My first mod to my car was a 3 inch downpipe. I was N/a at the time. Now this was 5 years back but From what I can remember the loss of low end wasnt really noticeable, but top end pull was slightly better, I noticed much better pull with the plog/DP setup. But Having only run it for 8 months and doing headers after boosting it wasnt worth the time or price. Just get some SSAC's or what ever header you want now so your not kicking yourself in 8 months when you want more power