On Mon, 31 Aug 1998, Holloway,Frank T wrote:
> DML,
> Here is where we are at with the TB's. The first one that Bruce installed
> appears to be working fine (no check engine light, or dead spots off idle).
> The next will
> have larger thinner brass throttle plates and a stainless steel throttle
> shaft installed. Hopefully he will be installing the new one the weekend of
> Sept 12th. I will be
> installing one identical to the new one for Bruce this coming weekend. Bruce
> had some concerns about interference with the manifold and larger throttle
> plates,
> and I need to check this out on my truck (see if it is unique to Bruce's
> truck), flow numbers will follow. Additionally, I'll be running my truck on
> the dyno to check
> for power and lean conditions. If everything goes according to plan, we
> should have some additional numbers next week. Cost, we don't know yet but
> were kicking
> around a figure between $50 - $100 each, what do you think????
> Frank
Frank,
I've done some porting on my TB already (knocked off "stonehenge" blocks,
knife-edged the divider, removed the ridge in the bores) but I'm very
interested in the larger bore one. I'll be looking forward to hearing your
flow/dyno/mixture results.
One concern that Bill (Tierney) and I were discussing at the track
one night was about a possible lean condition. If the TB bores are bigger,
I assume that would let more air through, so you'd need to up the fuel
in order to keep that 14.7(?) ratio. It should be interesting to see
how well the computer handles this below WOT.
Anyway, the main concern was with running nitrous. At WOT, the
fuel mixture will (I believe) come from the static tables within
the PCM, and the O2 sensor won't be used to regulate flow. (I've
heard that the Magnums run slightly rich at WOT, which might help
a little.) Anyway, the concern is that the wider bores will lean out
the mixture, and when nitrous is added... boom? The kits from NOS
and the like are set up to increase the fuel to a specific flow, so
the fuel plus the air from the TB plus the nitrous should be within
tolerances. More air than stock from the TB might be a problem. I
guess if I were to do a more or less custom nitrous setup, I could
up the fuel a bit to compensate, but I'm not sure how much leeway
there is with the manufactured kits.
PS: Just so everyone's clear and there aren't any misunderstandings,
would that $50-100 price include the TB, or just the work, plates, and
shaft?
-Jon-
.--- stei0302@cs.fredonia.edu ----------------------------------------.
| Jon Steiger * AOPA, DoD, EAA, MP Race Team, NMA, SPA, USUA * RP-SEL |
| '96 Dodge Dakota v8 SLT CC (14.85@90.72), '96 Kolb FireFly 447 |
`--------------------------- http://www.cs.fredonia.edu/~stei0302/ ---'
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