kPa under boost

[Bruce Plecan]

----- Original Message -----
From: Glen Beard <gbeard1 at nycap.rr.com>
Subject: Re: kPa under boost


| Bruce Plecan wrote:
| I'm actually A MAF system, but I completely agree...  WAY less
| than optimum.  I am just starting to open up the can'o'worms so
| to speak on computer tuning.  I believe I am maxing out the stock
| MAF sensor.  Above this, the computer (as I understand it) runs
| like a MAP system.
| >   Your fuel pressure regulator (FMU) will give a slight increase in fuel
| > delivery.
| The FMU is an 8:1 unit.  Take the base FP of around 45# and add
| 8# fuel for every one pound boost.  With the 6# blower pulleys I
| see about 90-95# FP at 5800rpm.  Yes, I get a slight increase in
| fuel delivery...

It takes a big pump to have good volume at 90-95PSI.  Makes me leery.
You do release as the pressure demand goes up on a pump it volume decreases.
We just covered FMUs in the last couple days, if you missed it.
|
| > But, the timing is constant from N/A to what ever level of boost your
| > running.
|
| I use a the Crane HI-6TR ignition that came with the Vortech
| kit.  It has adjustable timing retard which I keep set to around
| one degree of retard for every one pound of boost.  (Mostly for a
| safety margin as the last time I ran it at zero, I broke
| ringlands...)

Run more retard.
The trick is the least amount of timing, for a given level of performance,
not running as much timing as possible, lots of folks keep missing that
point.

I firmly beleive in keeping as much as possible in the ecm without a bunch
of tack on items.
Grumpy
|
| I know that I have a real challenge ahead of me trying to tune
| this to optimum, but I am learning more everyday I read the list
| and archives.  With some patience, trail and error, and a little
| luck I'll figure it out.
|
|
| --
| Glen Beard  95 T/A conv M6
| 355, Vortech, heads, cam...
| http://home.nycap.rr.com/gbeard1/TransAm.html
|