[cv70chall]

I'm on the home stretch with this car and I've got a couple of decisions to make regarding the exhaust.
I've gone with headers and will be installing a set of Flowmaster mufflers but I don't know whether I should install the resonators in back as well.
???
Will resonators hurt or help the sound? I want have some stock looks, as installing the resonators and head shields would do just that.

Thoughts?

[fbernard]

Resonators are before the mufflers (and the axle), not after.
And Flowmasters are NOT mufflers (but that's just a matter of personal opinion).

Most aftermarket exhaust systems just have a pair of mufflers before the axle, and nothing rearward.

What will be the tube size?

[cv70chall]

My mistake! Wow, sometimes it just isn't my day. I have a set of resonators- and I mistook them as mufflers. The resonators are before the tank and mufflers would mount alongside the tank.The mufflers are what I am asking about. Would adding them to my exhaust (headers/ mufflers) change the sound/ performance?
I believe my pipes are 2.5" diameter all the way to the chrome tips.

Thanks and my apologies!

[fbernard]

I believe the OEM system used 2 1/4 tubing, so OEM mufflers will probable by in that size.
You can find OEM-looking Challenger exhaust tips in 2.5" though, and you can probably find round-shaped mufflers which can be used alongside the tank.

If you only have resonators before the axle, you need the mufflers out back.
If you install mufflers under the rear seats, you may do without the mufflers at the rear (that's how most aftermarket exhaust systems are designed). That will make more noise though, and may cause drone inside the car if you pick the wrong muffler.

I have tried quite a flew mufflers in the past, both in 3.0" and 2.5".
I have tried "turbo" mufflers, Flowmasters, and I've recently installed the new VT Dynomax model (back to 3.0") which is basically a turbo muffler with a spring-operated valve inside it.
The worst I have encountered were the Flowmasters (series 70), which turned a mild drone I had around 2500 RPM with the turbos into a big drone from 2200 to 4000...
Until now, the best (I should say the least noisy) I've heard are the turbo-style. Way noisier than stock anyway (but I'm miles away from stock in the engine department too).
I have no opinion on the new VT yet, I have not started the engine since the last rebuild.
But it should be fairly close tho the turbo-style, since the construction is quite similar.

My opinion is this : if you are installing mufflers under the floor (front of the axle), you must pick a free-flowing muffler if you don't want drone.

If your engine is not too far from stock, a stock configuration with resonators and rear mufflers might be best.

[Adrian Worman]

That's a good answer Fabien, did you notice any particular type gave more or less power?

[fbernard]

That's a good answer Fabien, did you notice any particular type gave more or less power?

Frankly, no. But I only have tried 2.5" with cutouts or 3.0" systems, so there's not much restriction. And even if it did change HP a bit, I don't race often enough to really pinpoint such changes.

[cv70chall]

I'm currently running a 360 .30 over with a performance cam and performance pistons (Nothing crazy, just a nice amount of bump).
I have headers on it and will be using a set of Flowmasters but I'm not sure exactly what model they are. I will be installing the heat shields in the rear just in case I decide to go "more stock looking" and add the tube mufflers in the back.

[Adrian Worman]

I don't run any resonators either but I still use the heat shields especially on the passenger side cos it helps to protect the tank vent lines etc from road crud

[cv70chall]

As always, thanks Adrian!

[Adrian Worman]

As always, thanks Adrian!

Appreciate the sentiment Chuck but I think that thanks should be redirected to Fabien

[cv70chall]

Absolutely! Thanks to Fabian as well!

[Adrian Worman]

You gotta be very close now Chuck? Burdars 73 post must spur you on a bit
How about some more pics in members rides?

[cv70chall]

We've actually had several setbacks (thanks to my dumbass Brother in-law) which have pushed us back. I've had to completely REDO the trunk floor and will be replacing the driver's side floor- as the new one I purchased was actually installed incorrectly OVER the old one. Yikes!!!
Other than that, she's running, AC runs cold and I'm itching to get this beeyatch on the road!
Pix are being posted now sir.