c00lduke

I'm getting a little sick of the odor and am looking for a place to stick a catalytic converter. I have a RX-7 store mid pipe with a resonator and don't believe there is room for a cat but there seems to be a good deal of it the down pipe. By room I mean length of straight pipe to weld in an additional part. Most cats I see wouldn't work due to how large they are but I have seen some slim ones that look like they would fit.

So...

Do you?
What brand?
Is it even possible due to the heat?

neofreak

I have a davesport metal cat and a borla xr-1 in my midpipe. it got rid of the smell but I haven't put more than 1k on it, so who knows how long it'll survive.

scrubolio

iTrader: (8)

smb auto has a pretty slick metallic cat that is very small

i've used it one in my midpipe for 3000+ miles and it the comb is still in great condition

JKL is their US distributor

CrackHeadMel

iTrader: (2)

i had a randomtech 3" cat behind my stock ported t04s boosting cosmo re

i put 10k on that cat, upon removing it (doing a new setup) i had melted or deforemed a majoirty of the catalist

i however ran a very lean (15.5-16.0) cruise with alot of timming and very high egt's, alot of thoes miles were highway miles

the cat in my case was aprox 24" post turbine, maby a little more

Thats my only experience.

Dudemaaanownsanrx7

iTrader: (23)

i wouldnt be able to run a cat in my downpipe because my wideband is mounted at the end of it. you might take this into consideration if you decide to run a wideband o2 sensor or if you already are.

c00lduke

I have a bung down there but I was thinking more about running the cat in the downward sloping section of the down pipe.

Does anyone know whether a ceramic or metallic cat would handle the heat better?

Dudemaaanownsanrx7

iTrader: (23)

as long as the cat is after the bung you would be fine. a cat will skew your o2 readings if it's before the bung.

classicauto

iTrader: (3)

IMHO, no cat will take the heat that well. But your best bet is a metallic core.

I bought the +$200 3" Bonez cat from rx7.com, mounted it midway through my mid pipe, and blew it out on the Dragon after only ~3,000kms of use, most of which was break-in driving.

c00lduke

While being too close would expose it to too much heat is there a chance of it being too far away?

classicauto

iTrader: (3)

Possible, yes. But being too far away wouldn't cause my cat's front half to completely melt and squish into the back half

But I doubt a mid pipe is too far away, thats where nearly every main cat is in any OEM system, the middle.

Dudemaaanownsanrx7

iTrader: (23)

most likely you will have to remove the resonated midpipe. the cat will still dampen the sound if your worried about increased noise

JIMMY54

iTrader: (2)

Im running a Catco 3" Cat, it has about 7000km on it. Its mounted about halfway down the exhaust... Seen lots of heat, and still looks new inside. While this isnt an FD, its a ported 13bt in a FB, that sees some abuse

silentblu

iTrader: (1)

i heard max cooper and a few others used these.
I called random tech, and Dave had some knowledge of them being run on rotaries.
Main failure of most cats are because of untunned decel maps, spitting too much fuel

i'm contemplating on going with the randomtech 4inch in/out 5inch casing

CrackHeadMel

iTrader: (2)

My decel maps while they were not optimum were fairly tuned.

i think the majority of my problem was the high egt's i ran and having it right at the end of my dp.

If i use another cat ill move it farther down.

-Jacob