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allright, i did a search but i'm not finding anything useful...what's the consensus on the best hi-flo cat for our cars? i don't want one i'm going to have to replace in six months or something.

the reason i ask is my engine may not be blown, afterall! my mechanic says the main cat is melted, and the plugs were completely fouled, and that may why it did what it did saturday night (died).

so other than asking for everyone to keep their fingers crossed for me, what cat should i go with? i've got a downpipe, and am planning on going with a used N1 catback a friend's looking to get rid of.

SexyRexyR1

Well, i have the bonez hi-flo from RP ... it's been on there for over 2 years.

I like it so far (bought the car 2 months ago).

Mahjik

iTrader: (1)

Bonez here as well.

Supposedly some of the others flow a little better than Bonez, but Bonez is a direct bolt on replacement and a little better crafted (better longevity).

I have no idea if that's the case or marketing PR....

Mahjik

iTrader: (1)

BTW, I'm glad it doesn't sound like your engine is toasted. I told ya to find out what's wrong first!

Badog

N-Tech going strong for over 2 years.

SexyRexyR1

Question ... i was wondering if there were any midpipes that have a hook-up for the airpump? Course, i have no idea where the airpump blows into on the exhaust system ... dp or cat?

Mahjik

iTrader: (1)

Unless you have a cat, there would be no need to hook up the air pump (so it wouldn't be useful on a midpipe).

jpandes

I just installed the N-tech hi flow cat. This sucker flows TOO well...Now I have to install a restrictor plate to control boost creep.

dclin

iTrader: (4)

I have a Random Tech, and the shop that put in my single turbo said that their experience is that it holds up better with the airpump disconnected better then most. Since they did not try to sell me a new/different one, I trust there is a little truth to it at the very least.

The Random Tech does have one end pipe that needs to be welded on, but any muffler shop can take care of that in a few minutes.

Cheers!

i think by not having the air pump connected the cat will run slightly cooler rather then hotter then the temperature for the optimal catalyst reaction, thus you cat won't get clogged as easily due to stuff being melted... but i'm not sure on this.

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bear with me here...i've had a vew bevbearges and just got home.....

i'm leaving the air pump connected so i can pass emisions - i don't want to deal with that hassle. maybe that discussion wasn't related to my question?

far as if my engine is blown or not, i'm trying not to get too hopeful, but now i'm hearing that my symptoms are not those of a lbown engine, but of a clogged cat and fouled plugs. i'll find out tomorrow, so keep your fingers and toes crossed for me! tomorrow's wednesday btw. remind me to smack ryan next time i see him for not telling me all this before i almost had a nervous breakwodn monday!!!!1 'course, it stsil could be the engine i suppose, especially knowing my crappy luck.

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another q....i think i remember reading that the stock cat has an 80,000/10 year warranty required by law? is this true, and does it transfer from owner to owner? if so, i'll just sock to mazda and get them to buy me a new stock cat.

skunks

Why not get a MP???

KINETIK_FD3S

and get flames:-)

Mahjik

iTrader: (1)

He probably doesn't want emissions or police hassles since they are illegal in Missouri.

blackscorpio

id get a mp and buy a used dtock cat for emissions time

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\

Bingo! Honestly, flames aren't worth the trouble of going through swapping out exhaust parts come inspection time, and also don't want my car to be so loud it's irritating, which I've read a lot of complaints of that being the case when the cat is removed.

One of my stated goals is to have one of the fastest *street legal* RX7s in my area when I finally get everything done that I want to do.

Further, if I go midpipe I need to start looking into more fuel management solutions, and I'm not willing to take that jump right now. For starters, I still don't know if my engine is NOT blown, and even if it isn't, this whole experience has emphasized my need to start an "engine went Boom!" fund

Not to get too far off topic, but I'm going to fix what's wrong with it now, probably get a piggy-back ecu, then start working on suspension and exterior mods.

So after all that, I'll take some more suggestions on which cat to go with

WhtRocket

ANbody else have any info? My mechanic said the after market high flow cats do not have the temp resistance of the stock main cat and will melt sooner. I'm getting to the point where there's not too many other bolt-on's and was eyeing a high flow cat. Which one flows best? Which one handles heat better?

Definately want to keep a cat because: 1) removing the main cat is a BIG *** TICKET in Cali and can easliy be inspected on the spot 2) it's loud enough with the apex dual n1. A really loud FD might get stopped and checked over. I don't want to draw any more attention.

On a totally unrelated note....At least I'm old enough now when cops dog my car they drop it fast when they see me. Once a cop pulled me over and said, "sorry to stop you sir, I'll get you on your way as soon as possible." I felt like saying, "see that you do son, I'm a very busy man!" Of course I didn't. I just took my ticket and was happy he didn't say,"step out of the car sir."

dclin

iTrader: (4)

Probably true of your local muffler shop special, but remember that the stock cat is also very restrictive - and therefore heat backs up at this spot, and possibly cause higher temperatures. With a hi-flow cat, it would be less restrictive and theoretically have less build up of heat.

I'm sure there a difference in build quality and design, but can not say if any given catalytic - whether hiflow or stock - is better made.

Also, classsifying a cat a hiflow type is relative, according to Random Tech's website. A less then honest shop may put a hiflow cat that was rated for a smaller exhaust flow need (say a 4 cylinder) on a car that requires more flow volume ( say a V8). Technically, it is a hi-flow cat - but for a 4 cylinder app. Just a extreme hypothetical example - but gives you the idea.

I say stick with a major aftermarket brand, and you should be ok.

JONSKI

An air pump in a MP would slightly help emissions and really help the flames.



It will run cooler, but as for the catalytic reaction, hotter is better. The air pump serves a dual purpose. It helps keep the temperature up and it provides oxygen to burn any left-over hydrocarbons that will eventually clog the device.

Mahjik

iTrader: (1)

And how would an air pump help with no catalytic converter in place?

All it's doing is supplying air... Adding fresh air into an exhaust that has no catalytic system will do nothing for emissions.

suganuma

bonez