To respond of what I know, the 4.7 has only two headers version that I am
aware of; Borla and JBA. The only version of headers that are currently
being made are the shorty version.
I had talk to the wholesaler outlet for Borla but never received a Dakota
dyno sheet of HP/TQ gains. Borla headers can be found on the
www.truckperformance.com.
With the JBA version, I am the current test vehicle on the 4.7 motor and the
current (2nd mod for CARB approved version only) shorty header produced 9
rwhp. Expect release of the JBA headers is sometime in January timeframe.
There is a third mod on the shorty headers on the flange now.
Both are made of high quality material and have a outstanding QC department.
I have to agree with Bernd statement on the exhaust size and type. You can
talk to Bruce Bridges on exhaust Flowmetrics at bbridges@flometrics.com.
Anything we can do to help a DMLer to achieve more performance from his/her
truck.
-------------------------------------------
Steven St.Laurent
Test Engineer
Test Branch, GSD, MCTSSA
MARCORSYSCOM, USMC
760-725-2506 (DSN 365-2506)
Work:mailto:stlaurents@mctssa.usmc.mil
Home:mailto:saint1958@home.com
-----Original Message-----
From: bernd@texas.net [mailto:bernd@texas.net]
Sent: Wednesday, December 27, 2000 8:02 AM
To: dakota-truck@buffnet.net
Subject: Re: DML: May I ask for you help?
Patrick,
I'm no "guru" and the other 4.7L owners on this list would be more versed on
the availability of headers for the 4.7L. (Wasn't JBA working on something
for
them?)
As for the cat-back system: Gibson, Dynomax, or Flowmaster seem to be
the "choice" of the DML. (Borla included...but slightly overpriced in my
opinion.) Gibson and Dynomax sound about the same, with a nice rumble at
idle
but a V8 growl under WOT. The Flowmaster has a sound of its own...tinny at
idle and "pops" under decelleration, but it's still an excellent system.
(The
Ravin muffler doesn't do this but at $140 for a muffler...spend your money
elsewhere.)
For street applications, don't bother with anything larger than 2.5" on a
dual-
tip system (unless it's a single tip exit...then 3"). You will loose some
bottom-end power but will gain it back on the top-end. Now if you want to
race
your Dakota on a daily/weekend basis...a more agressive exhaust system (3"
free/high-flow) would be better. But...don't be persuaded by the flow
ratings
of the mufflers, the color (Chrome), or by the "Hype" of their advertising.
A
500-700cfm muffler will perform just as well as a 1000+cfm muffler on the
street as a daily driver. If your out for all out racing...1000+cfm is the
choice though.
The combined knowledge gained from the folks on the DML (and other Dakota
related sites) is incredible...isn't it. ;)
Regards,
- Bernd
(Now eating a lot of toast due to an excess of butter on his plate.) ;)
> Bernd
>
> I have been reading the DML archives for about 6 months and just recently
> signed up on the list. I have observed an learned a lot about the Daks and
> the people who love working on them.
>
> From the material I have read, it appears you are not only technically at
> the top of this game, but you do a good job of sticking to the facts and
> letting the performance of the products and techniques employed by you and
> the group determine you recommendations.
>
> Now that I have buttered you up ;-) I would like to ask for your help with
> my selection of headers and cat back system. I would appreciate engaging
in
> a dialogue with you on this.
>
> I am asking for your help off list. Feel free to decline or accept my
> request without prejudice. Regardless of your response, thanks for your
> contributions to the list. (more butter).
>
> Have a safe new year.
>
> Patrick O'Day
> 2000 Dak, 4.7L
>
>
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