Notices
GM Engine & Exhaust Performance EFI | GEN I/GEN II/GEN III/GEN IV Engines |Small Block | Big Block |

Thinking about going true dual

Thread Tools
 
Search this Thread
 
Old 07-21-2008, 12:41 AM
  #1  
Wearin' da big hat
Thread Starter
iTrader: (10)
 
00ChevyScott's Avatar
 
Join Date: Jan 2008
Location: Over There
Posts: 10,262
Received 9 Likes on 4 Posts
Default Thinking about going true dual

What do you guys think?

I'm thinking about cutting up the pacesetter Y pipe before it joins and getting someone to make me a true dual exhaust system out of peices of pipe to avoid getting bent pipe at a shop.
It would most like be dual 3" into an X pipe, with dual 2.5 to the back? And I would buy another cutout to run before the X pipe.

Would I gain anything from this, given my mods. How much louder could I expect it to be?
Old 07-21-2008, 10:17 AM
  #2  
TECH Resident
 
TarheelZ's Avatar
 
Join Date: Dec 2003
Location: SW Virginia
Posts: 791
Likes: 0
Received 0 Likes on 0 Posts
Default

I suspect you'd lose some noticeable low-end torque with the setup you described, which could be significant with the ECSB's weight.
Old 07-21-2008, 10:21 AM
  #3  
2nd fastest 5.3 ECSB
iTrader: (14)
 
trever1t's Avatar
 
Join Date: Oct 2005
Location: NorCal
Posts: 26,690
Likes: 0
Received 1 Like on 1 Post
Default

I have 3" to 2 1/2 " behind the x as you describe, I gained ~10hp over the stock Y and 3" cat back but then I am probably pumping a bit more air than you.
Old 07-21-2008, 12:43 PM
  #4  
Wearin' da big hat
Thread Starter
iTrader: (10)
 
00ChevyScott's Avatar
 
Join Date: Jan 2008
Location: Over There
Posts: 10,262
Received 9 Likes on 4 Posts
Default

Originally Posted by trever1t
I have 3" to 2 1/2 " behind the x as you describe, I gained ~10hp over the stock Y and 3" cat back but then I am probably pumping a bit more air than you.
just a bit

I guess I'll just buy Zzebes exhaust off him then.

which he needs to show me pics of asap
Old 07-21-2008, 11:13 PM
  #5  
TECH Senior Member
iTrader: (45)
 
dirt track racer 81's Avatar
 
Join Date: Jun 2005
Location: Hennessey, Oklahoma
Posts: 9,439
Likes: 0
Received 11 Likes on 5 Posts
Default

i didnt notice anything on the lower end but up top it would pull pretty good
Old 07-21-2008, 11:32 PM
  #6  
TECH Resident
iTrader: (2)
 
InchUp's Avatar
 
Join Date: Feb 2008
Posts: 939
Likes: 0
Received 0 Likes on 0 Posts
Default

Anyone on here running dual 3" pipes had better be pushing 600hp or more. Briefly looking at trever1t's setup, I'd say he's matched his exhaust to his power well. Necking down in size as the exhaust route travels rearward is also a smart decision, as it will keep velocity more consistent as the exhaust gas temps cool.

Dual 2.5" is still overkill for most guys. Going from a single 3" to a dual 2.5" is an increase of 39% pipe area for exhaust gas to travel down. Is your motor making 39% more power as well? Hrmmm...300fwhp 5.3L with an additional 39% increase in power puts the motor at a 417fwhp motor. For ***** and giggles, going from a single 3" to a dual 3" means your motor must put out 200% it's stock power output to make use of the dual 3" choice. 300fwhp with an additional 200% increase in power is...well, 600hp. See the wasted pipe here for a stock motor?
Old 07-21-2008, 11:44 PM
  #7  
TECH Senior Member
iTrader: (45)
 
dirt track racer 81's Avatar
 
Join Date: Jun 2005
Location: Hennessey, Oklahoma
Posts: 9,439
Likes: 0
Received 11 Likes on 5 Posts
Default

Originally Posted by InchUp
Anyone on here running dual 3" pipes had better be pushing 600hp or more. Briefly looking at trever1t's setup, I'd say he's matched his exhaust to his power well. Necking down in size as the exhaust route travels rearward is also a smart decision, as it will keep velocity more consistent as the exhaust gas temps cool.

Dual 2.5" is still overkill for most guys. Going from a single 3" to a dual 2.5" is an increase of 39% pipe area for exhaust gas to travel down. Is your motor making 39% more power as well? Hrmmm...300fwhp 5.3L with an additional 39% increase in power puts the motor at a 417fwhp motor. For ***** and giggles, going from a single 3" to a dual 3" means your motor must put out 200% it's stock power output to make use of the dual 3" choice. 300fwhp with an additional 200% increase in power is...well, 600hp. See the wasted pipe here for a stock motor?
i wouldnt suggest dual 3 for a 5.3 unless the air is being forced through it..2.5 is the biggest id go on a 5.3 and thats what i had on mine. i have dual 3 on my 370 though..any how i just cant get out my head of dual 2.5 into 3, in my screwed up head it seems like dual 2.5 into dual 1.5, 3/2 is 1.5
Old 07-22-2008, 12:20 AM
  #8  
Wearin' da big hat
Thread Starter
iTrader: (10)
 
00ChevyScott's Avatar
 
Join Date: Jan 2008
Location: Over There
Posts: 10,262
Received 9 Likes on 4 Posts
Default

Originally Posted by InchUp
Anyone on here running dual 3" pipes had better be pushing 600hp or more. Briefly looking at trever1t's setup, I'd say he's matched his exhaust to his power well. Necking down in size as the exhaust route travels rearward is also a smart decision, as it will keep velocity more consistent as the exhaust gas temps cool.

Dual 2.5" is still overkill for most guys. Going from a single 3" to a dual 2.5" is an increase of 39% pipe area for exhaust gas to travel down. Is your motor making 39% more power as well? Hrmmm...300fwhp 5.3L with an additional 39% increase in power puts the motor at a 417fwhp motor. For ***** and giggles, going from a single 3" to a dual 3" means your motor must put out 200% it's stock power output to make use of the dual 3" choice. 300fwhp with an additional 200% increase in power is...well, 600hp. See the wasted pipe here for a stock motor?
I said I wanted to do dual 3" into the X pipe, then dual 2.5 out...
Old 07-22-2008, 12:35 AM
  #9  
TECH Junkie
iTrader: (10)
 
ZZebes's Avatar
 
Join Date: Feb 2007
Posts: 3,111
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by 00ChevyScott
just a bit

I guess I'll just buy Zzebes exhaust off him then.

which he needs to show me pics of asap
Bitch Bitch Bitch

I'll send pics in a few
Old 07-22-2008, 02:31 AM
  #10  
TECH Enthusiast
iTrader: (6)
 
PathfinderJr's Avatar
 
Join Date: Nov 2006
Location: Texas
Posts: 721
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by 00ChevyScott
I said I wanted to do dual 3" into the X pipe, then dual 2.5 out...
right, but even 2.5" duals are decently big for only 325 cubes. 2.25" duals is just a tad larger x-sectional area compared to a 3" single. It just doesn't sound as manly to say 2.25" duals I guess...

Just for a comparison, even though its different generations of small-block, the hopped up 350 in my '66 truck made ~400hp/~415lb-ft torque on an engine dyno. Torque was about 400 lb-ft at 3.5k all the way until about 5k. This was running through 1-5/8" headers with 2.5" collectors, and has 2.5" duals on the truck with an x-pipe.

I could be wrong, but I doubt the engine in your truck is that strong, and you'd have more area under the torque curve in the usable rpm range that you'd be in on a day to day basis with 2.25" dual. But hey, its your truck, so do whatever pulls your trigger.


Quick Reply: Thinking about going true dual



All times are GMT -5. The time now is 01:34 PM.