zeeboost Posted December 3, 2006 Share Posted December 3, 2006 I've upgraded my exhaust system recently, but now I have this really bad rattling/resonating sound at certain rpms. The guy that did the work said it's a common problem with mufflers at the very end of the exhaust system, and that older vettes had that same problem. He does some great work, and he's been doing it for at least a good 15-20 years, so I trust him...I don't think he's just trying to shrug me off. So, I'm going to get rid of the flowmaster on there right now and go with some dynomax ultraflo bullet mufflers. I think that'll be a bit too loud for my taste, but I gotta at least try it. Anyways, background: Old exhaust setup - hedman headers with true dual 2" pipe, ending with two 2-chamber flowmaster mufflers (can't remember exact details). Yes, that setup sucked, but was all I could get at the time. This one's a flash video: http://s95.photobucket.com/albums/l159/zeeboost/?action=view¤t=v8Old_exhaust1.flv New setup - JTR ceramic-coated headers, 2.5" pipe to single 3" with Super Delta 40 series Flowmaster. You can kind of hear the rattle noise in the video when I start taking off, but it sounds nothing like in real life. I know that both exhaust systems sound very similar in the videos, but the new setup actually has a very deep, throaty growl. I love the way it sounds, I just can't stand the resonance. Plus, I know flowmasters have relatively crappy flow numbers so I was going to install electric cutouts, but the car is so low that the cutouts would probably be damaged in no time. So I'll see if I can feel any difference with the ultraflo mufflers. I'm sure the audible increase will bias my buttometer. Streetfire hosted this one: http://videos.streetfire.net/video/e6c858b5-6131-4815-90a4-988c011c518a.htm I love roasting 1st and 2nd to redline - can't you tell? I'll keep you updated when I get the ultraflos mounted. Let me know if the old exhaust vid doesn't work. Quote Link to comment Share on other sites More sharing options...
MONGO510 Posted December 4, 2006 Share Posted December 4, 2006 Sounds sweet from here! Quote Link to comment Share on other sites More sharing options...
Duke Posted December 4, 2006 Share Posted December 4, 2006 Do you have an H pipe or X pipe crossover? You should. Also I'd set the mufflers further up the system and use resonators like Monzas at the ends. But it sounds really good in motion. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted December 4, 2006 Share Posted December 4, 2006 If you are talking about the horrible droning sound at speed, what you have is common...especially with only 1 muffler. Many use a resonator or second (first in the line) under the car with a larger muffler out back. The short length of the system is what contributes to the droning noise, so you have to cancel out that sound with a second muffler. Also, you should have an X pipe or an H pipe in there too if you don't already have one. This is actually a thread for "exhaust" I believe, not the V8 forum even though it is loosely tied to it. The are other threads (good ones too!) covering this same topic. Davy Quote Link to comment Share on other sites More sharing options...
zeeboost Posted December 4, 2006 Author Share Posted December 4, 2006 Because of the limited space and ground clearance, that's pretty much the only option for muffler location. I suppose I could have a piece of pipe welded between the two 2.5" pipes before they turn into the single 3", but I'm not sure how much that would help. I figure I'm going to try out the bullets and find out they're too loud, so then I'll try the Ultraflo SS muffler (rectange design) and see how that turns out. If it still resonates, I'll try the home-made H-pipe. I always thought the H and X pipes were just for exhaust scavaging. I didn't know they were used as resonators. Quote Link to comment Share on other sites More sharing options...
zeeboost Posted December 4, 2006 Author Share Posted December 4, 2006 If you are talking about the horrible droning sound at speed, what you have is common...especially with only 1 muffler. Many use a resonator or second (first in the line) under the car with a larger muffler out back. The short length of the system is what contributes to the droning noise, so you have to cancel out that sound with a second muffler. Also, you should have an X pipe or an H pipe in there too if you don't already have one. This is actually a thread for "exhaust" I believe, not the V8 forum even though it is loosely tied to it. The are other threads (good ones too!) covering this same topic. Davy I was also thinking of slapping the dynomax bullet muffler behind the flowmaster. It wouldn't harm the flow, but I didn't know how well it would act as a resonator. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted December 4, 2006 Share Posted December 4, 2006 I was also thinking of slapping the dynomax bullet muffler behind the flowmaster. It wouldn't harm the flow, but I didn't know how well it would act as a resonator. I'm not too familiar with the ZX, but if you can get a bullet type under the car shortly after the tranny, that will help. A typical S30 system would be something like downpipes into a single 3" pipe, into a bullet style muffler, into a 3" tube into a Flowmaster or Dynomax Turbo muffler, into an exhaust tip. Or from the downpipes, into an X pipe, into two bullets OR flat Spintech or fairly flat muffler with dual in & out, then dual pipes back to a dual in dual out muffler out back or two mufflers side by side out back. Feh, this is getting complicated (I hope I typed it out correctly). Just put two mufflers in the line, essentially, and you should cancel out most, if not all, of that droning. Davy Quote Link to comment Share on other sites More sharing options...
LLave Posted December 4, 2006 Share Posted December 4, 2006 a bit off topic but has anyone tried spin techs? Quote Link to comment Share on other sites More sharing options...
wheelman Posted December 5, 2006 Share Posted December 5, 2006 I've never liked the rattly, poppy sound of the Flowmasters, in fact I removed a couple from my 93 Mustang right after I bought it. I have basically the same exhaust you have. Headman tight tubes into 2 1/2" pipe into a Y-Pipe (right in front of the diff) and 2 1/2" into Hooker Aero-Chamber muffler. I have a very slight drone around 1500 RPM but the sound out the back is deep and throaty not rattly and poppy like the Flowmasters. You should check into the Aero-Chamber muffler, I think you'd like it. Wheelman Quote Link to comment Share on other sites More sharing options...
Guest 280ZForce Posted December 5, 2006 Share Posted December 5, 2006 a bit off topic but has anyone tried spin techs? my friend had 1 on his carbed L-series 240z and it sounded badass! Wish I had a video of it. Quote Link to comment Share on other sites More sharing options...
zeeboost Posted December 7, 2006 Author Share Posted December 7, 2006 I've had an '03 Mustang Gt come on the shop with spin techs on - they sounded great when I saw it drive by, but I didn't care for the way they sounded inside the cockpit while driving. Then again, Fords sound different than Chevys, so I may like the way it sounds on mine. I don't think I've heard the Aero-Chamber mufflers before. IMO, what sounds the best is open headers at WOT - that's why I really liked the idea of the electric cutouts. I'll see how close the ultraflo bullets can replicate it. Quote Link to comment Share on other sites More sharing options...
wheelman Posted December 7, 2006 Share Posted December 7, 2006 Here is a link to a short wav file of my exhaust. It's just at idle with a couple blips of the throttle but it will give you an idea of how the Aero-Chamber sounds. http://www.vikingds.com/zcarguy/z_exhaust.wav Wheelman Quote Link to comment Share on other sites More sharing options...
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