What performance wise does the efeni Y pipe change... and is it used on the stock twin turbo setup?

 

Yes, it is used with the stock twins. This was put on the '99 models in Japan. Gives better top end power with stock turbos (between 6500 and 7500 rpms). Not sure how many HP's, but you can definately feel the difference when starting from a stock setup.


I personally think it is worthy of the $200.00

Jeff

 

Oh, and it also eliminates a boost coupler that is famous for splitting. Better reliability!

Jeff

 

there's a few threads on this if you search for "efini" mazadaspeed (or some racing team, forgot) claimed i think 10hp. but personally i'm a little skeptical. i'm sure it helps a little, but probably nothing i can notice. but others say they can feel the difference. it does make the engine look a little less plasticky.

 

appreciate the response... will have to investigate further.

 

The Efini Y-pipe is an aluminum pipe that replaces the factory plastic crossover pipe. Thus it connects the stock turbos to the intercooler. The OEM FD pipe has a rubber connector that is very prone to splitting and causing boost leaks. The Efini pipe replaces the rubber and plastic pieces. It has been a factory piece since 1996 in Japan. It also moves the PCV(?) away from the airstream in the pipe. It's supposed to flow better and also increase boost pressure slightly (I believe someone has measured a .5-1psi increase).

eric

 

The efini pipe is a nice upgrade if you are going to keep your car "sorta stock". It is also emissions legal if that is a concern in your area.

Part of the reason for the 10 hp gain is the elimination of the rubber coupler between the y-pipe and the crossover tube. During boost, the rubber coupler allows the crossover tube to flex upward at the front, expanding the "accordian" joint to the intercooler. When you get on the boost, part of the boost is used to expand the "accordian "joint. With no rubber coupler, there is no expansion, and no lost boost.