Dumps??

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DDDDDDRRRRRRROOOOOOONNNNEEEEE :notnice:

I have a set of MAC pro dumps that were on my car that were ok for the time being but after a year of driving it all the time, just on long drives it gets to ya.. Sounds awsome though.. Gonna put them back on once the new engine goes in..
 
Yea good point.. Does free up alot and also gives a clean look.. I swapped over to a Magnaflow cta back, and I have wide tires in the rear.. No rubbing on exhaust only body once in a while with someone in the car.. There 275's BFG dr's on Weld Rodlites
 
I heard that dumps cause lots of moisture under the rear of the car and makes it rust big time!...

I have dumps right know but I think I will go back to tailpipes cause I want more clean and hollowie sound from my 2 chambers.
 
Fumes are worse, and it will get sooty under there. Just opt for the chassybath at the car wash. I've been running with the tailpipes cut off at the muffs for over a year now, no rust yet.
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You cut the pipes off after the mufflers. And if you put turndowns on it helps with the drone. Don't get me wrong it still drones , but it helps. I like mine it is loud and mean. I can see where it might get old after awhile though. Mine only really drones badly if going really slowly and it shifts into second (AOD) it drones horribly when the RPM's drop.
 
I have had dumps for a while now. At first I just had the pipes cut after the mufflers, it was so much louder and meaner sounding. Then I put on turndowns and it quieted it down alot, it's amazing what 5" of pipe will do. I have no cats and a B cam, smell exaust a little but not bad. As far as drone, longtubes seemed to have cured my drone for the most part, and I have a H pipe, dumps, and flows, which should be horrible but isn't.
 
yep, turndowns do help, especially if you aim them 20 degrees or so toward the sides. I love dumps, the tone is much more bassy and throaty. But the dreaded drone does get old. It's much more controllable if you have a manual tranny, cuz you can work the throttle or change gears to avoid the rpm/loads that drone the worst.

Interestingly, some combos actually drone less with dumps compared to tailpipes, especially with a 3" tailpipe. The sound just bounces around in those big pipes. If you think about it, a pipe of a given diameter and length is going to have a resonant frequency, the same as a port in the intake manifold or the port in a subwoofer enclosure. So it makes sense that there's a drone at a certain rpm for any combo of pipes/muffler.

Also, if you have longtube headers, the drone peak is not so sharp. It'll be spread out over a wider rpm band compared to shorties. That applies to tailpipes as well.
 
Just a warning. I can neither confirm or deny. I have read that if you do not install turn downs the exhaust(which is aimed directly at your tank) can actually heat your fuel tank and cause the fuel to vaporize, especially when the fuel level is low. After I hacked off my tails I did start to notice some fuel smells, and also very high tank pressure when removing the fuel fill cap. A friend of mine also has dumps and no turn downs and he also suffers from mysterious fuel smells(he just opens fill cap to remove pressure and the smell goes away. Again I can not say for sure this is from the dumps with no turndowns for sure. It could be evap system problems(valves, leaks). I haven't istalled turn downs yet but when I do if this thread is still around I'll post if it cures the fuel smell problems. By the way I have mac shorties, o/r x, and flowpaths dumped and it sounds awsome. It sounded cool with the tails but when I hacked them off it sounded insane.
 
Bad fumes. I rode in a friends car that had them, very noticable exhaust fumes inside the car.
And I would definitely not dump them without turn downs, I have also heard that can pose a hazard.
They do sound nice though...!
 
If the tank pressure goes up after cutting off the pipes, the exhaust is definately heating the fuel. Not good. It is much safer to install turndowns. Not worth risking safety at all.

By the way, turndowns can be clamped on if you wish to avoid welding. The muffler bracket is not affected on '86-'93 when you cut off the pipes. On '99 and newer it's a bit harder to run dumps, you have to modify the hanger but it's still workable.