MikeyLeblanc

iTrader: (1)

Hey everyone. I have a 3" turbo back exhaust and i installed a high flow cat(megan racing) to pass the emissions test. My buddy says i should leave the high flow cat in because The hfc says it increases horsepower by 5-10. Will i get more horse power with the highflow cat or the test pipe and are there any problems with this? Thanks

ciclops04

iTrader: (2)

high flow cat's still has the ceramic honeycomb on the inside so it is still restrictive

Erik@MIL.SPEC

iTrader: (94)

It depends on what you're looking for. To pass emissions, you should keep your OEM cat. For horsepower, you either go with a test pipe (the smell gets old after awhile, IMHO) or you go with the highest-flow cat possible...which would be a 100 cell metallic cat. With both the test pipe and the 100 cell cat, you'll need a mechanical CEL fix since they flow so much.

If you're interested, pm me because I happen to have a 100 cell cat for sale.

72Tornado

iTrader: (5)

Your friend is clueless. Test pipe is better for pure performance.

BluEVOIX

iTrader: (69)

Power wise in order from lowest to highest gains.

Non high flow cat
High flow cat
Testpipe (resonated/non)

The high flow cat will increase hp but that is compared to the stock cat or non hfc. Leaving the hfc will not cause any problems unless your pushing super high horsepower numbers then it might start being restrictive above desired levels. A testpipe will yield more power because it has no restrictions inside. The difference between a hfc and test pipe is minimal but progresses as you increase the horsepower to high levels.

I believe that a resonated test pipe and a non resonated testpipes do not differ that much because both are straight flow through with no median in the exhaust flow path. But the resonated testpipe is quieter because of the resonator.

Oh and from what I've been reading a testpipe will net you a faster spool compared to running a cat.

You can try searching for more info. I hope what i wrote answered your questions.

ciclops04

iTrader: (2)

for sure on the fasterspool i have a testpipe and felt the difference

Silver SRT4

Just get a test pipe and use a Spark plug non fouler to fool the PCM in thinking you have a Cat , Problem solved. And a test pipe is more beneficial(Power wise) .

and still pass emissions.

EJEvo

iTrader: (18)

Who's your buddy? Al Gore?

Seriously, I doubt you'll notice much difference between a good quality hi-flo cat and a test pipe on the street. How often are you cranking out dyno runs and need the extra few HP? Do the world a favor - run the cat.

Silver SRT4

Who gives a **** about a Cat. Run non fouler mod trust me. its really simple. You can sell your hi-flo cat and spend it else where.

This was taken from another forum and its proven to work. This how too was made for a SRT4 but still the same steps.

-------------------------------------------------------------------

Parts Needed: ( 20 dollars if u dont have bits or compressed air.)

18mm Spark Plug Non-Fouler (come in 2 per pack)
Avail at local auto store (5 bux)

7/16th drill bit (5 bux)

Compressed air (outta can will work) (5 bux)

7/8th wrench (o2 socket will not work) (5 bux)

Drill

How To:

Jack up car
locate 2nd o2 sensor harness and disconnect
Grab 7/8th wrench and remove sensor
Take non fouler out of package and secure (preferably in
a vise) and drill out the inside of the non fouler. (if u try
to screw in o2 into non-fouler ull see y) just a bit needs
removed. DO NOT GO ALL THE WAY THROUGH THE NON
FOULER. You just need to open up the inside of the non
fouler so the o2 will fit inside it.blow out shavings with air.
Screw in o2 into non fouler then install non fouler into o2 bung


* May not work if u dont have an extra 3/4" of clearance around o2 sensor, u can get an exhaust shop to install an extra o2 bung if u need the clearance and u can plug the extra bung with an oil drain plug of m18x1.5


With this mod the o2 get heat for the heater circuit still reads a minimal amount of exhaust (just the tip of o2) making it seem to the 02 there is a difference from o2 #1 t o2 #2.

3 weeks with no cel as of yet.




here is where u bore out the inside of the non fouler the circle in yellow needs to open up to 7/16th so the sensors probe will fit inside.

subydudesti

iTrader: (21)

Yeah bro, just get a test pipe and get the o2 eliminator and you will be good to go.

BluEVOIX

iTrader: (69)

Actually cats are not as good as we think for the world. Catalytic converters create nitrous oxide which is 300 times more potent than carbon dioxide. It traps heat and is one of the more common of the gases that is heating the atmosphere causing global warming. Studies have also shown that a car that averages 19 mpg produces .27 grams of nitrous oxide per mile. You might that it is not that much, but imagine how many cars there are and remember that nitrous oxide is 300 time more potent.

We're screwed either way with or with out catalytic converters. But I still think that its better to run a cat for our environment than not to.

It is also believed that most of the conversion to nitrous oxide occurs during the warming stage of the catalytic converter. That is why some cars come with 2 cats. One closer to the motor to warm up quicker and perform its duty, the other further down to ensure complete emissions control during its fully operational state.

I'm not promoting to run cars with out catalytic converters, just thought it would be interesting to share this info in case anyone didnt know. There is a lot of info on the web, feel free to google.

ciclops04

iTrader: (2)

yeah lancershop sells the test pipe with o2 simulator

Erik@MIL.SPEC

iTrader: (94)

In my opinion, this post muddies the waters because not all high flow cats are created equal. Almost all metallic substrate cats will outflow ceramic based cats and (all things being equal) metallic cats with lower density cell counts will outflow ones with higher density cell counts.

Silver SRT4

Just get a test pipe, and be done with me . You got nothing to lose.

MikeyLeblanc

iTrader: (1)

Alright, thanks for your help guys. I'm glad a friend told me about this site. You are all very helpful.