Re: MAF BLM based tuning

["Dave Zug" <dzug@delanet.com>]

The MAF just barely touches 231 as the automatic shifts, so NO its not
maxxed.  Now the LV8 rides at 255 except for a brief drop off just before
the shifts, in a WOT run.  All the talk about maxing out the MAF and my
stroker motor ain't there yet, but the E.T. numbers show it's pushing 350
HP.  If what is really meant is that the LV8 will max out, well I can see
that.

How am I modifying the prom? or what am I doing to it?  How I am modifying
it is with GMEPRO and a generic 27c128 burner. I started with ARAP as the
base (even with the agressive timing in there, and 10:1 CR, all the aluminum
is forgiving to knock).  What am I doing to it? well eventually, embarrasing
as it may be, I'll maybe post the NOTES file (a handy function in GMEPRO)
I'm keeping... thru 15 revisions so far. Some of the notes may be misguided,
but it's a history of how things went.  If by initial timing you mean lower
RPM/load timing.. the way a launch goes is like this: (in 0.1 sec
intervals):

Lv8   RPM

212   600
174   800
121   1400
129   1725
167   1800
214   1700 (knock)
190   2000
190   2350 (knock)
183   2550
157   2575
231   2450
223   2675
249   3300
252   3475 (knock)

So you see during a drag run it passes thru mid-range territory before it
gets to the WOT zone (208+) then stays there.  the timing in the
transitional areas was as much as 38 degrees.  Good for while the engine is
lazung around those areas, but apparently NOT good whan it is briefly
transitioning thru them. I reduced timing in that area and now I get only
ONE knock event immediately after punching the gas, then it gives all the
timing back at the full rate... trouble is, thats 3 seconds worth and I'm
scared to take the safety factor away.  I dont really know if its false
knock or not. I tried over-fueling initially and it had no effect. I have
not tried 110 octane yet, as a test.

No mods really planned. I'm replacing the injectors with 24 pounder SVO's..
I wanted to see if the stockers would cover a less-than-wild TPI 383, so
others can see theres a 'budget' choice. I'm also keeping the stock lower
intake till spring at least... too close to 12's to say I'm done ;-)


Tell me more about the Monte SS.

Here's mine:
www.delanet.com/~tgp  go to the 89 IROC page, then the 383 project link. Not
very up to date,  It ran a 13.14 @ 103 w/ 1.75 60' on 16" BFG Drags... the
knock off the line is making the launch pedal-finesse un-nessecary.. almost
like TRACTION CONTROL. I has run a few threads on EFI list and here on the
subject of using spark table as a crude 'static' traction control method.
Anyone who has stomped the gas pedal on a stock 305 TPI knows its
frustrating to drop back 3 car lenghts while you try and feather off the gas
just the right amount.  The way the knock is working for me, I don't have to
think on launches... 1.75 60', not a misprint. you should see the jump I get
on the 'stangs ;-))

sorry for the looong.. but EFI content this time anyway.



----- Original Message -----
From: Jim and Sharon Brady <bradyiii@shore.intercom.net>
To: <gmecm@diy-efi.org>
Sent: Monday, July 17, 2000 1:49 PM
Subject: Re: MAF BLM based tuning


> Dave,
>     Are you outflowing the MAF yet?  How are you modifying your ECM/PROM?
> Do you think knocking you initial timing back could help your knocking?
I'm
> running 87 octane w/9.3:1 compression (aluminum heads) with no knocks so
> far.  What mods(if any more) do you have planned for the future?
>
> Jim Brady
> '87 Monte SS 383 TPI 6 speed

<Snip>

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