What size is the stock diameter exhaust on our cars? (ls1's) Is it practical/ beneficial to put the cutout before the cat? Would it fit very well or would i need to buy a little plug in thing for a simulated o2 sensor back there?

what does everyone think about Qtec electric cutout plates?

 

Stock exhaust size is 2.75 inches so a 3" cutout would be most suitable for your application. The most common spot that many of us route them is right before the rear axle. If you have an LS1, then you have dual cats and it would be near impossible to run a cutout right before the cat on the drivers side due to the severe lack of space.

 

yup everything he said... I like my QTP cutout, it died about a month after I got it and sent it back to QTP and they replaced it with the newer style motor for free and I havent had any problems since then

 

Installed a 3 1/2 QTP on a Mufflex 3 1/2" Dia. system. Located in the Rt. rear seat area after the dual cats (1997). QTP is smaller profile than most. So far, I have had good luck with it, and, really allows the FI 383 to flow. Also, I'm running a Random Tech dual cat system, so, that also helps.