HFC?? Worth it,

anm6

Member
:
09 Speed 3
Hi guys,

Looking to get a little more out of the K04, I have a Catless Dp now and was thinking about replacing the other stock cat with a HFC? Is it worth the $$$ performence and any issue boost creep or anything, anyone here running the same thing??
 
I asked a similar question awhile back and got nothing as well. First, I'm not sure that most people get that HFC means high flow cat, as these aren't used much. Most folks go with a test pipe and (maybe) a catted downpipe. No one really makes a HFC for our cars. I've got one I'm hoping to get installed today, but it is a TurboXS test pipe that someone welded a HFC into. I'll let you know what I think once I get a few miles on it.
 
A Catted downpipe could be a good way to go. I don't know if the Cobb DP is still available, but there is another alternative.
 
I asked a similar question awhile back and got nothing as well. First, I'm not sure that most people get that HFC means high flow cat, as these aren't used much. Most folks go with a test pipe and (maybe) a catted downpipe. No one really makes a HFC for our cars. I've got one I'm hoping to get installed today, but it is a TurboXS test pipe that someone welded a HFC into. I'll let you know what I think once I get a few miles on it.


Hey Thanx let me know, My only option is a HFC instead of a test pipe. I have a catless DP now and was reading that a catless system will casue boost creap.
 
I know someone on the *other* forum did a back to back dyno of a catted DP vs a catless DP and the catless gained 3hp. I am not sure if it would be the same for the second cat but I just thought I'd let you know.
 
I know someone on the *other* forum did a back to back dyno of a catted DP vs a catless DP and the catless gained 3hp. I am not sure if it would be the same for the second cat but I just thought I'd let you know.

I don't think so. The stock cats are sux. Now stock DP
to aftermarket gains are about 20.
 
I installed a Magnaflow "HFC" on my Corksport test pipe. Not sure if it made a diffrence over none I always ran the car with it. But there is a huge diffrence over the stock set up.
I need a cat in my state to pass emissions so I never tried to run catless. If you need a cat high flow is the way to go.
 
Thanx Jeff, The Magnaflow is the one I was looking at also, Did you sound exhaust sound change much?
 
First thing I have ever bought from them. Thanx. I will let everyone know how it goes..
 
Well dropped the car off this am to have it installed WOW very well made peice, and comes with new nuts and bolts and the gasket :)
 

Attachments

  • Ultimate Racing HFC.webp
    Ultimate Racing HFC.webp
    410.1 KB · Views: 142
  • Ultimate Racing HFC-2.webp
    Ultimate Racing HFC-2.webp
    308 KB · Views: 131
OK after one night of driving I can say worth the money, Car feels a bit quiet and smoother to drive boost comes on faster.. Noise wise car actually sounds quieter? maybe the cat has to break in like a muffler does? I will try to get a vid and compare it the car when it was on the dyno.( Still have not posted those vids)
 
Please help me understand how adding a restriction in the exhaust, even a slight one, (the high flow cat) would allow boost to build faster.
 
I removed the factory cat( Restriction ) and add the HFC, If I went test pipe it would build quicker right? So I did not add a more restrictive part, Less restrictive.
 
Back