And on bikes (2 strokes) the shorter the rear silencer is the more low end power it will have and its thet same the other way, a longer silencer will give more top end power.

on turbo cars the less back pressure the better as it allows the turbos to spin more freely
Thats why evo's and skylines have massive exhaust systems

Back pressure is a bit of a science! My general understanding of it is that it moves the powerband about... more back pressure means more low down power (take off) whereas less usually means more power topend when overtaking etc which is why most race cars tend to reduce back pressure as they are always running high up in the rev range.

Only experience I have is that I ran a straight thru system (with the CAT) on my 1.2 16V and it seemed to make it slower than with a std system. I know that backpressure is VERY important in the bike tuning world...

Thinking about it I do know a fair bit about ICE and enclosures and I know how importatnt it is to 'tune' the port when you have a vented enclosure - I believe its a similar effect.

No one? :look:

Afternoon people

Back pressure..

I know back pressure within an exhuast system can happen at certain time but can someone please explain to me how this happens and what effects this has on the car?

i.e how do you know if you are losing power due to back pressure?

Thanks for any help it would be much appreciated. :)