RE: RE: Re: Dyno Check RD 52mm TB vs Stock

From: Holloway,Frank T (Frank.T.Holloway@KP.ORG)
Date: Tue Aug 31 1999 - 16:04:01 EDT


GS,

My truck was really really lean, WOT 14.2/1. The O2 did fix the problem
(reading .2 volts on the rich side). After replacement, WOT 13.2/1. Still
leaner than I would like to see. Took care of it with the larger injectors
and modified the software to take care of the rich condition at an idle and
during warm-up.
        Frank

> -----Original Message-----
> From: GS- [SMTP:GSWillhite@ualr.edu]
> Sent: Monday, August 30, 1999 8:04 AM
> To: dakota-truck@buffnet.net
> Subject: DML: RE: Re: Dyno Check RD 52mm TB vs Stock
>
> Ahh....so it was a .02 sensor causing the lean condition and
> not just the larger bores in the stage II TB. I know its a very
> complicated process, researching and modifying the TB's to work in
> certain power bands on specific engines. I thought with the mods he
> had and with a larger TB, it might have been running a little lean.
> Obviously there is more to it than just trying to richen the mixture
> with the IAT. Still curious about it tho.
>
> GS -
>
> Frank.T.Holloway@KP.ORG wrote:
> >
> > GS,
> >
> > The lean condition that I was experiencing with my truck was the result
> of
> > an O2 sensor stuck on the rich side. When the O2 was replaced, the
> problem
> > went away. The problem with TB modifications, is that you need to keep
> the
> > velocity up to get accurate MAP signals to the computer. The larger
> bores
> > can be made to work, but it requires computer mods to get it right
> (alter
> > MAP variables to the computer). Larger bores are needed when you clean
> up
> > the intake track (port work on the heads and intake) but these require
> > computer mods anyway. Any work on the TB's really does require the
> > assistance of a flow bench. Its not just a matter of removing the
> venturi
> > above the plates. The shrouding was placed in there for a purpose and
> the
> > computer was programmed with this in mind. The shrouding serves and is a
> > part of the total power band. Removing it does give the feeling of more
> > power (just above idle) but you need to look at the total power band,
> > because power is lost. The shaft even plays an important part of the
> total
> > equation. Any change in velocity is read by the computer. With the
> bigger
> > bore TB's we have been playing with, the torque and HP figures along the
> > whole powerband are variable, at certain RPM's they are higher and at
> > others, they are lower than stock.......
> >
> > Frank
> >
> > > -----Original Message-----
> > > From: GS- [SMTP:GSWillhite@ualr.edu]
> > > Sent: Friday, August 27, 1999 7:43 AM
> > > To: DML
> > > Subject: DML: Re: Dyno Check RD 52mm TB vs Stock
> > >
> > > >
> > > > I did a HP check with JBA headers, JBA down tubes, K & N Gen II, ASP
> > > > crank-pulley,
> > > > Bullet 3" by 24" muffler and 3" piping cat back to the rear axle.
> The TB
> > > > is stock
> > > > HP 222.3. I lost HP with the RD 52mm TB. That dyno check had 209 HP.
> BTW
> > > > the 52 mm TB makes a excellent paper weight.
> > > >
> > > > --



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