I recently added a pair of Hedman shorty headers, hedman y pipe, 3 inch highclow cat, and a 3 inch American Thunder Cat Back system to my 89 Camaro and it is as quiet as can be. Anyone know why? Maybe because the 3 inch piping?

 

Noise level is merely relative to the persons liking. The cat is deadening some noise. Perhaps the muffler needs to 'break in.'

The 3" piping is NOT the problem.

 

I have an american thunder system and it sounds friggin awsome.Perhaps it is the type of cat you have.

 

What kind of high-flow converter is it? It's also on an LO3 and power also equals sound and loudness. It should sound better with time. Does it have the 2 1/2" or 3" outlets?

 

I have a catco 3in cat and 3 in tips. This setup has such a quiet rumble, almost unoticeable. Maybe with all the flow, I am not dumping enough fuel on it.

 

how would it sound better with time?

 

Flowmaster mufflers tend to get louder as they get older.

I have edelbrock TES headers, no cat, and a 3'' hooker catback on mine. My idle is pretty quiet but when I open it up it screams. I really like the sound of the hooker over the old flowmasters I had.

 

It's all in your opinion when it comes to sound.

I for one don't like the hookers at all, but obviously several people think they're great. Same with everything else.

...I have no idea why, but yes, flowmaster's get louder with time.

 

Everyone I have talked to tells me that my camaro is the best sounding camaro they have ever heard. For some reason 4th gen guys seem to think the slp loudmouth sounds good...yuck. I wonder if they know loud and sounding good are 2 different things?

 

catco 3" converters are not usually really quiet right? I just ordered one on ebay today.

 

I had tes headers, a random tech cat and an american thunder cat back on my 88 305 tbi, and i mean, i've heard louder camaros (usually gutted cats, ect) but i def. would not even come close to calling that setup quiet, it screamed, i loved it. thats why its going on the 350 :lala:

 

My 3inch American Thunder is fairly loud but its on a L98. Nice mean raspy sound when opened up. I like that sound but it could be louder for my taste. It has gotten louder for some reason after some time I guess from burned out exhaust products that builds up on the walls of the pipe. You know, that black stuff.

As far as your sound goes, it is probably because your 305 TBI doesnt flow all that much air. The cam is tiny and the heads/intake dont flow much at all to make sound. Fast built up motors make sound because of the cam and heads flow lots of air. Mine sounds good behind the stock L98 but it should get louder and tone up a bit as it gets modded.