does removing the catalytic converter add HP? Options

[nate95]

Hey i was just wondering if i were to remove the catalytic converter if it would add any horse power? or what about getting a "Y" pipe before the cat. so i can still have the cat. but have it go straight out when i want to race?

[nate95]

how hard is it to remove?what do i have to do to take it off? im not worried about getting pulled over for it, is it worth doing?

[Yellow94GT]

how hard is it to remove?what do i have to do to take it off? im not worried about getting pulled over for it, is it worth doing?

I was wondering about naturally aspirated engines and removing the catalytic converter.

I thought that naturally aspirated engines with catalytic converters were typically enginered with cams that promote delayed exhaust valve timing. Since the converter is restrictive the exhaust valves remain longer and allow spent exhaust gases to pass through the catalytic converter before closing.

Without other modifications removing converters on a naturally aspirated engines would offer little or no benefit or unless other modifications were made. Adjustable timing gears that would allow the valves to close sooner and keep the exhaust gasses in the cylinder longer on the exhaust cycle and promote better power.

I thought that in some cases with some engines when the converters were removed on non turbo engines there was a loss of power at low rpm. Since the factory cam timing was designed to flow through the converter the intake valve may be opening before the exhaust is completely closed. This is not a problem with the factory cams and catalytic converter since the gasses haven't passed entirely though the converter. With converter removed the exhaust gasses may leave a vacume and intake cycle pressure may be flowing out the exhaust before the factory cam timing cycle is complete.

I thought this was why adjustable cam gears were used to account for the change in low rpm cycle pressure losses when using pipes without the "restrictive catalytic converter".

I found when I removed my catalytic converter on my former car (Not my Celica) the power was down through most of the lower rpm.

Just my experience and my opinion,
Yellow94GT

Just what






To take advantage of
By removing the converter with the factory cam timing some engine may actually have the intake and exhaust valves would be open