..”To 3 inch or not to go 3 inch, that is the question” I’m guessing that if Shakespeare were around today, he’d definitely be driving a Polo GTI, no doubt about it. ..and just like in Hamlet, he would have agonised over whether to upgrade his stock exhaust down pipe (DP) to either a 2.5” or 3”, to the point of despair.

Now, ..the majority of R&D and testing by the main exhaust manufacturers and developers have all essentially come to the same conclusion – any bigger than 2.5” on a Polo GTI and you begin to get negative results. However, there’s one case study that has challenged this consensus and perplexed many of us – Timbo’s 3” DP mod. On two separate dynos, his car showed a gain of 13 kw atw with just that mod alone. How could that be?

Anyway, I decided to rework (customise) my stock exhaust and find out the hard way. In summary, here’s what happened:

3” DP – felt amazing up top, absolutely no restriction all the way into red-line. Down low it felt sluggish. On the dyno, there was zero gain power wise when compared to my very 1st base dyno (chip/CDA). …also at 4000rpm, the boost just, well ..died!

2.5”/3” combo DP – this felt a lot better, and gave another 6 kw atw gain, and showed a much improved power curve, eg boost sustained to 5.5rpm. ..although, it still didn’t feel quite right and lacked in low/mid end.

2.5” DP – perfect, a well proportioned increase in power that was spread evenly across the powerband. Yet to dyno but I don’t even feel it’s necessary – it’s spot on!

If you’re contemplating a DP upgrade, my experience may be worth taking into consideration when making that choice.