Re: Re: Aftermarket Muffler Options

From: Mark Haney (mphaney@home.com)
Date: Fri Sep 07 2001 - 00:43:14 EDT


I'm not about to say that anyone is all wet, but what about the fact that
these are only cat-back setups? Aren't you getting the required
backpressure from the intermediate pipe and cat?

As far as choices go, I went with the dual side-exit Gibson on my 00 CC 4.7
5-speed. It sounds absolutely fantastic, going from a nice burble
(technical term <grin>) at idle to a fairly serious growl at the higher
RPM's. And I am quite certain that I lost NO power. In fact, just the
opposite is true. The motor seems very happy to swing the tach needle HARD
to the right. The best part of the whole setup is that my mileage has gone
up by 1 to 2 MPG's (depending on if I'm able to keep my foot out of the
throttle or not). On the ride home from Nag's Head back to Pittsburgh, I
averaged 20.8 MPG at a fairly constant 70 MPH with the a/c on.

Just my $0.02 worth.

Mark...
----- Original Message -----
From: "Andy Levy" <andylevy@yahoo.com>
To: <dakota-truck-moderator@bent.twistedbits.net>
Sent: Thursday, September 06, 2001 11:37 AM
Subject: Re: DML: Re: Aftermarket Muffler Options

> It's not even that specific. If you relieve too much backpressure, you'll
lose
> power. If you have too much backpressure, you'll lose power. Finding the
sweet
> spot is part science, part black art. So far, we know that for a stock to
mildly
> modified engine, a single 3" is really nice. To go larger, you'd better
have
> serious engine work (I think the ViperTruck has 3 1/2" or 4", but Austin
has more
> than a little work on that thing).
>
> Once you get into duals, things get even trickier. Stock, I think you've
got a
> 2.5" pipe, which works out to 4.90625 sq. in. cross-section. Dual 2"
pipes have
> a total cross-sectional area of 6.28 sq. in. Dual 2.5" is 9.8125 sq. in.
A
> single 3" is 7.065 sq. in. A dual 3" is 14.13 sq. in. So a dual 3" will
leave
> you with precious little backpressure, and your truck will be a slug.
2.5" is
> probably the largest you can safely go on duals, and 3" on a single pipe,
> without major engine work. I know quite a few people are running a
Gibson
> dual-exit on their V8s with good results.
>
> If I'm all wet here, please let me know, folks.
>
> Paul Macey wrote:
>
> > On Thu, 6 Sep 2001, Sterling wrote:
> >
> > > Stick with flowmaster, I got a Ravin, it sounds great outside but the
incab
> > > noise level is nearly unbarable. And who says you can't put a 3" on
any
> > > model of Dakota?
> >
> > I thought it depended on single -vs- dual exhaust, and for the 4.7, a
dual
> > 3 inch exhaust would actually rob you of power and decrease HP and/or
> > torque.
> >
> > For best performance gains for the 4.7, believe the common thought is to
> > go with a 3 inch single exhaust.
> >
> > Now as regards to gibson -vs- flowmaster on the single exhaust, I've
seen
> > quite a few posts saying people were disappointed with the gibson (not
> > much louder than stock) and took them off and re-installed a flowmaster
> > setup.
> >
> > > ----- Original Message -----
> > > From: <s_villaire@yahoo.com>
> > > To: DML <dakota-truck@buffnet.net>
> > > Sent: Thursday, September 06, 2001 8:21 AM
> > > Subject: DML: Aftermarket Muffler Options
> > >
> > >
> > > >
> > >
> > >
>



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