Thinking about going true dual

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Jul 22, 2008 | 08:57 AM

#11

00ChevyScott

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From: Over There

Quote:

Originally Posted by PathfinderJr

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.

I'd say I'm in the 380-390 hp range at the crank man. And i see plenty of guys running true dual on completely stock trucks around here with no problems. but I'm still thinking about going with zzebes exhaust.

Jul 22, 2008 | 09:08 AM

#12

bluecajun5.3

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From: Breaux Bridge, LA

alright, don't listen to us then.
let your performance suck with 3" into 2.5" true duals

what zzebes has?

Jul 22, 2008 | 10:28 AM

#13

InchUp

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Quote:

Originally Posted by 00ChevyScott

I said I wanted to do dual 3" into the X pipe, then dual 2.5 out...

It's still a power sacrifice across your entire rev range except for maybe 6500 rpms. If that's where you think the motor will be revving all the time then sure, dual 3" it is.

If you think you're in the 380-390hp range, dual 2.5" is all your motor requires. I'd go as far as necking down to 2.25" after the X-pipe to keep exhaust gas velocity up.

Jul 22, 2008 | 02:03 PM

#14

ChevyTruck

something else

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From: Newark, DE

i have 2.5" all the way to the mufflers then 3" from there on out. noticed a difference from silngle 3 from high flow cats on out, to the dual exaust.

Jul 22, 2008 | 02:37 PM

#15

00ChevyScott

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From: Over There

Quote:

Originally Posted by bluecajun5.3

alright, don't listen to us then.
let your performance suck with 3" into 2.5" true duals

what zzebes has?

no, his exhaust is 3" single.

Aug 21, 2008 | 10:42 PM

#16

supercharged tahoe ss

Staging Lane

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From: Ontario Canada

old set up stock y pipe magnoflow 1 into 2.5 inch dual 451 torque new set up pacesetters high flow IMCO metal core cats x pipe 2 16 inch imco mufflers 3 inch from front to back new set up 492 torque. engine is out right now getting all forged new dyno numbers comming soon.