After getting a Cobb TBE with HFC, I've been thinking that maybe changing the HFC with a test pipe will gain me more power. After I took off the HFC and looked inside, there was so much restriction that I believe it doesnt allow that much of air to go out freely. It is much better than stock ofcourse, but what do you guys suggest? Shall I change it? I heard that at least 10whp are lost when using a HFC rather than a testpipe. Is it true?

 

i am useing a khs hi power test pipe and 3in downpipe and when i put the test pipe on i deflly felt a big diffrence in throttle responce and power and it made it sound so much better under boost so i would say do it

 

How loud will it be? I mean going from a HFC to a testpipe. The testpipe is a plain 3" pipe unlike the HFC, so will it be a lot ouder? I'm concerned about the noise, the HFC is really good for highway speed.

 

If you want to run a cat use MILSPEC 100 cell cat.
You will see gains switching to a test pipe.
How much ?? It all depends on your mods.

 

Since your running the Cobb exhaust, I don't think it would get much louder.

 

I am using a cat already, and I want to know how much gain will a have after switching to a testpipe. My car has a drop in filter, TBE with HFC, LICP, and 3" FMIC.

 

The thing is, Cobb states that the TBE with HFC is 94 db and with testpipe is 98 db. So I want to know how loud is that? I mean isn't 4 extra db are loud enough?