Case Study: 1984 911 Carrera
By Steve Wong, firstname.lastname@example.org
I have used the LM-1 for quite a while now and have logged hundreds of runs
with the setup not only on my car but on numerous local clients' cars when
we do a custom reprogram of the chip and the air fuel ratios. With is numerous
data logging capabilities, it has since replaced the NTK wideband system which
I have been using for the past three years. With laptop emulation, I make changes
on the fly with the engine still running, dialing in the AFR to a targeted
ratio for maximum power. The following is a screenshot of an initial run of
a modified Carrera with 'company X's' chip which as you can see runs way too
lean at WOT. This engine had just been rebuilt for blown pistons from all the
7 run iterations later, retuning the air fuel ratios, we get a safer and
much more power optimized AFR through the rpm range. LogWorks allows you
sessions, and you can see the initial session as the dotted lines. Comparing
the black rpm lines, you can see the decrease in acceleration times by
the steeper rpm rise curve, just as in Ingo's chart. The solid lines represent
the data after remapping:
The aux cable and rpm clamp is essential if you intend on using the device
a lot. You can log RPMs, along with other efi signals, such as in the above
charts, which the red line represents the WOT switch, and the green line represents
the afm voltage. It makes tuning work a lot faster and easier. If you only
intend to use the device occasionally, I suppose one could use an assistant
to 'log” AFR data. Just don't try to do it by yourself while driving
- not very smart.
Since the LM-1 has about 45 minutes data logging capability, here is a screenshot
of a data log from a 911 at Willow Springs. After the car pits in, the data
is downloaded into a laptop, evaluated, fuel mapping changes are made, and
the new program is uploaded into the DME's emulator before its next session.
The process is then repeated.
Finally just as a data point, here is a screenshot of a stock chip on a basically
stock Carrera motor. We can see the AFRs are not optimized for power, and refining
this is part of the secret to obtaining maximum power.
For more information on Innovate products, visit www.tuneyourengine.com
or call 949.388.4442. For more information on 911 Chips, visit www.911chips.com
or call 323.953.0722.