I've never heard of it being done, plus it doesn't sound like a good idea in general. You could do like Carl Meritt and just gut the hell out of your NA and get it down to ~3000lbs. But if you're just having trouble keeping up in the straights, a TT with stock turbos would give you more than enough extra power to carry you the distance. You could eventually go with a small HKS or Mitsubishi turbo set-up in the future if you want more power and minimal lag.