"It's whats for breakfast."
:^)
Sam
www.socaldakota.com
619-274-1292
>
> From: "Tony Cellana" <acellan1@tampabay.rr.com>
> Date: 2004/01/08 Thu AM 09:30:37 EST
> To: <dakota-truck@dakota-truck.net>
> Subject: Re: DML: Throttle body..
>
>
> Math and physics with morning coffee. Woohoo.
>
> Just shoot the pics over when you can. Thanks.
>
> TonyC
>
> -----Original Message-----
> From: BKBridges <bbridges@flometrics.com>
> To: dakota-truck@dakota-truck.net <dakota-truck@dakota-truck.net>
> Date: Wednesday, January 07, 2004 7:24 PM
> Subject: Re: DML: Throttle body..
>
>
> >
> >Tony,
> >Yes! The Speed/Density system used on Mopars relies on the manifold
> >pressure and throttle posistion (and air temp) to estimate mass air flow.
> >If the manifold pressure sensor and TPS are not "synched" (dont match or
> >come close to the original look up tables) all kinds of poor performance
> >issues can occur (the PCM "cant do the math")! If other sensors (O2, AIT
> >etc) are also on one side or the other, additional situations can crop up
> >that will hurt performance. Instead of one big vacuum based control system
> >(carburetor) we've got multiple sensors and a computer to meter fuel. I
> >wish it were as simple as it seems sometimes, but there is a "trick" to
> >throttlebody sizing that will optimize your performance if handled
> properly!
> >Also: My camera was "out on loan" but its back now. Ill send you those
> pics
> >we talked about
> >Bruce
> >
> >----- Original Message -----
> >From: "Tony Cellana" <acellan1@tampabay.rr.com>
> >To: <dakota-truck@dakota-truck.net>
> >Sent: Wednesday, January 07, 2004 1:48 PM
> >Subject: Re: DML: Throttle body..
> >
> >
> >>
> >> On your second point, I beg to differ. Put too large a TB on, and whack
> >it
> >> wide open, and there will be a bit of a hesitation. Too much air too
> >quick
> >> from an idle. The computer has trouble compensating THAT quickly.
> >>
> >> I agree that in theory, it shouldn't happen, but real world results
> differ
> >> some.
> >>
> >> TonyC
> >>
> >> -----Original Message-----
> >> From: david.clement@verizon.net <david.clement@verizon.net>
> >> To: dakota-truck-moderator@bent.twistedbits.net
> >> <dakota-truck-moderator@bent.twistedbits.net>
> >> Date: Wednesday, January 07, 2004 4:46 PM
> >> Subject: Re: DML: Throttle body..
> >>
> >>
> >> >
> >> >In article <016801c3d3a7$8c4a8900$d75f2241@a.tampabay.rr.com>,
> >> >acellan1@tampabay.rr.com ("Tony Cellana") writes:
> >> >>
> >> >>
> >> >> Some miscellaneous ramblings on the topic:
> >> >>
> >> >> Not knocking anyone's product or thoughts, just tossing mine into the
> >> mix.
> >> >>
> >> >> TBs are a controlled hole in the intake manifold that will allow a
> >> certain
> >> >> amount of air into the motor. Some motors need more air than others.
> >> The
> >> >> amount depends on CID, RPM, and the tuning characteristics of the
> >intake
> >> >> manifold, cam and valvetrain.
> >> >
> >> >It is fairly easy to determine if you need a bigger TB. If you have
> (more
> >> than
> >> >approximately 1/2" H2O) vacuum in the intake manifold at WOT then you
> >have
> >> a
> >> >restriction and a bigger TB is warranted.
> >> >
> >> >> Some motors want more air than others. TOO much air isn't always a
> >good
> >> >> thing though. It can cause bogging, off idle hesitation and/or
> >stumble.
> >> >> This is often seen when abruptly opening the throttle from idle or
> near
> >> idle
> >> >> (think jumping off alight or drag racing).
> >> >
> >> >The bog, hesitation and/or stumble is a carb characteristic. This does
> >not
> >> >happen with a port injected engine with a dry TB. When a carb is too big
> >> you
> >> >loose too much air velocity as you open the throttle if it's too big
> >> resulting
> >> >in a loss of vacuum that is needed to pull fuel from the bowls. This is
> a
> >> non
> >> >issue with port injection. If you were so inclined you could take the TB
> >> off
> >> >the engine and use your hand to control rpm.
> >> >
> >> >Dave Clement
> >> >99 SLT+ CC 4x4
> >> >
> >>
> >>
> >>
> >
> >
> >
>
>
This archive was generated by hypermail 2b29 : Sun Feb 01 2004 - 16:29:49 EST