that annoying exhaust drone



that annoying exhaust drone

Postby grumpyvette » June 24th, 2011, 7:17 am

http://www.autolounge.net/calculators/e ... nance.html

viewtopic.php?f=89&t=10341

https://www.holley.com/types/Maximum_Flow.asp

http://www.dynomax.com/mufflers?muffler ... ameter=171

http://www.jegs.com/p/Flowmaster/Flowma ... Ntt=744765

http://www.summitracing.com/parts/wlk-1 ... 7AodgW4AYg

http://www.summitracing.com/parts/sum-638270

http://www.summitracing.com/parts/pye-mvr70

I don,t know the size mufflers used ,theres dozens of similar ones sold by several manufacturers


DON,T BE IN A RUSH to start a wholesale swap-out of your current exhaust components, the cure may be a simple minor change to the current systems tendency to vibrate, at its current frequency. that (DRONE) is simply the exhaust pulse frequency,amplified by an exhaust system wide amplification or sympathetic vibration in the exhaust system, IN general , longer length components vibrate at lower frequency's and shorter ones at higher frequency's.
installing an (H) or (X) pipe can either increase or cure the problem as a result of changes in the systems effective length, adding a second (H) or (X) pipe in the system frequently cure the problem, as can swapping to a different muffler or longer tail pipes.
As a general rule youll want to place an (X) pipe as close to the header collector exits as under the car clearances allow , and the mufflers as far to the rear as clearances allow, the (X) pipe allows the exhaust pulse strength to blend and be reduced as it splits into two separate, and roughly pressure balanced paths to exit the car,on some cars a second (x) or (H) balance pipe mounted just before the mufflers helps reduce the drone tendency.
Like a TUNNING FORK, if you change, or add more rubber hanger exhaust system support points and rubber hanger locations on the exhaust or IF YOU change the length , or CHANGE INE INTERNAL LENGTH OF THE PIPES,you change the vibration frequency, if its changed to well above or below the engine exhaust pulse frequency the drone is destroyed or prevented.


http://www.kettering.edu/physics/drusse ... Frame.html

http://www.dynomax.com/ (click on video and watch it)

http://crgis.ndc.nasa.gov/crgis/images/ ... fflers.pdf

Image
Jim Rockford wrote:Just figured I'd post this up to start a flame war..lol
Muffler Comparision Thread.



The results in HP order:
1.Flowtech Warlock (open) 374.2 hp/ 333.1 tq
2.Bassani Real Street 373.7 hp/ 333.8 tq
3.Hooker Maxflow 373.5 hp/ 333 tq
4.Borla XS 373.3 hp/ 332.6 tq
5.Magnaflow 372.8 hp/ 332.5 tq
6.MAC 372.3 hp / 331.5 tq
7.Flowtech Afterburner 372.3 hp/ 330.1 tq
8.Hooker Aerochamber 372.1 hp/ 330.4 tq
9.Bassani 372 hp/ 333.5 tq
10.Spintech 371.6 hp/ 332.2 tq
11.Edelbrock Performer RPM 370.9 hp / 331.3 tq
12.Borla XR1 370 hp/ 334 tq
13.Flowtech Terminator 369.5 hp / 331.3 tq
14.Dynomax Ultra Flo 369.4 hp/ 333.2 tq
15.Flowmaster 369.4 hp / 331.8 tq
16.Flowtech Warlock 366.3 hp / 325.3 tq
17.No muffs 365.2 hp / 330.1 tq

Sound Off in Quietest to Loudest (Decibels):

1.Borla XS, 80db at idle, 90db at 2,000 rpm, 110db at WOT.
2.Hooker Maxflow, 80db at idle, 90db at 2,000 rpm, 120db at WOT.
3.Magnaflow, 82db at idle, 91 at 2,000 rpm, 114db at WOT.
4.Flowmaster, 82db at idle, 93 at 2,000 rpm, 115db at WOT.
5.Flowtech Warlock, 83db at idle, 92 at 2,000 rpm, 112db at WOT.
6.Dynomax UltraFlo, 83db at idle, 94 at 2,000 rpm, 113db at WOT.
7.Borla XR1, 83db at idle, 96db at 2,000 rpm, 118db at WOT.
8.Bassani Street, 83db at idle, 96db at 2,000 rpm, 120db at WOT.
9.Edelbrock RPM, 84db at idle, 93db at 2,000 rpm, 118db at WOT.
10.Bassani Real Street, 84db at idle, 96db at 2,000 rpm, MAX. (120+db).
11.Flowtech Afterburner, 86db at idle, 94db at 2,000 rpm, 115db at WOT.
12.Flowtech Terminator, 86db at idle, 94db at 2,000 rpm, 119db at WOT.
13.Hooker Aerochamber, 87db at idle, 94db at 2,000 rpm, 114db at WOT.
14.SpinTech, 87db at idle, 97db at 2,000 rpm, 116db at WOT.
15.MAC, 87db at idle, 98db at 2,000 rpm, 119db at WOT.
16.No Muffler, 91db at idle, 103db at 2,000 rpm, MAX. (120+db).




And I have listed here a muffler shootout test done by CAR CRAFT, they show the best bang for the buck, and show the db's

The Mufflers
MAKE MODEL Part No. COST
SUMMIT Turbo 630125 $14.75
THRUSH Magnum Glasspack 24214 $16.50
THRUSH Boss Turbo 17718 $23.95
HOOKER Competition 21006 $25.95
DYNOMAX Super Turbo 17733 $28.50
DYNOMAX Race Magnum 24215 $31.95
HOOKER Super Competition 21106 $35.95
SUMMIT Fully Welded 630325 $38.69
FLOWTECH Afterburner 50322 $39.95

MUFFLER FLOW TEST

MUFFLER Flow at 28-in H20
DynoMax Race Magnum 528.64 cfm
Thrush Magnum Glasspack 507.40 cfm
Summit Fully Welded 343.38 cfm
Flowtech Afterburner 342.20 cfm
DynoMax Super Turbo 333.94 cfm
Hooker Competition 232.46 cfm
Hooker Super Competition 320.96 cfm
Summit Turbo 331.16 cfm
Thrush Boss Turbo 297.36 cfm

MUFFLER Idle dB WOT dB
DynoMax Super Turbo 89 123
DynoMax Race Magnum 94 133
Flowtech Afterburner 92 124
Hooker Competion 92 122
Hooker Super Competion 90 125
Summit Turbo 89 124
Summit Fully Welded 92 125
Thrush Boss Turbo 90 123
Thrush Magnum Glasspack 92 128

DYNO TEST
All mufflers were dyno-tested on a 355-cube SBC with 10.0:1 compression, Air Flow Research 190 aluminum heads, a CompCams 292 hyd. a Victor Jr. intake, a Holley 750-cfm double-pumper, and 1 5/8 Headman headers.


MUFFLER HP TORQUE 2,500-6,000rpm Average
Hooker Competition 397.4 381.1 286.8hp/351.9 lb-ft
Thrush Boss Turbo 407.1 384.9 292.1 hp/357.5 lb-ft
DynoMax Race Magnum 409.5 394.3 298.8 hp/366.9 lb-ft
Flowtech Afterburner 409.7 391.2 294.8 hp/361.7 lb-ft
Thrush Glasspack 409.5 389.8 297.7 hp/365.3 lb-ft
Summit Turbo 411.5 386.3 291.5 hp/357.4 lb-ft
DynoMax Super Turbo 412.7 387.2 292.6 hp/358.6 lb-ft
Hooker Super Comp 413.8 387.2 292.8 hp/359.0 lb-ft
Summit Fully Welded 415.4 390.7 295.6 hp/362.4 lb-ft








i have another test here on my computer but i don't know how to upload it onto this site because it is in a adobe pdf file.


more numbers for ya'll who like numbers.

All tests via an independent lab
All tests @ 15” wc

2 “ Straight Pipe 283 CFM
2 ¼ “ Straight Pipe 365 CFM
2 ½ “ Straight Pipe 521 CFM

2 ¼” Typical Bent tailpipe 268 CFM
2 ½” Typical Bent Tailpipe 417 CFM

2 ¼” Inlet/Outlet_ Glass Pack Tips- No Louvers- Smooth 274 CFM
2 ¼” Inlet/Outlet- Glass Pack Tips-Louvered 133 CFM
Same as above set for reverse flow 141 CFM
2 ¼” Cherry Bomb 239 CFM
2 ½” Cherry Bomb 294 CFM

2 ½” Inlet/Outlet Dynomax Super Turbo 278 CFM
2 ½” Inlet/Outlet Ultraflow Bullet 512 CFM
2 ½” Inlet/Outlet Gibson Superflow 267 CFM
2 ½” Inlet/Outlet Flowmaster ( 2 Chamber) 249 CFM
2 ½” Inlet Outlet Flowmaster ( 3 Chamber) 229 CFM
2 ¼” Inlet/Outlet Thrush CVX 260 CFM
2 ½” Inlet/Outlet Maremount Cherry Bomb 298 CFM
2 ½” Inlet/Outlet Hooker Aero Chamber 324 CFM
2 ½” Inlet/Outlet Hooker Max Flow 521 CFM
2 ½” Inlet/Outlet Borla Turbo 373 CFM
2 1/2" Inlet/Outlet Magnaflow 284 CFM


Standard OEM 2 ¼” Inlet/Outlet 138-152 CFM
Standard OEM 2 ½” Inlet/Outlet 161-197 CFM

and some real world testing to back up some numbers
http://www.pontiacstreetperformance.com ... haust.html
http://www.mustang50magazine.com/techar ... index.html

"Recommendations:

1. Always use a crossover of one kind or another. Our tests indicate that the X type gives additional improvements over the H type.

2. Mount the mufflers as far to the rear of the chassis as possible. An important characteristic of the exhaust system (behind the headers) is its ability to dissipate heat energy. Heat loss brings with it, gas volume reduction, enabling smaller mufflers and pipes to be used without penalty.

3. Always us the largest case muffler that you can fit under the chassis possible. The larger internal volume allows additional acoustical energy to be absorbed ,dissipated and eliminated.

4. Unless an engine is in the 500+ horsepower level or run at very high RPM, the maximum tailpipe size required for minimal power loss is probably 2.5" diameter. When the exhaust pipes and mufflers drop the temperature significantly, the volume of the exhaust gas is reduced and tailpipe sizes is not as critical.

5. When you must adapt various pipe sizes, always use long tapered cone reducers, such as, those available from Flowmaster. You can also use a crossover that has reduced pipe sizes built into it."

And this get alot of folks in trouble..the back pressure myth.
http://my.prostreetonline.com/forums/sh ... php?t=1639


MANY people think its caused by the brand of mufflers used or that swapping mufflers will eliminate it, its a frequency related problem, and both exhaust diameter and length effect the frequency it occurs at, exhaust hanger design and placement can effect the frequency and failure to extend the exhaust exit length past the rear of the car also effects the sound level in the car,PLACEMENT OF THE EXHAUST CROSS PIPE "(X) PIPE " has a huge effect on the rpm point you hear the drone
all pipes will have a natural vibration frequency , the shorter it is the higher the frequency, if you can move the frequency of the exhaust system high enough that you rarely reach that natural frequency you eliminate the potential problem, in most cases thats fairly easy to do by placing an (X) or in some cases a (H) pipe as close to the header collectors as possible, thus raising the frequency above your useful RPM range
Image
Image
Image
dynomax recently introduced a valved exhaust muffler that shows some promise as it will reduce any reversion pulse strength
THE dynomax mufflers with the valve have a reputation for rattling like a tin can full of marbles with a radical cam and true dual pipe muffle exhaust, the rattle is the result of individual exhaust pulse flow from individual cylinders reaching and rapidly forcing an opening in the one way exhaust flow gate valve, that opens as the exhaust volume of gas flow hits it and forces it open,then momentarily wanes (is reduced) the gate closed as the spring forced it closed,(SEE PICTURE) resulting in the rattle as the exhaust flow mass is far from consistent.
Image


mounting a dual (X) PIPE tends, to reduce the individual exhaust pulse flow mass and energy, the (X) pipe in front of the muffler tends to greatly reduce the individual pulse strength and velocity by dividing and slowing the flow as the internal cross sectional area rapidly increased and even out the flow as it hits the flow gate, having two in a series works even ore effectively.
Image

viewtopic.php?f=56&t=495

IF you have an exhaust that produces an annoying exhaust drone its basically a result of an exhaust pulse frequency thats amplified as a harmonic frequency that the exhaust system can vibrate at , now if you destroy that pulse frequency ,in that exhaust by altering its physical vibration characteristics, o it vibrates at a frequency above or well below what the engine exhaust produces,or you can change component placement, the exhaust systems tendency to vibrate at that frequency will be altered so you cure the problem and the DRONE, inserting exhaust cones in the system either behind the (X) pipes or in the tail pipes or lengthen the exhaust pipe exit tip length have both proven to reduce or eliminate that tendency to allow the sympathetic frequency or "DRONE"
remember both sides of the exhaust tend to FEED OFF the other side in some designs, so if you for an example put an exhaust cone inside the exhaust pipe in one leg behind the (X) pipe, and the other side in front of the muffler entrance the distances would be significantly altered and the sides would vibrate differently canceling that sympathetic tendency

Image
Image
viewtopic.php?f=56&t=1503
mufflers designed to trap and destroy reversion pulse strength also help
Exhaust noise is the perceived vibration or resonance caused by the high pressure pulse of exhaust gases exiting the engine in strong intermittent pulses that match the engine rpm, you reduce the perceived noise by absorbing or dissipating the strength of the individual pulses and by damping or blending the low and high pressure peaks in the pulse strength, this has been well proven, to be helped by adding an (X) pipe to the exhaust as it doubles the cross sectional area, thus instantly reducing the gas velocity and blends the pulsed thus effectively changing the two exhaust pulse per cylinder bank per rotation into four less intense pulses past the (X) pipe , this also tends to equalize the exhaust flow rates, reduce flow restriction and thus change and in most cases MELLOW or LOWER the strength of each individual pulse by interrupting the original frequency range caused by the engines exhaust pulse strength in the process.
Image
Ive found that mounting DUAL in series (X) pipes has both a slight beneficial increase in exhaust scavenging, and a noise reducing tendency, the use of dual in series (X) pipes, very defiantly changes the rpm range and tone of any exhaust note!
Image
Image
several of my friends have chosen to install those muffler eliminators and obviously each of us has a individual tolerance for noise level and the type of exhaust note or rumble we prefer
I know many of the younger guys seem to like that raspy exhaust sound and I was amazed at how quiet the car actually is with no mufflers at all,just those muffler eliminators, if you run the dual (X) pipes but I think many of us older guys will still find mufflers preferable.
http://www.ecklerscorvette.com/corvette-quad-power-mufflers-stainless-steel-quad-zr1-style-tips-1984-1991.html It has a nice rumble at idle.Image

placing two x pipes in sequence seems to work well at both mellowing the exhaust note, and increasing the exhaust scavenging of the cylinders as it blends and smooths out the exhaust flow by allowing the individual cylinder pulse strength to dissipate rapidly, the first (x) reduces flow restriction, the second allows the exhaust pulse to run into itself further disrupting the individual pulse strength


PLACING A MUFFLER OR RESONATOR LIKE THESE DIRECTLY BEHIND AN (X) PIPE tends to significantly reduce that drone sound and can increase scavenging efficiency in some cases
Image
Image
http://www.summitracing.com/parts/WLK-17554/?rtype=10 ($120)
A simplistic statement goes like this: (from a Monte Carlo forum)

"Drone in the exhaust is due to the engine driving the exhaust system
at its resonant frequency. You can't get rid of it, any length of pipe has
a natural frequency, but you can change the frequency (RPM) it happens at.
Stock exhaust systems are tuned to put the resonant frequencies outside the normal RPM range the engine is run in. Sometimes they add resonators for this purpose.
To raise the resonant frequency of a system, shorten its
length. To do this, you can try tail pipes that exit by the wheel (like
GN's have), or you can try a muffler with a shorter internal flow path. If
you have a true dual system, you can change the natural frequency of the
system dramatically by adding a balance tube. If you can't shorten the
system, then you can add slightly less than one wavelength of pipe. This
will also raise the resonant frequency of the system. The wavelength in a
single converter system (not true dual) is a little less than three feet at
3000 RPM. Shortening the system by a foot or so will move a resonance at
2000 RPM to about 3000 RPM.
To move a resonance, calculate the wavelength at the RPM that gives
the resonance you want to move. Then calculate the wavelength at the RPM you would rather it be at. The difference is the length of pipe you need to add or delete.
Add to lower the RPM, delete to raise it. If you want to raise it but you can't cut any pipe out, then add one wavelength of pipe minus the amount you calculated. This will have the same affect. If you add or subtract a multiple of a wavelength exactly, you will not change the resonant RPM.


Wavelength = 1100 X 60 X 1/RPM X 1/4 X 1/2

or

Wavelength = 8250 / RPM

Wavelength = standing wavelength
1100 = speed of sound in air in feet per second
60 = convert RPM to Revs per second
RPM = RPM
1/4 = four cylender firings per revolution (make this 1/2 for "true
dual")
1/2 = standing wavelength is half the wavelength of a "normal" wave

Submitted by: Richard Kwarciany kwar at FNAL.FNAL.GOV"


THE (X) BY FAR is more effective, the (H) may equalize the pressure to a great extent but the (X) blends and equalizes the flow,
http://www.uucmotorw...etorquemyth.htm

whats the difference?
lets say for the example the exhaust pulse is a quart to water moving at several hundred feet per second, but unlike water it can be compressed,since the exhaust pipe inside diam. is set the length of the pulse or slug of exhaust exiting the engine every 90 degrees of rotation (v8) has inertia/energy/mass, if it passes a right angle low pressure exit point, at first it flows into both routes but as the mass passes the opening a slight negative pressure forms and it reverses and the flow changes, put a vacuum gauge on the (h) and it vibrates, wildly.
install an (X) and the flow from both sources is FORCED to BLEND, line up, equalize and BOTH sections of the up stream flow benefit from the
as each inertia/energy/mass, and slight negative pressure that forms, but its far more equalized.
put another way if one side was pumping out dark green water and one side was pumping clear, an (H) would have dark green exiting one side and light green exiting the other, an (X) would have both sides an equal, slightly lighter green flow .now at low rpms , or with a smaller than ideal pipe diam. thats no big deal, but at high rpms, BOTH the SCAVENGING of the cylinders your trying to enhances and the reduction of the restriction to flow tends to be better with the (X) put a vacuum gauge on the (X) and it vibrates. but not to nearly the same extent, and the changes in pressure reading remain more consistent

DON,T be thinking that either is a mandatory huge improvement, it may or may not help the power, the degree of restriction, displacement, compression ratio, cam timing and the efficiency of the headers has a good deal to do with your results, and sticking restrictive mufflers on past the (X) or (H) can effectively kill most of the potential benefits
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: that annoying exhaust drone

Postby 61ragtop » July 17th, 2011, 8:37 pm

I wish it was possible to have either an X or H pipe in my X-frame chevy! My exhaust drives my family crazy with it being to loud.
61ragtop

 
Posts: 29
Joined: January 1st, 2009, 1:24 am

Re: that annoying exhaust drone

Postby grumpyvette » August 26th, 2011, 11:25 am

Ive usually tig welded stainless exhaust on mine and used straight argon and purged the system as well, as duct taped the ends to limit weld oxygen exposure .
I made mine from 304 stainless tube.IF YOUR WELDING STAINLESS USE A MINIMUM 16GA 18 GA is too THIN, FOR STAINLESS HEADERS OR EXHAUST PIPE, AND DON,T FORGET TO PURGE THE BACK GAS WHEN WELDING , and 321 is superior to 304 stainless
I have been a tig welder for years ,but fluxing the inner surfaces with the paste linked to below
http://www.solarflux.com/Pages/Productinfo.html
and flushing the pipes with argon is mandatory, or the welds tend to look like crap and may crack, stainless will crack if its not welded properly. mig may be OK but tig would be better and be sure to get 100% penetration, you well exhaust pipe try to do it off the car as much as possible and be sure you disconnect both battery leads while welding to limit exposure to the vehicle electronics to damage. you want to weld 1/3"-3/4" sections then go to the opposite side of the 3" pipe joint, to limit warping.

Image

Image
Image
Image
http://www.summitracing.com/parts/WLK-17554/?rtype=10 ($120)


Image
http://www.summitracing.com/parts/WLK-17963/ ($120 x 2= $240)


Image
http://www.stainless-specialties.com/products2a.htm

http://www.classictube.com/products_exhaust.asp

http://www.jegs.com/i/Patriot-Exhaust/7 ... tId=897250

http://www.jegs.com/i/Patriot-Exhaust/7 ... tId=897250

viewtopic.php?f=56&t=1166&p=8363&hilit=stainless+paste#p8363

http://www.solarflux.com/Pages/Productinfo.html

viewtopic.php?f=60&t=1283&p=2745&hilit=stainless+welding#p2745

viewtopic.php?f=60&t=1108&p=2185&hilit=stainless+welding#p2185

I have not tried these yet but this looks extremely promising , in a full 3" exhaust, as the muffled (X) pipe, should have an advantage at blending exhaust flow and valved dual outlet mufflers should both control sound and provide a good deal of increased flow compared to most stock systems at a reduced price, and anyone who has decent welding skills should be able to fabricate a decent exhaust system from easily available 3" stainless pipe and these stainless components
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: that annoying exhaust drone

Postby phantomjock » August 26th, 2011, 5:22 pm


Image



I have the impression - and hope I'm right - that my Stahl 360s won't generate the "same" drone. The 3, 5, 4 and 6 are under the engine and I've got to make mods to the headers - the oversize oil pan and Rack and Pinion are more than a "bit "of a problem. Anyway, 3 joins with 2; 4 with 7; 5 with 8; and 6 with 1.

The theory (as I get it) the initial pluse down the pipe (after the collector) "assists" the following pluse. I'll be cutting the primarys and joining over th etop of the engine - then back down to the underside - aft of the intake - and just at the firewall - where the Dizzy used to be. (Crank Trigger now)

Grumpy - Any computations for a set up like that? Seems like the chance of hitting resonance will be significantly change with this header set up. Thoughts deeply appreciated.

Cheers - Jim
You do not have the required permissions to view the files attached to this post.
Returned - Baghdad, Iraq
phantomjock

User avatar
 
Posts: 23
Joined: April 14th, 2010, 5:13 pm
Location: Red Neck Riveria

Re: that annoying exhaust drone

Postby grumpyvette » August 26th, 2011, 5:35 pm

the DRONE is caused by the exhaust pulse frequency , making the exhaust system vibrate like a tuning fork as a certain resonance frequency,is reached and maintained. you can fight the symptoms, or reduce the level of sound, with rubber exhaust hangers and playing with longer tail pipe extensions,until you tend to make the exhaust system unbalanced so it won,t hold and maintain that vibration level or frequency nearly as well. or you can reduce the cause, by reducing the exhaust pulse strength by blending and splitting the exhaust pulses as they exit the header collectors with an x pipe, mounted as close as possible to those collectors, it might help if you realize each pulse is like a moving column of mass, if that mass suddenly hits the x pipe junction its effective speed and energy is cut almost in half at that point as the effective cross sectional area that was a single header collector diam. suddenly almost doubles, the shorter the distance the higher the rpm level of the frequency.
the key is breaking up or moving that pulse generating frequency, or moving it to an rpm range your seldom operating the engine in,
an X pipe mounted as close as clearances allow to the header collectors will usually move that frequency to a high enough power band that its well above cruise rpms where it would be the most annoying.
a 180 degree header changes the frequency and sound but its is not always a cure for the exhaust drone , as neither the number of exhaust pulses at any given rpm nor the total volume of the exhaust gas flow changes much.

READ THESE THREADS, AND SUB LINKED INFO

viewtopic.php?f=56&t=260&p=315&hilit=smurf#p315

viewtopic.php?f=56&t=185&p=774&hilit=smurf#p774

viewtopic.php?f=56&t=2537&p=6752&hilit=smurf#p6752

viewtopic.php?f=56&t=1503

viewtopic.php?f=56&t=3383

viewtopic.php?f=56&t=3155
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: that annoying exhaust drone

Postby grumpyvette » May 5th, 2014, 6:55 pm

BILLY-G wrote:Grumpy I have a 1966 big block chevelle with a 350 hp, rated 396 bbc , we added a L88 flat tappet cam, and headers and a 3.73;1 rear gear,,its got a muncie 4 speed, and the better valve springs , but even though the performance picked up noticeably the exhaust sound really sounds terribly, any ideas??



as usually the first step is knowing what your dealing with before making changes, but a dual 3" EXHAUST WITH LOW RESTRICTION MUFFLERS AND AN (X) PIPE TO SPLIT AND LOWER FLOW RESTRICTION WOULD BE WHERE I'd START,Youve got lots of options, but remember youll want to have an exhast that will allow about 500hp to allow for future mods without the exhaust restricting power output levels, theres a great deal of related info youll find useful to refer to in these threads, and sub links, yeah! you can ignore the links, but if you take the effort to read the links and sub links,youll be amazed at what youll learn and the options youll find, so0mething similar to this PYPES 3" dual exhaust will wake up most big block combos
Image
http://www.summitracing.com/parts/pye-s ... /model/gto
Image

REFERENCE MATERIAL

viewtopic.php?f=56&t=495

viewtopic.php?f=56&t=1503

viewtopic.php?f=56&t=3155&p=37114&hilit=pontiac+exhaust#p37114

viewtopic.php?f=56&t=1166

viewtopic.php?f=56&t=1303

https://www.holley.com/types/Maximum_Flow.asp

http://www.dynomax.com/mufflers?muffler ... ameter=171

http://www.jegs.com/p/Flowmaster/Flowma ... Ntt=744765

http://www.summitracing.com/parts/wlk-1 ... 7AodgW4AYg

http://www.summitracing.com/parts/sum-638270

http://www.summitracing.com/parts/pye-mvr70

I don,t know the size mufflers used ,theres dozens of similar ones sold by several manufacturers
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida


Return to Exhaust and Mufflers

Who is online

Users browsing this forum: No registered users and 3 guests