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