+1 on the header. I bought it for the quality and the decent flexible braided joint section (and because it looks pretty ), but it made a lot of power, too.it's the header. I suspect this is car has no cat also. Without the header, gotham tune on these cars is 237whp (w/decat). Header adds 20 up top which is almost what I got.
i'll know tomorrow probably, supposed to be retuning a 260 211 then.Be interesting to compare with the latest 211 ECU.
that graph does show the irratic nature of the base 255 map but the new 260 one is in a completely different league and makes the car more driveable on the road.
Did you get those gains just from installing the header without any retuning? I have heard repeatedly that the header goofs up the stock tuning, usually running very lean, although maybe the 211 tune is more forgiving.We got 7hp mid range and 5hp peak from the header. The rest is the tune.