Re: Changing Injector Size (Bernd)

From: Shane Moseley (smoseley@ix.netcom.com)
Date: Wed Feb 28 2001 - 17:13:02 EST


Frank T Holloway wrote:

> Tom,
>
> It depends on how rich it is. The fault triggered is a benign code (no adverse effects).
> But excessively rich conditions slow fuel burn (less power)........

On that note (excessively rich conditions) - Recognizing the fact that at WOT we transition
from a closed-loop fueling (and timing) strategy to an open-loop strategy -and- the fact
that during open-loop the factory engineers provide a preset excessively rich condition, has
anyone had success in approaching the "how do I make more power" question from that
particular angle? My scantool tells me that my min TPS is around 12% and max is around
72%. I wonder what defines WOT? Greater than 70% perhaps? That would be a blanket
assumption and surely everyone's vehicle is not this way (12/72) - or is it? I would think
the PCM could somehow interpret min and max and assign a percentile variable to these
extremes - but - this has to occur before we even TOUCH the pedal which doesn't compute for
me 8-). Any ideas here?

I was doing some testing w/my GTechPro last night after work and I've noticed a huge
performance difference between WOT and just less than WOT. I have noticed this difference
before but now that my truck is in a higher state of tune - it is making a much larger
impression.

Oh yeah - remember when I said that I am running 15s in my 5000+lb full-sized Ram? I'm
thinking that I might have actually had a 14s run last night which has me really stoked. I
made 2 runs - first one I must have got excited and blew away the tires. Ran an awful 16.7
or something like that - but the mph was a 86-7 if I remember correctly - which translates
to low 15s I think- Wow! What is that formula anyway?... 87 miles / 3600 secs = 0.25 miles
/ X seconds maybe? Solving for X....no? Next run I decided that I would not let the tire
spin (peg leg 3.55 rear). I launched like I would from a stop light (feather touch) and
then got on it - didn't take long for me to realize I had a problem. My rpms were climbing
higher than they ever had before - whats up - no shift - oh shit - I look down at my tach
and holy cow 5900rpm - foot automatically raises off the accel pedal at which point I get
shift-shift (what? two shifts?) - look up at my OD/noOD and sure enough it is set to OD on
- mistake.

Next as I am still coasting down I notice my GTech clicks off a 15.3 et at 87.5 mph. After
calming down a few seconds - I realize that I might have actually ran a 14s run had I
selected OD off. Cool. Now I just need to find an open track for the paper confirmation...

Latr,

Shane

--
'96 IndyRam-HisIndy-MPI/TB/Pulleys/AccelCoil/MPComp/HookerSuperComps/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)



This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 11:59:34 EDT