Contour Enthusiasts Group Archives Forums Modifications Duratec Performance True Duals Question

Thank you for the info Demon I am now going to do a dual 2" or 2.25".

Originally posted by DemonSVT:

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Originally posted by bnoon:

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For an SC'ed 3L, I'd start with dual 2.25" and only go to dual 2.5" if you P&P the heads and/or add boost or a water to air aftercooler...

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I think that 2.5" duals is just too large.

Most high powered turbo'd cars run single 3"

2.25" duals have ~10% more pipe (flow) area than single 3" & should support 400-450HP without any problems.

Dual 2.5" piping has ~37% more piping area! (over 150% greater then stock SVT exhaust - sans resonator of course)
Significant loss of velocity versus dual 2.25" I don't see even a boosted 3L engine pushing enough air to sustain optimum velocity. Not saying it's not possible however, but flowing around 50lb/min of air into a 3L would be a tremendous accomplishment.
I'd sure like a ride though!

For reference - Dual 2" has only ~13% less area then single 3". (and NO Y either, but thats another story)

We won't even get into trying to fit 2.5" dual piping in the space provided.

I recommend dual 2.25" for any S/C Duratec and dual 2" for any NA Duratec.

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P&P and intercooled 3L will *need* 2.5", Buckshot already has it on his car (albeit friggin crush bends from Doug's Muffler in MI), so it does fit. Your HP support range of 2.25" pipe I agree with... Kinda tells you what he's pushing for, doesn't it?

Also, with the P&P heads and the 3L upper intake, the exhaust will become the restriction on my NA 3L. 2.25", here I come!

anyone ever see the side exhaust on the mustangs? would we be able to swing that where those things come off the ground fx kits to jack up the car? i mean if the square tip came out right there.

Here is my theory on the duals with 2.5" the SVT has 2.5" for single and it runs great so how can you justify using dual 2.5" piping??? you will lose power. I was thinking 2" would be about perfect.

I have already planed the side exit exhaust on my tour. it is the roush style. you have to move the fuel and brake lines of use some kinda heat shield on them otherwise you will have to vaporlock to worry about. my plan was to use the SVT side skirts and use fiberglass to fill the space between the jack instert and the side skirt making it all one peice then getting a square tip and cutting a space for it. or getting Roush side skirts and molding the tip exit to the SVT side skirts.

Originally posted by StaticTour96:

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Here is my theory on the duals with 2.5" the SVT has 2.5" for single and it runs great so how can you justify using dual 2.5" piping??? you will lose power. I was thinking 2" would be about perfect.

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For 2.5" we're talking one monster of a 3L Vortech SC'ed Contour or Cougar pushing 450-500 crank HP. Think we're justified?

Dual 2" would be great for a 2.5 or mild 3L. 2.25" is great for a hot 3L...

ok that is justified. That is a lot of HP there son... I would be happy to give that car the first run

Originally posted by StaticTour96:

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Here is my theory on the duals with 2.5" the SVT has 2.5" for single and it runs great so how can you justify using dual 2.5" piping??? you will lose power. I was thinking 2" would be about perfect.

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Actually the SVT has 2.25" single pipe from the factory. (with a 2" resonator) Even most aftermarket exhausts still use the undersized 2.25" single (bassani, borla, etc)

I thought it was 2.5"... I dont own an SVT so I wouldnt know I know I have 2.5" on my SE now though since I decided to become a curb muncher and total out my flowmaster exhaust and ther rearend on my car