Well it ended up NOT being my clutch, the flipping LSD that I JUST installed failed. :( Really damn frustrating. OS Given Super Lock LSD Spec-S is supposed to be top notch. Here's my timeline:

We installed at our shop on 2/11. We put over 600 break in miles then had it on the dyno to have a fine tune in place (previously tuned but I wanted a specific tuner to look over the vehicle.

After the dyno, we drove another 300 miles just regular driving and the first time I went wide open throttle in second gear, we had no acceleration. This was on 2/20 so just 9 days later. I was thinking it was the clutch so we purchased a new ATS Carbon Clutch from Japan that took 3 months to arrive bc of the virus, went to have it installed and have discovered it was actually the differential. So that Diff lasted 9 days.

Has anybody seen this happen? Any recommendations or where to go from here? Reached out to who I bought the LSD from but who knows how that'll go or how long to correct.

Wowwwww!!! BTW Ryan I would've gotten Seb some log runs but it's been 100 degrees if it wasn't raining here so I'm looking for some lower temps. Other than that it's great. Only odd thing is that before the manifold it would peak 1-2psi above target boost. Now it consistently sticks a hair under target, i.e. 14psi reads 13.9, 16psi reads 15.9 , 18psi reads 17.9 and 21psi reads 20.9. (Wierd to me.)


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I changed the lube in mine around a 1,000 miles. Use only the OS Giken gear lube. Have over 4,000 on it so far.

That’s awesome man!! Sounds like it’s holding the pressure better! Curious did y’all run the dyno on the current setup prior to the new manifold being installed? Curious how you’ll know if there’s a power gain

Yea that’s all we used. I was at right about that 1k Mark, even had the fluid in my garage to change it to :\ did you completely stay off boost in that first thousand? I mean that’s the only thing I can think of as to why it failed so quickly. Maybe I did the dyno pulls too soon and needed to break it in more? Seems like 600 miles would have been plenty. Unless OSG dif is literally that fragile

Guess you'll find out for sure when you drop the diff. Would love to see pictures.

My car went from OS Giken install to right on the dyno with zero miles on it. No issues at all. I've put around 500 (not break in miles) miles on it since. I'm getting ready to change the fluid and it's going back on the dyno.

Awesome! Thanks for the insight. i was really hoping some had experience with this and puts me at piece of mind that I didn't do anything wrong.

Exactly, that's the frustrating part of it, I don't think the shop opened it up to be sure. They replaced the clutch, found that the car was having the same issue. Drained the dif fluid and said it was "burnt black" like it toast and then claimed that was the issue. I feel like there should have investigating.

I'm bringing the OEM dif back to him tomorrow so hopefully I'll have more info then.

No issues with mine and I have over 30k on it. Only the last 7k with the built motor etc. I did install a diff cooler during the TT install.

Yea that sounds like a must! We never got on it enough for it to burn up this fast BUT before we go to the track, I’ll definitely want to add that!

I have a diff cooler too with gauge. When it's 90F, the diff temp will be around 250F after about 30 minutes of driving at 65+ mph. Turn the pump and fan on. The diff temp will drop to around 190F.

Mine is setup to be automatic. Comes on via a thermister. I have an override switch just in case.

Make sure you have the correct stub axles in it. Z1 did my install a long time ago.

That’s a hell of a difference man! I definitely need to snag one up!

MA-Motorsports can hook you up.

Yea man, with the way he took care of me with my clutch, he’ll be my go to every time! If I can’t get them to warranty my OSGiken LSD, I’ll probably be going to him for a new diff as well.

As an update, it’s definitely the diff. The driveshaft spins, even both rear wheels spin when the entire car is off the ground. It’s when there’s any sort of load the car can’t drive. OSGiken is a clutch diff so we are thinking one of the clutches inside of there is just toast. Sucks man. Putting the OEM back in for now just so I can get on the road again.

Like I said, make sure you have the correct stub axles. If one of them is too short, it will burn up the clutches.

Motor is coming out right now.

Something, something, useless, something, pictures.

Started driving this morning around 11am. Temps around 100F. Once the diff temp got to 260F. I turned both the pump and fan on. Left them on until I parked the car for the night. That's around 750 miles. The diff temps stayed around 190F to 205F. My avg speed was 80 mph. Some places was over 90. :driving:

:worthless:

Lol

You know my response. LOL

;)

I will absolutely look into that! Wouldn’t that cause problems with the OEM dif tho if that was the case?

Hell yes man!! It’s happening!! Love that are coming back stronger than ever!

It’s freaking insane to me that’s how hot it gets at normal cruise speeds. Can only imagine what it’s like on the track

It's ok. Joby sent me pics yesterday :tup:

The OEM VLSD takes different stub axles than the OS Giken. When it was installed, if they just swapped them over, that is the problem. One needs to be changed.

Here's a pic of the stub axles. The one in the middle gets replaced with the one on the right.

I was trying to find that picture earlier. Glad you knew where it was.

It's in with the rest of my pictures.

Engine is out. They had to order a couple more parts to do the swap. They are not wasting any time.

Thinking about the front end lift Aero problem I have. Brainstorming on what to try.

The vents like Rusty has on his fenders maybe?

Has to create aero under the car. Box and seal
Off the front end.

https://youtu.be/lxGwr7yi0UY

Never felt like my front end got light

Stock, I never did either. That is a whole new ballgame now. It may just be I need to make a rear height adjustment so my car won't squat so much under power. I may need to redo the whole rear suspension with better pickup points.
MA can do it but it won't be cheap.

When you can count the tracspec vents in the hood, you might have a problem. LOL

Ahhh makes sense. Tuning

I have never had issues with lift even at 160 and stock setup. Well the stock undertray came unbuttoned that is. Anyway, the only thing was that I was lower on Teng lowering springs. I have seen CFD rendering and the Nismo aero stops working at about 90 to 100mph and you start getting lift from that point. Lowering the car 1" significantly decreases drag and lift but it will still be a factor without a front splitter and removing area of high pressure. The hood vents remove the highest area of high pressure, the next place is the fenders. There is a reason all racecars have a way to remove high pressure from the wheel wells.

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That is why I am leaning toward the suspension setup. it's free, may go with Phunks idea and raise the rear. I will have better traction and an even car at WOT.

Still kicking around ideas. I can lower the front some more. That may be the way to go. I am at 1/8in. rake right now. Maybe I go to a 1/4in. rake.