Cats

[DREMEN]

Just a few questions regarding cats

1. How do you gut a cat?

2. Is it easy for the police/epa to tell if your cat has been gutted

Thanks

Ben

[Roy]

If they get you to do an emissions test its easy, otherwise on visual inspection i think its pretty hard.

But my thoughts are dont do it. A good 3" cat will flow well and is legal. Some things we cant avoid like running re-written ECUs and aftermarket ECUs.

Then there is the shady topic of legaility concerning BOVs/Filters/Intercooler etc etc, but one thing we can do is run cats on our road cars.

[Guest INASNT]

also gutting the cat slows down the air velocity in the exhaust coz the air slows down once it reaches the big void where u have guttered all the material in the cat and then has to speed up again.

[akeenan]

you can put a straight pipe where the cat is and the shell of the cat round the pipe and make it look authentic.

[Guest INASNT]

Originally posted by akeenan

you can put a straight pipe where the cat is and the shell of the cat round the pipe and make it look authentic.

when u go for a epa test they stick a probe near the cat and can tell if its working properly.

But think about it would u rather have that extra 5kw or be able to breath clean air???

[akeenan]

yeah, i wasnt talking about doing it myself .... im rather happy with my hi flo cat as it is.... i was just adding info to the topic of gutting cats etc and you air velocity stuff.

[holdens_r_better]

Its easy to gut a cat just run over it. nah the cops prob wouldnt find ya lol

[Ronin 09]

i had a cat-out pipe for a while. It will spool the turbo faster, but doesn't really do much for emissions. You are likely to only gain about 2-5rwkW so bugger it. And a gutted cat will likely flow worse than a hi-flow and hence make less power; as has been said it slows the velocity of the exhaust and causes more turbulence around the empty cat.

Just get a highflow from BATMBL and be done with it - i have and am very happy with it.

[akeenan]

ahmen

[floody]

Dunno about the cops, but I reckon the RSPCA would be onto you.....

seriously though, Why do it? its cheaper than a high flow cat, granted, but I doubt there would even be a noticeable increase over a healthy cat convertor. A clogged one would be a restriction though, but a healthy, fresh one , in a decent size, would be a negligible benefit

[JimX]

My motorcycle didn't come with a cat, and it's not legally required to have one on there. I don't actually know why, because the bike requires premium (toxic) fuel as well, so in theory it should have come with a cat. Strange.

[Ronin 09]

Bikes don't need a cat by law because basically they don't fit on there. But i'm sure that as emissions rules tighten, and the technology to manufacture smaller and more efficient cats comes closer, new bikes will require a cat.

[JimX]

Cats do fit on bikes. The current model VFR800 has one for a couple of years now (since 2001 I think) and it fits well enough (just smaller than a car one). A few other models have them too, like the Gold Wing.

In California I think all new motorcycles are required to have them. A trend that will probably follow elsewhere.

[Ronin 09]

ahh, and the last great uncatalysed smell of burnt fuel passes away. Still miss the smell of uncatalysed leaded - probably didn't do much for the brain cells though

[JimX]

I actually wonder what happened to the old rotten egg gas smell that unleaded cars used to get. It doesn't seem to happen anymore. They must have removed a lot of sulfur from fuels.

As for motorcycle cats, I think as long as the general population and the politicians remain ignorant as to just how polluting motorcycles are (especially 2 strokes) then we won't be forced to put them on just yet