skyydiver

iTrader: (1)

Okay, before people start flamming me for not using the "search" function, please understand my question first.

I am getting ready to purchase Fast Intentions Intimidator exhaust system. They are also having a sale on their high flow cats. But before I spend another $530 just for cats, I want to absolutely know for sure (obviously the only true way to know for 100% sure is to buy the cats and dyno the car before and after cat install...DOH!) that it is going to be worth the expense.

I have been reading posts for days about pro's and con's of aftermarket cats.

Pro's:
Lighter than stock by 15-20lbs
Allows higher flow of exhaust gases (obviously )
Changes exhaust tone (bonus)

Con's:
Expensive!!!! (HP/$ ratio blows...pun intented)

I didn't want to call Fast Intentions and ask them because obviously they are in the business of making money. So I wanted to get some unbiased feedback here...

It is to my understading that putting on HFC's on a N/A car will yield approx 4 - 7rwhp with an aftermarket exhaust. This equates to a HP/$ ratio of $132/HP - $75/HP. This in my opinion is not worth it. I am however thinking of going F/I sometime next year (if I can keep my credit card locked safely away until that time) and HFC's might make a difference. I am thinking Vortech or Stillen for SC or TN Single Turbo...which brings up another question, if I do choose Single Turbo, can the cats even be used with their kit based on the turbo exhaust piping configuration?

So even after reading a multitude of posts about "cats", I still can not derive an informed decision. While I am not asking for someone to make the decision for me, I just want to know (and not by the "butt-o-meter") are the gains worth the expense?

And I know there are a multitude of you out there screaming "GO WITH TEST PIPES YOU FOOL!". But before you do, know that I am not interested in test pipes because I am still spending $250 -$350 just for the pipes...the exhaust could possibly wind up being way too loud for my taste...and if I go with either the Stillen or Vortech SC, both companies strongly recommend against running their kits without cats (yes, I know there are many of you out there that live life on the edge and are doing just that...Vortech with test pipes).

Thanks for taking the time to read my post and I appreciate all constructive feedback.

-Joe

Dubai

iTrader: (15)

If I were you I'd get a set of UTR resonated test pipes and call it a day.

Beeker

iTrader: (5)

I am in the same situation as you. I am pretty much done modding my car for now. I am considering high flow cats before getting either a reflash, a utec or wait for the new Cobb tuner to be released over the winter. I will not get test pipes because of the noise, smell and CEL problems.

After reading just about every post about test pipes and hi flow cats over the last year, this is my recommendation:

Install the exhaust first. Allow it to break in for about a month. That way you can decide if you like the way it sounds with the stock cats. If it is too quiet or you could deal with an increase in noise then get a set of hi flow cats. Just keep in mind that the more you mod your car the more important tuning becomes.

I made more power with just headers and pop charger installed. I lost power since installing the Borla exhaust and 5/16th spacer. The reason why is because of the stock ecu. Once I get an ecu solution and tuned I will see the gains.

I must say I haven't seen any before and after dyno charts of just hi flow cats. But with a proper tune there is no way hi flow cats wouldn't increase power over stock cats. I'm not saying you are going to gain 20hp but 5-7 seems possible with a good tune.

Now, is 5-7hp worth $500.00 thats up to you. Of course the other benefits are the weight savings and sound. Since I have the Borla, which is relatively quiet, I would like the slight increase in exhaust volume. I haven't heard the fast intentions system which is why I recommend you install that first to see how it sounds with the stock cats.

plumpzz

iTrader: (10)

Test pipes or gut ur stock cats if your all about being legal.

quint1

I went with Borla for headers and cat-back after installing the CAI. After the CAI the HP increase was sharp and short around 5500 rpm. After the exhaust mod, the hp increase was thru-out the rpm range. I had ta hold on tite!! What a difference. For me it was money well spent. After the ECU reflash, it pulls hard all the way to 7000 rpm. Before any mod, it couldn't breathe after 5500 rpm.

Z1 Performance

iTrader: (564)

I love the high flow cats I have one my car...one of the nicest mods I've done

Alberto

iTrader: (14)

I'd never waste $$$ on HF cats. Maybe 3whp if your lucky. If you have basic wrenching skills do test-pipes and take 1 hour every 3 years (or whatever it is in your state) to swap em for emissions if you even have emissions. I passed emissions in MD with test-pipes but that is neither here nor there. TP > HF cats...

davidv

iTrader: (2)

There are a lot of questions in your post. First you have to make up your mind: high-flow catalytic converters or test pipes?

undrgnd

iTrader: (2)

I just installed the AAM HFCs last weekend. The sound is a plus, no CELs is a big plus, and the improved gas mileage is just gravy. Is it worth $600? Not really, but at least having spent it, I'm glad I got something that's high quality and will last, and did I say the sound is a plus? Not sure if it helped performance, but I did the MREV2 and APS plenum at the same time, and the combination is a killer. It is a different car above 4k RPM. I love it.

Satans350

iTrader: (5)

i would not spend 530 on HFC's. i came across a sweet deal on some low milage crawford cats. they make a hell of a differance on my car. No cel or nasty smell. just my $.02.

Z1 Performance

iTrader: (564)

see for me, it was $470 well spent (Ultimate Racing). No CEL, no smell, perfect fitment and sweet sound. The difference on an NA car between test pipes and high flow cats is minimal - the difference in sound and smell is significant. The only question is whether the noise, smell and slight power difference is worth the cost of the high flows.

Even the "resonated" test pipes, still smell alot when behind the car, and the resonators are so small, the hardly have an impact....though this varies with catback to catback

Hella

iTrader: (1)

I gained only 4whp from just hfc's with my other mods...........prior to UTEC and tune. You need a tune to bring out there all.

m1james@bellsou

From a cost per HP perspective, HFCs are not worth it. However, if you want a little more volume and hp it may be if you have the $. Don't go cheap as many posts talk of cracking/failing/rattling/fitment issues etc. I have Ultimate Racing HFCs on a GTR 6 speed with oem exhaust. It did help throttle response and improve the sound and make it louder. I can't say my *** can feel 3-5 hp but I am happy with the purchase. The reasons I went with Ultimate racing are:
1) No reports of cracking/failing/fitment issues
2) all stainless steel, not aluminized cheap stuff that will rot
4) 50,000 mile warranty
5) no CEL
6) OEM style mounting brackets
7) no need to hammer the floorboard for clearance
8) "reasonable" cost (less than $500 shipped from Z1)

Those that say it's an hour job to install are exagerating so don't believe the BS.

Test pipes stink and contribute pollution so why bother.

If you are installing an aftermarket exhaust, I would suggest waiting to see how you like it before spending the cash on the HFCs. If you want a little more noise, do the HFCs. If you're happy, spend the cash elsewhere.

rkd350z

iTrader: (3)

I got my used Random technology HFC for 170 bucks. than it's diff story.

skyydiver

iTrader: (1)

Gentlemen...thank you so much for all the feedback! Please keep it coming.

I do think I will take the advice that several of you mentioned and that is to just buy the exhaust for now, see how I like it, and then look into the HFC's. Afterall, that is an additional $500 that could be put towards my savings for F/I! :grin:

Thanks again,
Joe

kourosH

iTrader: (3)

good info

davidv

iTrader: (2)

Which did you buy?

ObiRedKenobi

I had an offroad mid pipe on a 97 Mustang and I really loved the sound but I'm a little older and a little wiser now. I like to breath and think its better to follow the law than to try and wiggle out of it just because I wanna do what I wanna do. I'm going to try and pick up a set of quality used hfc's next year so I can't tell you if your going to pick up any performance or not.

davidv

iTrader: (2)

Never mind I don't care anymore.

99atlantic

iTrader: (1)

from a cost/performance, nothing is worht it on these cars Hence why i'm building an FFR - 600hp/tq, 2000lbs, DROOOOOOOL factor = godlike