Now that I'm seeing more and more Vortech owners on the forums, I'm wondering how everybody feels about the high flow cats and how they sound/perform with their Vortech kits...

I upgraded my cats to Crawford HFC's after I installed my Vortech...and although the Crawfords sounds great when not in boost, when I go into boost I start getting raspiness out of it...

I guess this kind of makes sense since Vortechs tend to blow out more air onto the exhaust without turbos to baffle the noise/air, so maybe the Crawfords can't handle the added volume of air flowing through without rasping...

I spoke briefly with sentry on this and he recommended some fast intentions HFC's...

So how about the rest of y'all...how does your HFC's performs with you vortech? Rasp?

 

You just have to make your mind up between how much flow and how little of rasp you want .

I never heard Fast Intentions cats

RT cats flow the best and rasp the most
Crawfords flow a little less and rasp a little in the 3000rpm range
i would think the less they rasp ...the less they flow

 

I have the RT cats and it rasp.
But I have to say it performs very well.
The car pulls a lot harder after I had it installed.

 

Check the Berk Metallics

 

I have Kinetix cats paired with stillen exhaust. Barely any rasp. It only really rasps when getting close to redline.

 

Thanks for the comments guys....

Just to let you guys know my exhasut setup is: DC headers/Crawfords/JIC Ypipe/Amuse R1 Titan

As it is, I believe the Crawfords are already relatively restrictive compared to the rest of the metallic HFC's...so to get anything less restrictive will probably produce more rasp, if anything...the only thing that is probably more restrictive than the Crawfords are the stock cats and the Nismo HFC's (which I am not willing to pay $2k for anyway)...

It's kinda sad that I waste the lovely sound of the Amuse when I boost and it rasps, but I guess I wouldn't trade it for the 20 hp I gained with the Crawfords and freeing up more hp with less boost (safer on the engine)...probably should be happy with that....

 

i am running stillen headers,fast intensions 2.5" dual exhaust system with the intergrated x pipe/resonator they supply and aps 2.5" non resonated test pipes. i have no rasp what so ever!! honestly this exhaust system might be one of the best sounding systems i have ever heard on a z. i have had the aps 2.5" dual sytems as well as a custom system built and installed. they both sounded raspy unless i installed my HF cats. i highly recommend fast intensions produsts, the quality and customer service is great! the only down side is i had to wait 3 months for my exhaust to be built.

 

There may be hope yet...maybe Fast Intetions HFC's may do the trick...however I am running a single exhaust system with the Amuse, so I don't know if that will necessarily correlate...

 

Always got compliments with my stillen TD and Crawford hfc, no rasp to speak of, and made well over 400rwhp with the Vortech.

 

Hmmm...2 true duals exhausts with no rasp problems...I wonder if that is the trend, maybe because there isn't a y-pipe where the air smashes together...

 

I have resonated test pipes and have no rasp. I lost all the rasp when I installed the x-pipe muffler.

 

I ordered berk but I canceled it, they wouldn't have arrive when i needed. I might try get the used berk but if i can't, i'm going with UR metallic HFC.

Btw, ceramic ones are less rasp then metallic/TP also it can be matter with how exhaust designed.

Edit: You might wanna post this thread on G35driver, many G owners loves FI HFCs.

chefj

 

An X pipe MUFFLER....you slowed down the flow enough to muffle the rasp .

 

What if the O.P were to do this

Metallic HFCs--->Motordyne XYZ Pipe Resonated--->2.5 CB Exhaust

OR

Resonated TPs--->Motordyne XYZ Pipe Resonated---->2.5 CB Exhaust

Would he have rasp then? What if he substituted the Resonated XYZ Pipe for the XYZ-->Cat version?

How would that one flow? Would it have rasp in it too since its one Cat filtering his whole system?

I'm trying to solve this one myself bc I'm thinking of doing the last option with my FI setup I want to build and I'm wondering how that would flow and sound

 

The best part was that when I dynoed the car, I didn't lose or gain any power. I did regain some bottom end tq though.

 

05Z33, do you have any sound or video clips of your car? I'd love to hear your exhaust in action. How loud is the sound compared to stock?

 

Sorry but I don't have a video. As far as sound goes. The bypass valve is loud as excpected. When I go WOT it sounds like an exotic V8. Normal around town driving you can hear the exhaust, but it's not annoying loud at all. In fact the bypass valve is louder. I always get compliments on my setup, which is why I have a hard time justifing getting a different exhaust.

 

Jason,, sounds like you don't have Vortech anymore..?

 

Hey john, where have you been hiding.....long story,sold everything i'll shoot a pm.
Back on topic, i would deff go with hfc's over test pipes if i had to do it again!

 

Berk HFC, AAM Y pipe, AAM single exit no rasp... good over all sound at wot or cruising...