True dual 3" exhuast?
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From: Ft Campbell, KY
Car: 1991 Camaro RS/Z28
Engine: 357 Edelbrock Intake & Holley Carb
Transmission: WC T-5
Axle/Gears: whatever stock is
True dual 3" exhuast?
Has anyone tried to do a true dual 3" exhuast? I've got two cherry bomb 3" glasspacks on the way and wanted to know if anyone has done soemthing similar and did it sound good?
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Joined: Aug 2004
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From: Pasadena, TX
Car: 1991 RS
Engine: 5.0
Transmission: 700r4
Re: True dual 3" exhuast?
No i dont think so. You might just be the first ever. Seriously though, there is a sticky at the top of this thread with about a bazillion pictures. I think you'll find your answer there.
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From: Northern CA.
Car: '82 Z28
Engine: 350
Transmission: TH400 4,000 stall
Axle/Gears: Currie 9", 4.56 gears
Re: True dual 3" exhuast?
Going by the engine in your sig, dual 3 inch is way overkill. Probably end up sounding like some farm truck too.
Thread Starter
Senior Member
Joined: Nov 2008
Posts: 311
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From: Ft Campbell, KY
Car: 1991 Camaro RS/Z28
Engine: 357 Edelbrock Intake & Holley Carb
Transmission: WC T-5
Axle/Gears: whatever stock is
Re: True dual 3" exhuast?
I know that it will be overkill for the short term, but I have many parts planned for when I return from my deployment and this way the exhuast will be one less thing that I'll have to worry about when I return. I leave in a couple few months so I can deal with the 'off' noise until then. I'll have a couple thou sitting in the account waiting to be spent on the car when I get back.
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Joined: Apr 2006
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From: Rochester NY
Car: 1984 z28
Engine: 355
Transmission: 700r4
Axle/Gears: Moser 9" 4.11
Re: True dual 3" exhuast?
Your not pushing enough HP to be using a 3" true dual and I doubt you will be with any small upgrades your plannning.Stay with 2 1/2 if your going true duals. I wouldn't be worrying about the "off noise" rather the performance would be suffering.
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From: South Carolina
Car: 85 2M6, 87 'Bird 88 'burb
Engine: LX9, LG4, L05
Transmission: F23, 700r4, 700R4
Axle/Gears: 3.63, 2.73, 4.10
Re: True dual 3" exhuast?
I have 3 " true duals on my '83, excellent ground clearence too, but my floorpans didn't like it!
Thread Starter
Senior Member
Joined: Nov 2008
Posts: 311
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From: Ft Campbell, KY
Car: 1991 Camaro RS/Z28
Engine: 357 Edelbrock Intake & Holley Carb
Transmission: WC T-5
Axle/Gears: whatever stock is
Re: True dual 3" exhuast?
I've decided to post-pone the 3" exhuast until I get the car moving again. After I get the transmission issue fixed I'll worry about the exhuast so for now I'm going to put on the 2.5" single that I had already planned.
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From: Long Island,NY
Car: Bone stock 1989 Iroc T-Top,1991 Z28
Engine: 5.7, Carbed 383
Transmission: 700r4, T-56
Re: True dual 3" exhuast?
Would a true dual 3" be too much for a 383 with a Comp Cams 280 xfi cam, AFR 195's with 76cc Chambers, edelbrock performer RPM, Holley 750 DP and a set of Dougs LT's? Any ideas?
Last edited by remltr; Sep 30, 2009 at 08:44 AM.
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From: Lower Burrell, Pa
Car: 86 Iroc-Z28 Camaro/84 BMW M Power
Engine: 350TPI/ S50
Transmission: t-5 five speed/ 5 speed
Axle/Gears: 3.42 posi/ 3.73LSD
Re: True dual 3" exhuast?
I'd say 3inch dual is too big for any thing under 400cid. Personally 2.5 dual is plenty big enough for a highly modded 350 or 383. By putting too big of an exhaust on an engine bottom end power and torque will suffer alot.
Joined: Dec 2005
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From: Macon, GA
Car: 1992 Camaro RS
Engine: Vortec headed 355, xe262
Transmission: T56
Axle/Gears: 9-bolt 3.70
Re: True dual 3" exhuast?
Depends on the volumetric efficiency of the engine. A 383 may pump more air (ie - power) than a 400 if it has better heads/cam/induction.
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From: Long Island,NY
Car: Bone stock 1989 Iroc T-Top,1991 Z28
Engine: 5.7, Carbed 383
Transmission: 700r4, T-56
Re: True dual 3" exhuast?
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From: Bowdon, GA.
Car: 1988 Camaro
Engine: 355, 10.34:1, 249/252 @.050", IK200
Transmission: TH-400, 3500 stall 9.5" converter
Axle/Gears: Ford 9", detroit locker, 3.89 gears
Re: True dual 3" exhuast?
I'm running a homemade dual 3" X pipe system on mine. Almost 600 HP and should be in the 10's (was 11.40's with old 505 HP combo)
Heres pics
http://rides.webshots.com/album/573815401QtiPuM
Heres pics
http://rides.webshots.com/album/573815401QtiPuM
Joined: Sep 2003
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From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: True dual 3" exhuast?
dual 3 is good for a nitrous motor. I ran 3" y pipe to single 4" which is close to same flow as dual 3" and it was fine. Motor had plenty of ***** even when off the bottle. 400whp on motor, roughly 520 on spray.
dual 2.75 would be good for most fairly hot 383's but hard to find any pipes/muffler in 2.75". 2.5" is ok but I'd rather be abit too big than too small
General rule of thumb is 2.2 cfm of flow for each hp made. I've seen standard figures of 115cfm per every square inch of exhaust pipe area so you can figure it from there. I had 500hp estimated so i needed 1100 cfm of total flow. single 4" is good for 1445cfm. Dual 3" is like 1625 cfm. Dual 2.5" is like 1129. So on motor i wouldnt have had problems with dual 2.5" but i wanted to leave some room in case i planned on motor power and also the nitrous which does create more exhaust so the bigger pipes are welcomed
dual 2.75 would be good for most fairly hot 383's but hard to find any pipes/muffler in 2.75". 2.5" is ok but I'd rather be abit too big than too small
General rule of thumb is 2.2 cfm of flow for each hp made. I've seen standard figures of 115cfm per every square inch of exhaust pipe area so you can figure it from there. I had 500hp estimated so i needed 1100 cfm of total flow. single 4" is good for 1445cfm. Dual 3" is like 1625 cfm. Dual 2.5" is like 1129. So on motor i wouldnt have had problems with dual 2.5" but i wanted to leave some room in case i planned on motor power and also the nitrous which does create more exhaust so the bigger pipes are welcomed
Thread Starter
Senior Member
Joined: Nov 2008
Posts: 311
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From: Ft Campbell, KY
Car: 1991 Camaro RS/Z28
Engine: 357 Edelbrock Intake & Holley Carb
Transmission: WC T-5
Axle/Gears: whatever stock is
Re: True dual 3" exhuast?
I'm running a homemade dual 3" X pipe system on mine. Almost 600 HP and should be in the 10's (was 11.40's with old 505 HP combo)
Heres pics
http://rides.webshots.com/album/573815401QtiPuM
Heres pics
http://rides.webshots.com/album/573815401QtiPuM
For the time being, because of time and money constraints, I will deal with the single 2.5 dumped right into the muffler right below the passenger seat. I still want to do true duals and I'm still trying to see if I can find a system that I like the sound of.
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Joined: Feb 2009
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From: New Jersey
Car: 1988 Camaro Base model
Engine: 305 LO3 5.0L V8 TBI
Transmission: 700R4
Axle/Gears: 10Bolt Rear, Not sure the gearing
Re: True dual 3" exhuast?
What do y'all think would be the best set-up for an 83 Camaro Crossfire 305 TBI? Right now i got a single piple with like a flow master or something I want it true dual, do you think i need it? I was originally planning on having the exhaust manifold 2 high flow cats, then glasspacks right underneath the drivers and passengers seat with a turndown elbo pipe, but now i just want that but with a dual in dual out muffler in the stock location. Thank you
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From: Maryland
Car: 06 Corolla
Engine: 1zz-FE 1.93L lol
Transmission: c59
Axle/Gears: fwd ftl
Re: True dual 3" exhuast?
305 is pretty torqueless, muffler and cat delete with a 2.5inch ypipe and 2.0-2.5 all the way back with a resonator/glasspack/muffler has worked great for me, retains a little back pressure but still flows better then stock
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