[Diy_efi] Spark Plug readings

[Perry Harrington]

BTW, why are you using the F303 cam?  An E303 or stock 5.0 cam would be
better.  The F303 isn't designed for turbo apps.  The E303 has 0 overlap
and the stock has somewhere like -6 degrees or more of overlap.  The stock
cobra cam has -4 to -6 degrees of overlap and more duration than a stock
5.0 cam.

Also, why aren't you using the RT to log all this stuff?  You wouldn't
need a copilot if you were logging all the data.

Also, is this a complete incon kit?

IIRC they used 36lb injectors and provided a custom computer calibration.  That
setup was good for 525HP and 591lb/ft on a mildly modified 5.0 (FMS aluminum
heads, cobra intake, STOCK cam) at 13lbs of boost.

If you are having ANY detonation problems, there is something wrong.  You
said you calculated your compression ratio, could you post the following bits:

deck height (if milled, spec milled amount)
head gasket thickness and fire ring diameter
head cc volume (if milled, spec milled amount)
piston compression height
piston top ring height (from top ring to piston face)
piston dish cc (most pistons are flycut, include total dish)
rod length
stroke

I want to see what's going on in your combustion chamber.

I was looking at the incon kit a while back after reading about it.  The
people I talked to said that they had supply problems.  So, I started
thinking about TDC and their kits appear better engineered.  If I were you,
I would give Turbo People a call and get their advice.

Oh, another thing, when you 'command' a 10.8:1 AFR from the EEC-IV, you aren't
getting 10.8:1.  That is a pseudo AFR.  The Ford computer calculates the AFR
based on MAF and injector size.  Since the injector size is usually different
for the low and high slopes, it interpolates.  The real reason for the low
and high slopes is to get the car to run right and idle at low RPMS.  The
injector isn't really as sloppy as ford makes you believe.  Also, very few
people and tuners use the actual MAF curve, they just screw with the CID value.
This is successful for some, but it further skews what you 'command' from the
computer.  When you are 'command'ing 13.2:1, it could really be 14:1.  You
can verify this using widebands or narrowbands with datalogging against the
computer to find the stoic crossing.  You need to determine what your fudge
factor is.

BTW, is this a street legal car?  If not, ditch the stock computer.  I only
have the stock computer because I *have to* for CA emissions purposes.

I'm not running a turbo, just NA TFS heads/intake e303 306.  I've spent the
last year learning about these things to get mine right.  I'm still not happy
with it, but I should be closer once I get my datalogging up.

BTW, you can get a standalone datalogger called the SNEEC from Race systems.
It does EEC-IV datalogging and is supposedly fairly robust.  Check out
http://racesystems.com/

--Perry

On Mon, Jul 29, 2002 at 02:45:28PM -0400, Brian Renegar wrote:
> Uhh.  This is completely opposite of what I expected you guys to say.  I 
> thought it was running super rich.  The plugs are black like carbon.  The 
> fuel tables are set for very rich (about 10.8:1 commanded A/F ratio).  And 
> I accidentally had the MAF transfer curve entered wrong (reporting too much 
> air).  So I figured I fouled the plugs by running real rich.  I also have 
> the timing backed off some to be on the safe side.
> 
> BTW, this is a 5.0L V8, twin turbo'd, running 9# of boost, on 93 
> octane.  For all of the detailed specs, go 
> here:  http://www.twinturbostang.com/mods.html
> 
> My wideband is together now though.  So hopefully that will shed some light 
> on the issue.
> 
> Brian
> 
> 
> > > jpg1 you detonating and burning oil
> > > jpg 5 yr runnning very lean and detonation is
> > > occuring.
> > > jpg 8 severe detonation.
> >
> >Seconded. jpg 8 looks super lean and like there's some
> >bits of piston stuck to it. :(
> >
> >-Kenny
> 
> 
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-- 
Perry Harrington			Data Acquisition & Instrumentation, Inc	
perry at dainst dot com					 http://www.dainst.com/

Those who would give up essential liberty to purchase a little temporary safety
deserve neither liberty or safety. Nor, are they likely to end up with either.
                             -- Benjamin Franklin

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