interesting muffler test results

mike

Member
http://www.pontiacstreetperformance.com ... haust.html
three pages of info worth reading

viewtopic.php?f=56&t=1166&p=2387&hilit=+back+pressure#p2387

http://broaderperformance.com/muffler_flow_tests.htm

http://autospeed.com/cms/article.html?&A=0383&P=1

viewtopic.php?f=56&t=495

http://www.pypesexhaust.com/xpipes.html

http://www.fordmuscle.com/archives/2000 ... ndex.shtml

" QUOTE
X Versus H
It's long been known that connecting the two sides of a dual exhaust system, shortly after the headers, increases power and reduces sound. However in a traditional "H" pipe, only sound and pressure waves cross through the connection. Gasses take the route of lowest pressure, which is straight out the pipe, rather than making a 90 degree turn in to the H.
Indy and Nascar teams have been using "X" type crossovers for quite some time. In an "X" pipe the gasses from both cylinder banks actually pass through a common area. This not only provides the benefits of some sound wave cancellation, but also increases the scavenging effect, helping draw out spent charge from the combustion chamber.
So how much of an increase does an X gain over an H? It's hard to say, especially considering that every combination will yield varying gains. In theory an X will work better as rpms go up. Considering the Flowtech X-Terminator pieces are priced under $50; you're much better off getting that, rather than having a shop fab up a crude 'H' piece.

viewtopic.php?f=56&t=1507&p=3448&hilit=backpressure#p3448

"ok, basics
your noise level will tend to increase with larger diameter exhaust pipes but thats only ONE of MANY factors in the exhaust design and its not necessarily true that you can,t build a reasonably quiet performance exhaust.
glass packs tend to mellow the tone frequency but don,t tend to reduce the DB (noise levels a great deal)
noise is basically vibration strength,thats transmitted to outside the exhaust system. having rubber insulators or exhaust hangers helps,placing glass packs between the (X) pipe and the (H) pipe helps and having quality mufflers helps.
your exhaust noise level is dependent on several factors that you can control,but clearances and finances will effect your choices, basically the idea is to reduce the exhaust pulse strength , you can blend pulses with an (X) as close to the header collectors as clearances allow and placing a secondary (H) pipe before the muffler entrance points tends to further reduce the exhaust pulse strength, but the length of the pipes and muffler design also play a huge role.


read thru these links

http://www.pontiacstreetperformance.com ... haust.html

http://www.mustangmonthly.com/techartic ... index.html

viewtopic.php?f=56&t=1507&p=5456#p5456

ok, basics
your noise level will tend to increase with larger diameter exhaust pipes but thats only ONE of MANY factors in the exhaust design and its not necessarily true that you can,t build a reasonably quiet performance exhaust.
glass packs tend to mellow the tone frequency but don,t tend to reduce the DB (noise levels a great deal)
noise is basically vibration strength,thats transmitted to outside the exhaust system. having rubber insulators or exhaust hangers helps,placing glass packs between the (X) pipe and the (H) pipe helps and having quality mufflers helps.
your exhaust noise level is dependent on several factors that you can control,but clearances and finances will effect your choices, basically the idea is to reduce the exhaust pulse strength , you can blend pulses with an (X) as close to the header collectors as clearances allow and placing a secondary (H) pipe before the muffler entrance points tends to further reduce the exhaust pulse strength, but the length of the pipes and muffler design also play a huge role.
and/or you can insert baffles that will break up the pulse strength,
Tapered.jpg

a set of these in the collectors helps
dtc-72-32520_w.jpg



read thru these links

http://www.pontiacstreetperformance.com ... haust.html

http://www.mustangmonthly.com/techartic ... index.html

viewtopic.php?f=56&t=1507&p=5456#p5456


viewtopic.php?f=56&t=1507&p=3448&hilit=backpressure#p34

Ford Mustang Muffler Comparison Test - American Rumble

http://www.mustang50magazine.com/techar ... index.html

On the Dyno

Open Exhaust Bassani Bassani Real Street Borla XS Borla XR1 DynoMax Edelbrock Ultra Flo
RPM PWR TRQ PWR TRQ PWR TRQ PWR TRQ PWR TRQ PWR TRQ
2,750 103 196.7 87.1 182.9 89.9 188.8 111.7 213.4 102.1 195 105.1 200.7
3,000 138.9 243.1 109.1 208.4 107.2 204.7 148.3 259.6 141.1 247 140.9 246.7
3,250 168.6 272.4 146.2 255.9 148.6 260.2 176.6 285.4 168.9 273 168.4 272.2
3,500 189.6 284.5 173.2 279.8 177.1 286.2 195.4 293.2 189.1 283.7 189.3 284.1
3,750 202.3 283.3 192.3 288.5 194.8 292.3 207.9 291.1 203.7 285.3 204.5 286.4
4,000 214.6 281.8 204.8 286.8 208.3 291.8 219.2 287.8 215.6 283.1 214.9 282.2
4,250 239.6 296.1 216.6 284.3 220.7 289.8 244.3 301.9 243.2 300.5 243.1 300.4
4,500 269.5 314.5 241.3 298.2 244.7 302.4 274.1 319.9 270.9 316.2 271.9 317.3
4,750 291.6 322.4 272.3 317.8 274.1 319.9 294.6 325.7 295 326.2 295 326.1
5,000 308.7 324.2 293.7 324.7 295.5 326.8 310.1 325.7 311.7 327.4 310.9 326.5
5,250 326.3 326.4 308.7 324.3 310.9 326.6 329.4 329.6 330 330.2 329.2 329.3
5,500 345.7 330.1 329 329.1 330.8 330.9 348.3 332.6 349.8 334 349 333.2
5,750 359.2 328.1 349.3 333.5 349.6 333.8 363.8 332.3 362.4 331 362.8 331.4
6,000 365 319.5 361.4 330.1 364.1 332.6 370.9 324.6 370 323.9 368.7 322.8
6,250 365.2 306.9 369.3 323.3 371.2 324.9 373.3 313.7 369.6 310.6 369.4 310.4
6,500 358.8 289.9 372 312.6 373.7 314.1 369.2 298.4 369.8 298.8 367.4 296.9

Performer RPM Flowmaster Flowtech Afterburner Flowtech Terminator Flowtech Warlock FlowtechWarlock
(open)
RPM PWR TRQ PWR TRQ PWR TRQ PWR TRQ PWR TRQ PWR TRQ
2,750 105.3 201.2 102.8 196.3 103.9 198.4 102 194.8 102.6 195.9 109.5 209.1
3,000 143.9 251.9 140 245.1 140.9 246.7 138.9 243.2 142 248.6 151.5 265.1
3,250 170.6 275.7 168.9 273 168.4 272.2 170.3 275.1 169.4 273.7 178.9 289.1
3,500 190.2 285.5 189.4 284.1 189.8 284.9 189.1 283.8 185.6 278.5 193.3 290.1
3,750 203 284.4 202.8 284 202.9 284.1 202.4 283.4 199.7 279.7 207.1 290
4,000 215.1 282.4 213.2 279.9 212.9 279.5 213.2 279.9 211.6 277.8 220.8 290
4,250 242.6 299.8 242.2 299.3 240.5 297.2 241.6 298.6 237.8 293.9 248.1 306.6
4,500 272.2 317.7 271.7 317.1 270 315.1 270.7 316 264.4 308.6 276.9 323.2
4,750 294.6 325.7 291.2 322 292.7 323.6 294.1 325.2 281.9 311.8 292.9 323.9
5,000 310.3 326 306.6 322 306.8 322.3 307.4 322.9 295.7 310.6 306.2 321.7
5,250 328.2 328.4 327.6 327.7 325.9 326 326.8 327 318.3 318.4 328.5 328.7
5,500 347 331.3 347.4 331.8 345.7 330.1 346.9 331.3 340.7 325.3 348.8 333.1
5,750 362.2 330.9 361 329.7 359.7 328.6 361.3 330 356 325.2 362.3 331
6,000 368.7 322.7 369.4 323.3 368.4 322.5 368.4 322.5 363.1 317.8 370.7 324.5
6,250 370.9 311.7 368.3 309.5 372.3 312.9 369.5 310.5 366.3 307.8 374.2 314.4
6,500 366.1 295.8 363.7 293.9 366.3 296 366.2 295.9 363.7 293.9 369.7 298.8

Hooker Aerochamber Hooker MAXflow MAC MagnaFlow SpinTech
RPM PWR TRQ PWR TRQ PWR TRQ PWR TRQ PWR TRQ
2,750 103.4 197.4 102.1 195 104.6 199.8 105.3 201.2 105.2 201
3,000 140.5 246 142 248.6 142.3 249.1 143.8 251.8 142.2 249
3,250 168.3 272 172.5 278.8 166.3 268.7 171.3 276.8 167.3 270.3
3,500 190.7 286.2 189 283.6 188.6 283 189.4 284.3 190 285.1
3,750 203.2 284.7 204 285.7 202.9 284.2 204.3 286.1 203.6 285.1
4,000 213.6 280.4 214.7 282 213.1 279.9 215.8 283.4 213.3 280
4,250 240.2 296.9 244.8 302.6 240.2 296.8 244.5 302.1 240.7 297.5
4,500 270.6 315.9 274.8 320.8 268.5 313.4 274.2 320.1 269.5 314.6
4,750 293.5 324.5 296.1 327.4 292.7 323.6 294.1 325.2 293 324
5,000 308.3 323.9 309.9 325.5 310.3 325.9 308.8 324.4 310.8 326.5
5,250 327.1 327.3 329 329.2 328.2 328.4 328.9 329 329 329.1
5,500 346 330.4 348.7 333 347.1 331.5 348.2 332.5 347.9 332.2
5,750 360.4 329.2 362.7 331.3 362.7 331.3 363.6 332.1 362.2 330.8
6,000 368.8 322.9 370.3 324.2 368.7 322.7 370.6 324.4 369.6 323.5
6,250 372.1 312.7 373.5 313.9 372.3 312.9 372.8 313.2 371.6 312.3
6,500 368.8 298 371.8 300.4 363 293.3 369.1 298.3 369.5 298.6

There's so much data here, we simply don't have room to dissect it all, but you have it now, so you can choose the mufflers you are interested in and run the numbers through Excel if you are really serious about eking out every last horsepower. If so, Rick Anderson says to pay particular attention to the average horsepower between 4,700 and 6,600 rpm. This range is critical for drag racing this combo. Rick says the best muffler in that range is the Bassani Real Street, but it's probably too loud for the street (and that's saying something coming from Rick). The Hooker MAXflow, both Borlas, and the MagnaFlow closely followed the Bassani RS with good average horsepower in that range. In the end, we say find one that sounds good to you and your wallet and go have fun.

Sounding Off
Muffler Decibels At Idle Decibels At 2,000 RPM Decibels At WOT
No Muffler 91 103 Max.
Bassani Street 83 96 120
Bassani Real Street 84 96 Max.
Borla XS 80 90 110
Borla XR1 83 96 118
DynoMax Ultra Flo 83 94 113
Edelbrock RPM 84 93 118
Flowmaster 82 93 115
Flowtech Afterburner 86 94 115
Flowtech Terminator 86 94 119
Flowtech Warlock 83 92 112
Hooker Aerochamber 87 94 114
Hooker MAXflow 80 90 120
MAC 87 98 119
MagnaFlow 82 91 114
SpinTech 87 97 116
 
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