The Lotus Elise exhaust is purposely built by the factory to optimize engine performance but the exhaust manifold used with the S3 is a stock Toyota manifold designed for NA applications and a lot lower flow of exhaust gases. Even with a smaller supercharger pulley, you are limited to about 260hp.
PB racing developed this exhaust manifold to fit the standard exhaust and standard heatshield and massively improve flow.
Perfect an incredibly good value for money product.
We suggest using new exhaust manifold nuts and gasket when installing. Nuts are availbe here
If your exhaust manifold stud is corroded or damaged you can find genuine Toyota studs here.