When returning to a track after the rear diff mod, I got my best lap time from 1.02.529 to 1.01.663. Some of that was me being more aggressive, but I also have no doubt that the diff chipped in to help get me that gain.

 

especially notable if the lap time difference was present as an average of a whole sessions, so that not only your fastest improved, but more or less all of your times are about a second quicker.

My point was just that other readers don't expect to get in the car after that mod and go on a freeway on ramp and feel like its a totally different car. Some might feel it, but I didn't. I still think its an awesome mod, just trying to calibrate expectations for some that are considering it.

 

Has anyone done this mod, then switched over to a TRE or Shep rear diff? I'd personally like to see if there are any major noticeable differences from the people that have done this? Also, if you made more than one change during your diff upgrade what were they?

I'm on the fence about doing this or diff upgrade. I'd like to save some money so this seams like a viable option until I upgrade.

 

No reason not to do this first IMO; if you wait until you're due for a rear diff oil change it'll be free, other than the cost of some gasket maker.

 

^^^^^ What he said.

You can always go to a more aggressive custom diff later. Some might say that you don't need a better/tighter rear diff until you break this one. So maybe do this mod and see how long until you wear it out or break it (track abuse). Then, you need a new one and it will be the right time to get one.

 

^ TRE diff has a raise oil sight and fill....so you don't run the chance of starving the front bearing during accelerations or lateral Gs.

TRE diff also has a HD side bearing and they machine the ring gear housing to accept the much large bearing. This makes your diff WAY more robust when launching.

For the people saying they're the same thing... do a little reading. The TRE is phenomenally better than just swapping plates. Further more most people don't have the tools to set the proper pre-loads on the bearings WHILE maintaining the proper contact pattern.

Take it from me... I have a TRE diff.

 

I'm running the TRE 12 plate max lock with a Gruppe-S ACD controller and combined they help the car rotate quite a bit. In the 'Off Ramp' turn at Buttonwillow I'm at WOT in second gear as soon as I cross the apex. It's pretty ****ing nuts.

 

^^^
ACD reflash (mine is from ACD tuning) in combination with the TRE Max-lock is unbelievable. Car is totally altered dynamically - for the better. Can get on the throttle so much earlier

 

Don't think anyone is claiming the stock re arrangement and the customs are the same thing. At least not in this thread, or the ones related I have read.

I tried the Gruppe S ACD ECU at Big Willow and it makes more of a difference than I feel with the diff plate mod, at least to rotate. But comparing that to the diff plate mod dollar to No dollar the diff plate mod wins out.

 

I did the rear diff mod (OEM 8 Plate) today and tested it out after doing some figure eights to break it in. I now have power oversteer!!

 

Thats a pretty impressive simple demonstration. Too bad you don't have the same one from before the mod. Someone who is doing this, should video something like that before and after. That would be interesting to see.

I am assuming before the mod you would have just pushed doing that.

 

Yep, I attempted it a while back at the same place when I first bought the car and it would not kick the rear end out at all. The real catalyst for me doing the mod was a little 2.5 mile closed end road near San Diego I call the "Eastlake Proving Grounds" (Wueste Rd) where I have tested suspension setups for years. I was pushing the Evo there last week and on corner exit really noticed the understeer. I am excited to test her out soon and see how she handles differently.

I could rearrange the plates for you and get another video.

FYI, this was with Diaqueen and there is absolutely zero chatter or clunking. I am not sure I would want the car with more lockup than what it has. I came from a RWD car (Charger SRT8) and I like the "predictability" of the Evo now over the SRT8.

 

I have the 12-plate diff and reflash from ACD tuning. I asked Matt for an agressive setting on gravel and super agressive on snow while leaving tarmac as OEM. I have ended up just running the super agressive (snow) one all the time on track. I grew up driving old school RWD cars and with the diff and reflash these cars are truly AWD, throttle steering on command.

Oh and I run Redline NS (No Slip) in the diff as well, did I mention I like the rear end active?

 

I recognized the area in the video, my friend lives in IB. So you didn't make any other suspension mods for your before and after impression? I noticed my car much more active on long sweepers so that I can adjust the apex with the throttle, but I changed so many things during my build I can't really say which it is. Rear bar, bushings, struts, or this mod.

I also don't have any clunking or chugging that others have referred to. I am also using the dia queen.

 

I will be dropping the diff next week and am a bit confused about the bushings. Car has 75k on it so I figure while I'm down there I might as well put in new OEM bushings (I hear the poly ones make the car unbearable on the highway).

Which bushings do people refer to when they talk about replacing rear diff bushings? A, B, C? All? Figured this was a good place to ask.