delay the diff action (Weir sells then for like $35, and at least one evo owner has tried them and says they helped a lot with my issue), or trying friction modifier.

I've now got much stickier tires, 315 r-compound Nitto NT01, and the friction modifier, and still have some AOA left on my rear wing to try so I'm going to try this out May 18 on the track and see how I like it. If it's still too much I'll start disabling some plates as I want to have this sorted out before the Ultimate Track Car Challenge this year in July.

Here's an article that talks about some of the things above:
Project NSX Part 2, Tuning a Limited Slip Differential; Tricks of the Pros

 

[kchaazz]

^^ Have you tried any other fluid in the rear to see how it reacts yet? I dont believe you should use shockproof in a clutch type, mechanical dif like this as it is probably causing it to lock TOO much. Ive got a Kaaz front dif in my AWD, which is basically the same by design, just in the front slot, and Zimmer himself told me to use the Redline 80-140 NS (No slip) fluid in my transmission solely for the front dif to function properly, as this fluid is designed for these sort of difs and allows the plates and clutches to react properly. This is also a GL-5 fluid, so it should work in the rear as well.

 

[Joethefallen23]

It's actually not recommended to use shockproof in evo diffs. OEM diaqueen is the way to go.

 

[TSiAWD666]

Zimmer is the one who built my diff and told me to use the shockproof. I haven't tried another fluid yet, no. I'm aware the evo guys like diaqueen but I challenge you to find some actual track experience justifying liking it. I'm not saying it's not out there, but I haven't been able to find any concrete justification for it. Most are anecdotes from folks saying "yeah, it quieted mine down and hasn't broken!" in regards to their street driven or auto-x cars. That's not exactly feedback I need for my track car so I discount it greatly, and have just followed Tim's choice until I have better reason to deviate.

 

[ForcePower]

Zimmer is the one who built my diff and told me to use the shockproof. I haven't tried another fluid yet, no. I'm aware the evo guys like diaqueen but I challenge you to find some actual track experience justifying liking it. I'm not saying it's not out there, but I haven't been able to find any concrete justification for it. Most are anecdotes from folks saying "yeah, it quieted mine down and hasn't broken!" in regards to their street driven or auto-x cars. That's not exactly feedback I need for my track car so I discount it greatly, and have just followed Tim's choice until I have better reason to deviate.

Been using the Red Line Shockproof oils mixed with Red Line friction modifier in both drag and time attack cars with Kaaz LSD's for several years now. We do however change them regularly, due to the Lightweight Shockproof gelling on us once.

 

[Mike1992]

I purchased my stock EVo 8 diff off evom forums for $450 shipped.

I received it today from UPS and immediately got to tearing it down and re-organizing the clutch plates inside. Installed the ring gear and slapped it in with the original Eclipse bearings and shims. Gonna take it to a local gear works company to have it shimmed and the backlash set the way it should be, as I don't feel capable.

 

[TSiAWD666]

You made sure to get the inner cups with it, right?

 

[DSMReviver]

Does anybody know if they still make cusco center diffs? and where to get them.

And as scott mention the 4 spyder gear might be better option on the road course? I assuming with the stock viscous?

 

[cioc]

I've only used Diaqueen per Shephard's recommendation in my Evo 8 rear. My car only sees road course action and other than relearning how to drive the car, I have no complaints.

 

[TSiAWD666]

Does anybody know if they still make cusco center diffs? and where to get them.

And as scott mention the 4 spyder gear might be better option on the road course? I assuming with the stock viscous?

Not sure if they make it anymore but there is a build flaw in it that leads to premature failure fairly quickly. Until that's solved you probably don't want it.

So without that the only option I think we have right now is the four spider with the stock viscous.

 

[ileagleracing]

Does anybody know if they still make cusco center diffs? and where to get them.

And as scott mention the 4 spyder gear might be better option on the road course? I assuming with the stock viscous?

When Charles ESP car self destructed last year, it trashed the Cusco center diff, and we haven't been able to find a replacement. I believe that Charles was even calling Japan to track one down, no joy.

Samuel Krauss
08 Expedition
04 S4
98 Talon
95 Talon