I've attached video and the noise is faint, but you can hear the whine on decel. When I say acceleration in the video that also includes steady state driving so as long as it's not a hard decel there is no noise. Example, cruising down the highway in 5th gear and I don't have a noise unless I am going down a hill and the car is under a hard decel.

 

Thank you so much for the video I really appreciate that. It is not bad but it is probably louder when you are in car than what I hear. How do you like that 4.08 final drive? Aren't gears are too long? I dont know about your engine/turbo setup, but I have 2.0L build engine with 6466 turbo and it is making around 700whp on stock final drive. It feels like I need a little longer gears but not too long. Thats why I was thinking about 4.30 final drive but only mfactory making them. I found 4.11 final drive with helix angle direction same as stock so I think this final gear will not make a noise but I think 4.11 will slow the car down, and I cant decide what to do.

 

Thats pretty loud. Do you have all aftermarket motor mounts? I'm running stock mounts except for a front mount.

I ran the 4.31 final drive and didn't notice any more noise then usual. My rear diff has a slight whine on decel but it doesn't change between the two transmissions I've run. 4.31/4.11.

FWIW, A 4.11 from mitsubishi is full helical.

TRE built the 4.31 trans from a new evo 8 trans so maybe I got lucky?

 

Is your 4.31 from Mfactory? Or different brand. What 4.11 do you use that is from Mitsubishi? Oem Is 4.5 right?

 

My setup is a 2.15L stroker with a S362 SXE (6268) so fairly close to what you're running and made 600@wheels on 93 pump. When I ran the 6668 turbo it made 663@wheels on 93 pump. Part of the inspiration to change was that at the drag strip I was having to wind out the car to almost 9K in 4th to avoid hitting 5th at 131.8mph. Unless you car is a dedicated track car I don't think you're going to notice a huge difference when going from the 4.53:1 to a 4.11:1 despite what people say. For other platforms, a 4.11 is considered a very high (numerical) gear and the old school Z guys prefer a 3.54 or 3.70 on a turbo motor because it helps generate additional load for the turbo. However, my back to back comparison of the 4.53 to 4.08 showed absolutely no difference in spool.

It is louder than the video gives credit and I run new factory side mounts, megan rear mount (close to stock), and hardened front mount. The setup initially didn't have any noise until one day I gunned the car in first and the noise suddenly appeared. I put it on my buddies lift and we confirmed the noise was originating from the trans and not the transfer case.

 

yes, the 4.31 is Mfactory

4.11 is OEM Mitsubishi. I can't recall the part numbers but they are online somewhere.

OEM is 4.53

 

That is odd. Maybe its even louder because of the rear mount.

 

The Megan rear is not much stiffer vs stock and the noise is audible outside of the car as I confirmed when it was on the lift.

 

You 100% sure it is from trans not t case? When my t case failed, I started hearing noise from read diff, so I build rear diff and noise was still there, so I put the car on lift and I was hearing noise coming from transmission. I have another spare transmission so I install it and noise was still there so I finally opened my t case and 2 tooth's were missing hahaha. I should have check it first, but I learned my lesson.