Hey C5 friends.. I hope for a good advice.
I have a C5 automatic with the stock converter but now we have tuned the car and need another converter… But wich size to at car with these modifies:
IT IS VERY IMPORTANT THAT IT IS FOR DAILY DRIVE… Not a racecar, but I need Maximus HP and Torque out of the things I have already done to the car.

Vararam airfilter
LS6 intake / 80mm schrottle
Ported cylinder heads
Roller rockers/Lifters
Bryan Tooley Stage 2 camshaft
Stainless Long headers
Racing cats
Stainless X Flow
Corsa Extream exchaust

Hope for some good advise
BMS/Denmark

 

I have many of the same mods you listed (and other mods, too), and use a Circle D 3200 rpm stall Torque Converter (TC). Drives fine around town and adds to the “get up and go” when you get on the gas. I also added a B&M trans cooler to offset any potential heat build up if stuck in a lot of traffic.

Edit: I was trying to answer this on my iPad and and not the greatest typist on the small keys.

I would suggest talking to one of the techs at BTR about the converter stall speed they recommend. Unless their guidelines have changed in the last few years, a BTR Stage 2 can be driven without any upgraded TC, but you may have a little bucking at slow speeds; especially like a parking lot with speed bumps. Part of their recommendation is going to be driven by your intentions with your car - if you are not going to be doing any real drag racing (sanctioned - on a track), you may not need to change TC or you may just need a slightly higher rpm stall. I used the higher stall TC primarily for times when drag racing the car since the higher stall allows me to get the engine into a higher rpm range where the engine is making more horsepower.
Your current torque converter is approximately 1800rpm stall speed. Chevy used to have a TC with about a 2200rpm stall which may be sufficient but I am not sure if it is still around.
I did not notice if you mentioned your rear end ratio. The base gear ratio for the C5 with A4 is 2.73, with a Performance Option 3.15. You can look at your RPO list on the drop down glove compartment door. If it shows GU2 you have the 2.73 ration; if it shows G92 you have the 3.15 diff gears (assuming a prior owner did not change to another gear ratio).

For more information about Torque Converters and how they work - and how they affect vehicle performance your may want to look at: https://www.onallcylinders.com/2016/...r-stall-speed/ (this is part 1 of a 4 part series on TCs).
https://garage.grumpysperformance.co...ll-speed.1715/
And, https://www.tciauto.com/stall-speed-chart offers a simple guide to TC stall speed selection based upon the cam duration, rear end ratio, and basic engine characteristics.

 

Moved to C5 Tech for more assistance.