has anyone used a straight to muff exhaust on a gslse? i know that some of the ports are operated from the exhaust backpressure so would this still be possible if there were no cats and i had about a 2 inch pipe? i would probably switch to a header if i did this.

It will work, if you make the right pressure line for the 6 ports. It will also be very loud.

it doesnt need much pressure to open, but it will be very loud

Dont do it if its your daily driver/ it'll suck more gas and u'll fell a lag(hesitation) in the mid band RPM range(not all the time).......But its definitelly a gain in HP @about 4-6k RPM range (10)HP) and i think the (engine)runs better(cooler and freely) https://www.nopistons.com/forums/pub...IR#>/smile.png So i guess it is a good mod If you're not in CALIFORNIA!!! https://www.nopistons.com/forums/pub..._DIR#>/sad.png

BTW i 4got to mention that i tryed that with (wired opened secondary ports)

That's how I have mine. Just wired the actuators open. Not that big of a loss in the lower RPM. There was some loss just not that much. As for the gas milage.....mine didn't go down at all.

are there benefits to wiring them open as opposed to actually putting the back pressure line on there? also what size exhaust are you running back to the muff? ive got a pretty good muff on there (flowmaster 40 series i think, not a straight through muff) so i dont think it will be annoyingly loud but i guess well see. this is coming from a guy who drove around for a long time with a chevelle 350 running open headers. <-- man that was loud but it sure sounded good!

also, what are the benefits of removing the airpump?

Eventually that flowmaster muffler will go bad. Rotary's make a lot of heat and I have tried those mufflers and the best one if you want it to last is a dynomax. They work well.

ok but the flowmasters are rather cheap to replace and it doesnt seem like the heat will effect it very much bc the muff is at the very end of the car, now without cats it will get pretty hot. the muff casing is very thick so hopefully that is a sign of the inside quality too.