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Re: MAF BLM based tuning
Dave, when I want to tune I make a run and record it using diacom, and then
using GMe, print out the spark map. Then I scroll through the Diacom run
frame by frame, looking at rpm, LV8 and spark retard. The RPM and LV8
should put you at your actual spark as it is on the printed map, then I
write how many degrees of timing the ecm was pulling out on the map really
small. I also make sure that my 02 sensor is 850mv+, closer to 900 on my
app works better, the car seems to lay down if I let it get down to 850 mv,
(EGOR?!? HELP!)
I then decide if I am going to add timing or take timing out, do a chip and
retest. I now have the car tuned as close as I can for zero knock.
I used to think that the car ran the best pulling a couple of degrees of
timing out. I'm getting more conservative.
Mark (Over 300 chips so far!)
----- Original Message -----
From: "Dave Zug" <dzug@delanet.com>
To: <gmecm@diy-efi.org>
Sent: Tuesday, July 18, 2000 12:02 AM
Subject: Re: MAF BLM based tuning
>
> 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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