Re: Some thoughts on TB mods (long)

From: Tod Oace (tod@quay.com)
Date: Wed Jan 17 2001 - 22:37:22 EST


Uh....uh...uh... Nevermind. (Very cool info. though.)

Bruce, you're hired! :-)

Now where's that truck I ordered... -Tod

----- Original Message -----
From: "Bruce Bridges" <bbridges@flometrics.com>
To: <dakota-truck@buffnet.net>
Sent: Wednesday, January 17, 2001 9:15 AM
Subject: DML: Some thoughts on TB mods (long)

> Hey all,
> Bernd is right on! Dont go near the plates and bores around the plates
and
> you will be much better off. You need to keep the amount of air going in
> the TB at idle the same, which means the plates have to mate with the
bores
> the same way (they dont touch, but they are close). The riodges that you
> want to remove are there to linearize the response of the butterfly valve.
> A linear response is much easier to use for programming, and will give a
> smoother off idle performance. The first 15 degrees of rotation of a
> butterfly valve provide the largest amount of airflow rate change. The
> ridges shroud the first 10 or so degrees of rotation, blocking the flow
and
> reducing the flow rate increase per degree rotated. In theory, it
shouldnt
> block flow at WOT, but thats theory...Its hard to machine a really
effective
> venturi in that short a space. Sooo... remove the ridges and you will get
a
> larger air flow rate at WOT (+25% more or less) and a much faster off idle
> response. Make sure to radius the inlet of the bores as much as possible!
> Removing some of the shaft diameter by flattening it with a grinder is
good,
> but leave the teflon coating on it at the central bushing/bearing. Try
> painting it with a thin layer of a good etching primer to keep it from
> rusting. Make sure you block off the bearing bores to keep stuff from
> getting in the bearings during the whoel procedure. Also, its not the
> surface finish that gets the flow rate. As long as there are no "chunks"
> (+.008" high = chunk) the flow rate should not improve very much with
mirror
> like polishing. Looks nice though...
> Bruce
>
> ----- Original Message -----
> From: Bernd D. Ratsch <bernd@texas.net>
> To: <dakota-truck@buffnet.net>
> Sent: Wednesday, January 17, 2001 8:23 AM
> Subject: RE: DML: RE: TB modifications
>
>
> >
> > Liability.
> >
> > One word of caution...if you've never done any porting work...don't try
to
> > modify the TB by yourself. All it takes is one slip with the
> grinder/dremel
> > to really screw up the bores. If you can, take the TB to a local
machine
> > shop and have them do the milling/grinding for you.
> >
> > (I do have experience porting/modifying carbs and heads so please be
> careful
> > with the hand grinders on your TB's...one slip and $100+ later for a new
> TB)
> >
> > - Bernd
> >
> > -----Original Message-----
> > From: owner-dakota-truck@buffnet.net
> > Subject: Re: DML: RE: TB modifications
> >
> > So I have a question... If smoothing out the throttle body makes such a
> > good difference, how come they don't come that way out of the factory?
I
> > can understand it being too expensive to produce them with an ultra
smooth
> > finish, but couldn't they make 'em closer to what we're doing to them?
> What
> > are those ridges supposed to do anyway? Someone said they are
> > over-engineered... For strength I assume? Or for sound baffling? More
> > like Tod baffling...I can't figure it out. Is there some risk in taking
> > them out?
> >
> > Anyway, this mod sounds like something I want to try.
> >
> > This list sure is expensive... I wasn't planning on doing any mods.
Now
> I
> > have a growing list of them...and I don't even *have* a Dakota yet!
> Twenty
> > days since my order...and counting.... -Tod
> >
> >
>
>



This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 11:58:36 EDT