What's the story behund back pressure. I mean, do you want some back pressure or is having zero back pressure the way to go? i was under the impression you wanted to have some back pressure, but recently I was told you wanted none. Just confused. Thanks

 

you want none
however you dont want too big of an exhaust as you want the pulses to help
each other.

 

By pulses you mean the energy from the exhaust helping to pull exhaust out of the other cylinders? Same principle as a Mustang V8 using an X-pipe right?

So then theoretically (sp?) a test pipe should produce more HP than a cat? how does having zero back pressure affect torque? Will you loose torque with less back pressure?

 

you dont lose anything if the pipes are setup properly.
the "loss" you feel is all mental i assure you

 

You don't need backpressure! The only thing you need is to preserve the wave (pulses) energy from the exhaust gasses. This means don't narrow and don't widen the header tubes.