Exhaust tube Diameter - The 1947 - Present Chevrolet & GMC Truck Message Board Network

customizer76 · 12-07-2009, 09:14 AM

Well it's me again needing a little help from my Chevy community. Question of the day for me is now, that i have these new high dollar headers for my 79 c10. What size pipe to run for around 450 to 475 flywheel horses, yes i like the 3" but do i really need to go that big for this? I was told by some that 3" will give me more noise. Looking to not upset neighbors but dont wanna choke off my truck either going to small or getting 3" and not need it. The headers are the Hedman 1 3/4 runners down to which ever collector i wanna use 3 or 2.5.

swb85 · 12-07-2009, 12:11 PM

At that power level you are getting close to the point where you need 3" duals, but 2.5" duals will support it if that's the route you choose. Use mandrel bends and good flowing mufflers. I'm at the same power level as you and went with 3" duals just so I know I don't have a restriction and have room to grow. They definitely are a little louder than 2.5", but muffler selection will have some to do with that as well.

DubDubU · 12-07-2009, 01:27 PM

Quote:

Originally Posted by swb85

at that power level you are getting close to the point where you need 3" duals, but 2.5" duals will support it if that's the route you choose. Use mandrel bends and good flowing mufflers. I'm at the same power level as you and went with 3" duals just so i know i don't have a restriction and have room to grow. They definitely are a little louder than 2.5", but muffler selection will have some to do with that as well.

+1

Slick17 · 12-07-2009, 01:41 PM

I'm running 3" duals on mine and they are a little loud but more of a deep tone. I's say go with the 3" duals. That should be great for the ponies you're runnin.

willett · 12-07-2009, 04:27 PM

i quite enjoy my 3" duels.
my neighbours do not.

68 TT · 12-07-2009, 04:48 PM

Quote:

Originally Posted by willett

i quite enjoy my 3" duels.
my neighbours do not.

^x2

Adding tail pipes to my 3" dual system on the C-10 that used to be turned out in front of the rear wheels really dropped the noise level down. It sounds nice now when before it was a little loud and you didn't really get much of that classic Flowmaster sound.

I used to knock things off the wall of the neighbors house when I fired it up, with the full tail pipes it just shakes the windows when I drive away.

It has much more of the classic Flowmaster sound now.

Flowmaster makes a nice 50-series SUV performance muffler that will help quiet it down a little vs. the traditional 40-series muffler. I really like the way they sound on my Malibu and have a set I am putting onto the 68 Camaro.

Prerunner1982 · 12-07-2009, 04:58 PM

For mufflers you might try the Aerochambers. I know quite a few guys on here a couple years ago were switching to them and liked them a lot. They have a straight through design where the Flowmasters do not.

customizer76 · 12-08-2009, 08:33 AM

Quote:

Originally Posted by Prerunner1982

For mufflers you might try the Aerochambers. I know quite a few guys on here a couple years ago were switching to them and liked them a lot. They have a straight through design where the Flowmasters do not.

Thanks alot i will check them as well. I was looking at the magnaflow mufflers oval 5x8 to dampen some of the noise. I knew for sure i was not about to run the flowmaster's. Thats the U2 mufflers on the shore. LOL (I'm running flowmasters, yeah U2) LOL
Nothing against flowmaster they are great but just want something different.

customizer76 · 12-08-2009, 08:37 AM

I think i will do the 3" just run a different muffler, flowmaster also makes a 70 series that is next to the hushpower, but i was told they are to heavy and often break hangers. 3 i think is the way to go though. Thank you alot.

68 TT · 12-08-2009, 09:57 AM

Quote:

Originally Posted by customizer76

Thanks alot i will check them as well. I was looking at the magnaflow mufflers oval 5x8 to dampen some of the noise. I knew for sure i was not about to run the flowmaster's. Thats the U2 mufflers on the shore. LOL (I'm running flowmasters, yeah U2) LOL
Nothing against flowmaster they are great but just want something different.

I know there are several better flowing mufflers out there but I have been running Flowmaster mufflers on all the vehicles I build for over 20 years because I like they way they sound.

faribran · 12-08-2009, 10:34 AM

is anyone having RESONANCE problems with the larger pipes?

68 TT · 12-08-2009, 12:38 PM

Quote:

Originally Posted by faribran

is anyone having RESONANCE problems with the larger pipes?

Only in the walls of the house before i put the tail pipes on. It was way louder in the house than it was outside. Kind of weird.

customizer76 · 12-09-2009, 08:36 AM

Quote:

Originally Posted by 68 TT

I know there are several better flowing mufflers out there but I have been running Flowmaster mufflers on all the vehicles I build for over 20 years because I like they way they sound.

I cant say anything bad about flowmaster they sound great, its just that over here everyone has the same sound. I wanna be a little different.

68 TT · 12-09-2009, 09:50 AM

Quote:

Originally Posted by customizer76

I cant say anything bad about flowmaster they sound great, its just that over here everyone has the same sound. I wanna be a little different.

Nothing wrong with that. The Hooker Aero Chamber mufflers sound a little different and are priced similar to the Flowmaster.

You could do a search for Aero Chamber on youtube and probably find a few video clips so you can hear them.

68Timber · 12-09-2009, 10:22 AM

Also, the magnaflows are straight through but very mellow.

ironroad9c1 · 12-09-2009, 01:00 PM

Do you have a dyno slip saying you make that much? Not doubting you, but i see alot of folk slap on alot of bolt on and stuff and think that all the crap added togeather adds up to 400HP..lol when really its maybe 30.added HP. post up a list of what you have done. really for anything streetable with decent HP you only need 2 1/2 dual , you really want to keep the exhaust gas velocity up so it helps pull everything out of the Cyl when the exhaust valve opens up. good article to read about exhaust.
http://my.prostreetonline.com/forums...ead.php?t=1639

3r!c84 · 12-09-2009, 02:30 PM

i got 2 1/4 in pipeing with flowmaster 40s.how much hp will i piick up when i put in the longtube headers?
its just a 305 with nothin that good in it

68 TT · 12-09-2009, 03:14 PM

Quote:

Originally Posted by 3r!c84

i got 2 1/4 in pipeing with flowmaster 40s.how much hp will i piick up when i put in the longtube headers?
its just a 305 with nothin that good in it

Not much with a stock 305. Maybe 5 hp. 10 if you are lucky.

Manbearpig · 12-09-2009, 07:33 PM

I'd run a 2.5" y-pipe into a 3" single

BIG10 · 12-09-2009, 07:52 PM

Go 3". I'm a Magnaflow fan. I like the smooth, mellow sound.

12-07-2009, 09:14 AM	#1
customizer76 Registered User Join Date: Nov 2009 Location: Virginia Posts: 26	Exhaust tube Diameter Well it's me again needing a little help from my Chevy community. Question of the day for me is now, that i have these new high dollar headers for my 79 c10. What size pipe to run for around 450 to 475 flywheel horses, yes i like the 3" but do i really need to go that big for this? I was told by some that 3" will give me more noise. Looking to not upset neighbors but dont wanna choke off my truck either going to small or getting 3" and not need it. The headers are the Hedman 1 3/4 runners down to which ever collector i wanna use 3 or 2.5.

12-07-2009, 12:11 PM	#2
swb85 On a budget like Fred Sanford Join Date: Oct 2005 Location: Topeka, KS Posts: 2,031	Re: Exhaust tube Diameter At that power level you are getting close to the point where you need 3" duals, but 2.5" duals will support it if that's the route you choose. Use mandrel bends and good flowing mufflers. I'm at the same power level as you and went with 3" duals just so I know I don't have a restriction and have room to grow. They definitely are a little louder than 2.5", but muffler selection will have some to do with that as well. __________________ '85 Silverado swb: 383 stroker, 10.5:1, vortec heads, 232/238 roller cam, RPM air gap, performer 750 carb, stainless longtubes, 3" duals/super 44's, T56/4.11 383ci build / exterior refresh thread '98 Camaro z28: 370ci twin turbo 370ci build '01 Tahoe LT 4x4: 5.3, longtubes/ory, magnaflow duals, custom tune....wife's DD

12-07-2009, 01:41 PM	#4
Slick17 Registered User Join Date: Nov 2009 Location: Frederick, MD Posts: 158	Re: Exhaust tube Diameter I'm running 3" duals on mine and they are a little loud but more of a deep tone. I's say go with the 3" duals. That should be great for the ponies you're runnin.

12-07-2009, 04:27 PM	#5
willett Another Day, Another Dollar Join Date: Nov 2008 Location: North Vancouver, BC Posts: 1,316	Re: Exhaust tube Diameter i quite enjoy my 3" duels. my neighbours do not. __________________ -78 K20 Cheyenne 454 long box, 4" lift, 35" MT's, '84 cab, '80 box "its hip to be square"

12-07-2009, 04:58 PM	#7
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,906	Re: Exhaust tube Diameter For mufflers you might try the Aerochambers. I know quite a few guys on here a couple years ago were switching to them and liked them a lot. They have a straight through design where the Flowmasters do not. __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call

12-08-2009, 08:37 AM	#9
customizer76 Registered User Join Date: Nov 2009 Location: Virginia Posts: 26	Re: Exhaust tube Diameter I think i will do the 3" just run a different muffler, flowmaster also makes a 70 series that is next to the hushpower, but i was told they are to heavy and often break hangers. 3 i think is the way to go though. Thank you alot.

12-08-2009, 10:34 AM	#11
faribran Registered User Join Date: Jul 2005 Location: AL Posts: 1,828	Re: Exhaust tube Diameter is anyone having RESONANCE problems with the larger pipes? __________________ "

12-09-2009, 10:22 AM	#15
68Timber I know the pieces fit Join Date: Nov 2007 Location: MONTGOMERY, AL Posts: 5,523	Re: Exhaust tube Diameter Also, the magnaflows are straight through but very mellow. __________________ John 79 2wd Blazer (Bruiser) 85 M1009 Blazer (Sarge) build 74 Honda Z50 build

12-09-2009, 01:00 PM	#16
ironroad9c1 Master Hater Join Date: Apr 2006 Location: Temple,Tx. Posts: 402	Re: Exhaust tube Diameter Do you have a dyno slip saying you make that much? Not doubting you, but i see alot of folk slap on alot of bolt on and stuff and think that all the crap added togeather adds up to 400HP..lol when really its maybe 30.added HP. post up a list of what you have done. really for anything streetable with decent HP you only need 2 1/2 dual , you really want to keep the exhaust gas velocity up so it helps pull everything out of the Cyl when the exhaust valve opens up. good article to read about exhaust. http://my.prostreetonline.com/forums...ead.php?t=1639

12-09-2009, 02:30 PM	#17
3r!c84 Badass Join Date: Jan 2009 Location: lox. fl Posts: 4,586	Re: Exhaust tube Diameter i got 2 1/4 in pipeing with flowmaster 40s.how much hp will i piick up when i put in the longtube headers? its just a 305 with nothin that good in it __________________ Think outside the box? -84c10 (1stcar)→My Build← -00 Saturn 5spd drop a gear and disappear! 1/4:13:90

12-09-2009, 07:33 PM	#19
Manbearpig Registered User Join Date: Mar 2009 Location: Midland, Tx Posts: 418	Re: Exhaust tube Diameter I'd run a 2.5" y-pipe into a 3" single __________________ 1972 GMC C10 Last edited by Manbearpig; 12-09-2009 at 07:33 PM.

12-09-2009, 07:52 PM	#20
BIG10 Registered User Join Date: Dec 2008 Location: Jenks, OK Posts: 314	Re: Exhaust tube Diameter Go 3". I'm a Magnaflow fan. I like the smooth, mellow sound. __________________ Jay 1978 Big 10 Silverado, 355 + 700R4 + 3.42 + factory tach + A/C + dual tanks + working cruise control = awesome highway cruiser.

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