Anyone know why not to use ignition cut with cat in the car?

[«Cyph3r»]

Hi,

Just wondering why you shouldn't use a techtom iic460 ignition control computer that cuts ignition at set rpm with a cat converter? Is it because the dumped fuel ignites and flames or why?

Thanks

Jamie

[funkymonkey]

coz you can't run straight fuel thru the ceramic in your cat, it can:

1. condense inside your cat if its cold enough

2. only a small percentage of waste fuel is converted by the chemicals in your cat, too much and it corrodes

3. lack of flamage when your exhaust is hot enough. You don't want the hot fuel igniting before your cat and not having anywhere to go but backwards

I run a Bee-R rev limiter and an exhaust cutout that engages when the rev limiter LED goes on using a relay to activate a servo motor to pull on the cable that swings the spring loaded flap to direct exhaust flow into a straight pipe... so its all automatic