what size brake lines should I run?
 

Going to be putting brake lines in the new race car. What size should I use?

...any factors influence what I should use?

Stock 911/930 lines are 3/16(~4.5mm), if you are using larger calipers like 993 then 6mm(stock 993) is nice but not necessary

Bill -- Are you talk'n ID or OD? Calipers are GT3R (4 piston) front and 993RS rear.

Never thought about it, when shoping just ask for. Metric Threads, Bubble Flare 10-1.0MM, 3/16” line(aka 4.75mm) or 6mm line

i used an-3 stainless/teflon hoses through the whole car - no hard lines. the typical porsche caliper and master cylinder is 10mm threads. pegasus racing sells standard pre-made hoses with the ends already crimped on in many different lengths. you need 6 total hoses if you have a proprtioning valve.
-matt