![]() |
Register or Log In To remove these advertisements. |
|
|
![]() |
|
Thread Tools | Display Modes |
![]() |
#1 |
Registered User
Join Date: Aug 2011
Location: Ogden, Utah
Posts: 32
|
Why dual exhuast vs. single?
I have a stock 72 c20 with a 350. The stock exhaust needs to be replaced to due to age and wear. I was thinking to put dual exhaust on to let it breath better, but my mechanic says not to do it. The truck is a daily driver 108K orig miles on it. Ramhorn exhaust manifold and quadrajet carb.
What are peoples thoughts (aside from cost) regarding putting dual exhaust on my truck? Aside from a bit of HP increase (which I dont really need) what changes would be seen? I have read from other threads there is also a consideration of having too little back pressure, would that be a problem? Cheers! |
![]() |
![]() |
![]() |
#2 |
Active Member
![]() Join Date: Jul 2007
Location: Centrally located between Houston, Austin and Waco. BCS area.
Posts: 7,947
|
Re: Why dual exhuast vs. single?
Cool factor? I also like the sound of duals vs. single exhaust.
If you are trying to squeeze every ounce of h.p. it might help but in my case, a daily driver, I didn't notice any change and my mpg stayed the same. |
![]() |
![]() |
![]() |
#3 |
Registered User
Join Date: Oct 2005
Location: Overland Park, Ks.
Posts: 5,218
|
Re: Why dual exhuast vs. single?
Dual exhaust is the best single thing you can do for a v-8 engine. It breaths easier giving more power, better gas mileage & cooler running exhaust manifolds & ex. valves.
|
![]() |
![]() |
![]() |
#4 |
Special Order
![]() ![]() Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,858
|
Re: Why dual exhuast vs. single?
For me it's religion and it's been every V8 I've owned. I no longer can explain for I have lost sight with the origin of my ways.
![]() I'd like to answer that with two questions. One...what was the reason you mechanic gave you not to do it? Opinions are like trucks. Everyone has one. The second question is why V8? Why put 1/2 the engine's cylinders on one side and 1/2 on the other? I use a simple formula,one pipe for each cylinder bank. Why take one from one side to squeeze into the same pipe as the other side? The manufacturer did it to maximize profit. Why do all hot rods have dual exhaust? Ok,I'm asking way more that two now. Anyone who said dual exhaust doesn't give enough back pressure is too cheap to buy two pipes and using that as an excuse,because it's surely not true about back pressure.
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ |
![]() |
![]() |
![]() |
#5 | |
Registered User
Join Date: Oct 2010
Location: Largo Florida
Posts: 632
|
Re: Why dual exhuast vs. single?
Quote:
__________________
Lifes journey is not to arrive at the gate well preserved, it is to slide in sideways all used up and wore out yelling.....God what'a ride! Where patience fails, force prevails Stapp's Ironical Paradox "The universal aptitude for ineptitude makes any human accomplishment an incredible miracle." |
|
![]() |
![]() |
![]() |
#6 | |
Registered User
Join Date: Aug 2011
Location: Ogden, Utah
Posts: 32
|
Re: Why dual exhuast vs. single?
Quote:
What type of system would you recommend? Seems like the dual exhausts Ive seen are Xtype. |
|
![]() |
![]() |
![]() |
#7 |
Registered User
Join Date: Oct 2010
Location: Largo Florida
Posts: 632
|
Re: Why dual exhuast vs. single?
X-pipe is slightly better (bigger gain a high performance engines) but an H-pipe will work very well on a stocker. I used a Heartbeat system on my 1974 truck and it fit pretty well (did have to do a bit of changing) with a pair of Hemi Turbos from Walker. Nice and quiet but no h-pipe (got lazy). Find out what a muffler shop will charge to make up a dual system fofr your truck.
That old man is clueless, what would he say about the daul exhaust option that all the V8 cars and trucks could have. Kind of kills his facts all to heck.
__________________
Lifes journey is not to arrive at the gate well preserved, it is to slide in sideways all used up and wore out yelling.....God what'a ride! Where patience fails, force prevails Stapp's Ironical Paradox "The universal aptitude for ineptitude makes any human accomplishment an incredible miracle." |
![]() |
![]() |
![]() |
#8 | |
Registered User
Join Date: Aug 2011
Location: Ogden, Utah
Posts: 32
|
Re: Why dual exhuast vs. single?
Quote:
What about exhaust location? In front of wheel, behind wheel, straight out the back... Pros/Cons to locations? So no arguments for keeping the single exhaust then??? |
|
![]() |
![]() |
![]() |
#9 |
Registered User
Join Date: Oct 2010
Location: Largo Florida
Posts: 632
|
Re: Why dual exhuast vs. single?
Go over the axle and at least behind the rear wheels, after a long drive your ears will thank you.
__________________
Lifes journey is not to arrive at the gate well preserved, it is to slide in sideways all used up and wore out yelling.....God what'a ride! Where patience fails, force prevails Stapp's Ironical Paradox "The universal aptitude for ineptitude makes any human accomplishment an incredible miracle." |
![]() |
![]() |
![]() |
#10 |
Registered User
Join Date: Oct 2005
Location: Overland Park, Ks.
Posts: 5,218
|
Re: Why dual exhuast vs. single?
I believe in the Ram-Horns. Definitly exit behind the axle. I like the cool factor under the rear bumper, except panels or Burbs. Then behind the rear wheel. I dont see much advantage to X or H myself but I'm older then your mechanic so a lot of these guys know more about that.
|
![]() |
![]() |
![]() |
#11 | |
Special Order
![]() ![]() Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,858
|
Re: Why dual exhuast vs. single?
Quote:
![]()
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ |
|
![]() |
![]() |
![]() |
#12 |
Registered User
Join Date: Nov 2010
Location: Carlsbad, CA
Posts: 1,584
|
Re: Why dual exhuast vs. single?
If you ever need to remove the oil pan (like I just did the other day) you won't have to mess with removing the crossover pipe. I like duals. I can't imagine a V8 without.
__________________
- Jim - My Daily Driver is a 1969 Chevrolet Custom/20 Fleetside 350/TH400/Eaton H052 4.10 and its Project thread is here http://67-72chevytrucks.com/vboard/s...d.php?t=456911 |
![]() |
![]() |
![]() |
#13 |
Registered User
Join Date: Nov 2009
Location: castlegar,b.c
Posts: 277
|
Re: Why dual exhuast vs. single?
i changed out my single exhaust out to a dual setup, without x or h pipe. had the exhaust come straight out back. couldn't come out the side due to the trailing arms.
![]() haven't noticed improvement in mpg, and the sound isn't much louder than the rusted out single muffler ![]() |
![]() |
![]() |
![]() |
#14 |
Senior Member
Join Date: Aug 2002
Location: Valley Center KS
Posts: 3,525
|
Re: Why dual exhuast vs. single?
When my 69 got shipped to me, the shipping company ripped the old exhaust off. I got a quote from an exhaust shop for duals w/ 40 series flowmasters for a total of $800 or so!!!
I ended up getting this kit:http://www.summitracing.com/parts/HOK-16621HKR/ ![]() I put some cherry bomb turbo mufflers on it. I got lazy and dumped them before the axle, but the sound is not real loud.The total cost was less than $300 and I didn't have to hassle with taking it somewhere. |
![]() |
![]() |
![]() |
#15 |
Senior Member
![]() Join Date: Jun 2005
Location: Winona Lake, IN
Posts: 6,286
|
Re: Why dual exhuast vs. single?
The only argument I would have is if you were going with headers. With a lot of miles like that on the engine, it could make the engine start burning oil if you were to install headers.
I have experienced this at least twice with a high mileage engine. With manifolds I have never seen it. Anyone have an idea as to why this would be?
__________________
70 C/10 SWB 402/TH400/3.73 "The Needy Beast" 200,000 Mile Club Disc Brake Club Owner installed options: Front Sway Bar Power Steering Power Brakes Cigar Lighter Courtesy Lights Deluxe Side Markers Wiper Delay Power windows Power Locks Sniper EFI 2015 Silverado 1500 LS 4.3/6L80/3.23 lowered 2" front & rear |
![]() |
![]() |
![]() |
#16 | |
Account Suspended
Join Date: Jan 2007
Location: Tucson
Posts: 2,183
|
Re: Why dual exhuast vs. single?
Quote:
Now, all that said, I run headers, dual exhausts with an "X" pipe and it sounds great! so, it's a choice; style vs practicality, but the performance difference will not be noticeable with a stock motor. |
|
![]() |
![]() |
![]() |
#17 |
Registered User
Join Date: Nov 2007
Location: Indianapolis
Posts: 1,162
|
Re: Why dual exhuast vs. single?
run duals. they sound better, 2 pipes coming out the rear looks better and duals are better for your engine. run center dump manifolds 2 1/2 inch type. the keep the heat away from the starter unlike headers
|
![]() |
![]() |
![]() |
#18 | |
Registered User
Join Date: Apr 2001
Location: DALLAS,TX
Posts: 21,980
|
Re: Why dual exhuast vs. single?
Quote:
That being said, on a stock set-up there won't be much improvement & it probably isn't cost effective upgrading to duals. The slight improvements w/a properly sized system (whether its a new larger/better routed single or true duals) is better seat of the pants performance (feels stronger/more responsive) and/or efficiency (mpg's). Like others stated.... dual tail-pipes do look better to most enthusiasts.
__________________
67SWB-B.B.RetroRod 64SWB-Recycle 89CCDually-Driver/Tow Truck 99CCSWB Driver All Fleetsides @rattlecankustoms in IG Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive. It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar..... Cubic inches is like Indiana Jones with a cheap pistol. |
|
![]() |
![]() |
![]() |
#19 |
Devil's in the Details
Join Date: Sep 2008
Location: Southern Utah
Posts: 353
|
Re: Why dual exhuast vs. single?
My exhaust guy suggested running a single 3" system on my Suburban, but I requested a dual 2.5" system instead. It was simply what I wanted. It wasn't until I got home that I did the maths.
Dual 2.5” exhaust = 9.8 in2 Single 3” exhaust = 7.1 in2 I also later learned that the 1988 pickup my engine came from actually had 2.5" dual exhaust from the factory.
__________________
'70 K10 Suburban - TBI 454, 4L80E, NP241C, Dana 60 & 44 - The 10+ Year Project Thread Datsun 240Z, 510 2 door and an old Honda motorcycle Last edited by Beelzeburb; 12-12-2011 at 12:16 AM. |
![]() |
![]() |
![]() |
#20 | |
Active Member
![]() Join Date: Jul 2007
Location: Centrally located between Houston, Austin and Waco. BCS area.
Posts: 7,947
|
Re: Why dual exhuast vs. single?
Quote:
|
|
![]() |
![]() |
![]() |
#21 |
Old Duffer
![]() Join Date: Mar 2003
Location: Maine
Posts: 1,821
|
Re: Why dual exhuast vs. single?
I like duals, I like the sound, and it gets burned (no pun intended) into every hot rodders heart that duals are the way to go. I've had duals and headers on most of my hot rods and trucks, but like someone said earlier, they cost roughly twice as much as a single set up, and the performance difference on a DD may or may not justify the expense. I don't think Detroit's main reason for a single pipe was all profit margin. They've got some pretty savvy engineers on the payrole. What I was told a long time ago was Detroit was actually looking out for us. A single pipe is slower to rot out from acids and moisture because they tend to run hotter and all the bad stuff gets burned out, or dried out. Another reason is the exhaust pulse from one cylinder helps pull the next pulse through causing a scavenging effect. It's all above my understanding, but even serious header builders use this principle when they design a header by making the tubes a certain length so that the exhaust impulses don't collide at the collector.
There, you have it...JMHO ![]()
__________________
'68 Short C20 Flatbed Dually w/ 292 4bbl, Langdon cast headers, and WC T5 trans. '81 G10 Shorty Van "Good judgement comes from experience, and a lot of that comes from bad judgement." Will Rogers "Under promise, then over achieve." |
![]() |
![]() |
![]() |
#22 |
I am a Referee of life.
Join Date: Jun 2000
Location: Greensboro N.C.
Posts: 13,993
|
Re: Why dual exhuast vs. single?
I like the way duals sound run out the back.I also like quiet but throaty mufflers.The best advice is to listen to a few rides with duals.Find one you like and ask about it.If you plan on engine upgrades then that is the first step.If you don't it still sounds cool.I've almost always had duals until I started driving V6 and inlines and have even decided to convert to duals on a v6 when I need new ehuast.
__________________
The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil" |
![]() |
![]() |
![]() |
#23 |
Special Order
![]() ![]() Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,858
|
Re: Why dual exhuast vs. single?
Personally,I think an 8hp increase makes it worthwhile. It's definitely noticeable and I have no need for a bridge
![]() As far as noise level goes,dual vs single has nothing to do with it. That's all about the muffler(s). What do pretty wheels & paint jobs or chrome air cleaners & valve covers do for performance? We do what we do because we love our trucks. We buy little Japanese econo-boxes because it's practical.
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ |
![]() |
![]() |
![]() |
#24 |
Old member
Join Date: Jan 2002
Location: Liberty, & Garden City S.C. , U.S.
Posts: 19,936
|
![]()
I drive my truck everyday just about. In fact just got back home. I have duals in it but as stated a single will work just as good if sized properly. Cool factor is duals though.
A street engine you may tell a differance in the way it runs but over all it's a street truck D/D. Most want MPG out of them not performance on a D/D. I know I do. My truck isn't a race truck it's a D/D so MPG is more important to me than 8hp is. That being said I like my system but a single would be fine. In the end it's yor truck build it the way you want it. Oh, almost forgot I like the rams over headers. ![]() ![]()
__________________
1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 ![]() Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs. |
![]() |
![]() |
![]() |
Bookmarks |
Thread Tools | |
Display Modes | |
|
|