Guest Anonymous Posted October 30, 2001 Share Posted October 30, 2001 Hey all, wanted to ask you for opinions and feedback on what muffler to use for my setup... I'm building a 327 with ~400 ponies, as for my exhaust setup I'll be running 1 5/8" by 2 1/2" ceramic coated Flowtech block huggers connected by a Y pipe to single 3" piping. The only variable in this equation now is the muffler. I'm looking for something civilized as the car will be a daily driver and will do a lot of highway mileage. According to David Vizard, we need at least 2.2 cfm of flow per horsepower for optimal power, so we're looking at a muffler capable of >800 cfm. While rules out (if my sources are correct) most, if not all of the Flowmaster Line. Dynomax's Ultra-Flo line seems pretty promising... Anyone ever heard of Powertone mufflers? They seem pretty interesting. Finally I'm partial to the look of an Apexi N1 style muffler (yeah I know its ricey... so sue me! ) and would probably look good on the car, plus it comes with a "super silencer" that you can install for added back pressure & silencing. Also, if I'm using a straight-thru muffler I probably want it to be as long as possible for maximum silencing, or am I mistaken? Thanks Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 30, 2001 Share Posted October 30, 2001 there is only one exaust FLOWMASTERS #1 is exaust Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 30, 2001 Share Posted October 30, 2001 Flowmasters are popular and do work if you don't mind they're sound. I don't care for the hollow pipe sound when tooling around, wide open, yeah they sound rad. There are plenty of other good mufflers (spintech's to name just one.) that are equal if not better than flowmaster. As for eliminating them as a choice because they don't flow enough? That sounds pretty weird, I'm not disputing Vizards calculations, but thousands of racers from mild to monster horsepower application use them and flow isn't a problem, in many cases they increase horsepower. Something is wack with the numbers or what you've heard as they're flow ratings, because a 400 hp SBC will never flow enough to cause a big 3" system to have much restriction, some have even gone to 3.5" single systems and found little if any more power. As I say, I'm not disputing what you've read, only what others have used successfully for years on 400hp machines. Respectfully, Lone Quote Link to comment Share on other sites More sharing options...
DavyZ Posted October 30, 2001 Share Posted October 30, 2001 Omar, due to the space considerations under tha car, you are really limited to muffler choices that will perfectly fulfill David Vizards recommendations AND still be quiet enough for the street IMO. The subject of mufflers is bandied about often, although I can't think of anything recent about Powertones though Will this car be a daily driver? If so, read some of the past posts on the subject and get the guys opinions on the ones they are using. Although my system is not yet installed on the car, I have a single 3 inch mandrel bent system that starts with a Y-pipe, goes immediately into a Stainless steel 3" Borla (staight thru, under the car) and then goes back to a Dynomax SuperTurbo in the rear. The system is supposed to flow so well that going to the same setup in a 3.5 inch will NOT increase horsepower on a 450 hp motor--all according to the previous owner (he sold me his 3" before fabbing the same system in 3.5" for himself--he posted later that there was no hp difference & no 1/4 time difference). This is a quiet system that is supposed to flow well. Think hard about what you want to accomplish, how much it will cost, if it will really make a difference for the money involved, and if you'll be able to live with it when you are done. Just food for thought. Good luck. BTW, you might want to post this kind of topic in the High Tech or Misc Tech column, since it really does not belong in the Chevy (engine) forum. Davy [ October 29, 2001: Message edited by: DavyZ ] Quote Link to comment Share on other sites More sharing options...
Guest kc6wfs Posted October 30, 2001 Share Posted October 30, 2001 Hi Omar, I noticed you live in Pasadina. If you want to check out mine I'm in the SCV valley by Magic Mountain. The Flowmasters are the way to go. Listen to mine. I have a wav file on my site. Click on the link below. Mine also are blockhuggers,Y-1 3" on back. Take care. Dave Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 30, 2001 Share Posted October 30, 2001 quote: Originally posted by lonehdrider: As for eliminating them as a choice because they don't flow enough? That sounds pretty weird, I'm not disputing Vizards calculations, but thousands of racers from mild to monster horsepower application use them and flow isn't a problem, in many cases they increase horsepower. Something is wack with the numbers or what you've heard as they're flow ratings, because a 400 hp SBC will never flow enough to cause a big 3" system to have much restriction, some have even gone to 3.5" single systems and found little if any more power. As I say, I'm not disputing what you've read, only what others have used successfully for years on 400hp machines. Respectfully, Lone Lone , it doesn't matter how big the piping is, what matters is the biggest restriction in the flow. Imagine sucking on a pinched straw. According to autospeed.com baffled and turbo style mufflers flow between 50-60% of what an equivalently sized straight pipe would flow, whereas a straight thru muffler flows 85-90%. As far as I can tell, Flowmaster don't make any straight-thru mufflers, check these two graphs out The reason Flowmasters usually don't cause much of a restriction is that they are used in pairs, doubling their flow. I will only be using one muffler, so I need something that flows well and isn't too loud... Would it be wise to stick a race muffler or something behind the main muffler to quiet things down some? What else can be done to reduce noise given my setup? [ October 30, 2001: Message edited by: Omar ] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 30, 2001 Share Posted October 30, 2001 I understand the numbers, and obviously you've done your own research and I respect your position. I am merely saying (flowmaster or not) that 400HP isn't a very big number to worry about such restriction. Straight through exhaust have to be (IMHO) rather long to effectively muffle and as Davy pointed out, there isn't much room under there. You may be able as you inquired to use a race muffler (like say a Borla bullet, or any number of other small race mufflers) under it to knock the droning down before it reaches your main muffler, then perhaps another straight thru design in the rear would be sufficient. I will close by saying the only situation (IMHO) that requires absolute minimal backpressure (like none) is a turbocharged engine. Most normally aspirated four stroke engines, like a little bit of back pressure to help with scavenging. Thats why theres often power gains with mufflers vs straight pipes. Of course this is all my own speculation based on my experience and of course is my own opinion. Whatever way you end up going, I wish you the best of luck with the project! Regards, Lone Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 30, 2001 Share Posted October 30, 2001 I too had space restriction problems. (no room for two mufflers) With just a 3" Edelbrock SS flowthrough unit, the noise level was borderline legal. (11.3-1 compression) I simply added a 16.5 inch Dynomax "Bullet" style race muffler to the end of the "Y" collector. In hindsight, I should have gone with the 23.25 inch unit. Although the `16.5 inch unit dropped a full 3 decibels out of the note, the exhaust noice still attracts too much attention under load. I don't know how much more quieting the longer bullet could make, but I have to believe that it would be some additional amount. The sound of a single exhaust on a V8 has very distinctive authority which I prefer over my old 2" dual setup. Besides, single exhaust is stealthier in appearance to the unfamiliar. I flanged the 2.5 inch header collectors which allows for reasonably quick removal of the entire system should servicing of the trans be necessary. I was amazed at how light this system is as compared to the old dual pipe system. I would like to find a slightly quieter good flowing final muffler at this point. Be sure to post your results as they become evident. By the way, the here in Idaho, the decibel meter used for lawful judgment of noise level is a "Radio Shack" unit. The law specifically denotes this! Who knew? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 30, 2001 Share Posted October 30, 2001 Yes Davy, the car is intended to be a daily driver/freeway cruiser, so I wanna kill as much noise as I can, and avoid nasty booms and resonances. You guys are right, this is indeed going to be very difficult, but I just stumbled on Car Chemistry's exhaust inserts (about time don't you think ) and they might be the solution to my problem. Anybody have any experience with these? I was thinking of using one or two in conjunction with a straight through muffler. How do you think that'll sound? Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted October 30, 2001 Share Posted October 30, 2001 ahh, the classic 400hp sbc I want to be quiet and decently freeflowing....I've wrestled with this a few times now...my 'next' plan off my 2.5" Y pipe to single 3" pipe is a race type muffler or 'resonator' (dynamax makes an ultraflow round ~24" long 5.5" diameter one WITHOUT fibreglass I'm leaning towards) and a decent flowing muffler out back (normal 'turbo' mufflers just don't take enough out for me My father has the above setup, dynomax central 'red devil?' and dynomax turbo muffler out back....I love it's stealthiness, quiet at idle (truly quiet, not annoying to condo neighbours etc at all, not a giveaway at the lights) and even at WOT it's not annoying. I'm NOT a flowmaster fan, just annoying to me but I've got a ringing in my ears already from some nasty drug tx that saved my ass so quiet is my preference. Downside is that central 'resonator' can reduce ground clearance significantly. PS what doesn't work is a single 3" with turbo muffler (too loud), single 2.5" with turbo muffler (too loud), single 2.5" with resonator and muffler (quiet but damned restrictive), all relative to my sound tolerances/opinion of course. I've greatly enjoyed 'stealthy' tires (more $$$ they're quieter on slip/shredding;^) and want the exhaust to pair up for my daily comfort and cloaking Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 31, 2001 Share Posted October 31, 2001 [ October 30, 2001: Message edited by: Omar ] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 31, 2001 Share Posted October 31, 2001 [ October 30, 2001: Message edited by: Omar ] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 31, 2001 Share Posted October 31, 2001 Yes stealthiness is definitely a pro... That Mustang or Camaro driver will never know what hit him! Johnny Law doesn't mess with you, and your ears avoid a pounding So about these Car Chemistry headers, they definitely look interesting, and I would love to know what you guys think of them. What would be the quietest combination per $ spent? I could either get 1 3" 3-disk insert and install it after the Y-pipe I could install 2 2.5" 2-disk inserts in the header collecter Or I could go all out and put 2 2.5" 3-disk inserts in the collector. Ideas comments suggestions anyone? [ October 30, 2001: Message edited by: Omar ] Quote Link to comment Share on other sites More sharing options...
fl327 Posted October 31, 2001 Share Posted October 31, 2001 theres nothing wrong with a meineke super turbo mufler, i run two 2.25's into one full length 2.5 and i sound like nothing.... Quote Link to comment Share on other sites More sharing options...
johnc Posted October 31, 2001 Share Posted October 31, 2001 Omar, Coast Fab: http://www.coastfab.com/. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 7, 2001 Share Posted November 7, 2001 i have an APEX'i N1 on my 76. it isnt ricey...the quality is exceptional and it sounds the best on a big displacement car. im not a big fan of borla or flowmasters... Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 7, 2001 Share Posted November 7, 2001 quote: Originally posted by S30: i have an APEX'i N1 on my 76. it isnt ricey...the quality is exceptional and it sounds the best on a big displacement car. im not a big fan of borla or flowmasters... Personally I think it looks tite! Do you have any pics to share? How does it sound (how loud is it) and do you use it with the super silencer? Are you using any other muffler in series with it? Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted November 7, 2001 Share Posted November 7, 2001 Check out th eSebring stainless mufflers. Mine is polished and looks GREAT. However it's a bit loud, I expect to add two bullets to fix that Pics on my site... Quote Link to comment Share on other sites More sharing options...
Guest super280z Posted November 7, 2001 Share Posted November 7, 2001 Omar, i hear what your sayin about flow numbers and all. yes more flow is better for a high horsepower motor but as was aforementioned, more CFM out the tailpipe = less low end TQ. if this is something you'd be willing to sacrifice i'd suggest a straight through muffler like the one you mentioned. i have an ultra-flo round 23" i think.. and i would suggest modding it order to have some noise reduction function (yes i did say mod a muffler hehe.. ) sorry if this turns out long but here goes. i was sitting at work the other day thinking about those dadgum collector inserts and it just hit me, why not make an insert for a muffler that diffuses the sound but really dosent affect you flow numbers drastically and you'd still manage some decent TQ as well. something like flowmaster's Delta idea inside of an ultraflow. im going to try it here in about 2 weeks when i get the car going (God willing.. ) i'll soon have a page up to post details. i cant believe im going to say this but the only other reasonable alternitave seems to be to add a highflow cat. i hope this dosent come across as utter insanity but good luck. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 7, 2001 Share Posted November 7, 2001 The only reason you get less low end torque when having very little backpressure is because during the overlap phase, some of the incoming air-fuel ratio "spills" out of the combustion chamber and out the exhaust due to the lesser restriction. On the other hand, (and please correct me if I'm wrong on this) you reduce exhaust reversion, partially offseting your losses. You can recover the lowend losses by using a cam with a higher LSA or lower overlap (with maybe a bit more duration). Its all about the right tuning. With a straight through muffler you've got more than enough flow volume, but you don't have much silencing capability, and that's what I'm trying to find... I wanna hear what you guys think of the CC Inserts. I don't think adding "deltas" in a straight through muffler would make much of a difference to noise as they are designed to work with a turbo style muffler where they can bounce the sound waves against the case a few times to dissapate energy. You can't really do that very effectively if at all with a straight through muffler. So you end up increasing backpressure by quite a bit without reducing noise much. What you could do , is use/fabricate something like the Apexi Super Silencer which bolts on to the end of the muffler to quiet things down and increase backpressure/raise low end torque. Again, I think I'm a believer in CC's inserts and would use those. Love to hear more thoughts on this. Thanks Quote Link to comment Share on other sites More sharing options...
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