[T3] Giving up Stock FI

[Keith Park]

Yea, with the 71 in stock form, 27-8 on the highway was the Norm and 20ish
in town, I know I was running a bit rich but with the heavy loads I towed on
a regular basis I didnt want to find a hole in a piston if I was running in
the other direction.

With the stock 2056, Im getting 22-3 on the highway, about what I would
expect but it sits in the lean zone there so that makes sense, around town
its 15-16 and Id expect 17-18 but around town its at light throttle more and
thats the rich zone, so Im curious what mileage to expect if it were running
a modern closed loop system and the curve and spark etc. were optimized over
the entire curve.

I can further lean out the Djet, and then I run in the 15's AFR on the
highway in the lean zone BUT, as Ray Greenwood states, those numbers may not
be accurate with that type of injection and stock exhaust, and when I did
run those AFR's it didnt seem to run oil temps any hotter or head temps, and
didnt detonate so it was PROBABLY fine.

Keith


Topnotch Restorations
topnotch at nycap.rr.com
http://www.topnotchresto.com
71 Squareback  "Hothe"
65 Notchback  "El Baja Rojo"
93 RX7  "Redstur"
95 Chrysler Cirrus Lxi "Cirfogsalot"
"hanging out at the tail end of the bell
curve, and loving every minute of it!" 
-----Original Message-----
From: type3-vwtype3.org [mailto:type3-vwtype3.org-bounces at lists.vwtype3.org]
On Behalf Of Phil Hof
Sent: Monday, December 24, 2018 12:33 PM
To: type3-vwtype3.org at lists.vwtype3.org
Subject: Re: [T3] Giving up Stock FI

Regarding gas mileage, my '71 with almost-stock D-Jet gets about 25 in
normal use, which includes short (5mile) trips to work, errands in town, and
occasional cruises to the coast.  On the last couple of highway/freeway
cruises (Cost Rally and Meet in the Middle) it was more like 30-32.

My setup is a 1776 with larger injectors, and tuned a few years ago using a
F/A meter with the sensor right at the neck of the resonator where it clamps
to the main muffler body.  Now that it's broken in, and after I rebuild my
distributor, I'll probably recalibrate the MPS and do a few tweaks to smooth
transitions and improve the in-town mpg a little.

What's interesting, is that this difference of maybe 20-25% between highway
and town driving is much larger than it used to be.  When the car was pretty
new, and stock, it didn't really matter how I drove.  I could feather-foot
it, and get maybe 33-34; if I lead-footed it, it would still rarely drop
under 30, more like a 10% band.  I attributed this to the FI, which would
seek to have the right A/F mixture better even under widely varying loads.
So either that was a myth, or i need to lean out mine a little under power
and transitions.  I figure I'm a little rich on acceleration, but pretty
good on cruise.

-Phil
_______________________________________________
VWType3.Org mailing list - type3 at vwtype3.org
To unsubscribe or change subscription options, visit:
http://lists.vwtype3.org/listinfo.cgi/type3-vwtype3.org
If you need more help, contact: gregm at vwtype3.org