Hi,

I wanna ask you guys about hi flow cat. I just put greddy spectrum elite catback @ my car (I30) months ago. And after it I feel that I loss lot of lower engine power (my car is automatic).

Because my car is not equipped with Catalytic from the dealer then I make a test pipe after testing few miles, I added a "custom" resonator which has little restrictive design (It is hard to find hi flow cat in my country). I feel that my lower end power slightly improved. But it still to low on lower engine power compared to stock catback system.

Now I am thinking to get a hi flow cat to replace my "custom" resonator. And, I want to ask you guys,

What size I need to use (2.5" / 3")?
What brand I should buy?

I find that there is a website which belong to Australian that sell 100cpsi hi flow cat for AU$170 (venomexhaustworks.com.au). What do you think on this guys? Is it looks like some of chinese made? I want a good quality of hi flow cat if they can improve my lower engine power as big as before I put greddy catback.


Thanks in advance for your participate in this thread...

 

You will not gain that low end power back. Once you you get a free flowing exhaust you loose back-pressure which was giving you low end power. I have a y-pipe, hi-flo cat, and cat-back on an automatic so I know what you mean but then I got a S/C which fixed this issue. The only thing I can recommend for you is to look into those mufflers with a spring loaded flap.
http://forums.maxima.org/supercharge...er-review.html

 

Hmmm... I am glad that you can understand what I mean.

Hmmm... Do you think this muffler will give me lower end power back? Or I should find another real chambered muffler?

 

Get a true CAI that goes into the fender, you won't gain a thing from an HFC.

 

I found that somebody told me that using CAI on automatic cars will only scarify lower end power?

 

No sir SRI's will ruin your low end, trust me I've had both on my auto.