I see what you mean but if I unbolt the swaybar from the endlinks I might be able to angle it enough for clearance. If it doesn't work I can always try your method.

 

For those looking to replace the drain bolt washers, here are the specs I measured:

Drain bolt diameter = 17.5mm
Fill bolt diameter = 15.8mm

You'll need copper washers that have an inner diameter slightly larger than what I measured, since those are almost exact. The outer diameter is not going to matter much.

 

I had an autocross event today and was finally able to test this mod out in real world applications. My suspicion was that this mod would benefit road racers more. I confirmed it today. With autocross, the turns can be excrutiatingly slow at times, and you will not slide the rear end out until the boost hits. During really slow corners, the boost may not kick in until you are at the corner exit, which you probably don't need rear end rotation anymore.

I was able to capture a video of the rear end catching me off guard today, so I countersteered in reaction to the slide, as opposed to anticipation. This scenario would have definitely been understeered in the past--more gas would have pushed me off line, outward.

http://www.youtube.com/watch?v=uJlZZ7x9OMI

If you have corners that are faster and you're already in boost rpm mid-corner (road race corners, or bigger autocross venues), you'll do better with this mod then. It'll allow you to rotate the car as you approach the corner exit, therefore, letting you get on the gas sooner.

 

nice review. after hearing what you say i think i'd definitely recommend the tre 1.5 way for any autoxers not running in STU or lower. car can break loose whenever, and it will have more neutral/oversteer tendency under decel, since the stock diff is a 1 way. i wish i had a gopro, i'll see if I can post a vid one day of the cusco in action, it's pretty ridiculous

 

What does TRE do to make it a 1.5 way?

 

Upgrade your OEM 8 plate to a 12 plate.

 

IMO You're better off with a TRE MAX LOCK unit.

Reasons for doing a TRE... more plates, rebuilt with new bearings, ring and pinion contact points are precisely aligned, TRE can modify the rear cover to raise the fluid level & add a sight glass, TRE can also beef up the bearing that supports the ring gear end of the diff, by putting in a bearing that can support approx 3 times the load with a CNC'd backhalf. Not to mention gear detailing and shot peening.

You'd have to work for a drivetrain mgfr as an engineer to have a DIY solution that could come close to rivaling Jon's work. But certainly Jon's experience is unmatched.

I sound like a TRE sack swinger because I am. He does amazing work and I think everyone should know it. It transformed my car, and I recommend his rear diff service to ANYONE and EVERYONE with an Evo.

 

Can you add more detail to that comment? How does two additional plates tranlate to deceleration lock up? I need to research differentials.

 

That seems expensive but when you think about how much it is compared to just an aftermarket diff by itself its seems like a steal. How would it compare to an OS Giken 1.5 way?

 

i actually talked to jon a little about this while he was working on my cusco - obviously these aftermarket diffs are gonna perform better, but the TRE 1.5 way is the best bang for the buck. Said he liked the designed of the giken and the cusco very much though, but the TRE is the most cost effective solution.

Again though if you need to stick in a particular class this mod (rearranging plates) is the best bet

 

How our LSDs work is by clutch type.
http://auto.howstuffworks.com/differential4.htm

Since there's more discs, there's more bite. Like how a single disc compares to a twin disc clutch. You can daily a single disc easily every day but when you put 2 clutches in there, it has more friction to grab, which is why twin discs are either "on or off". No smooth engagement.

 

Are you 100% sure about that? I posted in the other thread too

The spider gears mount on the pinion cross shaft which rests in angled cutouts forming cammed ramps. The cammed ramps are not necessarily symmetrical. If the ramps are symmetrical, the LSD is 2 way. If they are saw toothed (i.e. one side of the ramp is vertical), the LSD is 1 way. If both sides are sloped, but are asymmetric, the LSD is 1.5 way.

http://en.wikipedia.org/wiki/Limited...rential#Clutch Type LSD

Seems like its about set up, not just more plates

 

Never said I was an expert. This was what Weir told me when I called him to see if chatter was normal for his kit. If one wheel is wanting to spin faster than the other, the plates lock up and fight it.

 

No offense, just checking.

 

I called my local dealer to see what they would charge to swap the plates.

$1012 + tax

I cant see spending that much to do this. I guess I should just do it myself.