Hi-fow vs no cats, (will be supercharged eventually)

[Jack B]

I am with you, I do not run cats and get no cabin fumes. Whether the car has cats or not does not change the fact that the engine has to get rid of the combustion by-products.

some of the fumes can be tuned out.

 

[Jack B]

The comment on fires pertains to all cats. If you run over-rich you can catch the cat on fire. I believe the Roe SC ran rich on 8 and 10, loading the cats and causing the problem. This is why it is necessary to use something like a VEC to modify the injector pulse to the offending cylinders. Please to not get me wrong, when the a/f is properly controlled, the chances of a failure are remote.

A cat fire is especially bad on the viper because the flames come up thru the floor/sill at the front of the door and into the cabin. The cat plugs and then the rich mixture catches on fire to the front of the restriction, it then burns thru the front of the cat or the turn-out, which ever is the thinnest.

Are these reports of fires from only the stock cats or modded hi-flows as well?

 

[speedracervr4]

Make sure your tune is good and keep an eye on it (with a wideband) if you do decide to go with high flows. I've had 7 years on my S/C Viper and they look fine. Bad 02 sensors or low voltage battery will cause over fueling issues.

 

[NO HEMI]

No cats, no fumes, no problem!!!, but
Of course mine's a Gen3( don't know if it would make a
Difference, although my exhaust exits on the side)!!

 

[Jack B]

Just to add a little more - contrary to belief, excess fuel in the exhaust does not always show up as a rich mixture. A bad plug or injector can cause excess fuel in the exhaust, however, it could show up as lean, O2 sensors measure the remaining oxygen and do not care about liquid fuel in the exhaust system.

Make sure your tune is good and keep an eye on it (with a wideband) if you do decide to go with high flows. I've had 7 years on my S/C Viper and they look fine. Bad 02 sensors or low voltage battery will cause over fueling issues.

 

[dragon rider]

I have metal cats and love the sound. Most people thing that I'm running catless. No fumes is a plus. Playing with modded GTR's may leave you disappointed. They are very easy to drive fast compared to Vipers in the 1/4 mile.