when I bought my 7 it came with no cats. it is over 20 years old so no emmissions need be done, but when safety checking do they look for cats? also what are the advantages/disadvantages of not running a cat?

 

No, but if a cop checks you'll get a ticket. All original smog equipment is supposed to be on the car. That's pretty much the only advantage, along with the fact that a cat will quiet it down a bit.

 

some Cops don't know a Presilencer From a Catalytic Converter...Mine is Big enough to "look like a Cat"....And NO,A Catalytic Converter is NOt a Requirement for a Safety..In Fact all you have to Really have is a pipe from the engine to Past the Passenger Compartment of the vehicle,and that pipe should be Free of leaks.No Fumes.leaks are allowed to Be Present around the Compartment,so no Gases are to enter The Cockpit...

 

would you happen to know the size of that ticket? also what other ways can i use to quiet down my 7, its loud...

 

Last one my buddy got for no cat/evap canistor or EGR was $386.XX. That was 1.5 years ago.

 

eep, thats a lot more than i expected. how many ppl here are running without cats?

 

you might be able to kill 2 birds with one muffler here, so to speak.

a large magnaflow oval offset stainless steel muffler works good to quieten down the car, and also to smooth out the tone. plus, if you put it in the middle of the system it could look like a cat.
i have done this on my car. it's basically header-->magnaflow SS oval-->straight 2.5-inch pipe-->maganaflow SS round muffler.

before i was running just header and two straight-through mufflers at the back and it was LOUD. i find now that it is still loud at WOT, but cruising around it is quite reasonable. the tone is nice too.

 

and what would be the retail on this magnaflow ss oval or something of similar function?

 

Magnaflow mufflers are very reasonably priced. they also come with a lifetime warranty.
this is the one i got: http://www.magnaflow.com/02product/s...ne=main&id=457

they have a bunch of other sizes also, depending what inlet/outlet diameter you need and length, etc.
you want to go with the biggest bodied muffler you can fit, and also the offset design helps to reduce noise further.

i got my mufflers from Joe at RPM. maybe talk to him about it.

 

Every RX-7 I've ever owned has never had any cats on them....its probably the first "mod" I do to all my vehicles, ditch the cat!

In my area there is no e-testing so I really dont have to worry about it, but I do drive to the GTA and other major city area's nearly once a week and still have never had a problem with cops.

If your looking at getting some Magnaflow products, then send me the part numbers and I can get you some good pricing on them.

 

exactly why i don't have cats on my car either Joe.

and yeah, i'm all for the world not blowing up and what not because of global warming, but i think the main reason to put something in your exhaust system other than straight pipe is to get it to sound tolerable, haha. if i didn't have that Magnaflow oval in there the car would be an insanely loud chainsaw!

this is my current header-back exhaust:

still a little loud, but sounds decent.

 

^ Cats do not reduce the amount of greenhouse emissions, they reduce smog forming emissions. CO2 is the by product of burning hydrocarbons that results in global warming. Smog causes asthma, etc. and kills sick and old people.

 

you are right. it's CO, NOx, and certain hydrocarbons i believe.

i can rephrase my previous statement:
"i'm all for not killing sick and old people and what not, but i think the main reason to put something in your exhaust system other than straight pipe is to get it to sound tolerable"

hmmm, actually that doesn't sound as good...

 

Meh, im catless as well.

I just love the sound of 3" headerback, ....so glorious

 

wow, that's a lot cheaper than I expected. But I guess Im going to need a new shorter downpipe to fit it in between the Y pipe. how much would a shorter downpipe cost me? not lookfing for anything performance wise really, bang for buck, but if thats too expensive then what sthe cheapest thing out there?

 

If you want the cheapest option, get an exhaust shop to weld up some pipe where you have issues. If you can do it yourself, even better. All you need is a welder (wire feed or mig prefered), some cheapo pipe and some way of cutting it. You can cut angles to create bends.

Why do you say that? A real problem with our species is that our gene pool is being diluted by the weak. Not only do the weak survive, but we do not promote the strongest, thus making our species worse than it should be. Running without cats is darwinian and it's beautiful.

(note: I am joking so don't take offense if someone close to you recently died)

 

^ haha, that was good. i never looked at it that way.

 

are you SURE to mass MVI the presilencer will be ok? In Nova Scotia?
I'd rather have the presilencer between the RB header and RB catback, but i dont want to buy it and then find out it's not going to pass, and have to buy a cat anyway.

 

just get a cat for testing/inspection, and after you are done take it off and put whatever you want. simple as that

 

haha yeah... theres an extra 250 dollars i'll just go outside and pick off my money tree. haha common, i'm a 20 year old Rx-7 owner, how much poorer can you get? :P
Thanks for the input tho. I was talking to a friend who is a mechanic at a local garage/dealership, he told me any car made before 1990 isn't required to have a cat to pass MVI, so i'm in the clear. Pre Silencer it is.

 

hey now, i'm 20. i get by. *credit cards*cough.

i didn't say to go get a new one. a stock RX-7 cat will do fine and is cheap.
but looks like that is non-issue for you anyways. have fun with unrestricted rotary noise/fumes!