lt1street

Im thinking about running a 12" bullit in place of my high flow cat. What do you think sound wise or should i leave the cat?. Emissions is not a problem

nonojoe66

ehh y bother, if ur just gonna take out the cat and leave the flowmasters then just put a strait pipe in there, it wont b THAT much louder, the only reason to do so is to make it louder, its not gonna give u more then 3hp so y take out a sound restriction and replace it with another restriction, if u have the stock y ur gonna need some kinda reducer

LameRandomName

I think that the only real advantage it will give you is the theoretical ability to run leaded fuel, although doing so is not generally considered healthy for your oxygen sensors anyway.

I also think that in the event that emissions BECOME an issue for you, it would be handy to already have them in place.

Finally, I think that if you want noise; you may find that an electric cutout is far more useful and convenient in day to day reality.

But it IS your car, so....

2000LS1Z28

Well, I did exactly what you're talking about...Ran a 12" Dynomax Bullet in place of where my original stock catylitic converter was when I had some Mac headers put on the car...Although I ended up replacing the bullet with a Random Tech highflow cat because I did not like the sound of the cat-back I was running at the time with the bullet...

Between the highflow cat & bullet, the car was a little tinny/raspy in the mid rpms with the bullet. And noticeably louder at full throttle. Idle & part-throttle sounded exactly the same...

Honestly, I don't think it's worth replacing your highflow cat if it's already on the car. I doubt you'll gain more than 1-2rwhp (if any at all) with the bullet. But if you are dead set on replacing the cat, just have a 3" offroad pipe welded in there like the other guy mentioned. You might gain a few ponies with this, but the car will mostly just get louder, raspier, & smell like gasoline at idle.

Mike