High Flow Cats? Magnaflow vs Thunderbolt vs..??

**5abivt** · 03-17-2010, 08:17 AM

So I ordered LTs and a Y pipe and I need cats to be installed in there somewhere. Not for emissions but for noise reduction really but passing emissions is obviously a little peace of mind from the local piglets.

Anyone have experience with magnaflows? thunder bolts? other brands? thunderbolts are $30 ish on ebay, the mags $65 ish.

**Mike0202** · 03-19-2010, 03:34 PM

Originally Posted by 5abivt

So I ordered LTs and a Y pipe and I need cats to be installed in there somewhere. Not for emissions but for noise reduction really but passing emissions is obviously a little peace of mind from the local piglets.

Anyone have experience with magnaflows? thunder bolts? other brands? thunderbolts are $30 ish on ebay, the mags $65 ish.

I have magnaflow catback with high flow thunder bolt cats. Sounds amazing. Quite at idle, but it screams at wot.

**5abivt** · 03-19-2010, 05:17 PM

Do you have th. Bullet 3" ones ? Still pass emissions?

**Mike0202** · 03-19-2010, 05:35 PM

Originally Posted by 5abivt

Do you have th. Bullet 3" ones ? Still pass emissions?

Not sure. I brought the car to my buddy at his shop and he said he had thunderbolt high flow cats in stock of a 98-99 ls1. Then he put them on. Didnt notice any difference in sound or performance. He said you would be luck to get a 3 hp gain with high flow cats.

**Brandon35thSS** · 03-21-2010, 07:43 AM

thunderbolt cats added to a tsp ory,pacesetter longtubes,lm1 = no rasp and very little drone.

[ame]http://www.youtube.com/watch?v=jDYDXfTPwJs&feature=player_embedded[/ame]