should it spin the wheels

Here is mine with the worn diff,still sending a decent amount of power to the rear to get off the line ok.

I suspect a good center diff would of maybe of spun the rears aswell but as above there is only so much it can handle in terms of power and rear grip, and with the open front diff it will always most likely spin a front wheel first before the rears.

Mine is 303bhp at the moment
And looks just like yours did when i launch.

I suspect my suspension ain't helping tho. Really stiff front and softer rear . Nothing i can do to adjust it

And it is defo putting power to the rear wheels as it goes like fook even tho it's spinning

I would not worry to much tbh mine was perfectly drivable still a lot of gtir's are the same imo,a good center diff would just send more of the power to the rear instead of losing it out the massively spinning front.

The center diff that came out of that box was noticeably leaking fluid though and would of only got worse.

The one thing that makes me think ...
Is i remember driving it in rain and putting foot down going round a corner up hill in second and front wheels spinning a little .
We are taking a little spin not loads

This is when it was circa 340 bhp  as it came onto full boost.
This was before clutch started slipping

.
Could this actually make car feel like clutch is slipping?
Is it my clutch?