GTM Performance Engineering: MHI Twin Turbo Official Release

Originally Posted by SAM@GTM

Anytime you run a small turbo with internal wastegates, there is a chance of having boost creep if you are not careful with your exhaust system choices. This is not a characteristic of the 16g specifically, it is a concern of anytime you run a small turbine housing. Even in our Garrett based stage 1 kit that comes with the .64 A/R housing, if someone wants to order it, we always ask what type of exhaust they have or what they plan on running so they don't have boost creep issues.

So if you are planning on buying the 16g kit even though we have done a very good job of polishing the wastegate port, I would not suggest running a high flowing 3" exhaust with internal wastegates. If you are planning on running factory exhaust or factory cats, then it is an excellent choice for an extremely responsive setup and you won't need to worry about boost creep. One other thing, is that an automatic puts more load and can exacerbate boost creep on small turbos. The car we tested on did extremely well on the factory exhaust and cats as far as boost control and also did well with test pipes and factory exhaust. But, when we switched to complete open exhaust, we did experience a couple psi increase of boost over our target boost setting.

We are very careful in recommending the right product to our customers so that there are no surprises and challenges after the install. Also, having all three trim options the same price will make this choice easier for the end user since money is not an issue: only desired performance.

We had two different members stop by our facility to check out our 18g test car and both were blown away by how fast and responsive the car was. Hopefully they'll post their experience.

The new manifold design is done and we are waiting on the pre-production pieces to arrive. Once we have them in hand, we will post the nice, shiny pictures.

The blow off valves can be setup for full vent to atmosphere, 50/50 or full recirculation on the MHI kit. Also, I saw that you asked about HKS blow off valves in a different post and we are willing to accommodate special requests like that.

Sam