Australian-made 3” Dump pipe, stainless steel, including Spigot flange to the turbo, 3” Race Flex Join (more reliable and durable than braided flex). Allocation for the factory heat shield. Designed to fit the factory location and bolt up to the factory exhaust.
Designed and made locally at Dynomotive.
* May bring on engine light.
Since beginning the development on the Dynomotive/Unichip i30N and the fabrication of our own 4” dump pipe we have always had the thought that a dump this size was overkill for a small 2.0L 4cyl turbocharged engine – over 70 years of combined mechanical and race engineering told us that, however, we accepted what the market was offering and produced what we believe is a dump pipe of the highest quality to match demand but always had the intention to try out a smaller diameter dump pipe.
Most of us are already aware of the power and torque benefits of replacing the standard Hyundai dump pipe with an aftermarket alternative.
We fabricated a 3” stainless dump pipe fitted with a 3” 100 cell catalytic converter and 3” race flex join. After running the i30N on the dyno to gather more accurate information such as power, torque, boost, AFR, and acceleration rate we removed the Dynomotive 4” dump pipe and fitted the Dynomotive 3” dump pipe.
From the graphs below you can see the difference between the two is unmeasurable.
Looking at the Power/Torque graph with the red line being the 4” and the blue line being the 3” the graph essentially draws over itself. There are very minimal differences which I would put down to slightly more or less heat soak instead of exhaust performance. The boost levels and AFR were exactly the same.
The second graph is a measurement of acceleration rate where a set load is applied to the rollers and the vehicle is then accelerated to the rev limiter at full throttle (this load amount is the same for both the 3” and 4” runs). In this case, the vehicle is held steady at 50km/h in 4th gear and then accelerated. Again there is literally no difference when looking at the speed at which the rev limiter is reached (the numbers along the bottom of the graph).
SO WHAT ARE THE DIFFERENCES?
• Sound – The 4” dump pipe gives a more hollow/ tinny sound, many of you like this. The 3” removes that tinny-ness and gives a deeper rumble (personally I prefer this). Note* Aside from the pitch of the pops and bangs they remain unchanged.
• Price – With the price of 3” stainless material being substantially cheaper than 4” the winner at the end of the day will be the end consumer.
Overall we were not surprised with the results, one of the most important calculations you can make when building/modifying a turbocharged engine is matching a dump pipe to the turbo size and in this case 4” has absolutely no benefit over the 3.”
Keep in mind we fabricate, sell, and have the Uni X to support both the 3” and 4” dump pipes so this information was produced by us to give you a better understanding and idea of what to buy or look at according to your own preferences and budget.
The testing carried out today clearly shows that neither one was better than the other – does size matter? You decide – thanks for reading.