| No, 19% is going to require more work to the rest of your car. The trouble is it's not a simple matter of creating more boost. With the S/C working harder you generate more heat.
A lot of people consider the 19% to be too small as it generates so much heat that the benefits of extra boost are wiped out over say a 17%
With a 15% pulley you'll need no other mods to make it work. The standard ECU settings are fine with this pulley. If you went 17% you'd probably need a remap also. With 19% you'd need a remap and a new intercooler at the least.
It was acceptable in the 80's | 
