Makes sense ^ ^. I'll PM him and find out his impressions on his HFCs. I'm running Berk Metallic HFCs so I think I should be fine.

The website says they're also great for FI use as well which is what made me question how the STS turbo would be at risk if the HFC was made to work in this application as well.

I'll let you know what he says

 

Just sent boozt on my350 a PM re: the metallic HFCs and their usage with this FI application. I'm curious to see what his thoughts are as well. I'll keep everyone posted

 

My OEM CATS blew out with my OEM engine, at 8psi, on a conservative (rich) tune. Turbo survived without any damage.

My Fast Intentions Metallic HFCs blew out with my GTM motor, at 14psi, on a conservative (rich) tune. The HFCs were Jet-Hot coated and header-wrapped. Turbo survived without any damage.

Now I'm on test pipes.

 

What! That's crazy. How long did the Cats last before they went out? Two what exactly causes them to go out?

 

I don't know when they precisely blew, because wasn't checking specifically for blown CAT bits. I just happened to notice debris when performing other modifications on downstream exhaust parts that I took down months later. However, if I were to give it an educated guess, I think the OEM CATS held up a few months, while the HFC CATS held up a few weeks.

Heat makes a CAT work. Too much heat makes a CAT die. Turbos cause your exhaust (especially the area between the motor and the turbo) to run hotter. Running too rich causes unburnt fuel to enter the exhaust. Fuel settling on the surface of a CAT seriously increases its heat exposure. JetHot coating and header-wrap are all designed to keep heat in the pipes. With our setups, I think there are a ton of ways we can configure our systems to kill CATs of any kind. So be prudent with your choices.

To STS's credit, the company owner says when tuned properly, their systems have not posed any significant risk to the destruction of OEM CATs.

Hope this helps.

 

FWIW I was running on stock cat for 10 months and was fine. I still have my OEM cat and they still look good though. I had about 8K and lots of WOT when I first got my car.

 

You just gave me a new lead to follow! Thanks Sillie. I've got some calls to make before I decide 100% this is the FI path for me.

The first problem I run into here in Chicago is passing emission tests. The second problem I run into is cops pulling me over for smelling exhaust fumes in traffic.

This is the reason I chose HFCs over test pipes for performance. I'm wondering if it's possible to have HFCs at all with this setup. How can the system be tuned properly so it won't destroy HFCs altogether?

 

Hey bro! For some reason your post didn't show up when I posted from my iPhone earlier.

Anyway, this is good to know. What differences did you see after you changed from OEM cats to your test pipes? (Smell, increased noise etc) Are those things amplified because you're running a rear turbo setup?

Two, how are you able to pass emissions w/o any cats?

 

I think sillief00l (Goosegoose) will agree with me that the smell is kinda sickening at times Sound is louder above 4000rpm too. I try to stay around 3000rpm in local street coz I'm afraid NYC cop will give me a ticket for excessive noise above 4000rpm or WOT. In short the TP did make my car louder. Not sure if I would go back to stock cat coz I love the throttle response with the TP.

In NY as long as you dont have any CEL and your car finished the "Readiness" then you will pass. I have the 2 non-fouler on both side and I dont get any error.

 

sillief00l is using the Motordyne HFC and he said Tony warrantied the HFC from blowing up. You may want to check that or see if you can get the same steel HFC boozt is using.

 

FI'ed thanks for the quick response. As for me, I'm using the Berk Metallic HFCs. On their site I remember it saying they can be used for Forced Induction as well. I don't think I'll have a problem with these especially if they're like goosegoose's HFCs.

Still we have to be cautious when we step into the realm of the unknown. I'm going to contact the mfgr Berk anyway and confirm this before I move forward to make sure they're warranted for this kind of FI use and to find out just what their lmitations are.

Does anyone else have experience with stock cats/HFCs with the STS that they'd like to share?

 

I started out with stock cats, Y-pipe, etc... I then switched to a pair of used FI HFC's and a used UTR Y-pipe. The HFC's lasted about 500 miles before they blew. I have a conservative tune (10.8-11.0 AFR @ WOT) and have all pipes wrapped (I believe the combo of running rich & wrapped caused them to blow).

I'm currently running stock exhaust manifold, test pipes, and an AAM Y-pipe which mates up to the stock mid-pipe. The sound is significantly louder but, sounds good (I receive quite a few compliments).

 

6Spd and Sillie, can you guys post up a couple clips of your exhaust? I'd like to hear what they sound like. I was thinking maybe something like a cold startup and idle clip, and a cabin cruising clip and or a flyby clip.

I really appreciate the info everyone has shared by the way. Any one of those clips would really help me to learn more about how the system sounds with different exhaust setups. Thanks in advance

-Mike

 

Give me a week or so and I will post some clips.

 

You got it bud. Thanks guys for laying everything out and answering my questions. The next step for me while I continue my FI research is to see it in action locally but that probably won't be for a while