back box extra power?
 

just a quicky,i got a 2005 wrx completely standard,except there is a cobra back box on it,5 inch tail pipe very loud deep base burble love it, how much more power would be expected from this mod? have anyone been on the dyno with increases in power.??

No extra power, just noise.

the reason for the question is that my insurance want another £90 because of the mod? stating that because the pipe is wider and its louder than standard it will increase the power,and from their point of view that is final.only way i can prove it is to get it dyno,d with printout to prove,i think its a rip off myself.

There will be no increase in power at all. If just the exit of the backbox is wider the gases will have reduced pressure for the last 6 inches of travel from the manifold, which will not give any more bhp. Make sure they know it's just a backbox and no change in CAT or centre pipes. Or call the manufacturer of the backbox up for an honest answer in writing.

Or tell them to stick it and call Keith Michaels or Green Light and change to a proper insurer, that'd be my option :thumb:

well luckily i haven't parted with the £90 yet,i had a feeling something was'nt right about what they were claiming.i am with esure.

They're pretty tight on mods then! I assume they'd do the same if you changed for a better air filter. Which will give you around 2bhp more :) I'd look to move insurer or give them something to really put your insurance up with and get a sports cat too :)

i will have to have another chat with them,as it does make sense that as long as manifolds and cats are standard then there will be no increase in power.i will try to convince them,wish me luck.