I gotcha...

No harm done, but I just hate the spreading of mis-information on the internet.

- Steve

 

i know for sure from helping with 2 Clutch jobs on Evos that it is the Front diff and LSD that are in the TC

 

my 05 is making just about 500whp with the ACD with no problems

 

Ahh, the joys of establishing a common vernacular...

I think perhaps the confusing part here (although clear if you view the diagram) is that the ACD clutch pack is in the transfer case while the actual center diff resides in the transmission case.

 

Ok, regardless of WHERE they are, lets get back to the question.

First, can someone identify exactly what parts are used for '03-'04, exaclty what parts were the major failure points, the different parts that are used in '05, and how these new parts affect the failure rate.

I think we are looking at 2 parts found on '05 GSRs that are not found on the '03-'04 GSRs, which are the front LSD and the ACD. Correct my erros please if there are any.

I think 1 post from TRE should be able to explain everything.

 

Can we all get off the "Where is the Diff" subject? This is covered in the top sticky in this forum that I wrote. It's plain as day, easy to understand, and tells you everything you need to know about how the torque is transfered through the drivetrain.

On topic...

I only see one problem with whether the ACD will hold the power or not. The torque at the Center Diff could overwhelm the clamping pressure of the ACD's Elecrohydraulic Clutch Pack. I do not know how the ACD works, but if it gives everyone a warm fuzzy I'll get the schematics out and disect it myself and figure it out.

If the system works as I envision it, a simple revalving of the hydraulic portion may increase line pressure and in turn increase the clamping pressure of the ACD. This will be detrimental to the behavior of the ACD in daily driving, but it will allow it to hold a greater torque load in a drag race situation. This is a similar approach to the revalving of an automatic transmission.

- Steve

 

You know, correct me if I'm wrong but the front differential is completely backwards in a non-ACD equipped car. *If* I recall correctly the ring gear sits on the transmission side of the transfer case housing. Does anyone have a diagram of a transfer case of a non-ACD equipped car?

 

There are two known failure points of the 03-04 Open Diff TC's that I am aware of.

1 - The Front Open Differential's powdered metal spider gears are very weak and prone to failure at high torque loads.

2 - The Ring and Pinion that send torque to the rear wheels have been known to fail when the improper fluid is used, the fluid level is too low, or there was a misalignment of the R&P from the factory.

I know of NO failures of the viscous coupling of the Center Diff.

 

I do, but my diagrams are at home, not at work. I can take a look at it tonight and verify this. But to tell you the truth, this wouldn't work. The driveshaft would end up spinning in the opposite direction. So unless the 05 Rear differentials are also flipped, I find this highly unlikely.

- Steve

 

could this hydraulic line be considered a point of failure if revalving or alteration of the ACD took place. Not 100% sure but wouldnt revalving mean more pressure in the lines and possibly a blown line? These are just thoughts im having after seeing talks of revalving so if im wrong please tell me

 

Ok now that that has been answered has anyone Experimented with a re designed "valve body" that would further increase line pressure as to have almost a "spool" like effect (ie NO SLIP)

I know it would be murder on the drive train but imagine the increased launch power.

 

It could be, but when we're talking upped line pressure I don't think it would be high enough to burst a line. And this is all theory, I have no idea if that would even work or not, or if it's even how the ACD works for sure. But to cover the line burst strength question. Most hydraulic lines and systems are designed with a certain factor of safety. Meaning the lines are rated to hold more pressure than they'd ever see in their intended application. So a nominal increase in pressure shouldn't be a danget to the lines.

- Steve

 

You're correct. The gear is oriented the same in the non-ACD center diff. The big difference is that there is no clutch pack nor viscous coupling in that space. Instead the housing is simply much smaller and compact.

Back to the program...

 

They offer ACD ECUs to modify line pressure thus locking force depending on various situations via the simple click of a mouse.

Regards,
Max Cudich

 

Tada!!!!

Now does anyone know if these are compatible with US cars? I've seen them for sale before.

- Steve