I just finished putting on my Dynomax cat-back system on my 350 IROC today, and when I started it it sounded damn quiet, almost quieter than stock. Will it get any louder over time because that would be nice?

Another interesting thing, when I would rev the engine with the stock muffler on it and let off quick, it would gurgle and growl through the exhaust as the engine wound down. The new one doesn't do that at all, what gives? Thanks guys.

 

It will eventually get louder when the seams rot away.

 

How soon will that be .

 

Hey JETHROIROC, I'm looking at a DynoMax system myself.. which one did you get? Thanks.


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89 RS Camaro, 305 TBI
Mostly Stock
Duel Snorkel Air intake

- Future Mods -
DynoMax Street Headers
DynoMax Cat Back

 

Got the super turbo system for dual cat cars, it was like $160 from Jeg's. It fit up good and looks nice, but be prepared to struggle with the I-pipe some and grab a sawzall if you can. It's just not any louder than stock, but maybe that will change over time.

 

My Dynomax Super Turbo catback was also too quiet when I first had it installed. After a month or 2, it started sounding a lot better and now it sounds great. I've had mine for 4 1/2 years and I drive my IROC in the rain and even some snow, and it only has a light coating of surface rust on parts of the intermediate pipe and none on the muffler.

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Greg Westphal
'87 IROC 305TPI/A4

 

From past experience i can tell you that dynomax mufflers get a lot louder over time, as the fiberglass packing blows out.
As for their f-body systmes, you guys are aware that the cheaper systems they sell are only 2.5" pipes. The only dynomax systems w/ 3" I pipes have both outlets on the driver's side (SLP style.), and they usually run about $200.
So, if you're looking for a performance upgrade the cheap dynomax isn't it.
...ed

 

I just wanted it to sound better without being out of the "wife-acceptability" range. I'll probably go with a single in/single out muffler next time for better performance. Thanks for the help, fellas. I was just a little disappointed with how quiet it was after I started it yesterday .

 

I have the 3" interm. dual 2-1/2 exits on BOTH sides and mine got a little louder in the 5 years Ive had it.
but I can honestly say it still isnt louder than any other system Ive heard for a thirdgen.
definately the quietest of the aftmk catbacks.
good quality though -- no rust at all and I lived in buffalo where they use SALT to clear the roads.!

 

Thanks for all the replies, fellas. Looks like I won't have to break out the sawzall again for a long time!

 

I just recieved my dynomax for my 89 But I am sending it back Because I need the 3 inch int pipe. I called jegs and They said they had the dynomax with the 3 inch intermediate pipe with tailpipes on the same side, but they said I had to get a Different Valance with cutouts? I Still didnt know what they were talking about so I called them back and talked with another guy He said the dynomax with the 3 inch Int pipe if for a 4 gen. Now I dont know if they have it or not any info would be great

 

even though it may be quiet ,all research I have seen shows the Super Turbo flows as much as, or even more than the other "loud" after market exhausts.

 

my super turbo was super quite when i got it. took about 3 months to open up. over a year later now, it seems that its really opening up more and more everymonth. Winter heat up and cool down, along with the fact that i was running lean for about 5 months might have something to do with it.

 

I got my Dynomax system 2 years ago and it definitely gets louder with time. Not much but it growls more now then it did new. If you are not looking for anything over 400 horses then the 2.5" i-pipe is just fine. The Dynomax outperforms almost any other muffler on the market and still has packing in. That speaks for itself.

 

Hey you guys remember the CVX Dynomax from Thrush?I used to have that system.Sorry I sold it.It sounded deep,and I paid only $128 for it in 95.Now Im looking for a new catback and am swamped with idead.I really had good experience with Dynomax,but they dont seem to offer the system with 3inch intermediate and 3 inch dual tips.Im really interested in the Mufflex system ,but the price ie really scaring me away Helpe out guys if you can.Thanks

 

Yeah, I don't think they have a system for dual cat cars with the 3-inch intermediate pipe. But don't they have one for cars with single cats that has the bigger I-pipe, the tailpipes just exit on the same side? I just got the one with the stock size I-pipe since it was the only Dynomax I could find for dual cat cars. Can't wait for that sucker to get louder .

 

from what i have seen, if u want to have a losd exaust... dont get dynomax. i had one on when i bought my car, it was dying, and old and was still quiet compared to my 80 series. I love the sound of my flowmaster

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89' Firebird Formula WS6 L98, MSD 6AL MSD Blaster, Hypertech chip, K/N filter cone,flowmaster 80 series, hypertech air foil, koni shocks, edelbrock trailing arms

 

Driving in PA winter weather with salt and everything killed my dynomax super turbo system in 4 years (not bad/not complaining)

It's amazing how the entire pipe was still shiny (aluminumized) except for the welded seam which rotted away. Aluminumized for longer life means nothing!
Running a cat would probably kill it quicker because the water vapor would rot the seam from the inside too.
Not bad for 260 odd bucks though. I got the SLP system now and does it sound ALOT better!



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'88 Camaro RS 2.8L
'88 Formula 350 (Too many mods to list...)

 

What about the DynoMax Ultra Flo? Does anyone use this? that design would probably not rust as easily as the Super Turbo?

 

Ultra Flow is stainless steel and LOUD. My dynomax super turbo (replaced the ultra flow a year ago) is also loud. Especially after I installed AFR heads and the ZZ4 cam. I am looking at replacing the muffler with a stock walker piece to smooth out the sound.

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Hybrid Black 5.7L 5 Speed
'95 Competition Yellow Corvette Coupe ZF6

 

I use the Ultra flo SS on mine, I went with the 2.5 I-pipe.. It' sounds a lot better than stock.. and after running is for a few months it sounds much better.. I really like it.


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89 RS Camaro, LO3 305 TBI
L69 Duel Snorkel Intake
Dynomax Ultra Flo SS Cat Back