lets race!

[Ed Doe]

So *insert other brand* exhaust is obviously so much better designed when it's essentially the same bar the baffles basically and obviously whether it's ss or mild steel etc..

Right, but if the output is higher then like the supercharged boys do, a bigger exhaust gives more power.. okay yeah as you say slightly lower bottom end, but on a cammed engine (usually poorer bottom end than standard anyway) it won't be spinning up down low but when it gets into it's powerband up top anyway, which as you say is where in the rev range a bigger exhaust would benefit you for more power..

The only way to prove it 100% is putting it on a dyno before and after putting the zorst on.. a 2.25" exhaust is probably good for up to 210ish hp before it starts to actually become restrictive

Ok so I was having a bit of a dig at the sportex's, but in general most performance exhausts do change the torque & power curves as previously described. The difference being that a properly designed exhaust for the car will account for reduction in back-pressure in the baffles by decreasing the bore of the exhaust. The key with the exhausts is to keep up gas velocity, hence afaik, they are designed with reduced bore the further back you go through the system.
Baffled zones are zoneswhere the gas pressure can be lost, reducing velocity. Hence they are removed or reduced in performance exhausts, encouraging a higher velocity, which can be better controlled through reduction of the exhaust bore...


As a point of note, you can't compare a supercharged or turbocharged engine to an n/a engine in terms of exhaust requirements. In an n/a engine, the back-pressure plays an important role in inducting air in the inlet side of the engine. Changing this can affect the draw of air into each cylinder, which affects the torque as described... With a any charged engine, the air is being forced in, so back-pressure is irrelevant. there is also a LOT more gas being expelled from the engine after combustion, so the larger bore/less restrictive the better!

You have to bear in mind, Peugeot didn't just cobble together the '6 exhaust from a few spare parts from a leftover 1.4 in the factory... It was very well designed and suited to the car and the characteristics of the engine... and I can't remember the exact figures, but I'm sure I'd read they were good for flow for up to 250hp n/a before they became a significant restriction...