Upgrading the 3 speed automatic transmission

I followed up with the company who rebuilt my transmission and viewed my receipt. We couldn't determine which valve bodies were used. However, if you Google Th400 valve bodies you will see a number of companies that offer them and many note how firm they can shift. Since the TH400 is such a rugged transmission, it is often used in dragsters, so beware you may find some very unusual kits that you should stay away from.

 

In any case these shift improvers are quite simple: it's usually a matter of drilling two larger holes in the separator plate (1.125' in 1-2 and 2-3 feed holes) and pluging the 2-3 acumulator with a step screw. Then play with the checkballs, and finaly disable the mechanism that prevents downshift to 1 at high rpm (flatten an axle). Replacing the modulator may help but not the governor as it is already highly tuned in our cars.

Any further upgrade requires to open the gearbox.

All in all that's quite basic, and the kits are very simple. They are good value for money though: sourcing the parts individually is more expensive.

 

Thanks again Raemin,

as told I'm waiting for the new torque converter before going on with any other mods !
Yesterday I faced another problem as I discovered the car wouldn't start when hot if you leave it for say half an hour.
It works fine if you either do it 5 minutes later or when cold but impossible after 30 minutes.
I suspect some vaporlock here ??
I'll talk to the guy who rebuit the complete fuel lines (injection)
We'll see.

Another thing is I replaced the rear Koni shocks (not too expensive)with some new ones but the price of the frt ones seems prohibitive
and I don't see the reason ???

 

Nice write-up by Steve M.:

https://www.ferrarichat.com/forum/threads/mondial-83-qv-fuel-pressure-regulator-question.704154/#post-150042442