Here's an Idea if you've got money to burn and want an extra boost.
Try putting in an electric supercharger in line with your turbo. This will eliminate the Turbo lag, compensating for the time it takes the turbo to kick in.
Also handy for when you want that extra bit of power, only downfall is you need to wait for the batteries to recharge and it’s very pricey.
Take a look at: http://www.boosthead.com/home.php