Larger exhaust For Diesel????

[welshdragon1611]

i have been given a reasonably large exhaust (4inch diameter on exit pipe,with small back box,if this is relvant) and i want to fit it onto my golf.iv got a mk3 1.9 TDi and was wondering how its going to sound if anyone knows??as iv been told it may not affect the sound at all as its a diesel.thanks daz

[S2AVANT]

It will affect the sound, but the turbo is a good silencer.

[welshdragon1611]

cheers, so it will be louder?how do you mean that the turbo will be a silencer?

[devonutopia]

Exhaust doesn't need to be too big. Mine is 2.25" straight through, with no fittings, and this is fine for me to push into the high 200s bhp.

TDIs generate enough back pressure through the turbo alone, so having an exhaust that maintains back pressure is not relevant. The best exhaust is the one which gets the exhaust gas out the fastest.

[ini]

I would go for a straight through (no CAT or mid box), but keep the backbox.

Your turbo will spool up quicker.

[Lord Nelson]

Just out of interest,
what would be the situation with an MOT if there is no CAT?