The disadvantage of sequential turbo setup is complication of piping work, control and known how of it. At this stage, the engine just work as a parallel twin turbo system. At this time, a flap in the exhaust manifold open wide and allow the exhaust gas of the second rotor to pump into the secondary turbo. When the engine speed goes higher, the primary turbo efficiency decreases and requires two turbo to work in parallel to generate enough boost for the engine. In low engine speed, both rotor's exhaust gas are pumped to the primary turbo, making the primary turbo spools up quickly so that the engine can have boost as soon as possible. Since the 13B rotary engine is an engine having wide range rpm, it is an ideal motor to having a sequential setup to maximize the torque on each rpm range and deliver the most out of it. The secondary turbo only works in mid-high rev range. The primary turbo works in all engine rev range. Take RX7 as an example, two turbo chargers exists in the system. Sequential turbo charging is a way to optimize both low and top end power of an engine. Everyone who experience with turbochargers know that using a large turbo can achieve high horse power with sacrifice of low end torque. This doesn't mean the stock setup is no good, it is because tuner's goal is aim for high HP numbers with simplicity. Tuners often change to twin parallel turbo or even one large turbo to replace the stock setup and achieve a high output engine. The 1990's Mazda RX7 and Toyota Supra are well known setup of sequential turbo charging system. To make it sort, I will only talk about twin turbo setup to simplify the introduction of sequential turbo. Sequential twin (or multiple) turbo setup goal is not just for high power but also taking care about low end grunt of an engine. Many forums I've seen on the Internet about turbocharging is mainly focusing on horse power. I've been looking for a forum and place on sharing ideas about sequential turbo charging.
1 Comment
|
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |