RE: Throttle Bodies Attn. Patrick

From: Holloway,Frank T (Frank.T.Holloway@kp.org)
Date: Sun Aug 23 1998 - 01:24:49 EDT


Colin,
Sounds like a GREAT idea. I was going to mill flats on the shaft anyway.
I don't have the shaft sitting here in front of me and don't remember
whether the
heads were on the top of the plate or the bottom, but I would think that
you would want to remove the half on top, that way you would still have
the support of the
shaft between the bores. After you finished with your modifications, did
you coat the throttle shaft with anything, (looks like black oxide to me
but it feels to
smooth). Again thanks for the info.
        Frank

> -----Original Message-----
> From: Vincent Heckathorn [SMTP:victorylane@iwaynet.net]
> Sent: Saturday, August 22, 1998 9:03 PM
> To: dakota-truck@buffnet.net
> Subject: Re: DML: Throttle Bodies Attn. Patrick
>
> Frank;
> FWIW!!!
> I have done a little something different on the throttle shaft. I have
> removed 1/2 of the shaft, the side that the bolts go through, then you
> can
> cut the back side just a little and use #10/32 round head machine
> screws and
> bolt the plates to the shaft.
> This seemed to wake up the engine a little.
>
> colin
>
> Holloway,Frank T wrote:
>
> > Patrick,
> >
> > I started work on two throttle bodies today and I found some
> > real interesting things. I was concerned about a dead spot off idle,
> and
> > was thinking about
> > re-clocking the TPS. I talked to one of my friends at
> Chrysler,
> > it turns out that re-clocking will not work. The ECM on startup
> looks
> > for the lowest voltage from
> > the TPS and sets the voltage as baseline (no adjustments). I
> did
> > flow one of the stock TB's at different throttle settings so I have
> a
> > baseline for my work. One
> > of the TB's will get 52MM plates (approx. 2.040 inch). The
> other
> > will use the stock throttle plates ( just under 2.00 inch). The
> stock
> > TB's are actually necked
> > down just above the plates ( this is actually there to
> shroud
> > the half of the plate(s) that swing up). Un-shrouding occurs at
> approx.
> > 15 degrees throttle
> > movement. On the TB that will receive stock plates, I opened
> the
> > bore above the plates .040 inch, and then I took and additional
> .020
> > off the bore on the
> > back side (rear of the engine where the plates swing down).
> and
> > blended the work to the actual bore where the plates are positioned.
> On
> > the TB that gets the
> > big plates, I just bored the TB to match the plates. The
> next
> > step will be to place both TB's up in one the lathes (4 jaw chucks
> work
> > nice to center the bores)
> > and open up the air horn and remove the web between the
> bores.
> > The shafts will be the next (mill flats above and below the plates.
> I'm
> > hoping to finish both
> > tomorrow and then off to the flow bench. I'll give you the
> flow
> > numbers when I'm done. I do have your TB down at the shop. Tomorrow
> I'll
> > take the IAC, MAP,
> > and TPS off. It should be on its way to you either Monday or
> > Tuesday.
> > Frank
>
>



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