Ok, so a little history on the old setup and the new one. Previously, the truck had this motor, a MPT70 turbo with .68 a/r. Built 4L60e tranny and TB Stall. Race weight was about 5400 with me in it. DA was about 8000+ (track is 4800') Best pass with that combo was 12.2@110mph with a 1.76 60' running 15psi of boost.

Now for today, TVS1900 being feed by BW S475 turbo. 4L80e tranny with 10.5" Circle D single disk 2800 stall. Race weight is about 120+lbs heavier with the blower, tranny and 3/4 tank of gas. DA was about 7800'. Was running about 13psi of boost.

First pass was fresh off the drive up there, track is about a hour drive away. Truck sat about 20 min with getting teched and all then strait to the staging lanes. It was VERY heat soaked, IAT's were hi just sitting there, 130* or so, then made the pass in full street trim. Was a 13.8@100 with a 2.3 60' Leaving with about 7psi of boost. IAT's where 160* at the end of the run which I know was pulling a bunch of timing. So I went over to the convince store across the street and bought a couple bags of ice and than back to the track. I filled my intercooler reservoir with as much as I could and got the water all cooled off and and made another pass in full street trim. Was much better, 13.3@105 with a 2.0 60'. IAT's started at 95 and 120 at the end of the run. AFR was 11.5-12.2 a tad leaner then I like to run, but I didn't bring my EFILive. Timing was about 20.5.

So I decided to see what it would do in normal full race trim. I pulled the spare, tail gate, head light and cutout plate. This was right at the lunch break for the track crew so it got to set for over an hour and cool everything off really well. Was MUCH happier with this run, I left on 9psi of boost and pulled a 12.7@109 with a 1.87 60', BUT, didn't want to make the 2-3 shift and bounced off the rev limiter (6400rpm) 2-3 times and I lifted briefly so I know that cost me a couple tenths. Since I didn't have my tuning software I couldn't fix it . Made another run, but bounce off the limiter a little harder and I didn't lift, so was a bit slower. So that was my day.

Oh, and one other thing, with 13psi of boost and cutout open, had 7-8psi of back pressure BEFORE the turbo


:::Cliff Note, truck ran best of 12.7@109:::