Bigpower

Lost a bit of terminal speed over the 1/4" mile I am thinking its exhaust restriction
I currently have 2 1/2" system with 3 silencers (although all straight through)

mongoose cat bypass silencer , middle magnex and rear powerflow.

Anyone done any rr before and after with 3 box -to single or 2 box?

Did it for trackday db's and neighbours lol ,but I now think I want to lose at least cat bypass box and maybe 2nd box.

Is it best to lose 1st box or last box or no differance for power gain?
(I was thinking lose 1st box as the exhaust is hotter)

Or maybe complete new exhaust 3" but don't really want the cost especially if the gains are minimum

my powers approx 290-300bhp at 1 bar low boost


cheers
Scott

If all your boxes are straight through there is no restriction unless one of them has gone faulty and dragged some wadding into the flow.
2 1/2" should be fine for the power you have. I have more than that out of my Pulsar with that size.
The only thing i would say is has the Powerflow part of the system got mandrel or press bends in it's construction. Press bends will be a restiction.
Losing a box will more than likely raise db too much. In theory you will be losing a bit of heat in the first resonator box and therefor slowing exhaust velocity fractionally, but not noticably.
Do you think the car has lost power recently. If so, have you changed something?
Doubt your lack of terminal speed is down to an exhaust problem.

Hope you get it sorted. Sticking it on a RR to may help establish where the problem is. Tired turbo perhaps.

Eddy