Yesterday, I had my UR HFCs installed. Admittedly, my expectations in terms of power gains were low. I didn't expect to feel much. Well, after 100 miles of driving between yesterday and today, I'm in love. I'm driving out 30 miles to my brother's house tomorrow, and I can't wait.

I've been out all day today with my girlfriend and we both can't get enough of how silky smooth the powerband and delivery is. The low range used to lack a bit up until 3500RPM, but not anymore. The car jumps with the slightest touch of the throttle...before I could modulate the throttle for slow and smooth starts, but it's become increasingly harder to do with the HFCs installed.

Power across the entire curve has definitely shifted upwards, as the low-end, mid-range, and high-end has opened up. Again, I was expecting to be disappointed with the end results, but I'm very happy to report that my car has responded to the mod extremely well. Even my girlfriend noted how much quicker the car feels and how much smoother the delivery is (yes, she's a bit into cars herself).

I'm also extremely happy that the exhaust note didn't change much during cruising and low-end acceleration. If anything, it may have gotten a bit quieter during cruising, as I've noticed driving uphill the exhaust doesn't sound-off as much anymore (I assume increased airflow contributes to this).

But when you nail it and shoot past 5000RPM, the car sounds absolutely stunning, it's a screamer. The sound is throaty, sharp and exotic - it's absolutely unique, and will never be called ricey.

Just figured I'd share my thoughts. I'd love to record some videos, but I honestly doubt they'd be able to capture how beautiful the sound of the exhaust is. Also, big thanks to the guys at Tantrum Auto for the install!

 

good

Edit: you had the OEM cat before?

 

Did you get the ceramic or metallic cats?

 

nice! I think the you get so much % of the benefits of aTP's but the HFC's keep the smell down and keep the EPA from bending you over if you have a cop who is throwing the book at you in a traffic stop. Congrats! next time DIY...it's not that many bolts!

 

Actually...looking at it done, it's a major pain in the *** to do this mod without a lift.

Phenom: Ceramic.

 

i thought you had the UR hfc for a while now?

i swear i saw them in your sig before you made this thread

but enjoy the hfc. congrats!

 

They were supposed to go on weeks back, so yes...you did see them in my sig earlier. They're on now, and I absolutely love them. I spent much of the day just driving yesterday and enjoying the changes.

 

some of the top bolts are a bish to get to, but overall this is a mod most people should be able to install themselves.

 

My God these HFCs are amazing. The power delivery is so vastly improved over the OEM ones, especially the low-end past 2K; it really feels like a new car. I highly, highly suggest people get rid of their OEM cats for either test pipes or HFCs. Best mod I've done to my car so far...and the sound they make. I've let my cousin, my two friends, and brother ride in the car and they all said the EXACT same thing...

"Damn...almost sounds like a Ferrari." I'm not even making this up. It especially sounds amazing in a tunnel. Orgasmic.

 

I just had a set of these cats installed last weekend along with a borla TD. I can't say that I have noticed any gains, but It seemed faster. I just assumed it was because I had my foot in it a lot harder to hear the exhaust.

The install went quick, I brought it over to my neighbor that has a lift, we swapped out the exhaust & cats in an hour. He has a wrench bent specificly to get the bolts on like a late 80s gm starter that worked perfect for the top bolts.

 

Do you by chance know what type of wrench that is or where he got it from? You could be a life saver here.lol

 

Goes to show just how different each Z reacts to mods. I'm definitely not hitting the throttle too much, quite the opposite; I have to layoff the throttle in order to avoid jumping the car from a stop. Also, max throttle when in gears is vastly different than in the past. Going 25MPH and in 3rd gear, for example, the car accelerates much quicker. Same goes for 4th, and 5th gear, and I used to be impressed with how the car pulled at low speeds in higher gears.

 

Not sure, most of his other tools are snap on though. It is basicly a double sideded box wrench with the ends bent in to form a boxy half moon shape. I am sure if you got a few cheapy china ones & bent them up with a torch you could get something really close.

use that shape as a guide.