LT1 open header question

How much will running open headers (uncapped) on my LT1 help my ET/MPH?
I have longtubes.

* I gained 00.10 (a tenth) after I removed the cat and another 00.10 after I opened my cutout. I still have the stock catback and muffler. I noticed that my muffler was hot after I made a pass, so some exhaust must still be flowing through. I'm sure I would gain something just because of the weight gain.
Thanks, Mike

http://memimage.cardomain.net/member_images/11/web/467000-467999/467742_37_full.jpg

I dont have any number answers, but the stock catback weights like 50lbs so there's about 00.05 sec right there. If you can get your car to not pull timeing then you should gain some hp, especially up top. You might want to raise your shift points a little to get the most out of it. You could run open headers on the dyno to see where you make peak hp.

I gained 2 tenths in the 1/4 running dual-open collectors w/ 18" extensions over the Y-pipe (no-cats) and a single cut-out. I have Kooks w/ 1-3/4 primarys and also lost 50 lbs by removing the Y-pipe, muffler and exhaust pipes.

new best: 11.22 @ 119 w/ 1.61 60ft (N/A)

WD

http://www.cardomain.com/ride/2189634