De-cat exhaust system

[aucorium]

Hi guys , has anybody had a de-cat done on their yaris , if so have you had any problems? any info will help as i want to de-cat my 1.3.

Thanks

[Capagotks]

i know a friend who de-catted their RX-7. Here (and probably in most parts of the world) it is illegal to remove the cat, as it removes most of the toxic gasses from the exhaust. (im pretty sure you can take it off for show cars/race cars). You will get a significant HP increase, but it is easy to notice if you have it off because if you rev it, flames might start coming out (and not just the occasional small one, i mean FULL ON) and your eyes start watering if your in a confined space/revving it up at the lights (but mainly for the people behind you)

[thomasward00]

Remember that our stock engines were designed to operate with a certain amount of back pressure, taking the cat off some stock engines will cause premature valve seal failure, it's not worth the gain, and besides it will kill your lower end.

[BailOut]

As Capagotks mentioned, the catalytic converter is there to greatly lessen your vehicle's emissions. If you remove it you will be dumping a lot of noxious emissions straight into your local atmosphere.

[aucorium]

thanks for all the advice guys , i really appreciate it!

[WRBlue]

OBDII cars (every car made post-1996) have 2 O2 sensors, one before and one after the cat to verify cat performance. Remove or gut the cat, you'll get a check engine light.

A high flow cat flows just as much as a straight pipe, doesn't give the CE light, and will pass a sniffer test.

There is other issues with gutting a cat, including turbulance and killing yourself slowly with the nasty crap that goes into a cat.

i know a friend who de-catted their RX-7. Here (and probably in most parts of the world) it is illegal to remove the cat, as it removes most of the toxic gasses from the exhaust. (im pretty sure you can take it off for show cars/race cars). You will get a significant HP increase, but it is easy to notice if you have it off because if you rev it, flames might start coming out (and not just the occasional small one, i mean FULL ON) and your eyes start watering if your in a confined space/revving it up at the lights (but mainly for the people behind you)

Thats something specific to a rotary. Because of how the work, alot of gas enters the exhaust and ignightes easily.
Scooby's do it too, cause they are a boxer. Especially bouncing off the rev limiter.
Most other cars it takes something wrong with them to do it.

[Capagotks]

speaking of rotaries, do you think onw would fit in a yaris, mounted sideways, and even if the front bumper had to be extended?

[jdium]

Originally Posted by Capagotks

speaking of rotaries, do you think onw would fit in a yaris, mounted sideways, and even if the front bumper had to be extended?

Absolutely, if you get the chance, check out the size of those lil engines. Tiny. But you're wallet will have to match the size...and you have to consider that you can't run FWD, as far as I know, there are no FWD rotories worldwide, so the swap would have to include a RWD conversion...but I'd love to see this done, in pretty much every platform...ooohhh the fun possible with 10k redlines and turbos

[Black Yaris]

only thing that is still stock on my exhaust is my cats, and only the cats... everything b4 and after has been opened up to larger diameter pipe.... and no CEL's

[WRBlue]

Originally Posted by jdium

Absolutely, if you get the chance, check out the size of those lil engines. Tiny. But you're wallet will have to match the size...and you have to consider that you can't run FWD, as far as I know, there are no FWD rotories worldwide, so the swap would have to include a RWD conversion...but I'd love to see this done, in pretty much every platform...ooohhh the fun possible with 10k redlines and turbos

A 12A is smaller than a beer keg ;) lol

But there was a FWD rotary. A crappy NSU, the Ro 80. The engines were crap - needed rebuilds at 30k, and all the cars came with an auto.

You could adapt a FWD tranny to a Rotary, but it'll be pricy.

Then there was the Norton Commander and the Suzuki RE5 - Rotary powered motorcycles. Those would definatly fit :D There are ways to adapt them to power a car FWD, but the Suzuki was only a 500cc making 60hp... It'd be alot lighter, but it would be hard to get over 120hp out of it. lol

[Capagotks]

what about a Suzuki GSX1300R (Hayabusa) engine? its not a rotary, but produces 129kw (175 HP) and its only 1299 cc, 4-stroke, four-cylinder, liquid-cooled, DOHC, 16-valve, TSCC. (from wikipedia), so I reckon it would easily fit in the yaris, and the 2008 model is bigger with 1340 cc, 4-stroke, four-cylinder, liquid-cooled, DOHC, 16-valve, TSCC and a compression ratio of 12.5:1 (up from 11:1). Then turbo it. then you've got yourself a deathtrap on wheels.

[Capagotks]

or even better, the Kawasaki Ninja ZX-14, with 1,352 cc Liquid-cooled, 4-stroke In-Line Four, 12:1 compression ratio, DOHC, 16 valves, fuel injection, digital ignition, electric starting 140 kw (187 hp) @ 9,500 rpm; 147.1 kw (200 ps)(197 hp) @ 9,500 rpm with RAM air; 154 Nm (113.5 lb/ft) @ 7,500 rpm and a 6-speed transmission.

[jdium]

Originally Posted by Capagotks

what about a Suzuki GSX1300R (Hayabusa) engine? its not a rotary, but produces 129kw (175 HP) and its only 1299 cc, 4-stroke, four-cylinder, liquid-cooled, DOHC, 16-valve, TSCC. (from wikipedia), so I reckon it would easily fit in the yaris, and the 2008 model is bigger with 1340 cc, 4-stroke, four-cylinder, liquid-cooled, DOHC, 16-valve, TSCC and a compression ratio of 12.5:1 (up from 11:1). Then turbo it. then you've got yourself a deathtrap on wheels.

Sounds kinda like this:

http://www.youtube.com/watch?v=xLVQtK04lig

SmartCar with a GSXR1000 in it...

[Capagotks]

pretty much. fool everyone in the bike lanes....

[eTiMaGo]

bike engines are nice, but they need to be revved up to crazy speeds to make much useful power. That's not too much of a problem on a bike as weight is very low, but a car is far heavier, wouldn't make things very sluggish at lower RPMs?

Although, I suppose, with this kind of swap, you wouldn't want to drive at low RPMs ever!

[Motorhead6T5]

If you delete the cat you will need a mil elim,since the ecu cannot be reflashed to turn the rear 02 circut off(yet). A mil elim is a malfunction indicator lamp eliminator. Its baisicly a resistor that tells your ecu that it is getting a clean reading ,it is pluged into the rear o2 harness.

[Black Yaris]

Originally Posted by Motorhead6T5

If you delete the cat you will need a mil elim,since the ecu cannot be reflashed to turn the rear 02 circut off(yet). A mil elim is a malfunction indicator lamp eliminator. Its baisicly a resistor that tells your ecu that it is getting a clean reading ,it is pluged into the rear o2 harness.

or you can do it the easy way and get defoulers for a few bux

[Vanderkitten]

I decatted and race-piped the Yaris last week... top end is GREAT... low end is brutally underserved. It did improve over 3-4 engine cycles, and it's in preparation for some un-normal aspiration, but now I am pondering Supercharger over Turbo!