I'll email you all the specs from my work but here's the basics. (Sitting
at home right now)
MAP Signal (Normally Aspirated)
Idle = 12-13"hg
Part Throttle = 8-10"hg
3/4 Throttle = 5-7"hg
WOT = 1-2"hg
** These readings were taken from a bone stock 1998 V6 **
MAP Signal (Supercharged)
Idle = 12-13'hg
Part Throttle w/mild boost (2-3#) = 14-18"hg (without check valve) - LEAN
Part Throttle w/mild boost (2-3#) = 10-12"hg (with check valve)
3/4 Throttle w/boost (3-4#) = 16-20" (without check valve)
3/4 Throttle w/boost (3-4#) = 15-17" (with check valve)
WOT w/boost (5-6#) = 28-30.8" (without check valve)
WOT w/boost (5-6#) = 24-28.8" (with check valve)
** These readings were taken from my truck and a '99 R/T with a Powerdyne.
**
Keep in mind that the readings taken were on flat roads without too many
uphill or downhill grades. Uphill will give a lower MAP reading (more load)
and downhill will give a higher reading (less load).
The voltage on the MAP runs from 1.7 - 4.3v (from what i've seen) with the
higher voltage being lower vacuum signals. The 1.7-2.0v being at idle
(factory specs as well) and 3.8+v being WOT/high load).
Now at 28-30.8"hg under boost conditions, that leans the engine enough to
"ping" unless the BTM is set at 1 on the START range (box) and at 3+ on the
selector (dial inside the cab). What I do is monitor the TPS signal
(4.2-4.4v being Wide Open on the blades) and then check it with the signal
from the MAP. If the MAP is at 1.5v or lower, it bypasses the signal and
replaces it with a preset voltage signal (3.3v - 4.5v). Once the TPS is
below it's set monitoring range (3.3v-4.5v) it resumes the MAP's standard
signal.
I'm wondering about the VEC1 and what else it has inside its box. It's not
a simple "Dual POT" system...i've tried (and built) that already. This way
also runs about $25 at Radio Shack vs. $300+ from what most other companies
are charging for a similar solution. Some fake the O2 signal, others fake
the MAP signal...it all depends on how you want to do it. Personally, I
found that the MAP signal is easiest to change and it resets itself
everytime you start the engine anyway...no chance for "relearning".
- Bernd
-----Original Message-----
From: owner-dakota-truck@buffnet.net
[mailto:owner-dakota-truck@buffnet.net]On Behalf Of Shane Moseley
Sent: Thursday, November 30, 2000 12:24 AM
To: dakota-truck@buffnet.net
Subject: DML: Re: MAP & TPS Signals
"Bernd D. Ratsch" wrote:
> It monitors TPS vs. MAP voltage and "adjusts" accordingly. It just
bypasses
> the incorrect MAP signals and sends the correct one instead (adjustable of
> course from 3 - 4.5v).
>
> <snip>
> Can I get the low down on it?
> Thanks,
> Tom(11s dak)
Yeah - do you mind elaborating? Specifically how the old "incorrect" TPS &
MAP
voltages map to the new "correct" ones. Like this maybe:
Old TPS New TPS Old MAP New MAP
0.0v = 0% 0.2v = 0% 3.0v = 1in.Hg 3.5v = 1in.Hg
0.5v = 5% 0.8v = 5% ...
Please nobody use these values as I just pulled them out of my head for an
example. Bernd, I'm just trying to understand which directions to "tweak"
them. Also, try to relate your explanations to a naturally aspirated engine
(like stock) if possible. I know you have been jumping thru hoops lately
w/all
that pressure in the intake 8-).
BTW, after all this experimenting - you still ordering the VEC1 or have you
got
it already and are playing w/it?
Thanks,
Shane
-- '96 IndyRam-HisIndy-MPI/TB/Pulleys/AccelCoil/HookerSuperComp/CompTAs '96 IndyRam-HerIndy-numbered(#142)"Track Truck" '74 Triple-Black Dodge Challenger Rallye 360 home-brew EFI R&D vehicle '68 Black Corvette Convertible 427 (For Sale)
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