Hello everyone. I just ordered an iPE valvetronic exhaust system (catback) for my 2012 mini coupe jcw. I am also considering a high flow downpipe but worried that it will make the car too loud even with the valve closed. (The iPE system doesn't come with a resonator) My question is will there be a huge sound difference between the factory jcw downpipe and a aftermarket highflow downpipe? I don't want my car to be loud with the valve closed. Thanks!

 

It's hard to quantify but I think the sound difference is noticeable between the stock and a catless DP. on my old 08 I had an iPE catless downpipe and jcw muffler, it was pretty drony on the highway. The exhaust sounded pretty mean but I don't think I'd be able to handle the drone for long highway trips. However everyone's tolerance is different so best way for you to know for sure is to try it out. Replacing the DP isn't a terrible job, once you do it a couple times.

 

The high flow IPE will be a little bit louder vs the stock JCW DP. But its not like a decat and then a straight pipe loud.

With the valve closed, you will be fine. Now when it opens you can tell it has a little louder tone with the high flow cat.

 

Will there be too much of a difference? Or they sound pretty similar? Because the iPE cat back is already pretty expensive. The high flow is also 1000+ dollars plus money for a stage 2 tune. If there aren't much difference, I'll just go with the stock downpipe.

 

Will there be too much of a difference? Or they sound pretty similar? Because the iPE cat back is already pretty expensive. The high flow is also 1000+ dollars plus money for a stage 2 tune. If there aren't much difference, I'll just go with the stock downpipe.

 

Noise levels are very subjective so a lot of people steer clear of giving advice on these issues. Stage 2 requires a high flow or decat however. Since noise is a concern for you I'd recommend steering clear of the decat. Generally speaking a high flow cat will prevent drone on the highway and mute the exhaust. The amount is determined by the number of cells. The factory cat is 400 cells per inch and high flows come in 200 and 100 cell varieties. The 200 cell results in a large reduction in backpressure with the least increase in noise. If your super sensitive to exhaust volume levels however you may want to stick with a Stage 1 tune and the factory cat.