Hi all,
I've been looking for a forum and place on sharing ideas about sequential turbo charging. Many forums I've seen on the Internet about turbocharging is mainly focusing on horse power. Sequential twin (or multiple) turbo setup goal is not just for high power but also taking care about low end grunt of an engine.
To make it sort, I will only talk about twin turbo setup to simplify the introduction of sequential turbo . The 1990's Mazda RX7 and Toyota Supra are well known setup of sequential turbo charging system. Tuners often change to twin parallel turbo or even one large turbo to replace the stock setup and achieve a high output engine. This doesn't mean the stock setup is no good, it is because tuner's goal is aim for high HP numbers with simplicity. Everyone who experience with turbochargers know that using a large turbo can achieve high horse power with sacrifice of low end torque. Sequential turbo charging is a way to optimize both low and top end power of an engine.
Take RX7 as an example, two turbo chargers exists in the system. These two turbo are the same size. The primary turbo works in all engine rev range. The secondary turbo only works in mid-high rev range. 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. 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. 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. 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 . At this stage, the engine just work as a parallel twin turbo system.
The disadvantage of sequential turbo setup is complication of piping work, control and known how of it. Nowadays we have a much better technology base then in 1990s. Does anyone know anybody in the world is doing some similar projects using a better design then the RX7 and Supra? I have been in this topic for many years, but I didn't have enough resources and time to build a prototype of it. I've done lots of design and research work in this area, but not seeing many of others is working on it. At the time I was studying, forum and blogs are not that common at all. Recently, I bought a R34-GTR, the engine revs from 1000 to 8500, with little modification it can go to 10000rpm. This engine is very tough. Currently, it is a parallel twin turbo setup and is missing low end grunt . I am looking to modify it to a sequential setup . I was trying to locate the Garret VNT (Variable Nozzle Turbine) turbochargers to achieve a similar goal, but can find very little information about it .
If anyone is in the field, please share.
I've been looking for a forum and place on sharing ideas about sequential turbo charging. Many forums I've seen on the Internet about turbocharging is mainly focusing on horse power. Sequential twin (or multiple) turbo setup goal is not just for high power but also taking care about low end grunt of an engine.
To make it sort, I will only talk about twin turbo setup to simplify the introduction of sequential turbo . The 1990's Mazda RX7 and Toyota Supra are well known setup of sequential turbo charging system. Tuners often change to twin parallel turbo or even one large turbo to replace the stock setup and achieve a high output engine. This doesn't mean the stock setup is no good, it is because tuner's goal is aim for high HP numbers with simplicity. Everyone who experience with turbochargers know that using a large turbo can achieve high horse power with sacrifice of low end torque. Sequential turbo charging is a way to optimize both low and top end power of an engine.
Take RX7 as an example, two turbo chargers exists in the system. These two turbo are the same size. The primary turbo works in all engine rev range. The secondary turbo only works in mid-high rev range. 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. 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. 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. 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 . At this stage, the engine just work as a parallel twin turbo system.
The disadvantage of sequential turbo setup is complication of piping work, control and known how of it. Nowadays we have a much better technology base then in 1990s. Does anyone know anybody in the world is doing some similar projects using a better design then the RX7 and Supra? I have been in this topic for many years, but I didn't have enough resources and time to build a prototype of it. I've done lots of design and research work in this area, but not seeing many of others is working on it. At the time I was studying, forum and blogs are not that common at all. Recently, I bought a R34-GTR, the engine revs from 1000 to 8500, with little modification it can go to 10000rpm. This engine is very tough. Currently, it is a parallel twin turbo setup and is missing low end grunt . I am looking to modify it to a sequential setup . I was trying to locate the Garret VNT (Variable Nozzle Turbine) turbochargers to achieve a similar goal, but can find very little information about it .
If anyone is in the field, please share.
