Reducing sound and remaining the boost.
Thread Starter
Newbie
Joined: Dec 2007
Posts: 8
Likes: 0
From: Istanbul
Reducing sound and remaining the boost.
Hello,
I have a 2007 Evo IX, in my exhaust system I have,
Nvidia O2 housing - Nvidia Downpipe - Custom test pipe (a smooth empty pipe of 3") - Hks Hipower Cat back.
I have also Evc 6, Ecutek, Injen Air filter in my car. Basically with this setup my car has a peak of 1.89 bars (27.4 psi) , and continuosly boost like ~1.6 bars (23.2 psi).
I am very happy with the performance but the sound is really so loud especially when I turn on the evc and after some compression. When I put my original catalytic back instead of Test pipe the sound gets very reasonable, but I can only boost like ~ 22 psi max at peak, also the continuous boost decreasing. I made couple research in forums and found that If I use a Vibrant performance metal core race cat. I may not lose so much power. But I am going to lose it anyway.
This is the link of the cat. - http://vibrantperformance.com/catalo...9d0e367c6651f5
So, I decided to use a 3" metal core cat of this brand but I want it to have permeability very close to a test pipe. Then, I found an idea of using two 3" metal cats connected parallel, total of 6" surface that air can flow, and connections will narrow back to the 3" at the front and back. Also that may reduce the sound level very much which is my another aim. What do you offer me? Do you know the permeability of a 3" metal race cat versus a test pipe? Do you think that parallel connection works?
Thanks for all advices, and paying attention.
Regards,
Btw: we use legally 100 octane gas in my country, thats why my boost may differ from a 92 octane user. And this boost info taken when the air is at 5 degrees.
I have a 2007 Evo IX, in my exhaust system I have,
Nvidia O2 housing - Nvidia Downpipe - Custom test pipe (a smooth empty pipe of 3") - Hks Hipower Cat back.
I have also Evc 6, Ecutek, Injen Air filter in my car. Basically with this setup my car has a peak of 1.89 bars (27.4 psi) , and continuosly boost like ~1.6 bars (23.2 psi).
I am very happy with the performance but the sound is really so loud especially when I turn on the evc and after some compression. When I put my original catalytic back instead of Test pipe the sound gets very reasonable, but I can only boost like ~ 22 psi max at peak, also the continuous boost decreasing. I made couple research in forums and found that If I use a Vibrant performance metal core race cat. I may not lose so much power. But I am going to lose it anyway.
This is the link of the cat. - http://vibrantperformance.com/catalo...9d0e367c6651f5
So, I decided to use a 3" metal core cat of this brand but I want it to have permeability very close to a test pipe. Then, I found an idea of using two 3" metal cats connected parallel, total of 6" surface that air can flow, and connections will narrow back to the 3" at the front and back. Also that may reduce the sound level very much which is my another aim. What do you offer me? Do you know the permeability of a 3" metal race cat versus a test pipe? Do you think that parallel connection works?
Thanks for all advices, and paying attention.
Regards,
Btw: we use legally 100 octane gas in my country, thats why my boost may differ from a 92 octane user. And this boost info taken when the air is at 5 degrees.
Thread Starter
Newbie
Joined: Dec 2007
Posts: 8
Likes: 0
From: Istanbul
Thanks for reply, I will order the parts asap but I think the online shops are not sending any response mail these days because of christmas. I also asked the vibrant performance technicians the technical data (like permeability?). But at the worst case I will find a way to make some test to catch same perm., I am an undergrad physician 
it wont be hard for me I think. I will share the results and hp gains/lost. I need info more like , this cat brand is better has more flow ... or it wont work coz..., another way of doing..
it wont be hard for me I think. I will share the results and hp gains/lost. I need info more like , this cat brand is better has more flow ... or it wont work coz..., another way of doing..