I got mufflers, tailpipes, etc put on my nearly finished 69 today. I should have bought Dynamax Super Turbos. I was short on time and put on what the muffler shop had-Magnaflows. The tailpipes are 2 1/4 inch coming from Heddman hedders. The engine is real mild-balanced with a small duration Comp cam. The sound produced reminds me of some of the kids that pass my house in their jacked-up Z71 4 wheel drive p/u's-lugging along with a blat-blat-blat sound. These Magnaflows are goners. Some folks might like that but I don't. I didn't do an x pipe and I think that was also a mistake. I have the Super Turbos on a bb 71 Chevelle and they sound good. I messed up. Fixing it will cost.
Mike

First, add either an "H" or an "X" pipe before them..

Then decide if you want to change them out.

pdq67

Upgrading to a 2.5" pipe will mellow out the sound too.

I just got rid of my Magnaflows for the same reason. I had 2 Spintech Sportsmans installed a couple of weeks ago and couldnt be happier.

Same here,..made the mistake of listening to wave files to determine the sound I wanted. Chose and installed the Magnaflows...they lasted a week, which is about how long it took for my Dynomax Turbos to arrive. I'm happy now, but paid the price.

For the record, I boxed up the Maganaflows and sent them back to their corparate offices in CA,..with a note detailing my dissatisfaction, and asking for a refund or credit. Didn't hear word from them.

Mario Andretti can KMA. Those things sounded like craaap.

Mike,

Sorry to hear about the Magnaflows not working out...I listened to the sound clips on the magnaflow website and they sounded just like what you described.

I think I'll stick to the Dynomax super turbos....


-Mark

I agree. I have the Dynomax Ultra Flo Welded mufflers (similar to Magnaflow in construction) with no crossover pipe. I hate 'em, but can't justify spending good money to replace brand new mufflers.

I have a 3" exhaust system after my headers. I'm running an X-pipe with the Dynomax Magnum Race Welded Mufflers (Ultra flo fully welded mufflers) and it dumps out right behind the tires. I love the sound and I have had nothing but compliments. Jegs sells these for $69.99.

An H-pipe will not get rid of the "glasspack" sound. An X-pipe will. You probably won't have any problem selling the Magnaflows.

No substitute for a Flow master!

No substitute for a Flow master!

There are substitutes if you want a high flow exhaust. Compare the CFM of the Flowmasters to other mufflers especially the Dynomax Ultra flo Welded mufflers. check out the link below.

http://www.dynomax.com/ultrafloweld.stm

The flowmaster website doesn't have the flow ratings of there mufflers, why?. :clonk:

I put the Dynamax Super Turbos on along with an H-Pipe (the x-pipe would not fit due to driveshaft/emergency brake cable clearance problems). The car sound much better-the glasspack sound is gone.
Anybody want to buy some almost new Magnaflows for pretty cheap?
Mike

I put a Magnaflow crossflow on my 69 406...very disappointing...sounds like a teenager driving a straight six trying to convince you he has a big block under the hood...just a loud resonating sound...no engine sound coming through...just muffler noise. DON'T BUY THIS UNIT.

2 1/4 with Flowmaster 40s.I like the way it sounds.

My car is a '68 with 454 (alum heads, roller cam) and Hooker Super Comp 2" headers, 3" X-pipe, reduced into 2.5" mufflers and full tails. Engine is around 525hp.

Interior resonance is my biggest gripe, and I have been trying all kinds of systems in the last few years. First was Flowmaster's American Thunder 2.5" H-pipe system with 40 series Deltas and tailpipes just behind rear wheels. Wicked loud inside and out, just way too loud overall. Then added Flowmaster full tailpipes exiting out rear. Better but still too loud. Then went to 50 series Deltaflow mufflers, real nice sound outside car but still the resonance. Then went to 3" X-pipe, retaining the 2.5" 50 series mufflers and full tails. Awesome sound outside, but interior resonace still there.

Then went to Magnaflow straight-through mufflers; worse interior resonance than the Flowmasters, plus they just plain sounded crappy to me. The Magnaflows lasted a grand total of about 30 minutes of driving for me.

I switched back to the Flowmaster 50 series and added some Car Chemistry inserts into the collectors, which really helped with interior resonance. Flowmaster sound is really nice, especially when it stays outside the car, LOL.

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I have an uncle who had the same problem on his 68 it had 2 1/4 tubing dumping into slowmasters I redid the exhaust with a jegs 2 1/2 in X pipe kit and some dynomax super turbos and it got rid of that glasspack sound and it felt more responsive

I started this thread in May 2004. I did buy the Dynamax Super Turbos for my now complete '69. They sound pretty awesome. I have a H-pipe behind the Heddman Hedders. The car sounds really good and has very little, if any, drone.
Mike

I started this thread in May 2004......

first post says the thread was started 9/8/05...........

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It does say that. I joined TC in May, 2004. I got confused. That is nothing new.
Mike

camaronut79, If your uncle had a glasspack sound, he didn't have Flowmasters on the car. I've run Flowmasters on alot of diferent vehicles and they won't produce a glasspack sound no matter how you have them set up. Yes there are different mufflers that'll perform better then the Flow's, but not enough that you'd notice on a street car, as long as the exhaust system is properly sized. On a street car just go with the sound you like and you'll never know the difference. Jim Hand is a long time Pontiac racer who wrote a book on building Pontiac engines. Even if you only build Chevys, there is alot of useful info in this book, including real world muffler testing. He tested many mufflers on a flow bench, then on the car to measure performance differences. It's good reading adn the results might just surprise you.It's worth picking up just for the years of info in the book that can be applied to any engine.

he said they were flowmaster super 40's and I have no reason not to believe him. I didnt check to see any markings on them when I tore them down the tubing was all 2''-2 1/4'' maybe it was to small and when I changed it to the 2 1/2'' x pipe that probably helped.