I was driving in the Wanna Go Fasts event in French Lick Indiana this summer and my car tended to really have a hard time going over 122mph in the 1/2 mile
I was very consistent and would have won some $$ if I were bracket racing but that's another story.
Had a Bama Tune, CAI, downpipe, and exhaust on it during the event. Letting the car cool down between runs didn't seem to help, so I don't think I had a heat soak problem. I tried various launch techniques, burnouts and tire pressures to speed things up at the start but still didn't improve top speed. I think the little engine just runs out of HP at the big end of the track. I think you (and I) NEED more Horsepower!!!
New additions of larger intercooler, turbo piping, wastegate, and BOV have made a seat of the pants improvement. But the weather is too crappy do a "scientific" test and measure the differences in speed and time. These might help raise the boost a bit and improve airflow and lower charge temp for small Peak HP gains, but the biggest improvement comes at mid-range rpm (from what I can tell by the dyno graphs from mfg). So top speed might not improve much, although acceleration should improve therefore dropping 60', 1/8 mile, and 1/4 mile times.
From what I've read, to make significant HP gains and really up the top speed you need to increase the turbo size. Bolt-on parts can only do so much for that little engine and stock turbo.
