Torque Converter Compatability and lowering stall speed.

[Kozy]

Hi all. Fairly new to Legacy ownership having bought a 2008 3.0R Spec B earlier this year. I went with the 5EAT option over the 6 speed manual and for the most part, I like it, but I find the torque converter to be significantly more mushy than my previous car, an E39 BMW 530D.

 

After looking in to how they work I believe the more direct feeling of the transmission in the BMW to be down to a lower stall speed to suit the Diesel engine, and this got me thinking about modifying the Legacy TC to have a lower stall speed for a more direct feel.

 

Now, first up; I know that the usual route for TC modifications is to increase stall speed for better launches, however I have never and will never go to a drag strip in this car (I live in the UK and drag racing doesn’t really exist here) and don’t generally enjoy hard launches anyway, so would be happy to sacrifice a bit of performance.

 

I know that I can send the stock TC off to a transmission shop and have them modify it for a lower stall, but one other consideration was whether the TC from the 2.0 diesel would fit. By nature of the fact that Diesel engines only rev to 5000rpm, it would seem unlikely that the diesel TC would have the same 3000rpm stall as the H6, and with them being broken at an alarming rate with the crankshaft issues, I figured this could be a cheap alternative, provided the unit physically fits.

 

Anyone have any thoughts on the matter?

Edited October 15, 2019 by Kozy

[Kozy]

On further research, it seems the Gen 4 diesels were never mated to the 5EAT, so that puts a firm stop on that possibility.