i never argue that ACD wasn't a true 50/50 when locked.

if Viscous Coupling is a true 50/50 split, then why can't you dyno your car on a 2WD dyno, why do you need a Viscous Coupling Eliminator to completely lock the diff to be able to dyno on a 2WD dyno? Viscous coupling is a Limited Slip Differential. More power is going to go to the wheels that slip, unlike a Full Locking diff where power is always 50/50 no mater what.

look at the bottom of the page to see the VCE.
also, look for the SPOOL on that same page which is use for locking the front and rear wheels so they turn at the same speed no mater what (50/50).
http://www.teamrip.com/GENUINE_FACTORY_AWD_PARTS.html

 

honda-guy you are wrong you need to look at the thread the OP posted
and it will set you straight

 

Open diff - 50:50 no matter what wheels have traction
Spool - anywhere from 100:0 to 0:100 depending on available traction

Honda-guy, I will ask you again. Please leave this thread. If you continue to post I will ask the mods to delete it all.

EVOlutionary

 

this thread exclusive to Cusco unit or would you be interested how the testing goes with the GSC 40/60 center diff?

n

 

Nils, I would appreciate any information you can share. I am just trying to compare torque transfer capabilities of the stock VCU vs. ANY aftermarket diff, be it Cusco, KAAZ, GSC.

I actually was not aware that GSC was working on one. Do you have a link to it, or can you share any info? Does it fit in the stock front diff location, and then you remove the VCU or ACD?? Also, is it an open diff or a true LSD?? Thanks!

EVOlutionary

 

to be honest with you I dont know too much about it.... this is from Greg:

2007 Gsc Product Release Calendar

Feb 7 - Evo Center Diff
The GSC 40/60 center differential transfers more power to the rear of the car than stock and maintains it. Works with ACD and non ACD cars. Designed for Road Racers to help control the power distribution and finally get rid of that push
Price $1995

I'll try to point Greg over here so he can comment on it.

I will be testing it in 2 weeks on road course... will update with info in this thread.

n

 

Yep, I saw that release info, but that is all I could find.

Please do keep us updated. Perhaps GSC would like to have it tested on the Solo2circuit! I am interested if it is the same as the Cusco unit (open gear only for tarmac) or if it some other design. Plus it is $1500 cheaper than the Cusco unit. . .

EVOlutionary

 

Evolutionary the main thing you need to understand is that the Cusco diff is setup for cars with AYC. our cars dont offer that so the diffs are slightly different as far as ratio's. as far as Kaaz i didnt even know they had one avalible. I'll run threw this thread and see what questions i can answer, or better yet what is being asked.

 

Sorry, I was under the impression the Cusco 35:65 tarmac gear was a stand alone unit that replaced the whole VCU or ACD system (as in could not be used with either the VCU or ACD). As you are surely aware, there is very very little info on the Cusco stuff in the US marketplace.

To save you searching, here are the questions I have about your new unit:
- How exactly does it work?
- Is it an open diff or an LSD?
- If LSD, what style? Helical? Clutch? VC?
- If you have a 400HP/400TQ EVO with the front wheels off the ground or on rollers, how much torque will be read at the rear tires on a 2wd dyno?
- Can I help you test one out in autocross racing? Doing ProSolo, National Tours, National Championship, Winged Warrior, and tons of local races this year.

Sorry, couldn't help throwing that last one in there as a shameless plug for myself! Looking forward to your input. Thanks!

EVOlutionary

p.s. While KAAZ has d/c their rear diff, they seem to still have a P/N for the center diff. http://www.kaazusa.com/products/Kaaz_Product_List.htm

 

Regarding the Cusco Tarmac unit (open center diff):
If the rear tires break loose, they will just spin and no power will go to the front wheels. Is this correct? In a 2WD car with an open diff, once one tire starts to spin, it ends up getting all the power because the open diff has no mechanism to divert the power to the other wheel. The power flows through the path of least resistance- the spinning wheel.

Regarding the S-AYC- how does that affect the center diff? I was under the impression that S-AYC was simply an electronically controlled rear LSD.

 

I don't really know. I believe that is how it works, but not sure. That's probably why it's sold/used as a tarmac gear - because it is open you want all 4 tires to have similar traction. There are a few in use in the USA, but so far to my knowledge no one has written up a review of exactly how it made the car handle.

 

i also would like to know if GSC's diff is going to use the stock VCU, making it a "true" lsd. you can have a different torque split front to rear with an LSD, but usually what i read about them is they are just open.

 

OK, this all seems to be as clear as mud and it seems that the addition of a center diff makes the whole works exponentially more complicated.

Now I KNOW this maybe off topic and if it is please scold me but the topic of other options has come up which leads me to ask about torque biasing differentials be they front, rear or center.

Quaife makes front and center (that I can find) for the EVO 8 and they state that their center diff eliminates much of the complexity of the clutch system which leads me to believe that it has no interaction with ACD, AYC or any other group of letters aside from traction.

Maybe someone would care to toss some thoughts at this in relation to the topic at hand? Anyone running any of these as my prior exposure to Quaifes would lead me to want to use them again.

please note, I think they have the pics and a little info bass ackwards in these links as the center seems to be the front and the front seems to be the center.

center- http://www.quaife.co.uk/Mitsubishi-L...B-differential

front- http://www.quaife.co.uk/Mitsubishi-L...B-differential

rear- none listed.

 

Center Diff - from the looks of it they show a center or front diff in the picture, but not an evo front diff. Very interesting in the tech dwg they say there are 14 bolts, well per my 2003 manual there are only 10 bolts.

Front diff - the picture is wrong, the tech dwg looks to be correct.

Still no real info though.

 

quaife's are helical/torsen diffs usually i believe, so they will transfer power when all wheels have grip, but cant when you loose grip. its all contained in the actual diff, whereas the stock uses a seperate Viscous coupling unit, or the ACD unit to make it an LSD. thats why it would be simpler. (center diff-wise)

also, AYC, is actually in the rear diff, so it really doesnt have anything to do with the center diff, until you look at how it interacts with the ACD. but AYC was on evos since the evo 4, and ACD wasnt available till the evo 7. AYC can function on its own, basically.