All stock '91 Z28 with the L98. Replaced the stock muffler with a Magnaflow direct fit, 2.5" inlet, dual 2.5" outlet. I was hoping for more rumble than the stocker and it seems to be quieter. Will the sound improve as the internal packing "breaks in"?
FYI I just got the car and am new on her but have been lurking for a little while doing research.

 

All exhaust will break in and get slightly louder some get even louder as time goes on. Magnaflow is known for being quieter at idle but a screamer at WOT.

 

Magnaflow typically is a system that idles with a little more rumble than stock, but when it is wide open has a really good tone without being obnoxiously loud.

What sound are you looking for?

 

I listened to sound clips on YouTube but it is difficult to get a true sense of sound for the mufflers but they seem to be louder than mine. I guess it needs break in time.
I was hoping for a little more "authority" on the exhaust note. Thanks for the input!

 

The 2 1/2 inlet is smaller than the stock 2 3/4 intermediate pipe
3" intermediate pipe and 3" inlet muffler would help.

 

I'm a truck and Jeep guy and totally new to this car thing. I've always run Flowmasters on my V8 Trucks but the consensus here is that they drone pretty bad on these cars. I'm sure I will be fine with it and if not, can always change it later. In the meantime I have a ton of suspension and brake parts to put on it before my wheels and tires arrive.

 

You might have been happier with a flowmaster 80 series.

 

If all you swapped out is the muffler and left of the exhaust stock dont expect much.

 

In order to get a decent tone out of any muffler you need at least a 3in. cat back preferably with 3in tips , and they do break in.

My Flowmaster American Thunder cat back with 80 Series has gotten a lot deeper tone over the last 8 years. Love it.......










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I HAVE AN 89 formula l-98 and replaced my stock muffler with a flowmaster 80 and love it there a ton of sound clips on youtube, what magnaflow muffler did you put on it

 

[QUOTE=Ron U.S.M.C.
In order to get a decent tone out of any muffler you need at least a 3in. cat back.
.[/QUOTE]

I should not have said "decent tone". That's not the case.

The Flowmaster American Thunder 3" cat back with 3in. tips using the 80 series will give the car a deeper tone than that same car using stock pipe.

 

My flowmaster exhaust sounded better after a few months I guess it got "broke in"

 

have someone else drive the car, listen from another car of the side of the road. Then see what you think

 

Good advice. I will have someone else give me a fly by in it. And allow some break in time. I didn't go Flowmaster because of the drone I read that it produced. If I'm not happy with the Magnaflow after some time I will switch it out.

 

I've got a Magnaflow cat-back on my 84. While my set-up is very different than yours there's one thing I seem to notice about mine,...... the tone changes once the RPM's start climbing. IMO; It's NOT the same sound @ idle as it is @ 3K.

I gotta' guess that this is due to the muffler and not the pipes.

My Flowmaster set-ups all seem to always have the same tone. I don't mean each system sounds the same compared to each other; just that any individual Flowmaster set-up is louder or quieter depending on RPM.

 

My magnaflow is much quieter than most flow masters at idle but about the same when I open it up. I really dont like the tone of the flow master they are always loud and drone bad when cruising. Although they do tend to make cams sound more aggressive at idle.

Personally I would get the rest of the exhaust upgraded then see how it sounds and then get what you like.

 

Here's my Magnaflow souls clip.

 

That sounds good! Mine seems a lot quieter but it only had been driven maybe 20 miles so no break in. I need to have a buddy give me a drive by.

 

That's a Vortec TPI 355 with 10.3 compression with a ZZ9 TPIS cam, Dyno Don's 1 3/4in headers, dual cats and 3in cat-back Magnaflow Exhaust System. It's. OT that loud inside the car but on the outside it is a little loud at idle but tame. It will set off car alarms. The headers helps make it sing. Break in period is B.S.