Exhaust mods? Yes or no?
 

Ive been working on my Peugeot 106 Diesel today. I noticed it has 2 ehaust boxs, one in the middle and then the back box. If i remove the middle box will this improve gas flow and help make the car more efficent? Ive know alot of people remove the catylatic convertor to improve preformance and mpg so i woundered if this would have the same results?

Thanks Owen

hi owen

I would keep the cat if it has one and ditch both silencers if you can put up with the noise, quite common on turbo diesels to get the turbo to boost earlier in the rev range by reducing back pressure, although on a non turbo 106, it might not make much difference.

I lean more to the enthusiast side of the game. Knowing the engine is an air pump, IMHO, removing restrictions on the exhaust side of the equation should increase efficiency of the pump, provided the exhaust sizing stays appropriate for the engine. 3" exhaust on a Metro would not be beneficial from a flow standpoint.

Removing resonators (extra mufflers) should reduce restriction, and increase the overall flow, which should be beneficial, provided the existing system is not oversized, and the resonators are actually putting in some needed backpressure. Since OEM's tend NOT to put oversize exhaust in vehicle from a cost standpoint, I would think it a safe move to remove the resonators for increased flow.