Anyone tried removing or hollowing out their catalytic converters? My impression is that three are a bit restrictive for a 290hps V-8. By elimintaing one of two of them, I'm thinking I'd gain more power and meaner sounding exhaust. Now hypothetically, if I were to bypass the cats, should I cut them out and weld in a pipe, or flatten the honeycomb filters inside of them. Am I onto something here???

 

Hey Lex400SC:
There are some companies out there that produce high flow peformance oriented catalytic converters which maintain your SC's legal emmissions flow and required backpressure but appear to not rob you of as much performance. I have not incorporated these into the mix of my SC yet, but if I do need a new forward section, I would do it in a heartbeat. For reference try this website...
http://www.randomtechnology.com/
They do not list Lexus parts for the SC but they do have Toyota Supra performance cats and they imply that they do custom work. I am sure there are other sources as well. I did have another website that had some but seem to have lost that URL.

 

I would reccomend against "gutting" out the cats; simply replace them with a straight pipe; or a free flowing cat as mentioned above.

 

Isn't this a '95 SC4? If that's the case, assuming it's stock, you have 250 flywheel hp to deal with (you're thinking of the '98-up 1UZ VVT-i motor). By the time it gets to the wheels, you're talking about 175-180hp on a '92-95 car (ten more hp and lbs ft on '96-97 cars, which have the motor that premiered in the '95 LS). Coming from someone who's gutted many catalysts (is Jake listening?) I don't feel that's enough to warrant gutting cats, not to mention that the inside of the cat's shell will create turbulence in the exhaust pulses. Additionally, at that power level, gutted cats or a 'test pipe' will cause you to lose a bit of low end torque, as some backpressure IS needed (unless you're juicing). Go with a large body aftermarket high-flow unit, but be careful, some flow far better than others.