how to make oem cat into a high flow one
08-30-2007, 10:28 PM
#51
the stig is my hero
Join Date: Feb 2006
Location: NC
Posts: 701
Likes: 0
Received 0 Likes
on
0 Posts
Ya know..., you guys can chalk up $500 for a MazdaSpeed exhaust. I have one, and god damned, it makes Rena purr. I've seen many RX8s around town, but none sound as good as Rena. It has an authentic rumble to it, unlike cheap "custom jobs" that any fool can tell from afar that you did it in your garage.
08-31-2007, 07:05 AM
#52
<3 Rotary
Join Date: Jun 2007
Posts: 527
Likes: 0
Received 0 Likes
on
0 Posts
Oh. I thought they were talking about taking out the "bulged parts" and gutting them.
08-31-2007, 07:14 AM
#53
No means yes
iTrader: (1)
Join Date: Nov 2006
Location: Jersey City NJ
Posts: 1,507
Likes: 0
Received 0 Likes
on
0 Posts
Don't you be touching my bulged parts...
Seriously though, this thread is about gutting the catalytic converter, which is under the car (yes, a bulged part... close to your transmission and what provides the cup warming effect)... It also happens to be the single most restrictive piece of the exhaust system, hence removing / gutting.
By the way, I seem to remember that the two parts of the cat actually clean the exhaust of two different gases, but for the life of me I can't remember where I read that.
08-31-2007, 07:29 AM
#54
<3 Rotary
Join Date: Jun 2007
Posts: 527
Likes: 0
Received 0 Likes
on
0 Posts
Well, thinking about it:
7" of consumable catalyst, and 3" of safety catalyst.
I'm guessing you're gutting it for a little extra horsepower (if not for acoustic purposes). So you mean..., the longer I drive this thing, the more power I get...? That honestly sounds farfetched.
Why is why I thought you guys should just get a MazdaSpeed exhaust.
7" of consumable catalyst, and 3" of safety catalyst.
I'm guessing you're gutting it for a little extra horsepower (if not for acoustic purposes). So you mean..., the longer I drive this thing, the more power I get...? That honestly sounds farfetched.
Why is why I thought you guys should just get a MazdaSpeed exhaust.
08-31-2007, 07:31 AM
#55
what the hell do you mean the longer you drive this thing the more power you will get? where did that come from?
And I am going to assume this is your first rotary vehicle? They run quite a bit louder than piston motors naturally so you can really tell Mazda used a very baffled muffler and cat from the factory to get the car as quiet as it is. With as much as the cat itself quiets down the car there is a good amount of restriction in that piece. You will see the biggest improvement in power by replacing the cat as compared to a cat back exhaust, header, intake, u/d pullies, etc.
And I am going to assume this is your first rotary vehicle? They run quite a bit louder than piston motors naturally so you can really tell Mazda used a very baffled muffler and cat from the factory to get the car as quiet as it is. With as much as the cat itself quiets down the car there is a good amount of restriction in that piece. You will see the biggest improvement in power by replacing the cat as compared to a cat back exhaust, header, intake, u/d pullies, etc.
Last edited by mac11; 08-31-2007 at 07:33 AM.
08-31-2007, 09:06 AM
#56
the stig is my hero
Join Date: Feb 2006
Location: NC
Posts: 701
Likes: 0
Received 0 Likes
on
0 Posts
anyway- I'm probably going to tackle this project tomorrow and see what kind of gains I can get. I figure if I REALLY screw something up, I can always buy a supercat like I was originally planning. I'll take pictures for everyone's enjoyment... maybe do a little DIY :-)
08-31-2007, 10:24 AM
#57
RIP My beloved SS
Join Date: Aug 2007
Location: Jacksonville, NC
Posts: 27
Likes: 0
Received 0 Likes
on
0 Posts
So, this is my first Rotary engine. I have been perusing the posts for about 2 months now to find out what kinds of mods i can do to get more audio/visual flare out of my car for little money (gotta love military salary). This seems like a good candidate as it sound fairly cheap and effective.
Question though: the flames, when do you start to see flames coming out...and is that only with an aftermarket muffler, i am thinking about making a custom exhaust come out the center, would this cat mod make a single exhaust too hot?
Question though: the flames, when do you start to see flames coming out...and is that only with an aftermarket muffler, i am thinking about making a custom exhaust come out the center, would this cat mod make a single exhaust too hot?
08-31-2007, 11:24 AM
#58
the stig is my hero
Join Date: Feb 2006
Location: NC
Posts: 701
Likes: 0
Received 0 Likes
on
0 Posts
Nope, I've gotten flames with a completely stock exhaust. The most effective way of producing them though is getting a hi-flow cat or midpipe. The stock muffler isn't too restrictive.
09-01-2007, 01:20 PM
#61
I don't buy Kool-Aid
Thanks to Stealth for this finding!!! You rock dude All that are interested please see the gutting your cat thread in this section. Stealth told us his finding and I am passing it on. The thread has this info and I will tell you how I got it done in a shorter period of time.
That 9" of "extra cat material" can be removed from the rear by just obtaining a 5ft section of 1/4 inch threaded rod from Home Depo/Lowes and ramming it repeatively into it. This size rod is thin enough to go around the bends of the assembly but strong enough to break up the ceramic.. Be sure to mark the rod to the dept you need(you dont want to go into the front section of the cat) and dont go past it. The rod can be bent on the end to increase the area it cleans as you go. Wear a mask when you are doing this as when you are shaking out the pipe to clear it --it can get a little dusty and I wouldnt think you want to beathe that stuff into your lungs.
Damn good find.
olddragger
From what I get you take a 5ft 1/4 inch threaded rod mark it, then hammer it into the _______ on the cat?
How deep do you need to go when your braking up the ceramic? 9"?
Shaking out the pipe to clear it. What pip? the one I'm useing to brak up the ceramic?
About how much time will this take?
Thank you
09-01-2007, 01:40 PM
#62
Right, I'm new to all this cat stuff. Can someone point out to me what we're doing?
From what I get you take a 5ft 1/4 inch threaded rod mark it, then hammer it into the _______ on the cat?
How deep do you need to go when your braking up the ceramic? 9"?
no further than the end of the rear brick of ceramic. or no further than the opening for the 02 sensor.
Shaking out the pipe to clear it. What pipe? the one I'm useing to brak up the ceramic?
the piece of pipe the catalytic is welded too. If you unbolt the section of pipe the cat is on and look at it the directions will make complete sense.
About how much time will this take?
hour. maybe 2. did this on an old car.
Thank you
From what I get you take a 5ft 1/4 inch threaded rod mark it, then hammer it into the _______ on the cat?
How deep do you need to go when your braking up the ceramic? 9"?
no further than the end of the rear brick of ceramic. or no further than the opening for the 02 sensor.
Shaking out the pipe to clear it. What pipe? the one I'm useing to brak up the ceramic?
the piece of pipe the catalytic is welded too. If you unbolt the section of pipe the cat is on and look at it the directions will make complete sense.
About how much time will this take?
hour. maybe 2. did this on an old car.
Thank you
09-01-2007, 02:32 PM
#66
Metatron
iTrader: (1)
First you have to take it out, and stand it upright, "front" part up.
The first pic shows the O2 sensor , this is the hole I used. Rods curved towards the back, smashed the ceramic substrate, the pieces fall out thru the resonator (pics 2 and 3)
Olddragger went in thru the resonator, with a carefully measured rods.
The piece of catalyst that must remain is in "front" of the O2 sensor space.
S
The first pic shows the O2 sensor , this is the hole I used. Rods curved towards the back, smashed the ceramic substrate, the pieces fall out thru the resonator (pics 2 and 3)
Olddragger went in thru the resonator, with a carefully measured rods.
The piece of catalyst that must remain is in "front" of the O2 sensor space.
S
09-01-2007, 02:36 PM
#67
Registered
Join Date: Feb 2006
Location: Conroe, Texas
Posts: 397
Likes: 0
Received 0 Likes
on
0 Posts
09-01-2007, 02:47 PM
#68
I don't buy Kool-Aid
First you have to take it out, and stand it upright, "front" part up.
The first pic shows the O2 sensor , this is the hole I used. Rods curved towards the back, smashed the ceramic substrate, the pieces fall out thru the resonator (pics 2 and 3)
Olddragger went in thru the resonator, with a carefully measured rods.
The piece of catalyst that must remain is in "front" of the O2 sensor space.
S
The first pic shows the O2 sensor , this is the hole I used. Rods curved towards the back, smashed the ceramic substrate, the pieces fall out thru the resonator (pics 2 and 3)
Olddragger went in thru the resonator, with a carefully measured rods.
The piece of catalyst that must remain is in "front" of the O2 sensor space.
S
and crap like this should fall out right?
Thanks
09-01-2007, 02:51 PM
#69
Metatron
iTrader: (1)
Absolutely not!
....of course, that would be WAY too easy!
Your cat should still look pristine like that when the job is finished, or you get a big fat FAIL!
Yes, the pieces will look like that. If you work thru the resonator, be SURE that stuff doesn't get rammed into that first bed.
S
....of course, that would be WAY too easy!
Your cat should still look pristine like that when the job is finished, or you get a big fat FAIL!
Yes, the pieces will look like that. If you work thru the resonator, be SURE that stuff doesn't get rammed into that first bed.
S
09-01-2007, 03:06 PM
#70
I don't buy Kool-Aid
Absolutely not!
....of course, that would be WAY too easy!
Your cat should still look pristine like that when the job is finished, or you get a big fat FAIL!
Yes, the pieces will look like that. If you work thru the resonator, be SURE that stuff doesn't get rammed into that first bed.
S
....of course, that would be WAY too easy!
Your cat should still look pristine like that when the job is finished, or you get a big fat FAIL!
Yes, the pieces will look like that. If you work thru the resonator, be SURE that stuff doesn't get rammed into that first bed.
S
Thanks
09-01-2007, 03:10 PM
#71
09-01-2007, 03:16 PM
#72
I don't buy Kool-Aid
No I hear you but, what I'm asking is;
If I take my cat off and do what you said;"First you have to take it out, and stand it upright, "front" part up." then I should be ok drilling out from the back of the cat starting with the part that is facing the back of the car right?
That make sense?
I mean can just drill the end out useing a drill bit on my black and decker and start drilling from the back of the cat up to the front where the O2 sensor is right? but dont pass the O2 sensor right?
**Thanks STL thats what I was looking for**
If I take my cat off and do what you said;"First you have to take it out, and stand it upright, "front" part up." then I should be ok drilling out from the back of the cat starting with the part that is facing the back of the car right?
That make sense?
I mean can just drill the end out useing a drill bit on my black and decker and start drilling from the back of the cat up to the front where the O2 sensor is right? but dont pass the O2 sensor right?
**Thanks STL thats what I was looking for**
Last edited by DOMINION; 09-01-2007 at 03:22 PM. Reason: PER PM
09-01-2007, 03:45 PM
#73
Started mine. Tight exhaust bolts is an understatement! After checking it out, DAM the 02 sensor hole is small! After about an hour of crunching from the 02 hole. Still unable to reach the rear portion of cat material, I did'nt have a long bar handy. Found my dewy gun cleanning rod would work. Will start later this afternoon when its cooler and start working it from both ends.
***For you people who already done this mod. Theres no way all the rear 9" portion of the cat can be cleanned up entirely(Clean). You're just doing this mod to increase flow. Right? Or is there more to this mod?***
***For you people who already done this mod. Theres no way all the rear 9" portion of the cat can be cleanned up entirely(Clean). You're just doing this mod to increase flow. Right? Or is there more to this mod?***
09-01-2007, 03:48 PM
#74
No I hear you but, what I'm asking is;
If I take my cat off and do what you said;"First you have to take it out, and stand it upright, "front" part up." then I should be ok drilling out from the back of the cat starting with the part that is facing the back of the car right?
That make sense?
I mean can just drill the end out useing a drill bit on my black and decker and start drilling from the back of the cat up to the front where the O2 sensor is right? but dont pass the O2 sensor right?
**Thanks STL thats what I was looking for**
If I take my cat off and do what you said;"First you have to take it out, and stand it upright, "front" part up." then I should be ok drilling out from the back of the cat starting with the part that is facing the back of the car right?
That make sense?
I mean can just drill the end out useing a drill bit on my black and decker and start drilling from the back of the cat up to the front where the O2 sensor is right? but dont pass the O2 sensor right?
**Thanks STL thats what I was looking for**
No, its not that easy! Craw under your car and check it out. From the rear end the rod has to snake through the resanator to reach the rear portion of the cat.
***THIS IS NOT AN EASY JOB!!!***
